Rewind chat or files from any user message (#1154)

* Add Pi extension-launch plumbing for in-process tree primitives

* Add Rewind controls for agent sessions

* Preserve SDK checkpoint env var so Claude file rewind works

The SDK injects CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTING=true when file checkpointing is enabled. The earlier parent-env stripping from c4782ec71c was too broad and removed that child flag along with real parent-session markers.

Keep stripping parent markers, but preserve the checkpoint flag so the SDK rewind path can run directly. With that boundary fixed, the JSONL file-rewind fallback is no longer needed.

* Update OpenCode history replay tests for rewind state

* Show Rewind actions in an adaptive sheet

* Fix rewind semantics across providers

* Refactor Pi IDs through extension capture

* Restore user message to composer after rewind

* Fix Claude rewind tool result mapping

* Fix Claude rewind session switch roundtrip

* Fix rewind and optimistic message regressions

* Tighten rewind test discipline

* Fix OpenCode optimistic message reconciliation

* Reconcile optimistic user messages by marker

* Reorder user message actions

* Unify provider user message contract

* Add Claude rewind flow Playwright contract

* Add Codex rewind flow Playwright contract

* Add OpenCode rewind flow Playwright contract

* Add Pi rewind flow Playwright contract

* Remove real-provider rewind Playwright contracts

* Gate real-provider rewind specs from CI Playwright

docs/providers.md

@@ -28,6 +28,8 @@ Pi RPC extension UI dialog requests (`select`, `input`, `editor`, `confirm`) are
 
 OpenCode MCP injection is dynamic and session-scoped. Call OpenCode's `mcp.add` endpoint with the MCP server config and do not follow it with `mcp.connect`; `connect` only toggles MCP servers already present in OpenCode's own config. New OpenCode versions return `McpServerNotFoundError`/404 for `connect` after a dynamic add because the server is not config-backed, while older versions silently swallowed the same missing-config path.
 
+OpenCode owns user message IDs. Do not pass Paseo-generated IDs to OpenCode prompt APIs; let OpenCode create `msg*` IDs and record the user timeline item from the `message.updated` event.
+
 Draft metadata lookups should avoid creating provider sessions when the upstream provider has top-level APIs for that metadata. Prefer `AgentClient.listModels`, `listModes`, `listCommands`, or `listFeatures` over creating a scratch `AgentSession`; scratch sessions can show up as empty native sessions in provider import/history UIs.
 
 ---

docs/testing.md

@@ -111,7 +111,7 @@ Vitest picks up tests by suffix. The suffix tells the runner which category it b
 | `*.real.e2e.test.ts`  | E2E that hits a real provider (Claude/Codex/Copilot/OpenCode/Pi) — needs creds in `packages/server/.env.test` | `npm run test:integration:real` / `test:e2e:real`                                    |
 | `*.local.e2e.test.ts` | E2E that needs a local-only resource                                                                          | `npm run test:integration:local` / `test:e2e:local`                                  |
 
-App-level Playwright browser E2E lives in `packages/app/e2e/*.spec.ts` and runs via `npm run test:e2e --workspace=@getpaseo/app` (separate from Vitest E2E).
+App-level Playwright browser E2E lives in `packages/app/e2e/*.spec.ts` and runs via `npm run test:e2e --workspace=@getpaseo/app` (separate from Vitest E2E). App Playwright specs that hit real providers use `*.real.spec.ts` and run through `npm run test:e2e:real --workspace=@getpaseo/app`; the default app E2E project ignores that suffix so CI does not need provider credentials.
 
 ### Test setup
 

packages/app/e2e/global-setup.ts

@@ -537,13 +537,22 @@ async function awaitRelayReady(
   }
 }
 
-async function startRelay(): Promise<number> {
+async function getAvailablePortExcluding(excludedPorts: Set<number>): Promise<number> {
+  for (;;) {
+    const port = await getAvailablePort();
+    if (!excludedPorts.has(port)) {
+      return port;
+    }
+  }
+}
+
+async function startRelay(excludedPorts: Set<number>): Promise<number> {
   const relayDir = path.resolve(__dirname, "..", "..", "relay");
   const maxRelayStartupAttempts = 5;
   let lastRelayStartupError: unknown = null;
 
   for (let attempt = 1; attempt <= maxRelayStartupAttempts; attempt += 1) {
-    const relayPort = await getAvailablePort();
+    const relayPort = await getAvailablePortExcluding(excludedPorts);
     const buffer = createLineBuffer();
     const state: RelayStreamState = { failureLine: null, readyForSelectedPort: false };
 
@@ -729,7 +738,7 @@ export default async function globalSetup() {
   const dictation = await resolveDictationConfig();
 
   try {
-    const relayPort = await startRelay();
+    const relayPort = await startRelay(new Set([port, metroPort]));
     metroProcess = startMetro(metroPort, metroLineBuffer);
     daemonProcess = startDaemon({
       port,

packages/app/e2e/helpers/rewind-flow.ts

@@ -0,0 +1,342 @@
+import { randomUUID } from "node:crypto";
+import { execFileSync } from "node:child_process";
+import { existsSync, readFileSync, rmSync, writeFileSync } from "node:fs";
+import { expect, type Page } from "@playwright/test";
+import { buildHostWorkspaceRoute } from "@/utils/host-routes";
+import { expectComposerEditable, submitMessage } from "./composer";
+import { connectTerminalClient, type TerminalPerfDaemonClient } from "./terminal-perf";
+
+export type RewindFlowProvider = "claude" | "codex" | "opencode" | "pi";
+export type RewindFlowMode = "conversation" | "files" | "both";
+
+export interface AgentHandle {
+  page: Page;
+  client: TerminalPerfDaemonClient;
+  agentId: string;
+  cwd: string;
+  provider: RewindFlowProvider;
+}
+
+export interface TranscriptMessage {
+  role: "user" | "assistant";
+  text: string | RegExp;
+}
+
+interface ProviderLaunchConfig {
+  provider: RewindFlowProvider;
+  model?: string;
+  thinkingOptionId?: string;
+  modeId?: string;
+}
+
+const SEND_TIMEOUT_MS = 240_000;
+const REWIND_TIMEOUT_MS = 120_000;
+
+function getServerId(): string {
+  const serverId = process.env.E2E_SERVER_ID;
+  if (!serverId) {
+    throw new Error("E2E_SERVER_ID is not set.");
+  }
+  return serverId;
+}
+
+function fullAccessConfig(provider: RewindFlowProvider): ProviderLaunchConfig {
+  switch (provider) {
+    case "claude":
+      return { provider, model: "haiku", modeId: "bypassPermissions" };
+    case "codex":
+      return {
+        provider,
+        model: "gpt-5.4-mini",
+        thinkingOptionId: "low",
+        modeId: "full-access",
+      };
+    case "opencode":
+      return { provider, model: "opencode/big-pickle", modeId: "full-access" };
+    case "pi":
+      return {
+        provider,
+        model: "openrouter/google/gemini-2.5-flash-lite",
+        thinkingOptionId: "medium",
+      };
+  }
+}
+
+function agentRoute(cwd: string, agentId: string): string {
+  return `${buildHostWorkspaceRoute(getServerId(), cwd)}?open=${encodeURIComponent(
+    `agent:${agentId}`,
+  )}`;
+}
+
+async function openAgent(page: Page, input: { cwd: string; agentId: string }): Promise<void> {
+  await page.goto(agentRoute(input.cwd, input.agentId));
+  await page.waitForURL(
+    (url) => url.pathname.includes("/workspace/") && !url.searchParams.has("open"),
+    { timeout: 60_000 },
+  );
+  await assertComposerIdle({ page });
+}
+
+function visibleChatMessages(page: Page) {
+  return page
+    .locator('[data-testid="agent-chat-scroll"]:visible')
+    .first()
+    .locator('[data-testid="user-message"], [data-testid="assistant-message"]');
+}
+
+async function transcript(
+  page: Page,
+): Promise<Array<{ role: "user" | "assistant"; text: string }>> {
+  const rawMessages = await visibleChatMessages(page).evaluateAll((elements) =>
+    elements.map((element) => ({
+      role: (element.getAttribute("data-testid") === "user-message" ? "user" : "assistant") as
+        | "user"
+        | "assistant",
+      text: (element.textContent ?? "")
+        .replace(/\s+/g, " ")
+        .replace(/\d{1,2}:\d{2}\s?(?:AM|PM)$/u, "")
+        .trim(),
+    })),
+  );
+
+  return coalesceAssistantTurnSegments(rawMessages);
+}
+
+function coalesceAssistantTurnSegments(
+  messages: Array<{ role: "user" | "assistant"; text: string }>,
+): Array<{ role: "user" | "assistant"; text: string }> {
+  const transcriptMessages: Array<{ role: "user" | "assistant"; text: string }> = [];
+
+  for (const message of messages) {
+    const previous = transcriptMessages.at(-1);
+    if (message.role === "assistant" && previous?.role === "assistant") {
+      const joinedText =
+        previous.text && message.text
+          ? `${previous.text}\n${message.text}`
+          : previous.text || message.text;
+      transcriptMessages[transcriptMessages.length - 1] = {
+        role: "assistant",
+        text: joinedText,
+      };
+      continue;
+    }
+
+    transcriptMessages.push(message);
+  }
+
+  return transcriptMessages.filter(
+    (message) => message.role !== "assistant" || message.text.length > 0,
+  );
+}
+
+function expectedTextMatches(actual: string, expected: string | RegExp): boolean {
+  if (typeof expected === "string") {
+    return actual === expected;
+  }
+  return expected.test(actual);
+}
+
+function formatExpectedMessage(message: TranscriptMessage): string {
+  const text = typeof message.text === "string" ? JSON.stringify(message.text) : message.text;
+  return `${message.role}:${text}`;
+}
+
+function escapeRegExp(text: string): string {
+  return text.replace(/[.*+?^${}()|[\]\\]/gu, "\\$&");
+}
+
+export async function launchAgent(input: {
+  page: Page;
+  provider: RewindFlowProvider;
+  cwd: string;
+  mode: "full-access";
+}): Promise<AgentHandle> {
+  execFileSync("git", ["init", "-b", "main"], { cwd: input.cwd, stdio: "ignore" });
+  execFileSync("git", ["config", "user.email", "paseo-test@example.com"], {
+    cwd: input.cwd,
+    stdio: "ignore",
+  });
+  execFileSync("git", ["config", "user.name", "Paseo Test"], {
+    cwd: input.cwd,
+    stdio: "ignore",
+  });
+  execFileSync("git", ["config", "commit.gpgsign", "false"], {
+    cwd: input.cwd,
+    stdio: "ignore",
+  });
+  writeFileSync(`${input.cwd}/README.md`, "# Paseo rewind flow\n", "utf8");
+  execFileSync("git", ["add", "README.md"], { cwd: input.cwd, stdio: "ignore" });
+  execFileSync("git", ["commit", "-m", "Initial commit"], { cwd: input.cwd, stdio: "ignore" });
+  const client = await connectTerminalClient();
+  const opened = await client.openProject(input.cwd);
+  if (!opened.workspace) {
+    throw new Error(opened.error ?? `Failed to open project ${input.cwd}`);
+  }
+  const agent = await client.createAgent({
+    ...fullAccessConfig(input.provider),
+    cwd: input.cwd,
+    title: `rewind-flow-${input.provider}-${randomUUID()}`,
+  });
+  const handle = {
+    page: input.page,
+    client,
+    agentId: agent.id,
+    cwd: input.cwd,
+    provider: input.provider,
+  };
+  await openAgent(input.page, { cwd: input.cwd, agentId: agent.id });
+  return handle;
+}
+
+export async function closeAgent(handle: AgentHandle): Promise<void> {
+  await handle.client.close().catch(() => undefined);
+}
+
+export async function sendMessage(handle: AgentHandle, text: string): Promise<void> {
+  const before = await transcript(handle.page);
+  await submitMessage(handle.page, text);
+  const finish = await handle.client.waitForFinish(handle.agentId, SEND_TIMEOUT_MS);
+  if (finish.status !== "idle") {
+    const suffix = finish.final?.lastError ? `: ${finish.final.lastError}` : "";
+    throw new Error(
+      `Expected agent ${handle.agentId} to become idle, got ${finish.status}${suffix}`,
+    );
+  }
+  if (finish.final?.lastError) {
+    throw new Error(finish.final.lastError);
+  }
+  await expect
+    .poll(async () => transcript(handle.page), { timeout: 30_000 })
+    .toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({ role: "user", text }),
+        expect.objectContaining({ role: "assistant" }),
+      ]),
+    );
+  await expect
+    .poll(async () => transcript(handle.page).then((messages) => messages.length), {
+      timeout: 30_000,
+    })
+    .toBeGreaterThanOrEqual(before.length + 2);
+  await assertComposerIdle(handle);
+}
+
+export async function assertChatTranscript(
+  handle: Pick<AgentHandle, "page">,
+  expected: TranscriptMessage[],
+): Promise<void> {
+  await expect
+    .poll(
+      async () => {
+        const actual = await transcript(handle.page);
+        if (actual.length !== expected.length) {
+          return JSON.stringify(actual);
+        }
+        const matches = actual.every(
+          (message, index) =>
+            message.role === expected[index]?.role &&
+            expectedTextMatches(message.text, expected[index]!.text),
+        );
+        return matches ? "match" : JSON.stringify(actual);
+      },
+      { timeout: 30_000 },
+    )
+    .toBe("match");
+
+  const actual = await transcript(handle.page);
+  if (actual.length !== expected.length) {
+    throw new Error(
+      `Expected ${expected.length} chat messages (${expected
+        .map(formatExpectedMessage)
+        .join(", ")}), found ${actual.length}: ${JSON.stringify(actual)}`,
+    );
+  }
+}
+
+export async function rewindMessage(
+  handle: AgentHandle,
+  userMessageIndex: number,
+  mode: RewindFlowMode,
+): Promise<void> {
+  const beforeEpoch = await fetchTimelineEpoch(handle);
+  const userMessage = handle.page.getByTestId("user-message").nth(userMessageIndex);
+  await expect(userMessage).toBeVisible({ timeout: 30_000 });
+  const userMessages = (await transcript(handle.page)).filter((message) => message.role === "user");
+  const userText = userMessages[userMessageIndex]?.text;
+  if (!userText) {
+    throw new Error(`No user message found at index ${userMessageIndex}`);
+  }
+  await userMessage
+    .getByText(new RegExp(escapeRegExp(userText)))
+    .first()
+    .hover();
+  const trigger = userMessage.getByTestId("rewind-menu-trigger");
+  await expect(trigger).toBeVisible({ timeout: 10_000 });
+  await trigger.click();
+  await expect(handle.page.getByTestId("rewind-menu-content")).toBeVisible({ timeout: 10_000 });
+  const modeItem = handle.page.getByTestId(`rewind-menu-${mode}`);
+  await expect(modeItem).toBeVisible({ timeout: 10_000 });
+  await modeItem.click();
+  await expect(handle.page.getByTestId("rewind-menu-content")).toHaveCount(0, { timeout: 10_000 });
+  if (mode !== "files") {
+    await waitForNextTimelineEpoch(handle, beforeEpoch);
+  }
+  await assertComposerIdle(handle);
+}
+
+export async function assertFileExists(filePath: string): Promise<void> {
+  await expect.poll(() => existsSync(filePath), { timeout: 10_000 }).toBe(true);
+}
+
+export async function assertFileMissing(filePath: string): Promise<void> {
+  await expect.poll(() => existsSync(filePath), { timeout: 10_000 }).toBe(false);
+}
+
+export async function assertFileContains(filePath: string, text: string): Promise<void> {
+  await assertFileExists(filePath);
+  await expect.poll(() => readFileSync(filePath, "utf8"), { timeout: 10_000 }).toContain(text);
+}
+
+export async function assertComposerIdle(handle: Pick<AgentHandle, "page">): Promise<void> {
+  await expectComposerEditable(handle.page);
+  await expect(handle.page.getByRole("button", { name: /stop|cancel/i })).toHaveCount(0, {
+    timeout: 30_000,
+  });
+  await expect(handle.page.getByTestId("turn-working-indicator")).toHaveCount(0, {
+    timeout: 30_000,
+  });
+}
+
+export async function cleanupRewindFlow(input: {
+  handle?: AgentHandle;
+  cwd: string;
+}): Promise<void> {
+  if (input.handle) {
+    await closeAgent(input.handle);
+  }
+  rmSync(input.cwd, { recursive: true, force: true });
+}
+
+async function fetchTimelineEpoch(handle: AgentHandle): Promise<string | undefined> {
+  const client = handle.client as TerminalPerfDaemonClient & {
+    fetchAgentTimeline: (
+      agentId: string,
+      options?: { direction?: "head" | "tail"; projection?: "canonical"; limit?: number },
+    ) => Promise<{ epoch?: string }>;
+  };
+  const timeline = await client.fetchAgentTimeline(handle.agentId, {
+    direction: "tail",
+    projection: "canonical",
+    limit: 0,
+  });
+  return timeline.epoch;
+}
+
+async function waitForNextTimelineEpoch(
+  handle: AgentHandle,
+  beforeEpoch: string | undefined,
+): Promise<void> {
+  await expect
+    .poll(async () => fetchTimelineEpoch(handle), { timeout: REWIND_TIMEOUT_MS })
+    .not.toBe(beforeEpoch);
+}

packages/app/e2e/helpers/terminal-perf.ts

@@ -2,6 +2,7 @@ import { expect, type Page } from "@playwright/test";
 import path from "node:path";
 import { pathToFileURL } from "node:url";
 import { randomUUID } from "node:crypto";
+import { readFileSync } from "node:fs";
 import { createNodeWebSocketFactory, type NodeWebSocketFactory } from "./node-ws-factory";
 import { buildHostWorkspaceRoute } from "../../src/utils/host-routes";
 
@@ -35,6 +36,10 @@ export interface TerminalPerfDaemonClient {
     timeout?: number,
   ): Promise<{ status: string }>;
   sendAgentMessage(agentId: string, text: string): Promise<void>;
+  waitForFinish(
+    agentId: string,
+    timeout?: number,
+  ): Promise<{ status: string; final?: { lastError?: string | null } | null }>;
   subscribeTerminal(
     terminalId: string,
   ): Promise<{ terminalId: string; slot: number; error: null } | { error: string }>;
@@ -68,6 +73,7 @@ interface TerminalPerfDaemonClientConfig {
   url: string;
   clientId: string;
   clientType: "cli";
+  appVersion?: string;
   webSocketFactory?: NodeWebSocketFactory;
 }
 
@@ -91,12 +97,22 @@ export async function connectTerminalClient(): Promise<TerminalPerfDaemonClient>
     url: getDaemonWsUrl(),
     clientId: `terminal-perf-${randomUUID()}`,
     clientType: "cli",
+    appVersion: loadAppVersion(),
     webSocketFactory,
   });
   await client.connect();
   return client;
 }
 
+function loadAppVersion(): string {
+  const packageJsonPath = path.resolve(__dirname, "../../package.json");
+  const packageJson = JSON.parse(readFileSync(packageJsonPath, "utf8")) as { version?: unknown };
+  if (typeof packageJson.version !== "string" || packageJson.version.length === 0) {
+    throw new Error(`Missing app version in ${packageJsonPath}`);
+  }
+  return packageJson.version;
+}
+
 export function buildTerminalWorkspaceUrl(workspaceId: string, terminalId: string): string {
   const serverId = getServerId();
   const route = buildHostWorkspaceRoute(serverId, workspaceId);

packages/app/e2e/rewind-flow.claude.real.spec.ts

@@ -0,0 +1,7 @@
+import { defineRewindFlowSpec } from "./rewind-flow.shared";
+
+defineRewindFlowSpec({
+  provider: "claude",
+  rewindMode: "both",
+  fileReverted: true,
+});

packages/app/e2e/rewind-flow.codex.real.spec.ts

@@ -0,0 +1,7 @@
+import { defineRewindFlowSpec } from "./rewind-flow.shared";
+
+defineRewindFlowSpec({
+  provider: "codex",
+  rewindMode: "conversation",
+  fileReverted: false,
+});

packages/app/e2e/rewind-flow.opencode.real.spec.ts

@@ -0,0 +1,8 @@
+import { defineRewindFlowSpec } from "./rewind-flow.shared";
+
+defineRewindFlowSpec({
+  provider: "opencode",
+  initialRewindMode: "both",
+  rewindMode: "both",
+  fileReverted: true,
+});

packages/app/e2e/rewind-flow.pi.real.spec.ts

@@ -0,0 +1,7 @@
+import { defineRewindFlowSpec } from "./rewind-flow.shared";
+
+defineRewindFlowSpec({
+  provider: "pi",
+  rewindMode: "conversation",
+  fileReverted: false,
+});

packages/app/e2e/rewind-flow.shared.ts

@@ -0,0 +1,88 @@
+import { mkdtempSync, realpathSync } from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { test } from "./fixtures";
+import {
+  assertChatTranscript,
+  assertComposerIdle,
+  assertFileContains,
+  assertFileExists,
+  assertFileMissing,
+  cleanupRewindFlow,
+  launchAgent,
+  rewindMessage,
+  sendMessage,
+  type AgentHandle,
+  type RewindFlowMode,
+  type RewindFlowProvider,
+} from "./helpers/rewind-flow";
+
+const FILE_PROMPT = "Use the Write tool to create ./qa.txt with the exact content: PASEO_QA_TOKEN";
+
+interface RewindFlowCase {
+  provider: RewindFlowProvider;
+  initialRewindMode?: RewindFlowMode;
+  rewindMode: RewindFlowMode;
+  fileReverted: boolean;
+}
+
+export function defineRewindFlowSpec(input: RewindFlowCase): void {
+  test.describe(`rewind flow - ${input.provider}`, () => {
+    test.setTimeout(600_000);
+
+    test("rewinds conversation and file-write turns without transcript drift", async ({ page }) => {
+      const cwd = realpathSync(
+        mkdtempSync(path.join(tmpdir(), `paseo-rewind-flow-${input.provider}-`)),
+      );
+      let handle: AgentHandle | undefined;
+
+      try {
+        handle = await launchAgent({
+          page,
+          provider: input.provider,
+          cwd,
+          mode: "full-access",
+        });
+
+        await sendMessage(handle, "hello");
+        await assertChatTranscript(handle, [
+          { role: "user", text: "hello" },
+          { role: "assistant", text: /.+/ },
+        ]);
+
+        await rewindMessage(handle, 0, input.initialRewindMode ?? "conversation");
+        await assertChatTranscript(handle, []);
+        await assertComposerIdle(handle);
+
+        await sendMessage(handle, "hello");
+        await assertChatTranscript(handle, [
+          { role: "user", text: "hello" },
+          { role: "assistant", text: /.+/ },
+        ]);
+
+        await sendMessage(handle, FILE_PROMPT);
+        await assertFileContains(path.join(cwd, "qa.txt"), "PASEO_QA_TOKEN");
+        await assertChatTranscript(handle, [
+          { role: "user", text: "hello" },
+          { role: "assistant", text: /.+/ },
+          { role: "user", text: /Use the Write tool/ },
+          { role: "assistant", text: /.+/ },
+        ]);
+
+        await rewindMessage(handle, 1, input.rewindMode);
+        if (input.fileReverted) {
+          await assertFileMissing(path.join(cwd, "qa.txt"));
+        } else {
+          await assertFileExists(path.join(cwd, "qa.txt"));
+        }
+        await assertChatTranscript(handle, [
+          { role: "user", text: "hello" },
+          { role: "assistant", text: /.+/ },
+        ]);
+        await assertComposerIdle(handle);
+      } finally {
+        await cleanupRewindFlow({ handle, cwd });
+      }
+    });
+  });
+}

packages/app/e2e/rewind-menu.ui-contract.spec.ts

@@ -0,0 +1,169 @@
+import { expect, test, type Page } from "./fixtures";
+import { buildHostWorkspaceRoute } from "@/utils/host-routes";
+import { connectTerminalClient } from "./helpers/terminal-perf";
+import { createTempGitRepo } from "./helpers/workspace";
+import {
+  composerLocator,
+  expectComposerDraft,
+  expectComposerVisible,
+  fillComposerDraft,
+  submitMessage,
+} from "./helpers/composer";
+
+// UI plumbing contract against the dev mock provider. Real-provider behavior is tested in `daemon-e2e/*-rewind.real.e2e.test.ts`.
+
+function getServerId(): string {
+  const serverId = process.env.E2E_SERVER_ID;
+  if (!serverId) {
+    throw new Error("E2E_SERVER_ID is not set.");
+  }
+  return serverId;
+}
+
+async function openAgent(page: Page, input: { cwd: string; agentId: string }): Promise<void> {
+  const agentUrl = `${buildHostWorkspaceRoute(
+    getServerId(),
+    input.cwd,
+  )}?open=${encodeURIComponent(`agent:${input.agentId}`)}`;
+  await page.goto(agentUrl);
+  await page.waitForURL(
+    (url) => url.pathname.includes("/workspace/") && !url.searchParams.has("open"),
+    { timeout: 60_000 },
+  );
+  await expectComposerVisible(page);
+}
+
+async function expectUserMessageCount(page: Page, expected: number): Promise<void> {
+  await expect(page.getByTestId("user-message")).toHaveCount(expected);
+}
+
+test.describe("Rewind sheet", () => {
+  test("rewinds from a user message sheet option", async ({ page }) => {
+    const repo = await createTempGitRepo("rewind-e2e-");
+    const client = await connectTerminalClient();
+    const firstPrompt = "emit 1 coalesced agent stream updates for first rewind turn.";
+    const secondPrompt = "Prepare deleted rewind turn assistant content.";
+    const replacementPrompt = "emit 1 coalesced agent stream updates for replacement rewind turn.";
+
+    try {
+      await client.openProject(repo.path);
+      const agent = await client.createAgent({
+        provider: "mock",
+        cwd: repo.path,
+        title: "Rewind e2e",
+        modeId: "load-test",
+        model: "ten-second-stream",
+        initialPrompt: firstPrompt,
+      });
+      await openAgent(page, { cwd: repo.path, agentId: agent.id });
+
+      await expect(page.getByText(firstPrompt, { exact: true })).toBeVisible();
+      await expectUserMessageCount(page, 1);
+      await submitMessage(page, secondPrompt);
+      await expect(page.getByText(secondPrompt, { exact: true })).toBeVisible();
+      await expect(page.getByText("Cycle 1", { exact: true })).toBeVisible();
+      await expectUserMessageCount(page, 2);
+
+      await page.getByText(firstPrompt, { exact: true }).hover();
+      await page.getByTestId("rewind-menu-trigger").first().click();
+      const rewindSheet = page.getByTestId("rewind-menu-content");
+      await expect(rewindSheet).toBeVisible();
+      await expect(rewindSheet.getByText("Rewind to this message", { exact: true })).toBeVisible();
+      await expect(
+        rewindSheet.getByText("This action cannot be undone", { exact: true }),
+      ).toBeVisible();
+      await page.getByTestId("rewind-menu-conversation").click();
+
+      await expect(page.getByTestId("rewind-menu-content")).toHaveCount(0);
+      await expect(page.getByText(secondPrompt, { exact: true })).toHaveCount(0);
+      await expect(page.getByText("Cycle 1", { exact: true })).toHaveCount(0);
+      await expectUserMessageCount(page, 1);
+      await expectComposerDraft(page, firstPrompt);
+
+      await submitMessage(page, replacementPrompt);
+      await expect(page.getByText(replacementPrompt, { exact: true })).toBeVisible();
+      await expect(page.getByText(secondPrompt, { exact: true })).toHaveCount(0);
+      await expect(page.getByText("Cycle 1", { exact: true })).toHaveCount(0);
+      await expectUserMessageCount(page, 2);
+
+      await fillComposerDraft(page, "");
+      await composerLocator(page).evaluate((element) => element.blur());
+      await page.getByText(replacementPrompt, { exact: true }).hover();
+      await page.getByTestId("rewind-menu-trigger").last().click();
+      await expect(page.getByTestId("rewind-menu-content")).toBeVisible();
+      await page.getByTestId("rewind-menu-files").click();
+      await expect(page.getByTestId("rewind-menu-content")).toHaveCount(0);
+      await expectComposerDraft(page, "");
+      await expectUserMessageCount(page, 2);
+
+      const preservedDraft = "Keep this human draft after rewind.";
+      await fillComposerDraft(page, preservedDraft);
+      await composerLocator(page).evaluate((element) => element.blur());
+      await page.getByText(replacementPrompt, { exact: true }).hover();
+      await page.getByTestId("rewind-menu-trigger").last().click();
+      await expect(page.getByTestId("rewind-menu-content")).toBeVisible();
+      await page.getByTestId("rewind-menu-files").click();
+      await expect(page.getByTestId("rewind-menu-content")).toHaveCount(0);
+      await expectComposerDraft(page, preservedDraft);
+      await expectUserMessageCount(page, 2);
+
+      await fillComposerDraft(page, "");
+      await composerLocator(page).evaluate((element) => element.blur());
+      await page.getByText(replacementPrompt, { exact: true }).hover();
+      await page.getByTestId("rewind-menu-trigger").last().click();
+      await expect(page.getByTestId("rewind-menu-content")).toBeVisible();
+      await page.getByTestId("rewind-menu-both").click();
+      await expect(page.getByTestId("rewind-menu-content")).toHaveCount(0);
+      await expectComposerDraft(page, replacementPrompt);
+      await expectUserMessageCount(page, 1);
+    } finally {
+      await client.close();
+      await repo.cleanup();
+    }
+  });
+
+  test("surfaces rewind failures without crashing the page", async ({ page }) => {
+    const repo = await createTempGitRepo("rewind-failure-e2e-");
+    const client = await connectTerminalClient();
+    const firstPrompt = "emit 1 coalesced agent stream updates for failed rewind turn.";
+    const rewindError = "No file checkpoint found for message rewind-failure-e2e.";
+
+    try {
+      await client.openProject(repo.path);
+      const agent = await client.createAgent({
+        provider: "mock",
+        cwd: repo.path,
+        title: "Rewind failure e2e",
+        modeId: "load-test",
+        model: "ten-second-stream",
+        featureValues: {
+          mockRewindError: rewindError,
+        },
+        initialPrompt: firstPrompt,
+      });
+      await openAgent(page, { cwd: repo.path, agentId: agent.id });
+
+      await expect(page.getByText(firstPrompt, { exact: true })).toBeVisible();
+
+      await page.getByText(firstPrompt, { exact: true }).hover();
+      await page.getByTestId("rewind-menu-trigger").first().click();
+      const rewindSheet = page.getByTestId("rewind-menu-content");
+      await expect(rewindSheet).toBeVisible();
+      await expect(rewindSheet.getByText("Rewind to this message", { exact: true })).toBeVisible();
+      await expect(
+        rewindSheet.getByText("This action cannot be undone", { exact: true }),
+      ).toBeVisible();
+      await page.getByTestId("rewind-menu-conversation").click();
+
+      await expect(page.getByTestId("app-toast-message")).toHaveText(rewindError);
+      await expect(page.getByText("Uncaught Error")).toHaveCount(0);
+
+      await page.getByText(firstPrompt, { exact: true }).hover();
+      await page.getByTestId("rewind-menu-trigger").first().click();
+      await expect(page.getByTestId("rewind-menu-content")).toBeVisible();
+    } finally {
+      await client.close();
+      await repo.cleanup();
+    }
+  });
+});

packages/app/e2e/user-message-contract.ui-contract.spec.ts

@@ -0,0 +1,92 @@
+import { expect, test, type Page } from "./fixtures";
+import { buildHostWorkspaceRoute } from "@/utils/host-routes";
+import { connectTerminalClient } from "./helpers/terminal-perf";
+import { createTempGitRepo } from "./helpers/workspace";
+import {
+  composerLocator,
+  expectComposerEditable,
+  expectComposerVisible,
+  fillComposerDraft,
+  submitMessage,
+} from "./helpers/composer";
+
+function getServerId(): string {
+  const serverId = process.env.E2E_SERVER_ID;
+  if (!serverId) {
+    throw new Error("E2E_SERVER_ID is not set.");
+  }
+  return serverId;
+}
+
+async function openAgent(page: Page, input: { cwd: string; agentId: string }): Promise<void> {
+  const agentUrl = `${buildHostWorkspaceRoute(
+    getServerId(),
+    input.cwd,
+  )}?open=${encodeURIComponent(`agent:${input.agentId}`)}`;
+  await page.goto(agentUrl);
+  await page.waitForURL(
+    (url) => url.pathname.includes("/workspace/") && !url.searchParams.has("open"),
+    { timeout: 60_000 },
+  );
+  await expectComposerVisible(page);
+}
+
+async function expectUserMessageCount(page: Page, expected: number): Promise<void> {
+  await expect(page.getByTestId("user-message")).toHaveCount(expected, { timeout: 15_000 });
+}
+
+async function expectIdleComposer(page: Page): Promise<void> {
+  await expectComposerEditable(page);
+  await expect(page.getByRole("button", { name: /stop|cancel/i })).toHaveCount(0, {
+    timeout: 15_000,
+  });
+}
+
+async function expectNoLoadingRegressionAfterIdle(page: Page): Promise<void> {
+  await expectIdleComposer(page);
+  await page.waitForTimeout(1_000);
+  await expectIdleComposer(page);
+}
+
+test.describe("User message UI contract", () => {
+  test("dedupes mock provider user_message echoes across multi-turn sends", async ({ page }) => {
+    const repo = await createTempGitRepo("user-message-contract-e2e-");
+    const client = await connectTerminalClient();
+    const prompts = [
+      "emit 1 coalesced agent stream updates for user message contract turn one.",
+      "emit 1 coalesced agent stream updates for user message contract turn two.",
+      "emit 1 coalesced agent stream updates for user message contract turn three.",
+    ];
+
+    try {
+      await client.openProject(repo.path);
+      const agent = await client.createAgent({
+        provider: "mock",
+        cwd: repo.path,
+        title: "User message contract e2e",
+        modeId: "load-test",
+        model: "ten-second-stream",
+      });
+      await openAgent(page, { cwd: repo.path, agentId: agent.id });
+
+      for (let index = 0; index < prompts.length; index += 1) {
+        const prompt = prompts[index]!;
+        await submitMessage(page, prompt);
+        await expect(page.getByText(prompt, { exact: true })).toBeVisible({ timeout: 15_000 });
+        await expect(page.getByText("stress-update-0", { exact: true }).first()).toBeVisible({
+          timeout: 15_000,
+        });
+        await expectUserMessageCount(page, index + 1);
+        await expectNoLoadingRegressionAfterIdle(page);
+      }
+
+      await fillComposerDraft(page, "append");
+      await composerLocator(page).evaluate((element) => element.blur());
+      await expectUserMessageCount(page, 3);
+      await expectIdleComposer(page);
+    } finally {
+      await client.close();
+      await repo.cleanup();
+    }
+  });
+});

packages/app/package.json

@@ -21,7 +21,8 @@
     "typecheck": "tsgo --noEmit",
     "test": "vitest run",
     "test:browser": "vitest run --project browser",
-    "test:e2e": "playwright test",
+    "test:e2e": "playwright test --project='Desktop Chrome'",
+    "test:e2e:real": "playwright test --project=real-provider",
     "test:e2e:ui": "playwright test --ui",
     "build": "npm run build:web",
     "build:web": "npm run build:workspace-deps && expo export --platform web",

packages/app/playwright.config.ts

@@ -27,6 +27,12 @@ export default defineConfig({
   projects: [
     {
       name: "Desktop Chrome",
+      testIgnore: ["**/*.real.spec.ts"],
+      use: { ...devices["Desktop Chrome"] },
+    },
+    {
+      name: "real-provider",
+      testMatch: ["**/*.real.spec.ts"],
       use: { ...devices["Desktop Chrome"] },
     },
   ],

packages/app/src/agent-stream/view.tsx

@@ -412,16 +412,21 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
       (layoutItem: StreamLayoutItem, item: Extract<StreamItem, { kind: "user_message" }>) => {
         return (
           <UserMessage
+            serverId={resolvedServerId}
+            agentId={agentId}
+            messageId={item.id}
             message={item.text}
             images={item.images}
             attachments={item.attachments}
             timestamp={item.timestamp.getTime()}
+            capabilities={agent.capabilities}
+            client={client}
             isFirstInGroup={layoutItem.isFirstInUserGroup}
             isLastInGroup={layoutItem.isLastInUserGroup}
           />
         );
       },
-      [],
+      [agent.capabilities, agentId, client, resolvedServerId],
     );
 
     const renderAssistantMessageItem = useCallback(

packages/app/src/components/composer-actions.test.ts

@@ -353,6 +353,7 @@ describe("dispatchComposerAgentMessage", () => {
     expect(userMessage.images).toEqual([image]);
     expect(userMessage.attachments).toEqual(call.options.attachments);
     expect(userMessage.id).toBe(call.options.messageId);
+    expect(userMessage.optimistic).toBe(true);
   });
 
   it("appends to the existing head when one is present", async () => {

packages/app/src/components/composer-actions.ts

@@ -135,6 +135,7 @@ export async function dispatchComposerAgentMessage(
     id: messageId,
     text: input.text,
     timestamp: new Date(),
+    optimistic: true,
     ...(wirePayload.images.length > 0 ? { images: wirePayload.images } : {}),
     ...(wirePayload.attachments.length > 0 ? { attachments: wirePayload.attachments } : {}),
   };

packages/app/src/components/message.tsx

@@ -102,15 +102,23 @@ import { useAttachmentPreviewUrl } from "@/attachments/use-attachment-preview-ur
 import { persistAttachmentFromBytes, persistAttachmentFromDataUrl } from "@/attachments/service";
 import type { DaemonClient } from "@server/client/daemon-client";
 import { isWeb, isNative } from "@/constants/platform";
+import type { AgentCapabilityFlags } from "@server/server/agent/agent-sdk-types";
+import { RewindMenu, type RewindMode } from "@/components/rewind/rewind-menu";
+import { useRewindAgentMutation } from "@/components/rewind/use-rewind-agent-mutation";
 export type { InlinePathTarget } from "@/assistant-file-links";
 
 type MarkdownStyles = Record<string, TextStyle & ViewStyle & { [key: string]: unknown }>;
 
 interface UserMessageProps {
+  serverId?: string;
+  agentId?: string;
+  messageId?: string;
   message: string;
   images?: UserMessageImageAttachment[];
   attachments?: AgentAttachment[];
   timestamp: number;
+  capabilities?: AgentCapabilityFlags;
+  client?: DaemonClient | null;
   isFirstInGroup?: boolean;
   isLastInGroup?: boolean;
   disableOuterSpacing?: boolean;
@@ -450,10 +458,15 @@ function getUserMessageAttachmentLabel(attachment: AgentAttachment): string {
 }
 
 export const UserMessage = memo(function UserMessage({
+  serverId,
+  agentId,
+  messageId,
   message,
   images = [],
   attachments = [],
   timestamp,
+  capabilities,
+  client,
   isFirstInGroup = true,
   isLastInGroup = true,
   disableOuterSpacing,
@@ -469,10 +482,17 @@ export const UserMessage = memo(function UserMessage({
     () => formatMessageTimestamp(new Date(timestamp)),
     [timestamp],
   );
+  const rewindMutation = useRewindAgentMutation({ serverId, agentId, client, messageId });
 
   const handlePointerEnter = useCallback(() => setIsHovered(true), []);
   const handlePointerLeave = useCallback(() => setIsHovered(false), []);
   const getMessageContent = useCallback(() => message, [message]);
+  const handleRewind = useCallback(
+    (input: { mode: RewindMode; rewoundText: string }) => {
+      return rewindMutation.rewindAgent(input);
+    },
+    [rewindMutation],
+  );
 
   const containerStyle = useMemo(
     () => [
@@ -510,7 +530,7 @@ export const UserMessage = memo(function UserMessage({
   );
 
   return (
-    <View style={containerStyle}>
+    <View style={containerStyle} testID="user-message">
       <View
         style={userMessageStylesheet.content}
         onPointerEnter={handlePointerEnter}
@@ -549,6 +569,14 @@ export const UserMessage = memo(function UserMessage({
         {hasText ? (
           <View style={trailingRowStyle} pointerEvents={showTrailingRow ? "auto" : "none"}>
             <Text style={userMessageStylesheet.timestampText}>{formattedTimestamp}</Text>
+            {capabilities ? (
+              <RewindMenu
+                capabilities={capabilities}
+                isPending={rewindMutation.isPending}
+                rewoundText={message}
+                onRewind={handleRewind}
+              />
+            ) : null}
             <TurnCopyButton
               getContent={getMessageContent}
               containerStyle={userMessageStylesheet.copyButton}

packages/app/src/components/rewind/composer-restore.test.ts

@@ -0,0 +1,31 @@
+import { describe, expect, test } from "vitest";
+import { restoreComposerTextIfEmpty } from "./composer-restore";
+import { shouldRestoreComposerForRewindMode } from "./rewind-mode";
+
+describe("restoreComposerTextIfEmpty", () => {
+  test("restores the rewound message when the composer is empty", () => {
+    expect(
+      restoreComposerTextIfEmpty({
+        currentText: "",
+        rewoundText: "message before rewind",
+      }),
+    ).toBe("message before rewind");
+  });
+
+  test("preserves an existing composer draft", () => {
+    expect(
+      restoreComposerTextIfEmpty({
+        currentText: "keep this draft",
+        rewoundText: "message before rewind",
+      }),
+    ).toBe("keep this draft");
+  });
+});
+
+describe("shouldRestoreComposerForRewindMode", () => {
+  test("restores only conversation-mutating rewind modes", () => {
+    expect(shouldRestoreComposerForRewindMode("conversation")).toBe(true);
+    expect(shouldRestoreComposerForRewindMode("files")).toBe(false);
+    expect(shouldRestoreComposerForRewindMode("both")).toBe(true);
+  });
+});

packages/app/src/components/rewind/composer-restore.tsx

@@ -0,0 +1,68 @@
+import {
+  createContext,
+  useCallback,
+  useContext,
+  useEffect,
+  useMemo,
+  useRef,
+  type ReactNode,
+} from "react";
+
+interface RewindComposerRestoreContextValue {
+  restoreTextIfComposerEmpty: (text: string) => void;
+}
+
+interface RewindComposerRestoreProviderProps {
+  text: string;
+  setText: (text: string) => void;
+  children: ReactNode;
+}
+
+const RewindComposerRestoreContext = createContext<RewindComposerRestoreContextValue | null>(null);
+
+export function restoreComposerTextIfEmpty(input: {
+  currentText: string;
+  rewoundText: string;
+}): string {
+  if (input.currentText.length > 0) {
+    return input.currentText;
+  }
+  return input.rewoundText;
+}
+
+export function RewindComposerRestoreProvider({
+  text,
+  setText,
+  children,
+}: RewindComposerRestoreProviderProps) {
+  const textRef = useRef(text);
+
+  useEffect(() => {
+    textRef.current = text;
+  }, [text]);
+
+  const restoreTextIfComposerEmpty = useCallback(
+    (rewoundText: string) => {
+      const nextText = restoreComposerTextIfEmpty({
+        currentText: textRef.current,
+        rewoundText,
+      });
+      if (nextText !== textRef.current) {
+        setText(nextText);
+      }
+    },
+    [setText],
+  );
+
+  const value = useMemo(() => ({ restoreTextIfComposerEmpty }), [restoreTextIfComposerEmpty]);
+
+  return (
+    <RewindComposerRestoreContext.Provider value={value}>
+      {children}
+    </RewindComposerRestoreContext.Provider>
+  );
+}
+
+export function useRewindComposerRestore(): RewindComposerRestoreContextValue | null {
+  return useContext(RewindComposerRestoreContext);
+}

packages/app/src/components/rewind/rewind-menu.tsx

@@ -0,0 +1,164 @@
+import { memo, useCallback, useMemo, useState, type ComponentType } from "react";
+import { Text, View } from "react-native";
+import { FileText, Layers, MessageSquare, Undo2 } from "lucide-react-native";
+import { StyleSheet } from "react-native-unistyles";
+import { AdaptiveModalSheet, type SheetHeader } from "@/components/adaptive-modal-sheet";
+import { Button } from "@/components/ui/button";
+import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
+import {
+  type RewindMenuItem,
+  type RewindMode,
+  useRewindCapabilities,
+} from "./use-rewind-capabilities";
+import type { AgentCapabilityFlags } from "@server/server/agent/agent-sdk-types";
+
+export type { RewindMode };
+
+interface RewindMenuProps {
+  capabilities: AgentCapabilityFlags;
+  rewoundText: string;
+  onRewind: (input: { mode: RewindMode; rewoundText: string }) => Promise<void> | void;
+  isPending?: boolean;
+  testID?: string;
+}
+
+const REWIND_HEADER: SheetHeader = { title: "Rewind to this message" };
+const SNAP_POINTS: string[] = ["42%", "72%"];
+
+function iconForItem(item: RewindMenuItem): ComponentType<{ color: string; size: number }> {
+  switch (item.mode) {
+    case "conversation":
+      return MessageSquare;
+    case "files":
+      return FileText;
+    case "both":
+      return Layers;
+  }
+}
+
+export const RewindMenu = memo(function RewindMenu({
+  capabilities,
+  rewoundText,
+  onRewind,
+  isPending = false,
+  testID = "rewind-menu",
+}: RewindMenuProps) {
+  const items = useRewindCapabilities(capabilities);
+  const [isSheetVisible, setIsSheetVisible] = useState(false);
+  const [pendingMode, setPendingMode] = useState<RewindMode | null>(null);
+  const handleOpen = useCallback(() => setIsSheetVisible(true), []);
+  const handleClose = useCallback(() => {
+    if (!isPending) {
+      setIsSheetVisible(false);
+    }
+  }, [isPending]);
+  const handleSelect = useCallback(
+    (mode: RewindMode) => async () => {
+      if (isPending) {
+        return;
+      }
+      setPendingMode(mode);
+      try {
+        await onRewind({ mode, rewoundText });
+      } catch {
+        // useRewindAgentMutation owns the toast; the sheet only owns flow state.
+      } finally {
+        setPendingMode(null);
+        setIsSheetVisible(false);
+      }
+    },
+    [isPending, onRewind, rewoundText],
+  );
+  const triggerIcon = useCallback((color: string) => <Undo2 size={16} color={color} />, []);
+  const tooltipContent = useMemo(
+    () => (
+      <TooltipContent side="top" align="center" offset={8}>
+        <Text style={styles.tooltipText}>Rewind to this message</Text>
+      </TooltipContent>
+    ),
+    [],
+  );
+
+  if (items.length === 0) {
+    return null;
+  }
+
+  return (
+    <>
+      <Tooltip delayDuration={0} enabledOnDesktop enabledOnMobile={false}>
+        <TooltipTrigger asChild>
+          <Button
+            accessibilityLabel="Rewind to this message"
+            disabled={isPending}
+            leftIcon={triggerIcon}
+            onPress={handleOpen}
+            size="xs"
+            style={styles.trigger}
+            testID={`${testID}-trigger`}
+            variant="ghost"
+          />
+        </TooltipTrigger>
+        {tooltipContent}
+      </Tooltip>
+      <AdaptiveModalSheet
+        desktopMaxWidth={420}
+        header={REWIND_HEADER}
+        onClose={handleClose}
+        scrollable={false}
+        snapPoints={SNAP_POINTS}
+        testID={`${testID}-content`}
+        visible={isSheetVisible}
+      >
+        <View style={styles.content}>
+          <Text style={styles.warningText}>This action cannot be undone</Text>
+          <View style={styles.actions}>
+            {items.map((item) => (
+              <Button
+                key={item.mode}
+                leftIcon={iconForItem(item)}
+                loading={pendingMode === item.mode}
+                disabled={isPending}
+                onPress={handleSelect(item.mode)}
+                size="md"
+                style={styles.actionButton}
+                testID={item.testID}
+                variant="secondary"
+              >
+                {item.label}
+              </Button>
+            ))}
+          </View>
+        </View>
+      </AdaptiveModalSheet>
+    </>
+  );
+});
+
+const styles = StyleSheet.create((theme) => ({
+  trigger: {
+    width: 24,
+    height: 24,
+    minHeight: 24,
+    paddingHorizontal: 0,
+    paddingVertical: 0,
+    alignItems: "center",
+    justifyContent: "center",
+  },
+  tooltipText: {
+    color: theme.colors.foreground,
+    fontSize: theme.fontSize.xs,
+  },
+  content: {
+    gap: theme.spacing[4],
+  },
+  warningText: {
+    color: theme.colors.statusWarning,
+    fontSize: theme.fontSize.sm,
+  },
+  actions: {
+    gap: theme.spacing[2],
+  },
+  actionButton: {
+    justifyContent: "flex-start",
+  },
+}));

packages/app/src/components/rewind/rewind-mode.ts

@@ -0,0 +1,5 @@
+import type { RewindMode } from "./use-rewind-capabilities";
+
+export function shouldRestoreComposerForRewindMode(mode: RewindMode): boolean {
+  return mode === "conversation" || mode === "both";
+}

packages/app/src/components/rewind/use-rewind-agent-mutation.ts

@@ -0,0 +1,80 @@
+import { useCallback } from "react";
+import { useMutation } from "@tanstack/react-query";
+import { useToast } from "@/contexts/toast-context";
+import type { DaemonClient } from "@server/client/daemon-client";
+import type { RewindMode } from "./use-rewind-capabilities";
+import { useRewindComposerRestore } from "./composer-restore";
+import { useSessionStore } from "@/stores/session-store";
+import { shouldRestoreComposerForRewindMode } from "./rewind-mode";
+import { clearOptimisticUserMessages } from "@/types/stream";
+
+interface UseRewindAgentMutationInput {
+  serverId?: string;
+  agentId?: string;
+  messageId?: string;
+  client?: DaemonClient | null;
+}
+
+interface RewindAgentInput {
+  mode: RewindMode;
+  rewoundText: string;
+}
+
+export function useRewindAgentMutation(input: UseRewindAgentMutationInput): {
+  rewindAgent: (input: RewindAgentInput) => Promise<void>;
+  isPending: boolean;
+} {
+  const toast = useToast();
+  const composerRestore = useRewindComposerRestore();
+  const { isPending, mutateAsync } = useMutation({
+    mutationFn: async ({ mode }: RewindAgentInput) => {
+      if (!input.client || !input.agentId || !input.messageId) {
+        throw new Error("Daemon client not available");
+      }
+      await input.client.rewindAgent(input.agentId, input.messageId, mode);
+      if (mode !== "files") {
+        if (input.serverId) {
+          const session = useSessionStore.getState().sessions[input.serverId];
+          useSessionStore.getState().setAgentStreamState(input.serverId, input.agentId, {
+            tail: clearOptimisticUserMessages(session?.agentStreamTail.get(input.agentId) ?? []),
+            head: clearOptimisticUserMessages(session?.agentStreamHead.get(input.agentId) ?? []),
+          });
+        }
+        const cursor = input.serverId
+          ? useSessionStore
+              .getState()
+              .sessions[input.serverId]?.agentTimelineCursor.get(input.agentId)
+          : undefined;
+        await input.client.fetchAgentTimeline(input.agentId, {
+          direction: "tail",
+          projection: "canonical",
+          ...(cursor ? { cursor: { epoch: cursor.epoch, seq: cursor.endSeq } } : {}),
+        });
+      }
+    },
+    onSuccess: (_data, variables) => {
+      if (!shouldRestoreComposerForRewindMode(variables.mode)) {
+        return;
+      }
+      composerRestore?.restoreTextIfComposerEmpty(variables.rewoundText);
+    },
+    onError: (error) => {
+      toast.error(error instanceof Error ? error.message : "Failed to rewind agent");
+    },
+  });
+
+  const rewindAgent = useCallback(
+    async (rewindInput: RewindAgentInput) => {
+      if (isPending) {
+        return;
+      }
+      await mutateAsync(rewindInput);
+    },
+    [isPending, mutateAsync],
+  );
+
+  return {
+    rewindAgent,
+    isPending,
+  };
+}

packages/app/src/components/rewind/use-rewind-capabilities.test.ts

@@ -0,0 +1,36 @@
+import { describe, expect, test } from "vitest";
+
+import { resolveRewindMenuItems } from "./use-rewind-capabilities";
+
+describe("resolveRewindMenuItems", () => {
+  test("returns no items when the provider declares no rewind capability", () => {
+    expect(
+      resolveRewindMenuItems({
+        supportsRewindConversation: false,
+        supportsRewindFiles: false,
+        supportsRewindBoth: false,
+      }),
+    ).toEqual([]);
+  });
+
+  test("returns only the capabilities declared by the provider", () => {
+    expect(
+      resolveRewindMenuItems({
+        supportsRewindConversation: true,
+        supportsRewindFiles: false,
+        supportsRewindBoth: true,
+      }),
+    ).toEqual([
+      {
+        mode: "conversation",
+        label: "Rewind conversation",
+        testID: "rewind-menu-conversation",
+      },
+      {
+        mode: "both",
+        label: "Rewind conversation and files",
+        testID: "rewind-menu-both",
+      },
+    ]);
+  });
+});

packages/app/src/components/rewind/use-rewind-capabilities.ts

@@ -0,0 +1,53 @@
+import { useMemo } from "react";
+import type { AgentCapabilityFlags } from "@server/server/agent/agent-sdk-types";
+
+export type RewindMode = "conversation" | "files" | "both";
+
+export interface RewindMenuItem {
+  mode: RewindMode;
+  label: string;
+  testID: string;
+}
+
+export function resolveRewindMenuItems(
+  capabilities:
+    | Pick<
+        AgentCapabilityFlags,
+        "supportsRewindConversation" | "supportsRewindFiles" | "supportsRewindBoth"
+      >
+    | null
+    | undefined,
+): RewindMenuItem[] {
+  if (!capabilities) {
+    return [];
+  }
+  const items: RewindMenuItem[] = [];
+  if (capabilities.supportsRewindConversation) {
+    items.push({
+      mode: "conversation",
+      label: "Rewind conversation",
+      testID: "rewind-menu-conversation",
+    });
+  }
+  if (capabilities.supportsRewindFiles) {
+    items.push({
+      mode: "files",
+      label: "Rewind files",
+      testID: "rewind-menu-files",
+    });
+  }
+  if (capabilities.supportsRewindBoth) {
+    items.push({
+      mode: "both",
+      label: "Rewind conversation and files",
+      testID: "rewind-menu-both",
+    });
+  }
+  return items;
+}
+
+export function useRewindCapabilities(
+  capabilities: Parameters<typeof resolveRewindMenuItems>[0],
+): RewindMenuItem[] {
+  return useMemo(() => resolveRewindMenuItems(capabilities), [capabilities]);
+}

packages/app/src/contexts/session-context.tsx

@@ -1664,6 +1664,9 @@ function SessionProviderInternal({ children, serverId, client }: SessionProvider
         id: messageId,
         text: message,
         timestamp: new Date(),
+        optimistic: true,
+        ...(images && images.length > 0 ? { images } : {}),
+        ...(attachments && attachments.length > 0 ? { attachments } : {}),
       };
 
       // Append to head if streaming (keeps the user message with the current

packages/app/src/hooks/use-agent-input-draft.ts

@@ -50,7 +50,7 @@ type DraftComposerState = UseAgentFormStateResult & {
   commandDraftConfig: DraftCommandConfig | undefined;
 };
 
-interface AgentInputDraft {
+export interface AgentInputDraft {
   text: string;
   setText: (text: string) => void;
   attachments: UserComposerAttachment[];

packages/app/src/hooks/use-agent-screen-state-machine.test.ts

@@ -99,6 +99,16 @@ function expectSyncErrorSync(state: ReadyState): void {
   expect(state.sync.status).toBe("sync_error");
 }
 
+function stateMachineLabel(state: AgentScreenViewState): "loading" | "resolving" | Agent["status"] {
+  if (state.tag === "boot") {
+    return state.reason;
+  }
+  if (state.tag === "ready") {
+    return state.agent.status;
+  }
+  return "error";
+}
+
 describe("deriveAgentScreenViewState", () => {
   it("returns boot loading before first interactive paint", () => {
     const memory = createBaseMemory();
@@ -383,6 +393,39 @@ describe("deriveAgentScreenViewState", () => {
     expect(ready.agent.status).toBe("running");
   });
 
+  it("keeps send lifecycle transitions forward-only across optimistic and authoritative handoff", () => {
+    let memory = createBaseMemory();
+    const transitions: Array<"loading" | "resolving" | Agent["status"]> = [];
+
+    for (const input of [
+      createBaseInput(),
+      {
+        ...createBaseInput(),
+        agent: createAgentWithStatus({ id: "agent-1", status: "idle" }),
+        placeholderAgent: createAgent("agent-1"),
+        shouldUseOptimisticStream: true,
+      },
+      {
+        ...createBaseInput(),
+        agent: createAgentWithStatus({ id: "agent-1", status: "running" }),
+        placeholderAgent: createAgent("agent-1"),
+        shouldUseOptimisticStream: true,
+      },
+      {
+        ...createBaseInput(),
+        agent: createAgentWithStatus({ id: "agent-1", status: "idle" }),
+      },
+    ] satisfies AgentScreenMachineInput[]) {
+      const result = deriveAgentScreenViewState({ input, memory });
+      memory = result.memory;
+      transitions.push(stateMachineLabel(result.state));
+    }
+
+    expect(transitions).toEqual(["loading", "running", "running", "idle"]);
+    expect(transitions.join(" -> ")).not.toContain("running -> loading");
+    expect(transitions.join(" -> ")).not.toContain("loading -> idle");
+  });
+
   it("keeps optimistic running status while authoritative agent is initializing", () => {
     const memory = createBaseMemory();
     const input: AgentScreenMachineInput = {

packages/app/src/hooks/use-agent-screen-state-machine.ts

@@ -1,10 +1,12 @@
 import { useRef } from "react";
+import type { AgentCapabilityFlags } from "@server/server/agent/agent-sdk-types";
 
 export interface AgentScreenAgent {
   serverId: string;
   id: string;
   status: "initializing" | "idle" | "running" | "error" | "closed";
   cwd: string;
+  capabilities?: AgentCapabilityFlags;
   lastError?: string | null;
   projectPlacement?: {
     checkout?: {

packages/app/src/hooks/use-draft-agent-create-flow.ts

@@ -133,6 +133,7 @@ export function useDraftAgentCreateFlow<TDraftAgent, TCreateResult>({
         id: machine.attempt.clientMessageId,
         text: machine.attempt.text,
         timestamp: machine.attempt.timestamp,
+        optimistic: true,
         ...(machine.attempt.images && machine.attempt.images.length > 0
           ? { images: machine.attempt.images }
           : {}),

packages/app/src/panels/agent-panel.tsx

@@ -11,6 +11,7 @@ import { AgentStreamView, type AgentStreamViewHandle } from "@/agent-stream/view
 import { ArchivedAgentCallout } from "@/components/archived-agent-callout";
 import { Composer } from "@/components/composer";
 import { FileDropZone } from "@/components/file-drop-zone";
+import { RewindComposerRestoreProvider } from "@/components/rewind/composer-restore";
 import type { ImageAttachment } from "@/components/message-input";
 import { getProviderIcon } from "@/components/provider-icons";
 import { ToastViewport, useToastHost } from "@/components/toast-host";
@@ -23,7 +24,7 @@ import { useIsCompactFormFactor } from "@/constants/layout";
 import { isNative, isWeb } from "@/constants/platform";
 import { useAgentAttentionClear } from "@/hooks/use-agent-attention-clear";
 import { useAgentInitialization } from "@/hooks/use-agent-initialization";
-import { useAgentInputDraft } from "@/hooks/use-agent-input-draft";
+import { useAgentInputDraft, type AgentInputDraft } from "@/hooks/use-agent-input-draft";
 import {
   type AgentScreenAgent,
   type AgentScreenMissingState,
@@ -69,6 +70,7 @@ interface ChatAgentStateShape {
   id: string | null;
   status: Agent["status"] | null;
   cwd: string | null;
+  capabilities?: Agent["capabilities"];
   lastError?: Agent["lastError"] | null;
 }
 
@@ -111,6 +113,7 @@ function selectChatAgentState(
     id: agent.id,
     status: agent.status,
     cwd: agent.cwd,
+    capabilities: agent.capabilities,
     lastError: agent.lastError ?? null,
     archivedAt: agent.archivedAt ?? null,
     requiresAttention: agent.requiresAttention ?? false,
@@ -130,6 +133,7 @@ function buildChatAgentFromState(
     id: state.id,
     status: state.status,
     cwd: state.cwd,
+    capabilities: state.capabilities,
     lastError: state.lastError ?? null,
     projectPlacement,
   };
@@ -945,70 +949,162 @@ function ChatAgentContent({
     effectiveAgent,
   });
   if (nonReadyView) return nonReadyView;
+  invariant(agentId, "agent id is defined when agent content is ready");
   invariant(effectiveAgent, "effectiveAgent is defined when the non-ready view is absent");
-  invariant(agentState.cwd, "agent cwd is defined when agent content is ready");
+  const agentCwd = agentState.cwd;
+  invariant(agentCwd, "agent cwd is defined when agent content is ready");
+  const showHistorySyncOverlay =
+    viewState.tag === "ready" &&
+    viewState.sync.status === "catching_up" &&
+    viewState.sync.ui === "overlay";
 
   return (
-    <View style={styles.root}>
-      <FileDropZone onFilesDropped={handleFilesDropped} disabled={isArchivingCurrentAgent}>
-        <View style={styles.container}>
-          <View style={styles.contentContainer}>
-            <ReanimatedAnimated.View style={animatedContentStyle}>
-              <AgentStreamSection
-                streamViewRef={streamViewRef}
-                serverId={serverId}
-                agentId={agentId}
-                agent={effectiveAgent}
-                pendingCreate={pendingCreate}
-                shouldUseOptimisticStream={shouldUseOptimisticStream}
-                canFinalizePendingCreate={canFinalizePendingCreate}
-                routeBottomAnchorRequest={routeBottomAnchorRequest}
-                hasAppliedAuthoritativeHistory={hasAppliedAuthoritativeHistory}
-                toast={panelToast.api}
-                onOpenWorkspaceFile={onOpenWorkspaceFile}
-              />
-            </ReanimatedAnimated.View>
-          </View>
+    <ChatAgentReadyContent
+      serverId={serverId}
+      agentId={agentId}
+      isPaneFocused={isPaneFocused}
+      isArchivingCurrentAgent={isArchivingCurrentAgent}
+      agentState={agentState}
+      effectiveAgent={effectiveAgent}
+      pendingCreate={pendingCreate}
+      shouldUseOptimisticStream={shouldUseOptimisticStream}
+      canFinalizePendingCreate={canFinalizePendingCreate}
+      routeBottomAnchorRequest={routeBottomAnchorRequest}
+      hasAppliedAuthoritativeHistory={hasAppliedAuthoritativeHistory}
+      panelToast={panelToast}
+      streamViewRef={streamViewRef}
+      animatedContentStyle={animatedContentStyle}
+      handleFilesDropped={handleFilesDropped}
+      handleAddImagesCallback={handleAddImagesCallback}
+      handleComposerHeightChange={handleComposerHeightChange}
+      handleMessageSent={handleMessageSent}
+      showPendingCreateSubmitLoading={showPendingCreateSubmitLoading}
+      showHistorySyncOverlay={showHistorySyncOverlay}
+      cwd={agentCwd}
+      attentionController={attentionController}
+      onOpenWorkspaceFile={onOpenWorkspaceFile}
+    />
+  );
+}
 
-          <AgentComposerSection
-            agentId={agentId}
-            serverId={serverId}
-            isPaneFocused={isPaneFocused}
-            isArchivingCurrentAgent={isArchivingCurrentAgent}
-            archivedAt={agentState.archivedAt}
-            cwd={agentState.cwd}
-            isSubmitLoading={showPendingCreateSubmitLoading}
-            onAttentionInputFocus={attentionController.clearOnInputFocus}
-            onAttentionPromptSend={attentionController.clearOnPromptSend}
-            onAddImages={handleAddImagesCallback}
-            onComposerHeightChange={handleComposerHeightChange}
-            onMessageSent={handleMessageSent}
-          />
+function ChatAgentReadyContent({
+  serverId,
+  agentId,
+  isPaneFocused,
+  isArchivingCurrentAgent,
+  agentState,
+  effectiveAgent,
+  pendingCreate,
+  shouldUseOptimisticStream,
+  canFinalizePendingCreate,
+  routeBottomAnchorRequest,
+  hasAppliedAuthoritativeHistory,
+  panelToast,
+  streamViewRef,
+  animatedContentStyle,
+  handleFilesDropped,
+  handleAddImagesCallback,
+  handleComposerHeightChange,
+  handleMessageSent,
+  showPendingCreateSubmitLoading,
+  showHistorySyncOverlay,
+  cwd,
+  attentionController,
+  onOpenWorkspaceFile,
+}: {
+  serverId: string;
+  agentId: string;
+  isPaneFocused: boolean;
+  isArchivingCurrentAgent: boolean;
+  agentState: ChatAgentSelectedState;
+  effectiveAgent: AgentScreenAgent;
+  pendingCreate: PendingCreateAttempt | null;
+  shouldUseOptimisticStream: boolean;
+  canFinalizePendingCreate: boolean;
+  routeBottomAnchorRequest: RouteBottomAnchorRequest;
+  hasAppliedAuthoritativeHistory: boolean;
+  panelToast: ReturnType<typeof useToastHost>;
+  streamViewRef: React.RefObject<AgentStreamViewHandle | null>;
+  animatedContentStyle: object[];
+  handleFilesDropped: (files: ImageAttachment[]) => void;
+  handleAddImagesCallback: (addImages: (images: ImageAttachment[]) => void) => void;
+  handleComposerHeightChange: (height: number) => void;
+  handleMessageSent: () => void;
+  showPendingCreateSubmitLoading: boolean;
+  showHistorySyncOverlay: boolean;
+  cwd: string;
+  attentionController: ReturnType<typeof useAgentAttentionClear>;
+  onOpenWorkspaceFile?: (request: WorkspaceFileOpenRequest) => void;
+}) {
+  const agentInputDraft = useAgentInputDraft({
+    draftKey: buildDraftStoreKey({
+      serverId,
+      agentId,
+    }),
+  });
 
-          {viewState.tag === "ready" &&
-          viewState.sync.status === "catching_up" &&
-          viewState.sync.ui === "overlay" ? (
-            <View style={styles.historySyncOverlay} testID="agent-history-overlay">
-              <ThemedActivityIndicator size="large" uniProps={foregroundMutedColorMapping} />
+  return (
+    <RewindComposerRestoreProvider text={agentInputDraft.text} setText={agentInputDraft.setText}>
+      <View style={styles.root}>
+        <FileDropZone onFilesDropped={handleFilesDropped} disabled={isArchivingCurrentAgent}>
+          <View style={styles.container}>
+            <View style={styles.contentContainer}>
+              <ReanimatedAnimated.View style={animatedContentStyle}>
+                <AgentStreamSection
+                  streamViewRef={streamViewRef}
+                  serverId={serverId}
+                  agentId={agentId}
+                  agent={effectiveAgent}
+                  pendingCreate={pendingCreate}
+                  shouldUseOptimisticStream={shouldUseOptimisticStream}
+                  canFinalizePendingCreate={canFinalizePendingCreate}
+                  routeBottomAnchorRequest={routeBottomAnchorRequest}
+                  hasAppliedAuthoritativeHistory={hasAppliedAuthoritativeHistory}
+                  toast={panelToast.api}
+                  onOpenWorkspaceFile={onOpenWorkspaceFile}
+                />
+              </ReanimatedAnimated.View>
             </View>
-          ) : null}
 
-          <ToastViewport
-            toast={panelToast.toast}
-            onDismiss={panelToast.dismiss}
-            placement="panel"
-          />
-        </View>
-      </FileDropZone>
+            <AgentComposerSection
+              agentId={agentId}
+              serverId={serverId}
+              isPaneFocused={isPaneFocused}
+              isArchivingCurrentAgent={isArchivingCurrentAgent}
+              archivedAt={agentState.archivedAt}
+              cwd={cwd}
+              isSubmitLoading={showPendingCreateSubmitLoading}
+              agentInputDraft={agentInputDraft}
+              onAttentionInputFocus={attentionController.clearOnInputFocus}
+              onAttentionPromptSend={attentionController.clearOnPromptSend}
+              onAddImages={handleAddImagesCallback}
+              onComposerHeightChange={handleComposerHeightChange}
+              onMessageSent={handleMessageSent}
+            />
 
-      {isArchivingCurrentAgent ? (
-        <View style={styles.archivingOverlay} testID="agent-archiving-overlay">
-          <ThemedActivityIndicator size="large" uniProps={foregroundColorMapping} />
-          <Text style={styles.archivingTitle}>Archiving agent...</Text>
-          <Text style={styles.archivingSubtitle}>Please wait while we archive this agent.</Text>
-        </View>
-      ) : null}
-    </View>
+            {showHistorySyncOverlay ? (
+              <View style={styles.historySyncOverlay} testID="agent-history-overlay">
+                <ThemedActivityIndicator size="large" uniProps={foregroundMutedColorMapping} />
+              </View>
+            ) : null}
+
+            <ToastViewport
+              toast={panelToast.toast}
+              onDismiss={panelToast.dismiss}
+              placement="panel"
+            />
+          </View>
+        </FileDropZone>
+
+        {isArchivingCurrentAgent ? (
+          <View style={styles.archivingOverlay} testID="agent-archiving-overlay">
+            <ThemedActivityIndicator size="large" uniProps={foregroundColorMapping} />
+            <Text style={styles.archivingTitle}>Archiving agent...</Text>
+            <Text style={styles.archivingSubtitle}>Please wait while we archive this agent.</Text>
+          </View>
+        ) : null}
+      </View>
+    </RewindComposerRestoreProvider>
   );
 }
 
@@ -1081,6 +1177,7 @@ function AgentStreamSection({
         id: pendingCreate.clientMessageId,
         text: pendingCreate.text,
         timestamp: new Date(pendingCreate.timestamp),
+        optimistic: true,
         ...(pendingCreate.images && pendingCreate.images.length > 0
           ? { images: pendingCreate.images }
           : {}),
@@ -1183,6 +1280,7 @@ function AgentComposerSection({
   archivedAt,
   cwd,
   isSubmitLoading,
+  agentInputDraft,
   onAttentionInputFocus,
   onAttentionPromptSend,
   onAddImages,
@@ -1196,6 +1294,7 @@ function AgentComposerSection({
   archivedAt: Date | null;
   cwd: string;
   isSubmitLoading: boolean;
+  agentInputDraft: AgentInputDraft;
   onAttentionInputFocus: () => void;
   onAttentionPromptSend: () => void;
   onAddImages: (addImages: (images: ImageAttachment[]) => void) => void;
@@ -1219,6 +1318,7 @@ function AgentComposerSection({
       isPaneFocused={isPaneFocused}
       cwd={cwd}
       isSubmitLoading={isSubmitLoading}
+      agentInputDraft={agentInputDraft}
       onAttentionInputFocus={onAttentionInputFocus}
       onAttentionPromptSend={onAttentionPromptSend}
       onAddImages={onAddImages}
@@ -1234,6 +1334,7 @@ function ActiveAgentComposer({
   isPaneFocused,
   cwd,
   isSubmitLoading,
+  agentInputDraft,
   onAttentionInputFocus,
   onAttentionPromptSend,
   onAddImages,
@@ -1245,6 +1346,7 @@ function ActiveAgentComposer({
   isPaneFocused: boolean;
   cwd: string;
   isSubmitLoading: boolean;
+  agentInputDraft: AgentInputDraft;
   onAttentionInputFocus: () => void;
   onAttentionPromptSend: () => void;
   onAddImages: (addImages: (images: ImageAttachment[]) => void) => void;
@@ -1270,12 +1372,6 @@ function ActiveAgentComposer({
     [serverId],
   );
   const handleArchiveSubagent = useArchiveSubagent({ serverId });
-  const agentInputDraft = useAgentInputDraft({
-    draftKey: buildDraftStoreKey({
-      serverId,
-      agentId,
-    }),
-  });
   const workspaceAttachmentScopeKey = useWorkspaceAttachmentScopeKey({
     serverId,
     cwd,

packages/app/src/timeline/session-stream-reducers.test.ts

@@ -276,8 +276,17 @@ describe("processTimelineResponse", () => {
   });
 
   it("sets cursor to null when reset=true but no cursors in payload", () => {
+    const existingTail: StreamItem[] = [
+      {
+        kind: "user_message",
+        id: "only-user",
+        text: "first turn",
+        timestamp: new Date(500),
+      },
+    ];
     const result = processTimelineResponse({
       ...baseTimelineInput,
+      currentTail: existingTail,
       currentCursor: { epoch: "epoch-1", startSeq: 1, endSeq: 5 },
       payload: {
         ...baseTimelineInput.payload,
@@ -288,6 +297,8 @@ describe("processTimelineResponse", () => {
 
     expect(result.cursor).toBe(null);
     expect(result.cursorChanged).toBe(true);
+    expect(result.tail).toEqual([]);
+    expect(getUserTexts(result.tail)).toHaveLength(0);
   });
 
   it("performs bootstrap tail init with catch-up side effect", () => {
@@ -933,6 +944,34 @@ describe("processAgentStreamEvent", () => {
     expect(result.sideEffects).toEqual([]);
   });
 
+  it("resets visible timeline when a new epoch starts at seq 1", () => {
+    const existingCursor: TimelineCursor = {
+      epoch: "epoch-1",
+      startSeq: 1,
+      endSeq: 5,
+    };
+    const currentTail = [makeAssistantItem("old timeline")];
+
+    const result = processAgentStreamEvent({
+      ...baseStreamInput,
+      event: makeTimelineEvent("rewound start", "user_message"),
+      seq: 1,
+      epoch: "epoch-2",
+      currentCursor: existingCursor,
+      currentTail,
+    });
+
+    expect(result.cursorChanged).toBe(true);
+    expect(result.cursor).toEqual({
+      epoch: "epoch-2",
+      startSeq: 1,
+      endSeq: 1,
+    });
+    expect(getAssistantTexts(result.tail)).toEqual([]);
+    expect(getUserTexts(result.tail)).toEqual(["rewound start"]);
+    expect(result.sideEffects).toEqual([]);
+  });
+
   it("initializes cursor when none exists", () => {
     const result = processAgentStreamEvent({
       ...baseStreamInput,

packages/app/src/timeline/session-stream-reducers.ts

@@ -623,6 +623,14 @@ export interface AgentStreamReducerEvent {
   timestamp: Date;
 }
 
+interface TimelineSequencingGateResult {
+  shouldApplyStreamEvent: boolean;
+  nextTimelineCursor: TimelineCursor | null;
+  cursorChanged: boolean;
+  resetLiveTimeline: boolean;
+  sideEffects: AgentStreamReducerSideEffect[];
+}
+
 export interface AgentStreamReducerAgentSnapshot {
   status: AgentLifecycleStatus;
   updatedAt: Date;
@@ -672,61 +680,91 @@ function applyAgentPatch(
   };
 }
 
+function processTimelineSequencingGate(input: {
+  event: AgentStreamEventPayload;
+  seq: number | undefined;
+  epoch: string | undefined;
+  currentCursor: TimelineCursor | undefined;
+}): TimelineSequencingGateResult {
+  const { event, seq, epoch, currentCursor } = input;
+  const base: TimelineSequencingGateResult = {
+    shouldApplyStreamEvent: true,
+    nextTimelineCursor: null,
+    cursorChanged: false,
+    resetLiveTimeline: false,
+    sideEffects: [],
+  };
+  if (event.type !== "timeline" || typeof seq !== "number" || typeof epoch !== "string") {
+    return base;
+  }
+
+  const decision = classifySessionTimelineSeq({
+    cursor: currentCursor ? { epoch: currentCursor.epoch, endSeq: currentCursor.endSeq } : null,
+    epoch,
+    seq,
+  });
+
+  if (decision === "init") {
+    return {
+      ...base,
+      nextTimelineCursor: { epoch, startSeq: seq, endSeq: seq },
+      cursorChanged: true,
+    };
+  }
+  if (decision === "accept") {
+    return {
+      ...base,
+      nextTimelineCursor: {
+        ...(currentCursor ?? { epoch, startSeq: seq, endSeq: seq }),
+        epoch,
+        endSeq: seq,
+      },
+      cursorChanged: true,
+    };
+  }
+  if (decision === "gap") {
+    return {
+      ...base,
+      shouldApplyStreamEvent: false,
+      sideEffects: currentCursor
+        ? [
+            {
+              type: "catch_up",
+              cursor: { epoch: currentCursor.epoch, endSeq: currentCursor.endSeq },
+            },
+          ]
+        : [],
+    };
+  }
+  if (decision === "drop_epoch" && seq === 1) {
+    return {
+      ...base,
+      nextTimelineCursor: { epoch, startSeq: seq, endSeq: seq },
+      cursorChanged: true,
+      resetLiveTimeline: true,
+    };
+  }
+  return {
+    ...base,
+    shouldApplyStreamEvent: false,
+  };
+}
+
 export function processAgentStreamEvent(
   input: ProcessAgentStreamEventInput,
 ): ProcessAgentStreamEventOutput {
   const { event, seq, epoch, currentTail, currentHead, currentCursor, currentAgent, timestamp } =
     input;
 
-  let shouldApplyStreamEvent = true;
-  let nextTimelineCursor: TimelineCursor | null = null;
-  let cursorChanged = false;
-  const sideEffects: AgentStreamReducerSideEffect[] = [];
-
-  // ------------------------------------------------------------------
-  // Timeline sequencing gate
-  // ------------------------------------------------------------------
-  if (event.type === "timeline" && typeof seq === "number" && typeof epoch === "string") {
-    const decision = classifySessionTimelineSeq({
-      cursor: currentCursor ? { epoch: currentCursor.epoch, endSeq: currentCursor.endSeq } : null,
-      epoch,
-      seq,
-    });
-
-    if (decision === "init") {
-      nextTimelineCursor = { epoch, startSeq: seq, endSeq: seq };
-      cursorChanged = true;
-    } else if (decision === "accept") {
-      nextTimelineCursor = {
-        ...(currentCursor ?? { epoch, startSeq: seq, endSeq: seq }),
-        epoch,
-        endSeq: seq,
-      };
-      cursorChanged = true;
-    } else if (decision === "gap") {
-      shouldApplyStreamEvent = false;
-      if (currentCursor) {
-        sideEffects.push({
-          type: "catch_up",
-          cursor: {
-            epoch: currentCursor.epoch,
-            endSeq: currentCursor.endSeq,
-          },
-        });
-      }
-    } else {
-      // drop_stale or drop_epoch
-      shouldApplyStreamEvent = false;
-    }
-  }
+  const sequencing = processTimelineSequencingGate({ event, seq, epoch, currentCursor });
 
   // ------------------------------------------------------------------
   // Apply stream event to tail/head
   // ------------------------------------------------------------------
-  const { tail, head, changedTail, changedHead } = shouldApplyStreamEvent
+  const { tail, head, changedTail, changedHead } = sequencing.shouldApplyStreamEvent
     ? applyStreamEvent({
-        tail: currentTail,
-        head: currentHead,
+        tail: sequencing.resetLiveTimeline ? [] : currentTail,
+        head: sequencing.resetLiveTimeline ? [] : currentHead,
         event,
         timestamp,
         source: "live",
@@ -771,11 +809,11 @@ export function processAgentStreamEvent(
     head,
     changedTail,
     changedHead,
-    cursor: nextTimelineCursor,
-    cursorChanged,
+    cursor: sequencing.nextTimelineCursor,
+    cursorChanged: sequencing.cursorChanged,
     agent: agentPatch,
     agentChanged,
-    sideEffects,
+    sideEffects: sequencing.sideEffects,
   };
 }
 

packages/app/src/types/stream.test.ts

@@ -1,8 +1,10 @@
 import assert from "node:assert/strict";
 import invariant from "tiny-invariant";
-import { describe, it } from "vitest";
+import { describe, expect, it } from "vitest";
 
 import {
+  applyStreamEvent,
+  clearOptimisticUserMessages,
   hydrateStreamState,
   mergeToolCallDetail,
   reduceStreamUpdate,
@@ -309,7 +311,7 @@ describe("stream reducer canonical tool calls", () => {
     const first = hydrateStreamState(updates);
     const second = hydrateStreamState(updates);
 
-    assert.strictEqual(JSON.stringify(first), JSON.stringify(second));
+    expect(first).toEqual(second);
     const assistantMessage = first.find((item) => item.kind === "assistant_message");
     assert.strictEqual(assistantMessage?.text, "Hello world");
   });
@@ -735,6 +737,7 @@ describe("stream reducer canonical tool calls", () => {
         id: messageId,
         text: "Analyze this image",
         timestamp: new Date("2025-01-01T11:10:00Z"),
+        optimistic: true,
         images: optimisticImages,
       },
     ];
@@ -935,4 +938,270 @@ describe("turn lifecycle events", () => {
       ["user_message", "user_message"],
     );
   });
+
+  it.each(["codex", "opencode", "pi"] satisfies AgentProvider[])(
+    "replaces an optimistic user message when a live %s provider-owned id echo arrives without text matching",
+    (provider) => {
+      const optimisticTimestamp = new Date("2025-01-01T15:02:00Z");
+      const serverTimestamp = new Date("2025-01-01T15:02:01Z");
+      const optimistic: StreamItem = {
+        kind: "user_message",
+        id: "msg_optimistic",
+        text: "same user text",
+        timestamp: optimisticTimestamp,
+        optimistic: true,
+        images: [
+          {
+            id: "image-1",
+            mimeType: "image/png",
+            storageType: "web-indexeddb",
+            storageKey: "image-1",
+            createdAt: optimisticTimestamp.getTime(),
+          },
+        ],
+        attachments: [
+          {
+            type: "text",
+            mimeType: "text/plain",
+            text: "attached context",
+            title: "context.txt",
+          },
+        ],
+      };
+
+      const state = reduceStreamUpdate(
+        [optimistic],
+        {
+          type: "timeline",
+          provider,
+          item: {
+            type: "user_message",
+            text: "server-owned rendered text",
+            messageId: "provider-owned-id",
+          },
+        },
+        serverTimestamp,
+        { source: "live" },
+      );
+
+      const userMessages = state.filter((item) => item.kind === "user_message");
+      assert.strictEqual(userMessages.length, 1);
+      const userMessage = userMessages[0];
+      invariant(userMessage?.kind === "user_message");
+      assert.strictEqual(userMessage.id, "provider-owned-id");
+      assert.strictEqual(userMessage.text, "server-owned rendered text");
+      assert.deepStrictEqual(userMessage.images, optimistic.images);
+      assert.deepStrictEqual(userMessage.attachments, optimistic.attachments);
+    },
+  );
+
+  it("replaces one optimistic plain-text user message with the next live server user message", () => {
+    const optimisticTimestamp = new Date("2025-01-01T15:03:00Z");
+    const serverTimestamp = new Date("2025-01-01T15:03:01Z");
+    const optimistic: StreamItem = {
+      kind: "user_message",
+      id: "msg_optimistic",
+      text: "typed plain text",
+      timestamp: optimisticTimestamp,
+      optimistic: true,
+    };
+
+    const state = reduceStreamUpdate(
+      [optimistic],
+      {
+        type: "timeline",
+        provider: "opencode",
+        item: {
+          type: "user_message",
+          text: "typed plain text",
+          messageId: "msg_opencode_provider_owned",
+        },
+      },
+      serverTimestamp,
+      { source: "live" },
+    );
+
+    const userMessages = state.filter((item) => item.kind === "user_message");
+    assert.strictEqual(userMessages.length, 1);
+    const userMessage = userMessages[0];
+    invariant(userMessage?.kind === "user_message");
+    assert.strictEqual(userMessage.id, "msg_opencode_provider_owned");
+    assert.strictEqual(userMessage.text, "typed plain text");
+    assert.strictEqual(userMessage.optimistic, undefined);
+  });
+
+  it("reconciles an optimistic user message that was pending in the streaming head", () => {
+    const optimistic: StreamItem = {
+      kind: "user_message",
+      id: "msg_head_optimistic",
+      text: "plain text in head",
+      timestamp: new Date("2025-01-01T15:03:02Z"),
+      optimistic: true,
+    };
+
+    const result = applyStreamEvent({
+      tail: [],
+      head: [optimistic],
+      event: {
+        type: "timeline",
+        provider: "opencode",
+        item: {
+          type: "user_message",
+          text: "plain text in head",
+          messageId: "provider-owned-head",
+        },
+      },
+      timestamp: new Date("2025-01-01T15:03:03Z"),
+      source: "live",
+    });
+
+    assert.strictEqual(result.head.length, 0);
+    const userMessages = result.tail.filter((item) => item.kind === "user_message");
+    assert.strictEqual(userMessages.length, 1);
+    assert.strictEqual(userMessages[0]?.id, "provider-owned-head");
+    assert.strictEqual(userMessages[0]?.optimistic, undefined);
+  });
+
+  it("replaces multiple optimistic user messages in FIFO order", () => {
+    const optimisticTimestamp = new Date("2025-01-01T15:04:00Z");
+    const serverTimestamp = new Date("2025-01-01T15:04:01Z");
+    const firstOptimistic: StreamItem = {
+      kind: "user_message",
+      id: "msg_optimistic_1",
+      text: "first typed text",
+      timestamp: optimisticTimestamp,
+      optimistic: true,
+    };
+    const secondOptimistic: StreamItem = {
+      kind: "user_message",
+      id: "msg_optimistic_2",
+      text: "second typed text",
+      timestamp: new Date("2025-01-01T15:04:00.500Z"),
+      optimistic: true,
+    };
+
+    const afterFirstEcho = reduceStreamUpdate(
+      [firstOptimistic, secondOptimistic],
+      {
+        type: "timeline",
+        provider: "opencode",
+        item: {
+          type: "user_message",
+          text: "first server text",
+          messageId: "provider-owned-first",
+        },
+      },
+      serverTimestamp,
+      { source: "live" },
+    );
+    const state = reduceStreamUpdate(
+      afterFirstEcho,
+      {
+        type: "timeline",
+        provider: "opencode",
+        item: {
+          type: "user_message",
+          text: "second server text",
+          messageId: "provider-owned-second",
+        },
+      },
+      new Date("2025-01-01T15:04:02Z"),
+      { source: "live" },
+    );
+
+    const userMessages = state.filter((item) => item.kind === "user_message");
+    assert.strictEqual(userMessages.length, 2);
+    assert.deepStrictEqual(
+      userMessages.map((item) => [item.id, item.text, item.optimistic]),
+      [
+        ["provider-owned-first", "first server text", undefined],
+        ["provider-owned-second", "second server text", undefined],
+      ],
+    );
+  });
+
+  it("appends a live server user message when no optimistic user message is pending", () => {
+    const state = reduceStreamUpdate(
+      [],
+      {
+        type: "timeline",
+        provider: "opencode",
+        item: {
+          type: "user_message",
+          text: "resumed session text",
+          messageId: "provider-owned-resume",
+        },
+      },
+      new Date("2025-01-01T15:04:03Z"),
+      { source: "live" },
+    );
+
+    const userMessages = state.filter((item) => item.kind === "user_message");
+    assert.strictEqual(userMessages.length, 1);
+    assert.strictEqual(userMessages[0]?.id, "provider-owned-resume");
+    assert.strictEqual(userMessages[0]?.optimistic, undefined);
+  });
+
+  it("does not match a server user message to an optimistic from a rewound turn after pending optimistics are cleared", () => {
+    const optimistic: StreamItem = {
+      kind: "user_message",
+      id: "msg_rewound_optimistic",
+      text: "rewound text",
+      timestamp: new Date("2025-01-01T15:04:04Z"),
+      optimistic: true,
+    };
+    const cleared = clearOptimisticUserMessages([optimistic]);
+
+    const state = reduceStreamUpdate(
+      cleared,
+      {
+        type: "timeline",
+        provider: "opencode",
+        item: {
+          type: "user_message",
+          text: "future server echo",
+          messageId: "provider-owned-after-rewind",
+        },
+      },
+      new Date("2025-01-01T15:04:05Z"),
+      { source: "live" },
+    );
+
+    const userMessages = state.filter((item) => item.kind === "user_message");
+    assert.strictEqual(userMessages.length, 1);
+    assert.strictEqual(userMessages[0]?.id, "provider-owned-after-rewind");
+    assert.strictEqual(userMessages[0]?.text, "future server echo");
+    assert.strictEqual(userMessages[0]?.optimistic, undefined);
+  });
+
+  it("keeps canonical repeated user messages distinct during hydration", () => {
+    const state = hydrateStreamState(
+      [
+        {
+          event: {
+            type: "timeline",
+            provider: "codex",
+            item: { type: "user_message", text: "repeat", messageId: "native-1" },
+          },
+          timestamp: new Date("2025-01-01T15:03:00Z"),
+        },
+        {
+          event: {
+            type: "timeline",
+            provider: "codex",
+            item: { type: "user_message", text: "repeat", messageId: "native-2" },
+          },
+          timestamp: new Date("2025-01-01T15:03:01Z"),
+        },
+      ],
+      { source: "canonical" },
+    );
+
+    const userMessages = state.filter((item) => item.kind === "user_message");
+    assert.strictEqual(userMessages.length, 2);
+    assert.deepStrictEqual(
+      userMessages.map((item) => item.id),
+      ["native-1", "native-2"],
+    );
+  });
 });

packages/app/src/types/stream.ts

@@ -59,6 +59,7 @@ export interface UserMessageItem {
   id: string;
   text: string;
   timestamp: Date;
+  optimistic?: true;
   images?: UserMessageImageAttachment[];
   attachments?: AgentAttachment[];
 }
@@ -184,10 +185,32 @@ function markThoughtReady(item: ThoughtItem): ThoughtItem {
   };
 }
 
+function buildUserMessageItem(input: {
+  id: string;
+  text: string;
+  timestamp: Date;
+  optimistic?: UserMessageItem | null;
+}): UserMessageItem {
+  const preservedImages = input.optimistic?.images;
+  const preservedAttachments = input.optimistic?.attachments;
+
+  return {
+    kind: "user_message",
+    id: input.id,
+    text: input.text,
+    timestamp: input.timestamp,
+    ...(preservedImages && preservedImages.length > 0 ? { images: preservedImages } : {}),
+    ...(preservedAttachments && preservedAttachments.length > 0
+      ? { attachments: preservedAttachments }
+      : {}),
+  };
+}
+
 function appendUserMessage(
   state: StreamItem[],
   text: string,
   timestamp: Date,
+  source: StreamUpdateSource,
   messageId?: string,
 ): StreamItem[] {
   const { chunk, hasContent } = normalizeChunk(text);
@@ -197,32 +220,33 @@ function appendUserMessage(
 
   const chunkSeed = chunk.trim() || chunk;
   const entryId = messageId ?? createUniqueTimelineId(state, "user", chunkSeed, timestamp);
-  const existingIndex = state.findIndex(
-    (entry) => entry.kind === "user_message" && entry.id === entryId,
-  );
-  const existing =
-    existingIndex >= 0 && state[existingIndex]?.kind === "user_message"
-      ? state[existingIndex]
-      : null;
-  const preservedImages = existing?.images;
+  const optimisticIndex =
+    source === "live"
+      ? state.findIndex((entry) => entry.kind === "user_message" && entry.optimistic)
+      : -1;
+  const optimistic = optimisticIndex >= 0 ? (state[optimisticIndex] as UserMessageItem) : null;
 
-  const nextItem: UserMessageItem = {
-    kind: "user_message",
+  const nextItem = buildUserMessageItem({
     id: entryId,
     text: chunk,
     timestamp,
-    ...(preservedImages && preservedImages.length > 0 ? { images: preservedImages } : {}),
-  };
+    optimistic,
+  });
 
-  if (existingIndex >= 0) {
+  if (optimisticIndex >= 0) {
     const next = [...state];
-    next[existingIndex] = nextItem;
+    next[optimisticIndex] = nextItem;
     return next;
   }
 
   return [...state, nextItem];
 }
 
+export function clearOptimisticUserMessages(state: StreamItem[]): StreamItem[] {
+  const next = state.filter((item) => item.kind !== "user_message" || !item.optimistic);
+  return next.length === state.length ? state : next;
+}
+
 function appendAssistantMessage(
   state: StreamItem[],
   text: string,
@@ -664,7 +688,9 @@ function reduceTimelineEvent(
   const item = event.item;
   switch (item.type) {
     case "user_message":
-      return finalizeActiveThoughts(appendUserMessage(state, item.text, timestamp, item.messageId));
+      return finalizeActiveThoughts(
+        appendUserMessage(state, item.text, timestamp, source, item.messageId),
+      );
     case "assistant_message":
       return finalizeActiveThoughts(
         appendAssistantMessage(state, item.text, timestamp, source, item.messageId),

packages/server/src/client/daemon-client.ts

@@ -64,6 +64,7 @@ import type {
   ProviderDiagnosticResponseMessage,
   DaemonGetStatusResponse,
   DaemonGetPairingOfferResponse,
+  AgentRewindResponseMessage,
   ListTerminalsResponse,
   CreateTerminalResponse,
   SubscribeTerminalResponse,
@@ -2232,6 +2233,40 @@ export class DaemonClient {
     await this.sendAgentMessage(agentId, text, options);
   }
 
+  async rewindAgent(
+    agentId: string,
+    messageId: string,
+    mode: "conversation" | "files" | "both",
+  ): Promise<AgentRewindResponseMessage["payload"]> {
+    const requestId = this.createRequestId();
+    const message = SessionInboundMessageSchema.parse({
+      type: "agent.rewind.request",
+      requestId,
+      agentId,
+      messageId,
+      mode,
+    });
+    const payload = await this.sendRequest({
+      requestId,
+      message,
+      timeout: 15000,
+      options: { skipQueue: true },
+      select: (msg) => {
+        if (msg.type !== "agent.rewind.response") {
+          return null;
+        }
+        if (msg.payload.requestId !== requestId) {
+          return null;
+        }
+        return msg.payload;
+      },
+    });
+    if (!payload.ok) {
+      throw new Error(payload.error ?? "Agent rewind failed");
+    }
+    return payload;
+  }
+
   async cancelAgent(agentId: string): Promise<void> {
     const requestId = this.createRequestId();
     const message = SessionInboundMessageSchema.parse({

packages/server/src/server/agent/agent-manager.test.ts

@@ -2192,9 +2192,10 @@ test("getAgent does not expose committed history internals once manager owns the
     cwd: workdir,
   });
 
-  manager.recordUserMessage(snapshot.id, "hello boundary", {
+  await manager.appendTimelineItem(snapshot.id, {
+    type: "user_message",
+    text: "hello boundary",
     messageId: "msg-boundary-1",
-    emitState: false,
   });
   await manager.appendTimelineItem(snapshot.id, {
     type: "assistant_message",
@@ -3442,7 +3443,7 @@ test("keeps updatedAt monotonic when user message and run start happen in the sa
 
   const nowSpy = vi.spyOn(Date, "now").mockReturnValue(1_750_000_000_000);
   try {
-    manager.recordUserMessage(snapshot.id, "hello");
+    await manager.appendTimelineItem(snapshot.id, { type: "user_message", text: "hello" });
     const afterMessage = manager.getAgent(snapshot.id);
     expect(afterMessage).toBeDefined();
     const messageUpdatedAt = afterMessage!.updatedAt.getTime();
@@ -3464,38 +3465,6 @@ test("keeps updatedAt monotonic when user message and run start happen in the sa
   }
 });
 
-test("recordUserMessage can skip emitting agent_state when run start will emit running", async () => {
-  const workdir = mkdtempSync(join(tmpdir(), "agent-manager-test-"));
-  const storagePath = join(workdir, "agents");
-  const storage = new AgentStorage(storagePath, logger);
-  const manager = new AgentManager({
-    clients: {
-      codex: new TestAgentClient(),
-    },
-    registry: storage,
-    logger,
-    idFactory: () => "00000000-0000-4000-8000-000000000121",
-  });
-
-  const snapshot = await manager.createAgent({
-    provider: "codex",
-    cwd: workdir,
-  });
-
-  const lifecycleUpdates: string[] = [];
-  manager.subscribe((event) => {
-    if (event.type !== "agent_state" || event.agent.id !== snapshot.id) {
-      return;
-    }
-    lifecycleUpdates.push(event.agent.lifecycle);
-  });
-  lifecycleUpdates.length = 0;
-
-  manager.recordUserMessage(snapshot.id, "hello", { emitState: false });
-
-  expect(lifecycleUpdates).toEqual([]);
-});
-
 test("runAgent assembles finalText from trailing assistant chunks", async () => {
   const workdir = mkdtempSync(join(tmpdir(), "agent-manager-test-"));
   const storagePath = join(workdir, "agents");
@@ -5088,99 +5057,6 @@ test("closeAgent persists one final closed snapshot", async () => {
   }
 });
 
-test("hydrateTimeline skips provider user_message items to prevent duplicates with recordUserMessage", async () => {
-  const workdir = mkdtempSync(join(tmpdir(), "agent-manager-history-dedup-"));
-  const storagePath = join(workdir, "agents");
-  const storage = new AgentStorage(storagePath, logger);
-
-  // Session whose streamHistory yields user_message + assistant_message items.
-  // This simulates Codex provider replaying its thread history on resume.
-  class HistoryWithUserMessagesSession extends TestAgentSession {
-    async *streamHistory(): AsyncGenerator<AgentStreamEvent> {
-      yield {
-        type: "timeline",
-        provider: this.provider,
-        item: { type: "user_message", text: "hello from user", messageId: "msg_client_1" },
-      };
-      yield {
-        type: "timeline",
-        provider: this.provider,
-        item: { type: "assistant_message", text: "hi there" },
-      };
-      yield {
-        type: "timeline",
-        provider: this.provider,
-        item: { type: "user_message", text: "second question", messageId: "msg_client_2" },
-      };
-      yield {
-        type: "timeline",
-        provider: this.provider,
-        item: { type: "assistant_message", text: "second answer" },
-      };
-    }
-  }
-
-  class HistoryUserMessageClient implements AgentClient {
-    readonly provider = "codex" as const;
-    readonly capabilities = TEST_CAPABILITIES;
-
-    async isAvailable(): Promise<boolean> {
-      return true;
-    }
-
-    async createSession(config: AgentSessionConfig): Promise<AgentSession> {
-      // Fresh session yields history with user messages (simulates Codex resume)
-      return new HistoryWithUserMessagesSession(config);
-    }
-
-    async resumeSession(): Promise<AgentSession> {
-      throw new Error("Not used in this test");
-    }
-  }
-
-  const manager = new AgentManager({
-    clients: {
-      codex: new HistoryUserMessageClient(),
-    },
-    registry: storage,
-    logger,
-    idFactory: () => "00000000-0000-4000-8000-000000000200",
-  });
-
-  const snapshot = await manager.createAgent({
-    provider: "codex",
-    cwd: workdir,
-  });
-
-  // Simulate canonical user messages already recorded by recordUserMessage
-  // (the path that session.ts takes when user sends a message)
-  manager.recordUserMessage(snapshot.id, "hello from user", {
-    messageId: "msg_client_1",
-  });
-  manager.recordUserMessage(snapshot.id, "second question", {
-    messageId: "msg_client_2",
-  });
-
-  const beforeHydrate = manager.getTimeline(snapshot.id);
-  const userMessagesBefore = beforeHydrate.filter((item) => item.type === "user_message");
-  expect(userMessagesBefore).toHaveLength(2);
-
-  // hydrateTimeline replays provider history which includes user_message
-  // items. These should NOT create duplicate rows since recordUserMessage
-  // already created canonical entries.
-  await manager.hydrateTimelineFromProvider(snapshot.id);
-
-  const afterHydrate = manager.getTimeline(snapshot.id);
-  const userMessagesAfter = afterHydrate.filter((item) => item.type === "user_message");
-
-  // Should still have exactly 2 user messages, not 4
-  expect(userMessagesAfter).toHaveLength(2);
-
-  // Non-user_message items from history should still be replayed
-  const assistantMessages = afterHydrate.filter((item) => item.type === "assistant_message");
-  expect(assistantMessages).toHaveLength(2);
-});
-
 test("hydrateTimeline keeps provider user_message items when no canonical user history exists", async () => {
   const workdir = mkdtempSync(join(tmpdir(), "agent-manager-history-keep-user-"));
   const storagePath = join(workdir, "agents");
@@ -5314,378 +5190,7 @@ test("hydrateTimeline preserves provider replay timestamps and marks missing one
   expect(timeline[1]?.timestamp).toEqual(expect.any(String));
 });
 
-test("hydrateTimeline suppresses only matching canonical user_message messageId", async () => {
-  const workdir = mkdtempSync(join(tmpdir(), "agent-manager-history-partial-dedup-"));
-  const storagePath = join(workdir, "agents");
-  const storage = new AgentStorage(storagePath, logger);
-
-  class HistoryWithMixedUserMessagesSession extends TestAgentSession {
-    async *streamHistory(): AsyncGenerator<AgentStreamEvent> {
-      yield {
-        type: "timeline",
-        provider: this.provider,
-        item: {
-          type: "user_message",
-          text: "hello from user",
-          messageId: "msg_client_hello",
-        },
-      };
-      yield {
-        type: "timeline",
-        provider: this.provider,
-        item: { type: "assistant_message", text: "hi there" },
-      };
-      yield {
-        type: "timeline",
-        provider: this.provider,
-        item: {
-          type: "user_message",
-          text: "hello from user",
-          messageId: "msg_provider_distinct",
-        },
-      };
-    }
-  }
-
-  class HistoryMixedClient implements AgentClient {
-    readonly provider = "codex" as const;
-    readonly capabilities = TEST_CAPABILITIES;
-    async isAvailable(): Promise<boolean> {
-      return true;
-    }
-    async createSession(config: AgentSessionConfig): Promise<AgentSession> {
-      return new HistoryWithMixedUserMessagesSession(config);
-    }
-    async resumeSession(): Promise<AgentSession> {
-      throw new Error("Not used in this test");
-    }
-  }
-
-  const manager = new AgentManager({
-    clients: { codex: new HistoryMixedClient() },
-    registry: storage,
-    logger,
-    idFactory: () => "00000000-0000-4000-8000-000000000204",
-  });
-
-  const snapshot = await manager.createAgent({ provider: "codex", cwd: workdir });
-
-  // Canonical user message that should dedupe the matching history item.
-  manager.recordUserMessage(snapshot.id, "hello from user", {
-    messageId: "msg_client_hello",
-  });
-
-  await manager.hydrateTimelineFromProvider(snapshot.id);
-
-  const timeline = manager.getTimeline(snapshot.id);
-  const userMessages = timeline.filter((item) => item.type === "user_message");
-  expect(userMessages).toHaveLength(2);
-  expect(userMessages.map((item) => item.messageId)).toEqual([
-    "msg_client_hello",
-    "msg_provider_distinct",
-  ]);
-  expect(userMessages.map((item) => item.text)).toEqual(["hello from user", "hello from user"]);
-});
-
-test("recordUserMessage normalizes blank/whitespace messageId to undefined", async () => {
-  const workdir = mkdtempSync(join(tmpdir(), "agent-manager-blank-msgid-"));
-  const storagePath = join(workdir, "agents");
-  const storage = new AgentStorage(storagePath, logger);
-  const manager = new AgentManager({
-    clients: {
-      codex: new TestAgentClient(),
-    },
-    registry: storage,
-    logger,
-    idFactory: () => "00000000-0000-4000-8000-000000000201",
-  });
-
-  const snapshot = await manager.createAgent({
-    provider: "codex",
-    cwd: workdir,
-  });
-
-  // Empty string should be treated as missing
-  manager.recordUserMessage(snapshot.id, "test empty", {
-    messageId: "",
-  });
-
-  // Whitespace-only should be treated as missing
-  manager.recordUserMessage(snapshot.id, "test whitespace", {
-    messageId: "   ",
-  });
-
-  // Valid messageId should be preserved
-  manager.recordUserMessage(snapshot.id, "test valid", {
-    messageId: "msg_valid_123",
-  });
-
-  const timeline = manager.getTimeline(snapshot.id);
-  const userMessages = timeline.filter(
-    (item): item is Extract<AgentTimelineItem, { type: "user_message" }> =>
-      item.type === "user_message",
-  );
-
-  expect(userMessages).toHaveLength(3);
-  // Empty string → undefined (not empty string)
-  expect(userMessages[0].messageId).toBeUndefined();
-  // Whitespace → undefined
-  expect(userMessages[1].messageId).toBeUndefined();
-  // Valid → preserved
-  expect(userMessages[2].messageId).toBe("msg_valid_123");
-});
-
-test("recordUserMessage preserves provided messageId in timeline item and dispatched event", async () => {
-  const workdir = mkdtempSync(join(tmpdir(), "agent-manager-msgid-passthrough-"));
-  const storagePath = join(workdir, "agents");
-  const storage = new AgentStorage(storagePath, logger);
-  const manager = new AgentManager({
-    clients: {
-      codex: new TestAgentClient(),
-    },
-    registry: storage,
-    logger,
-    idFactory: () => "00000000-0000-4000-8000-000000000202",
-  });
-
-  const snapshot = await manager.createAgent({
-    provider: "codex",
-    cwd: workdir,
-  });
-
-  const events: AgentStreamEvent[] = [];
-  manager.subscribe((event) => {
-    if (event.type === "agent_stream") {
-      events.push(event.event);
-    }
-  });
-
-  const clientMsgId = "msg_abc_123_def";
-  manager.recordUserMessage(snapshot.id, "hello", {
-    messageId: clientMsgId,
-  });
-
-  // Timeline item should have the messageId
-  const timeline = manager.getTimeline(snapshot.id);
-  const userMsg = timeline.find(
-    (item): item is Extract<AgentTimelineItem, { type: "user_message" }> =>
-      item.type === "user_message",
-  );
-  expect(userMsg).toBeDefined();
-  expect(userMsg!.messageId).toBe(clientMsgId);
-
-  // Dispatched stream event should also carry the messageId
-  const streamEvent = events.find((e) => e.type === "timeline" && e.item.type === "user_message");
-  expect(streamEvent).toBeDefined();
-  if (streamEvent?.type === "timeline") {
-    expect((streamEvent.item as { type: "user_message"; messageId?: string }).messageId).toBe(
-      clientMsgId,
-    );
-  }
-});
-
-test("live provider user_message echo is suppressed when recordUserMessage was called first", async () => {
-  const workdir = mkdtempSync(join(tmpdir(), "agent-manager-live-echo-dedup-"));
-  const storagePath = join(workdir, "agents");
-  const storage = new AgentStorage(storagePath, logger);
-
-  // Session whose live turn echoes the user message (as Claude does)
-  class EchoUserMessageSession extends TestAgentSession {
-    override async startTurn(): Promise<{ turnId: string }> {
-      const turnId = "turn-echo-1";
-      setTimeout(() => {
-        this.pushEvent({ type: "turn_started", provider: this.provider, turnId });
-        // Provider echoes user message during live run
-        this.pushEvent({
-          type: "timeline",
-          provider: this.provider,
-          item: {
-            type: "user_message",
-            text: "hello from user",
-            messageId: "msg_client_echo_1",
-          },
-          turnId,
-        });
-        this.pushEvent({
-          type: "timeline",
-          provider: this.provider,
-          item: { type: "assistant_message", text: "hello from assistant" },
-          turnId,
-        });
-        this.pushEvent({ type: "turn_completed", provider: this.provider, turnId });
-      }, 0);
-      return { turnId };
-    }
-  }
-
-  class EchoClient implements AgentClient {
-    readonly provider = "codex" as const;
-    readonly capabilities = TEST_CAPABILITIES;
-    async isAvailable(): Promise<boolean> {
-      return true;
-    }
-    async createSession(config: AgentSessionConfig): Promise<AgentSession> {
-      return new EchoUserMessageSession(config);
-    }
-    async resumeSession(): Promise<AgentSession> {
-      throw new Error("unused");
-    }
-  }
-
-  const manager = new AgentManager({
-    clients: { codex: new EchoClient() },
-    registry: storage,
-    logger,
-    idFactory: () => "00000000-0000-4000-8000-000000000400",
-  });
-
-  const snapshot = await manager.createAgent({ provider: "codex", cwd: workdir });
-
-  // Canonical recording (what session.ts does before starting stream)
-  manager.recordUserMessage(snapshot.id, "hello from user", {
-    messageId: "msg_client_echo_1",
-  });
-
-  // Run triggers startTurn(), which echoes user_message
-  await manager.runAgent(snapshot.id, { text: "hello from user" });
-
-  const timeline = manager.getTimeline(snapshot.id);
-  const userMessages = timeline.filter((item) => item.type === "user_message");
-
-  // Should be exactly 1 (canonical), not 2 (canonical + provider echo)
-  expect(userMessages).toHaveLength(1);
-  // The canonical one must carry the client messageId for optimistic matching
-  expect(userMessages[0].messageId).toBe("msg_client_echo_1");
-
-  // Assistant messages from the run should still appear
-  const assistantMessages = timeline.filter((item) => item.type === "assistant_message");
-  expect(assistantMessages).toHaveLength(1);
-});
-
-test("live provider user_message with different messageId is NOT suppressed", async () => {
-  const workdir = mkdtempSync(join(tmpdir(), "agent-manager-live-different-msgid-"));
-  const storagePath = join(workdir, "agents");
-  const storage = new AgentStorage(storagePath, logger);
-
-  class DifferentMessageIdSession extends TestAgentSession {
-    override async startTurn(): Promise<{ turnId: string }> {
-      const turnId = "turn-diff-msgid-1";
-      setTimeout(() => {
-        this.pushEvent({ type: "turn_started", provider: this.provider, turnId });
-        this.pushEvent({
-          type: "timeline",
-          provider: this.provider,
-          item: {
-            type: "user_message",
-            text: "hello from user",
-            messageId: "msg_provider_other",
-          },
-          turnId,
-        });
-        this.pushEvent({ type: "turn_completed", provider: this.provider, turnId });
-      }, 0);
-      return { turnId };
-    }
-  }
-
-  class DifferentMessageIdClient implements AgentClient {
-    readonly provider = "codex" as const;
-    readonly capabilities = TEST_CAPABILITIES;
-    async isAvailable(): Promise<boolean> {
-      return true;
-    }
-    async createSession(config: AgentSessionConfig): Promise<AgentSession> {
-      return new DifferentMessageIdSession(config);
-    }
-    async resumeSession(): Promise<AgentSession> {
-      throw new Error("unused");
-    }
-  }
-
-  const manager = new AgentManager({
-    clients: { codex: new DifferentMessageIdClient() },
-    registry: storage,
-    logger,
-    idFactory: () => "00000000-0000-4000-8000-000000000402",
-  });
-
-  const snapshot = await manager.createAgent({ provider: "codex", cwd: workdir });
-
-  manager.recordUserMessage(snapshot.id, "hello from user", {
-    messageId: "msg_client_echo_2",
-  });
-
-  await manager.runAgent(snapshot.id, { text: "hello from user" });
-
-  const timeline = manager.getTimeline(snapshot.id);
-  const userMessages = timeline.filter(
-    (item): item is Extract<AgentTimelineItem, { type: "user_message" }> =>
-      item.type === "user_message",
-  );
-  expect(userMessages).toHaveLength(2);
-  expect(userMessages.map((item) => item.messageId)).toEqual([
-    "msg_client_echo_2",
-    "msg_provider_other",
-  ]);
-});
-
-test("live provider user_message without messageId is NOT suppressed", async () => {
-  const workdir = mkdtempSync(join(tmpdir(), "agent-manager-live-no-msgid-"));
-  const storagePath = join(workdir, "agents");
-  const storage = new AgentStorage(storagePath, logger);
-
-  class NoMessageIdSession extends TestAgentSession {
-    override async startTurn(): Promise<{ turnId: string }> {
-      const turnId = "turn-no-msgid-1";
-      setTimeout(() => {
-        this.pushEvent({ type: "turn_started", provider: this.provider, turnId });
-        this.pushEvent({
-          type: "timeline",
-          provider: this.provider,
-          item: { type: "user_message", text: "hello from user" },
-          turnId,
-        });
-        this.pushEvent({ type: "turn_completed", provider: this.provider, turnId });
-      }, 0);
-      return { turnId };
-    }
-  }
-
-  class NoMessageIdClient implements AgentClient {
-    readonly provider = "codex" as const;
-    readonly capabilities = TEST_CAPABILITIES;
-    async isAvailable(): Promise<boolean> {
-      return true;
-    }
-    async createSession(config: AgentSessionConfig): Promise<AgentSession> {
-      return new NoMessageIdSession(config);
-    }
-    async resumeSession(): Promise<AgentSession> {
-      throw new Error("unused");
-    }
-  }
-
-  const manager = new AgentManager({
-    clients: { codex: new NoMessageIdClient() },
-    registry: storage,
-    logger,
-    idFactory: () => "00000000-0000-4000-8000-000000000403",
-  });
-
-  const snapshot = await manager.createAgent({ provider: "codex", cwd: workdir });
-
-  manager.recordUserMessage(snapshot.id, "hello from user", {
-    messageId: "msg_client_echo_3",
-  });
-
-  await manager.runAgent(snapshot.id, { text: "hello from user" });
-
-  const timeline = manager.getTimeline(snapshot.id);
-  const userMessages = timeline.filter((item) => item.type === "user_message");
-  expect(userMessages).toHaveLength(2);
-});
-
-test("provider user_message is NOT suppressed when no prior recordUserMessage", async () => {
+test("provider user_message is recorded from the live stream", async () => {
   const workdir = mkdtempSync(join(tmpdir(), "agent-manager-no-prior-record-"));
   const storagePath = join(workdir, "agents");
   const storage = new AgentStorage(storagePath, logger);
@@ -5738,7 +5243,6 @@ test("provider user_message is NOT suppressed when no prior recordUserMessage",
 
   const snapshot = await manager.createAgent({ provider: "codex", cwd: workdir });
 
-  // No recordUserMessage — run directly
   await manager.runAgent(snapshot.id, { text: "do something" });
 
   const timeline = manager.getTimeline(snapshot.id);

packages/server/src/server/agent/agent-manager.ts

@@ -55,6 +55,7 @@ import {
 import { ForegroundRunState, type ForegroundTurnWaiter } from "./foreground-run-state.js";
 import { getAgentProviderDefinition } from "./provider-manifest.js";
 import { IMPORTABLE_PROVIDERS } from "./provider-registry.js";
+import { invokeRewindCapability, type RewindMode } from "./rewind/rewind.js";
 
 const RELOAD_SESSION_CLOSE_TIMEOUT_MS = 3_000;
 const INTERRUPT_SESSION_TIMEOUT_MS = 2_000;
@@ -65,6 +66,9 @@ const STORED_AGENT_CAPABILITIES: AgentCapabilityFlags = {
   supportsMcpServers: false,
   supportsReasoningStream: false,
   supportsToolInvocations: true,
+  supportsRewindConversation: false,
+  supportsRewindFiles: false,
+  supportsRewindBoth: false,
 };
 
 type TimeoutResult = "completed" | "timed_out";
@@ -132,6 +136,11 @@ export interface SubscribeOptions {
   replayState?: boolean;
 }
 
+interface HydrateTimelineOptions {
+  force?: boolean;
+  broadcast?: boolean;
+}
+
 export type ImportablePersistedAgentQueryOptions = ListPersistedAgentsOptions & {
   /**
    * When set, only providers in this set are scanned, in addition to the
@@ -220,7 +229,6 @@ interface StreamEventFlags {
 
 interface HandleStreamEventOptions {
   fromHistory?: boolean;
-  canonicalUserMessagesById?: ReadonlyMap<string, string>;
 }
 
 interface ManagedAgentBase {
@@ -374,28 +382,6 @@ function validateAgentId(agentId: string, source: string): string {
   return result.data;
 }
 
-function normalizeMessageId(messageId: string | undefined): string | undefined {
-  if (typeof messageId !== "string") {
-    return undefined;
-  }
-  const trimmed = messageId.trim();
-  return trimmed.length > 0 ? trimmed : undefined;
-}
-
-function isDuplicateLegacyUserMessage(
-  item: AgentTimelineItem,
-  canonicalUserMessagesById: Map<string, string>,
-): boolean {
-  if (item.type !== "user_message") {
-    return false;
-  }
-  const eventMessageId = normalizeMessageId(item.messageId);
-  if (!eventMessageId) {
-    return false;
-  }
-  return canonicalUserMessagesById.get(eventMessageId) === item.text;
-}
-
 function buildExplicitTimelineSeedForRegister(
   now: Date,
   options:
@@ -1459,39 +1445,6 @@ export class AgentManager {
     return true;
   }
 
-  recordUserMessage(
-    agentId: string,
-    text: string,
-    options?: { messageId?: string; emitState?: boolean },
-  ): void {
-    const agent = this.requireAgent(agentId);
-    const normalizedMessageId = normalizeMessageId(options?.messageId);
-    const item: AgentTimelineItem = {
-      type: "user_message",
-      text,
-      messageId: normalizedMessageId,
-    };
-    const updatedAt = this.touchUpdatedAt(agent);
-    agent.lastUserMessageAt = updatedAt;
-    const row = this.recordTimeline(agentId, item);
-    this.dispatchStream(
-      agentId,
-      {
-        type: "timeline",
-        item,
-        provider: agent.provider,
-      },
-      {
-        seq: row.seq,
-        epoch: this.timelineStore.getEpoch(agentId),
-        timestamp: row.timestamp,
-      },
-    );
-    if (options?.emitState !== false) {
-      this.emitState(agent);
-    }
-  }
-
   async appendTimelineItem(agentId: string, item: AgentTimelineItem): Promise<void> {
     const agent = this.requireAgent(agentId);
     this.touchUpdatedAt(agent);
@@ -1984,9 +1937,47 @@ export class AgentManager {
    * timeline is empty (e.g., imported agents that have provider history
    * on disk but no persisted timeline rows). No-ops if already hydrated.
    */
-  async hydrateTimelineFromProvider(agentId: string): Promise<void> {
+  async hydrateTimelineFromProvider(
+    agentId: string,
+    options?: HydrateTimelineOptions,
+  ): Promise<void> {
     const agent = this.requireSessionAgent(agentId);
-    await this.hydrateTimelineFromLegacyProviderHistory(agent);
+    await this.hydrateTimelineFromLegacyProviderHistory(agent, options);
+  }
+
+  async rewind(agentId: string, messageId: string, mode: RewindMode): Promise<void> {
+    const agent = this.requireSessionAgent(agentId);
+    const hadActiveRun =
+      Boolean(agent.activeForegroundTurnId) || this.foregroundRuns.hasPendingRun(agentId);
+    if (hadActiveRun) {
+      await this.cancelAgentRun(agentId);
+    }
+
+    const lock = this.foregroundRuns.createPendingRun(agentId);
+    try {
+      this.logger.info(
+        { agentId, provider: agent.provider, messageId, mode },
+        "agent.rewind.start",
+      );
+      await invokeRewindCapability(agent.session, { messageId, mode });
+      if (mode !== "files") {
+        await this.hydrateTimelineFromProvider(agentId, { force: true, broadcast: true });
+      }
+      await this.refreshRuntimeInfo(agent);
+      await this.persistSnapshot(agent);
+      this.logger.info(
+        { agentId, provider: agent.provider, messageId, mode },
+        "agent.rewind.complete",
+      );
+    } catch (error) {
+      this.logger.warn(
+        { err: error, agentId, provider: agent.provider, messageId, mode },
+        "agent.rewind.failed",
+      );
+      throw error;
+    } finally {
+      this.foregroundRuns.settlePendingRun(agentId, lock.token);
+    }
   }
 
   async deleteCommittedTimeline(agentId: string): Promise<void> {
@@ -2074,19 +2065,6 @@ export class AgentManager {
     return await this.durableTimelineStore.getLastItem(agentId);
   }
 
-  private async hasCommittedUserMessageFromStores(
-    agentId: string,
-    options: { messageId: string; text: string },
-  ): Promise<boolean> {
-    if (this.timelineStore.hasCommittedUserMessage(agentId, options)) {
-      return true;
-    }
-    if (!this.durableTimelineStore) {
-      return false;
-    }
-    return await this.durableTimelineStore.hasCommittedUserMessage(agentId, options);
-  }
-
   async waitForAgentEvent(
     agentId: string,
     options?: WaitForAgentOptions,
@@ -2627,20 +2605,53 @@ export class AgentManager {
     }
   }
 
-  private async hydrateTimelineFromLegacyProviderHistory(agent: ActiveManagedAgent): Promise<void> {
-    if (agent.historyPrimed) {
+  private async hydrateTimelineFromLegacyProviderHistory(
+    agent: ActiveManagedAgent,
+    options?: HydrateTimelineOptions,
+  ): Promise<void> {
+    if (agent.historyPrimed && !options?.force) {
       return;
     }
+
+    if (options?.force) {
+      const historyEvents: Extract<AgentStreamEvent, { type: "timeline" }>[] = [];
+      for await (const event of agent.session.streamHistory()) {
+        if (event.type === "timeline") {
+          historyEvents.push(event);
+        }
+      }
+
+      this.agentStreamCoalescer.flushAndDiscard(agent.id);
+      await this.deleteCommittedTimeline(agent.id);
+      this.timelineStore.delete(agent.id);
+      this.timelineStore.initialize(agent.id, { timestamp: new Date().toISOString() });
+      agent.historyPrimed = true;
+
+      for (const event of historyEvents) {
+        const row = this.recordTimeline(
+          agent.id,
+          event.item,
+          event.timestamp ? { timestamp: event.timestamp } : undefined,
+        );
+        if (options?.broadcast) {
+          this.dispatchStream(agent.id, event, {
+            seq: row.seq,
+            epoch: this.timelineStore.getEpoch(agent.id),
+            timestamp: row.timestamp,
+          });
+        }
+      }
+      this.touchUpdatedAt(agent);
+      this.emitState(agent);
+      return;
+    }
+
     agent.historyPrimed = true;
-    const canonicalUserMessagesById = this.timelineStore.getCanonicalUserMessagesById(agent.id);
     try {
       for await (const event of agent.session.streamHistory()) {
         if (event.type !== "timeline") {
           continue;
         }
-        if (isDuplicateLegacyUserMessage(event.item, canonicalUserMessagesById)) {
-          continue;
-        }
         this.recordTimeline(
           agent.id,
           event.item,
@@ -2882,42 +2893,11 @@ export class AgentManager {
   private async onStreamTimelineEvent(params: {
     agent: ActiveManagedAgent;
     event: Extract<AgentStreamEvent, { type: "timeline" }>;
-    options:
-      | {
-          fromHistory?: boolean;
-          canonicalUserMessagesById?: ReadonlyMap<string, string>;
-        }
-      | undefined;
+    options: { fromHistory?: boolean } | undefined;
     isForegroundEvent: boolean;
     flags: StreamEventFlags;
   }): Promise<void> {
-    const { agent, event, options, isForegroundEvent, flags } = params;
-    // Skip provider-replayed user_message items during history hydration.
-    if (options?.fromHistory && event.item.type === "user_message") {
-      const eventMessageId = normalizeMessageId(event.item.messageId);
-      if (eventMessageId) {
-        const canonicalText = options?.canonicalUserMessagesById?.get(eventMessageId);
-        if (canonicalText === event.item.text) {
-          flags.shouldDispatchEvent = false;
-          flags.shouldNotifyWaiters = false;
-          return;
-        }
-      }
-    }
-
-    // Suppress user_message echoes for the active foreground turn.
-    if (!options?.fromHistory && event.item.type === "user_message" && isForegroundEvent) {
-      const eventMessageId = normalizeMessageId(event.item.messageId);
-      if (
-        eventMessageId &&
-        (await this.hasCommittedUserMessageFromStores(agent.id, {
-          messageId: eventMessageId,
-          text: event.item.text,
-        }))
-      ) {
-        return;
-      }
-    }
+    const { agent, event, options, flags } = params;
 
     if (options?.fromHistory) {
       this.recordTimeline(
@@ -2971,12 +2951,7 @@ export class AgentManager {
     event: Extract<AgentStreamEvent, { type: "turn_failed" }>;
     eventTurnId: string | undefined;
     isForegroundEvent: boolean;
-    options:
-      | {
-          fromHistory?: boolean;
-          canonicalUserMessagesById?: ReadonlyMap<string, string>;
-        }
-      | undefined;
+    options: { fromHistory?: boolean } | undefined;
   }): Promise<void> {
     const { agent, event, eventTurnId, isForegroundEvent, options } = params;
     this.logger.warn(
@@ -3139,10 +3114,7 @@ export class AgentManager {
     agent: ActiveManagedAgent,
     provider: AgentProvider,
     message: string,
-    options?: {
-      fromHistory?: boolean;
-      canonicalUserMessagesById?: ReadonlyMap<string, string>;
-    },
+    options?: { fromHistory?: boolean },
   ): Promise<void> {
     if (options?.fromHistory) {
       return;

packages/server/src/server/agent/agent-projections.ts

@@ -196,6 +196,9 @@ export function buildStoredAgentPayload(
     supportsMcpServers: false,
     supportsReasoningStream: false,
     supportsToolInvocations: true,
+    supportsRewindConversation: false,
+    supportsRewindFiles: false,
+    supportsRewindBoth: false,
   } as const;
 
   const createdAt = new Date(record.createdAt);

packages/server/src/server/agent/agent-prompt.ts

@@ -118,7 +118,7 @@ export interface SendPromptToAgentParams {
   agentId: string;
   /** Prompt to dispatch to the provider (may include image blocks or wrapped text). */
   prompt: AgentPromptInput;
-  /** Raw user text to record in the timeline. Required when recordUserMessage is true. */
+  /** Raw user text. Required when userMessageVisible is true. */
   userMessageText?: string;
   messageId?: string;
   runOptions?: AgentRunOptions;
@@ -131,17 +131,17 @@ export interface SendPromptToAgentParams {
    */
   unarchive?: boolean;
   /**
-   * Default true. When false, the prompt is dispatched to the provider but
-   * no user-message turn is added to the timeline — the app shows nothing.
+   * Default true. When false, the prompt is dispatched to the provider as an
+   * invisible/system prompt — the app shows no user-message turn.
    * Use false for system-injected prompts.
    */
-  recordUserMessage?: boolean;
+  userMessageVisible?: boolean;
   logger: Logger;
 }
 
 /**
  * Full send-prompt orchestration: (optional unarchive) → load → (optional
- * mode change) → (optional record user message) → start run.
+ * mode change) → start run.
  *
  * Every surface that sends a prompt to an agent (Session/WS, MCP, CLI-through-MCP,
  * chat mentions, notify-on-finish) MUST go through this so behavior can never
@@ -154,10 +154,10 @@ export async function sendPromptToAgent(
   params: SendPromptToAgentParams,
 ): Promise<{ outOfBand: boolean }> {
   const unarchive = params.unarchive ?? true;
-  const recordUserMessage = params.recordUserMessage ?? true;
+  const userMessageVisible = params.userMessageVisible ?? true;
 
-  if (recordUserMessage && params.userMessageText === undefined) {
-    throw new Error("userMessageText is required when recordUserMessage is true");
+  if (userMessageVisible && params.userMessageText === undefined) {
+    throw new Error("userMessageText is required when userMessageVisible is true");
   }
 
   const record = await params.agentStorage.get(params.agentId);
@@ -178,17 +178,6 @@ export async function sendPromptToAgent(
     await params.agentManager.setAgentMode(params.agentId, params.sessionMode);
   }
 
-  if (recordUserMessage && params.userMessageText !== undefined) {
-    try {
-      params.agentManager.recordUserMessage(params.agentId, params.userMessageText, {
-        messageId: params.messageId,
-        emitState: false,
-      });
-    } catch (error) {
-      params.logger.error({ err: error, agentId: params.agentId }, "Failed to record user message");
-    }
-  }
-
   return startAgentRun(params.agentManager, params.agentId, params.prompt, params.logger, {
     replaceRunning: true,
     runOptions: params.runOptions,
@@ -225,7 +214,7 @@ export function setupFinishNotification(params: SetupFinishNotificationParams):
       agentId: callerAgentId,
       prompt: formatSystemNotificationPrompt(body),
       unarchive: false,
-      recordUserMessage: false,
+      userMessageVisible: false,
       logger,
     });
   }

packages/server/src/server/agent/agent-sdk-types.ts

@@ -123,6 +123,9 @@ export interface AgentCapabilityFlags {
   supportsMcpServers: boolean;
   supportsReasoningStream: boolean;
   supportsToolInvocations: boolean;
+  supportsRewindConversation?: boolean;
+  supportsRewindFiles?: boolean;
+  supportsRewindBoth?: boolean;
 }
 
 export interface AgentPersistenceHandle {
@@ -144,6 +147,7 @@ export interface AgentRunOptions {
   outputSchema?: unknown;
   resumeFrom?: AgentPersistenceHandle;
   maxThinkingTokens?: number;
+  messageId?: string;
 }
 
 export interface AgentUsage {
@@ -545,6 +549,9 @@ export interface AgentSession {
   setModel?(modelId: string | null): Promise<void>;
   setThinkingOption?(thinkingOptionId: string | null): Promise<void>;
   setFeature?(featureId: string, value: unknown): Promise<void>;
+  revertConversation?(input: { messageId: string }): Promise<void>;
+  revertFiles?(input: { messageId: string }): Promise<void>;
+  revertBoth?(input: { messageId: string }): Promise<void>;
   /**
    * Out-of-band prompt handler. When non-null, the manager runs the returned
    * handler instead of allocating a turn. The handler emits stream events

packages/server/src/server/agent/agent-timeline-store-types.ts

@@ -56,10 +56,6 @@ export interface AgentTimelineStore {
   getCommittedRows(agentId: string): Promise<AgentTimelineRow[]>;
   getLastItem(agentId: string): Promise<AgentTimelineItem | null>;
   getLastAssistantMessage(agentId: string): Promise<string | null>;
-  hasCommittedUserMessage(
-    agentId: string,
-    options: { messageId: string; text: string },
-  ): Promise<boolean>;
   deleteAgent(agentId: string): Promise<void>;
   bulkInsert(agentId: string, rows: readonly AgentTimelineRow[]): Promise<void>;
 }

packages/server/src/server/agent/agent-timeline-store.ts

@@ -26,14 +26,6 @@ function cloneRow(row: AgentTimelineRow): AgentTimelineRow {
   return { ...row };
 }
 
-function normalizeTimelineMessageId(messageId: string | undefined): string | undefined {
-  if (typeof messageId !== "string") {
-    return undefined;
-  }
-  const normalized = messageId.trim();
-  return normalized.length > 0 ? normalized : undefined;
-}
-
 interface FetchContext {
   state: AgentTimelineState;
   direction: NonNullable<AgentTimelineFetchOptions["direction"]>;
@@ -282,35 +274,6 @@ export class InMemoryAgentTimelineStore {
     return chunks.toReversed().join("");
   }
 
-  getCanonicalUserMessagesById(agentId: string): Map<string, string> {
-    const entries = this.requireState(agentId).rows.flatMap<[string, string]>((row) => {
-      if (row.item.type !== "user_message") {
-        return [];
-      }
-      const messageId = normalizeTimelineMessageId(row.item.messageId);
-      if (!messageId) {
-        return [];
-      }
-      return [[messageId, row.item.text]];
-    });
-    return new Map(entries);
-  }
-
-  hasCommittedUserMessage(agentId: string, options: { messageId: string; text: string }): boolean {
-    const messageId = normalizeTimelineMessageId(options.messageId);
-    if (!messageId) {
-      return false;
-    }
-
-    return this.requireState(agentId).rows.some((row) => {
-      if (row.item.type !== "user_message") {
-        return false;
-      }
-      const rowMessageId = normalizeTimelineMessageId(row.item.messageId);
-      return rowMessageId === messageId && row.item.text === options.text;
-    });
-  }
-
   private requireState(agentId: string): AgentTimelineState {
     const state = this.states.get(agentId);
     if (!state) {

packages/server/src/server/agent/mcp-server.test.ts

@@ -116,7 +116,6 @@ function buildAgentManagerSpies() {
   return {
     createAgent: vi.fn(),
     waitForAgentEvent: vi.fn(),
-    recordUserMessage: vi.fn(),
     setAgentMode: vi.fn().mockResolvedValue(undefined),
     setAgentModel: vi.fn().mockResolvedValue(undefined),
     setAgentThinkingOption: vi.fn().mockResolvedValue(undefined),

packages/server/src/server/agent/mcp-server.ts

@@ -1089,14 +1089,6 @@ export async function createAgentMcpServer(options: AgentMcpServerOptions): Prom
         logger: childLogger,
       });
 
-      try {
-        agentManager.recordUserMessage(snapshot.id, trimmedPrompt, {
-          emitState: false,
-        });
-      } catch (error) {
-        childLogger.error({ err: error, agentId: snapshot.id }, "Failed to record initial prompt");
-      }
-
       try {
         startAgentRun(agentManager, snapshot.id, trimmedPrompt, childLogger);
         if (notifyOnFinish && callerAgentId) {

packages/server/src/server/agent/provider-launch-config.test.ts

@@ -85,7 +85,7 @@ describe("createProviderEnv", () => {
     expect(env.PATH).toBe("/custom/path");
   });
 
-  test("strips parent Claude Code session env vars", () => {
+  test("strips parent Claude Code session env vars without removing SDK child flags", () => {
     const base = {
       PATH: "/usr/bin",
       CLAUDECODE: "1",
@@ -102,7 +102,7 @@ describe("createProviderEnv", () => {
     expect(env.CLAUDE_CODE_ENTRYPOINT).toBeUndefined();
     expect(env.CLAUDE_CODE_SSE_PORT).toBeUndefined();
     expect(env.CLAUDE_AGENT_SDK_VERSION).toBeUndefined();
-    expect(env.CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTING).toBeUndefined();
+    expect(env.CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTING).toBe("true");
   });
 });
 

packages/server/src/server/agent/provider-launch-config.ts

@@ -174,7 +174,6 @@ const PARENT_SESSION_ENV_VARS = [
   "CLAUDE_CODE_ENTRYPOINT",
   "CLAUDE_CODE_SSE_PORT",
   "CLAUDE_AGENT_SDK_VERSION",
-  "CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTING",
 ];
 
 export interface ProviderEnvOptions {

packages/server/src/server/agent/provider-registry-wrap.test.ts

@@ -0,0 +1,197 @@
+import { describe, expect, test } from "vitest";
+
+import type {
+  AgentCapabilityFlags,
+  AgentPromptInput,
+  AgentSession,
+  AgentStreamEvent,
+  AgentRuntimeInfo,
+} from "./agent-sdk-types.js";
+import { wrapSessionProvider } from "./provider-registry.js";
+
+type OptionalAgentSessionMethodName = {
+  [K in keyof AgentSession]-?: undefined extends AgentSession[K]
+    ? NonNullable<AgentSession[K]> extends (...args: never[]) => unknown
+      ? K
+      : never
+    : never;
+}[keyof AgentSession];
+
+const OPTIONAL_AGENT_SESSION_METHOD_NAMES = [
+  "listCommands",
+  "setModel",
+  "setThinkingOption",
+  "setFeature",
+  "revertConversation",
+  "revertFiles",
+  "revertBoth",
+  "tryHandleOutOfBand",
+] as const satisfies readonly OptionalAgentSessionMethodName[];
+
+type MissingOptionalAgentSessionMethod = Exclude<
+  OptionalAgentSessionMethodName,
+  (typeof OPTIONAL_AGENT_SESSION_METHOD_NAMES)[number]
+>;
+
+const _allOptionalAgentSessionMethodsAreCovered: MissingOptionalAgentSessionMethod extends never
+  ? true
+  : never = true;
+
+const CAPABILITIES: AgentCapabilityFlags = {
+  supportsStreaming: true,
+  supportsSessionPersistence: true,
+  supportsDynamicModes: true,
+  supportsMcpServers: true,
+  supportsReasoningStream: true,
+  supportsToolInvocations: true,
+  supportsRewindConversation: true,
+  supportsRewindFiles: true,
+  supportsRewindBoth: true,
+};
+
+const RUNTIME_INFO: AgentRuntimeInfo = {
+  provider: "claude",
+  sessionId: "session-1",
+};
+
+class FakeSession implements AgentSession {
+  readonly provider = "claude";
+  readonly id = "session-1";
+  readonly capabilities = CAPABILITIES;
+  readonly features = [];
+  readonly recordedCalls: string[] = [];
+
+  async run() {
+    this.recordedCalls.push("run");
+    return { timeline: [] };
+  }
+
+  async startTurn() {
+    this.recordedCalls.push("startTurn");
+    return { turnId: "turn-1" };
+  }
+
+  subscribe(_callback: (event: AgentStreamEvent) => void) {
+    this.recordedCalls.push("subscribe");
+    return () => {};
+  }
+
+  async *streamHistory() {
+    this.recordedCalls.push("streamHistory");
+    yield* emptyHistory();
+  }
+
+  async getRuntimeInfo() {
+    this.recordedCalls.push("getRuntimeInfo");
+    return RUNTIME_INFO;
+  }
+
+  async getAvailableModes() {
+    this.recordedCalls.push("getAvailableModes");
+    return [];
+  }
+
+  async getCurrentMode() {
+    this.recordedCalls.push("getCurrentMode");
+    return null;
+  }
+
+  async setMode(_modeId: string) {
+    this.recordedCalls.push("setMode");
+  }
+
+  getPendingPermissions() {
+    this.recordedCalls.push("getPendingPermissions");
+    return [];
+  }
+
+  async respondToPermission() {
+    this.recordedCalls.push("respondToPermission");
+  }
+
+  describePersistence() {
+    this.recordedCalls.push("describePersistence");
+    return null;
+  }
+
+  async interrupt() {
+    this.recordedCalls.push("interrupt");
+  }
+
+  async close() {
+    this.recordedCalls.push("close");
+  }
+
+  async listCommands() {
+    this.recordedCalls.push("listCommands");
+    return [];
+  }
+
+  async setModel() {
+    this.recordedCalls.push("setModel");
+  }
+
+  async setThinkingOption() {
+    this.recordedCalls.push("setThinkingOption");
+  }
+
+  async setFeature() {
+    this.recordedCalls.push("setFeature");
+  }
+
+  async revertConversation() {
+    this.recordedCalls.push("revertConversation");
+  }
+
+  async revertFiles() {
+    this.recordedCalls.push("revertFiles");
+  }
+
+  async revertBoth() {
+    this.recordedCalls.push("revertBoth");
+  }
+
+  tryHandleOutOfBand(_prompt: AgentPromptInput) {
+    this.recordedCalls.push("tryHandleOutOfBand");
+    return {
+      run: async () => {
+        this.recordedCalls.push("tryHandleOutOfBand.run");
+      },
+    };
+  }
+}
+
+async function* emptyHistory(): AsyncGenerator<AgentStreamEvent> {
+  for (const event of [] as AgentStreamEvent[]) {
+    yield event;
+  }
+}
+
+describe("wrapSessionProvider", () => {
+  test("forwards every optional AgentSession method", async () => {
+    const session = new FakeSession();
+    const wrapped = wrapSessionProvider("custom-claude", session);
+
+    await wrapped.listCommands?.();
+    await wrapped.setModel?.("sonnet");
+    await wrapped.setThinkingOption?.("high");
+    await wrapped.setFeature?.("feature-1", true);
+    await wrapped.revertConversation?.({ messageId: "message-1" });
+    await wrapped.revertFiles?.({ messageId: "message-1" });
+    await wrapped.revertBoth?.({ messageId: "message-1" });
+    const handler = wrapped.tryHandleOutOfBand?.("/compact");
+    await handler?.run({ emit: () => {} });
+
+    expect(session.recordedCalls).toEqual([
+      "listCommands",
+      "setModel",
+      "setThinkingOption",
+      "setFeature",
+      "revertConversation",
+      "revertFiles",
+      "revertBoth",
+      "tryHandleOutOfBand",
+      "tryHandleOutOfBand.run",
+    ]);
+  });
+});

packages/server/src/server/agent/provider-registry.ts

@@ -331,7 +331,7 @@ function mergeModelAdditions(
   );
 }
 
-function wrapSessionProvider(provider: AgentProvider, inner: AgentSession): AgentSession {
+export function wrapSessionProvider(provider: AgentProvider, inner: AgentSession): AgentSession {
   return {
     provider,
     id: inner.id,
@@ -360,6 +360,10 @@ function wrapSessionProvider(provider: AgentProvider, inner: AgentSession): Agen
     setModel: inner.setModel?.bind(inner),
     setThinkingOption: inner.setThinkingOption?.bind(inner),
     setFeature: inner.setFeature?.bind(inner),
+    revertConversation: inner.revertConversation?.bind(inner),
+    revertFiles: inner.revertFiles?.bind(inner),
+    revertBoth: inner.revertBoth?.bind(inner),
+    tryHandleOutOfBand: inner.tryHandleOutOfBand?.bind(inner),
   };
 }
 

packages/server/src/server/agent/providers/acp-agent.ts

@@ -158,6 +158,9 @@ const DEFAULT_ACP_CAPABILITIES: AgentCapabilityFlags = {
   supportsMcpServers: true,
   supportsReasoningStream: true,
   supportsToolInvocations: true,
+  supportsRewindConversation: false,
+  supportsRewindFiles: false,
+  supportsRewindBoth: false,
 };
 
 const ACP_CLIENT_CAPABILITIES: ACPClientCapabilities = {

packages/server/src/server/agent/providers/claude/agent.test.ts

@@ -1519,6 +1519,12 @@ describe("ClaudeAgentSession context window usage", () => {
     const result = await session.run("turn");
     await session.close();
 
-    expect(result.timeline).toEqual([{ type: "assistant_message", text: "Here is the answer." }]);
+    expect(result.timeline).toEqual([
+      {
+        type: "assistant_message",
+        text: "Here is the answer.",
+        messageId: "assistant-third-party-1",
+      },
+    ]);
   });
 });

packages/server/src/server/agent/providers/claude/agent.ts

@@ -41,6 +41,7 @@ import {
 import { appendOrReplaceGrowingAssistantMessage, runProviderTurn } from "../provider-runner.js";
 import { renderPromptAttachmentAsText } from "../../prompt-attachments.js";
 import { claudeQuery, type ClaudeOptions, type ClaudeQueryFactory } from "./query.js";
+import { realClaudeRewindSdk, revertClaudeConversation, revertClaudeFiles } from "./rewind.js";
 import { normalizeProviderReplayTimestamp } from "../../provider-history-timestamps.js";
 
 import {
@@ -191,6 +192,15 @@ interface PersistedTimelineEntry {
   timestamp?: string;
 }
 
+interface ClaudeRewindTurnAnchor {
+  userMessageId: string;
+  assistantMessageId: string | null;
+}
+
+type ClaudeConversationRewindTarget =
+  | { kind: "fresh-session" }
+  | { kind: "fork"; messageId: string };
+
 const CLAUDE_CAPABILITIES: AgentCapabilityFlags = {
   supportsStreaming: true,
   supportsSessionPersistence: true,
@@ -198,6 +208,9 @@ const CLAUDE_CAPABILITIES: AgentCapabilityFlags = {
   supportsMcpServers: true,
   supportsReasoningStream: true,
   supportsToolInvocations: true,
+  supportsRewindConversation: true,
+  supportsRewindFiles: true,
+  supportsRewindBoth: true,
 };
 
 const DEFAULT_MODES: AgentMode[] = [
@@ -1046,7 +1059,7 @@ class TimelineAssembler {
       !isClaudeTranscriptNoiseText(nextAssistantText)
     ) {
       state.emittedAssistantLength = state.assistantText.length;
-      items.push({ type: "assistant_message", text: nextAssistantText });
+      items.push({ type: "assistant_message", text: nextAssistantText, messageId: state.id });
     }
 
     const nextReasoningText = state.reasoningText.slice(state.emittedReasoningLength);
@@ -1157,7 +1170,25 @@ function isSyntheticUserEntry(entry: unknown): boolean {
   if (!candidate) {
     return false;
   }
-  return candidate.isSynthetic === true || candidate.isMeta === true;
+  return (
+    candidate.isSynthetic === true || candidate.isMeta === true || Boolean(candidate.toolUseResult)
+  );
+}
+
+function isToolResultUserEntry(entry: unknown): boolean {
+  const candidate = toObjectRecord(entry);
+  if (!candidate) {
+    return false;
+  }
+  const message = toObjectRecord(candidate.message);
+  const content = message?.content;
+  return (
+    Array.isArray(content) && content.some((block) => toObjectRecord(block)?.type === "tool_result")
+  );
+}
+
+function isSyntheticHistoryUserEntry(entry: Record<string, unknown>): boolean {
+  return isSyntheticUserEntry(entry);
 }
 
 function firstTrimmedString(sources: readonly unknown[]): string | null {
@@ -1170,6 +1201,15 @@ function firstTrimmedString(sources: readonly unknown[]): string | null {
   return null;
 }
 
+function readTranscriptUuid(message: SDKMessage): string | null {
+  const root = toObjectRecord(message) ?? {};
+  const messageType = readTrimmedString(root.type);
+  if (messageType !== "user" && messageType !== "assistant") {
+    return null;
+  }
+  return firstTrimmedString([root.uuid]);
+}
+
 export function readEventIdentifiers(message: SDKMessage): EventIdentifiers {
   const root = toObjectRecord(message) ?? {};
   const messageType = readTrimmedString(root.type);
@@ -1177,7 +1217,10 @@ export function readEventIdentifiers(message: SDKMessage): EventIdentifiers {
   const streamEventMessage = toObjectRecord(streamEvent?.message);
   const messageContainer = toObjectRecord(root.message);
 
-  const messageIdFromUuid = messageType === "user" ? root.uuid : undefined;
+  const messageIdFromUuid =
+    messageType === "user" || messageType === "assistant" || messageType === "system"
+      ? root.uuid
+      : undefined;
 
   return {
     taskId: firstTrimmedString([
@@ -1566,7 +1609,6 @@ class ClaudeAgentSession implements AgentSession {
   private queryPumpPromise: Promise<void> | null = null;
   private queryRestartNeeded = false;
   private pendingInterruptAbort = false;
-  private lastForegroundPromptText: string | null = null;
   private foregroundHasVisibleActivity = false;
   private activeTurnHasAssistantText = false;
   private lastContextWindowUsedTokens: number | undefined;
@@ -1574,6 +1616,9 @@ class ClaudeAgentSession implements AgentSession {
   private lastStreamRequestInputTokens: number | undefined;
   private lastStreamRequestOutputTokens: number | undefined;
   private userMessageIds: string[] = [];
+  private readonly emittedUserMessageIds = new Set<string>();
+  private readonly rewindTurnAnchors: ClaudeRewindTurnAnchor[] = [];
+  private pendingFreshSessionId: string | null = null;
   private recentStderr = "";
   private closed = false;
 
@@ -1689,7 +1734,9 @@ class ClaudeAgentSession implements AgentSession {
     }
 
     const sdkMessage = this.toSdkUserMessage(prompt);
-    this.lastForegroundPromptText = this.extractPromptText(prompt);
+    const sdkUserMessageId =
+      typeof sdkMessage.uuid === "string" && sdkMessage.uuid.length > 0 ? sdkMessage.uuid : null;
+    this.rememberRewindUserAnchor(sdkUserMessageId);
     const turnId = this.createTurnId("foreground");
     this.activeForegroundTurnId = turnId;
     this.foregroundHasVisibleActivity = false;
@@ -1727,6 +1774,11 @@ class ClaudeAgentSession implements AgentSession {
       }
       this.startQueryPump();
       this.input.push(sdkMessage);
+      setTimeout(() => {
+        if (this.activeForegroundTurnId === turnId) {
+          this.emitSubmittedUserMessage(sdkMessage, turnId);
+        }
+      }, 0);
     } catch (error) {
       this.finishForegroundTurn(
         this.buildTurnFailedEvent(error instanceof Error ? error.message : "Claude stream failed"),
@@ -2004,6 +2056,36 @@ class ClaudeAgentSession implements AgentSession {
     return Array.from(commandMap.values()).sort((a, b) => a.name.localeCompare(b.name));
   }
 
+  async revertConversation(input: { messageId: string }): Promise<void> {
+    const target = this.resolveConversationRewindTarget(input.messageId);
+    if (target.kind === "fresh-session") {
+      this.startFreshConversationSession();
+      return;
+    }
+    await revertClaudeConversation({
+      sdk: realClaudeRewindSdk,
+      sessionId: this.claudeSessionId,
+      messageId: target.messageId,
+      resolveMessageId: (messageId) => this.resolveClaudeMessageId(messageId),
+      setSessionId: (sessionId) => {
+        this.rebindConversationSession(sessionId);
+      },
+    });
+  }
+
+  async revertFiles(input: { messageId: string }): Promise<void> {
+    const messageId = await this.resolveClaudeMessageId(input.messageId);
+    await revertClaudeFiles({
+      query: await this.ensureQuery(),
+      messageId,
+    });
+  }
+
+  async revertBoth(input: { messageId: string }): Promise<void> {
+    await this.revertFiles(input);
+    await this.revertConversation(input);
+  }
+
   private resolveSlashCommandInvocation(prompt: AgentPromptInput): SlashCommandInvocation | null {
     if (typeof prompt !== "string") {
       return null;
@@ -2150,10 +2232,6 @@ class ClaudeAgentSession implements AgentSession {
       }
     };
 
-    const historyIds = this.readUserMessageIdsFromHistoryFile();
-    for (let idx = historyIds.length - 1; idx >= 0; idx -= 1) {
-      pushUnique(historyIds[idx]);
-    }
     for (let idx = this.persistedHistory.length - 1; idx >= 0; idx -= 1) {
       const entry = this.persistedHistory[idx];
       if (entry?.item.type === "user_message") {
@@ -2167,35 +2245,49 @@ class ClaudeAgentSession implements AgentSession {
     return candidates;
   }
 
-  private readUserMessageIdsFromHistoryFile(): string[] {
-    if (!this.claudeSessionId) {
-      return [];
-    }
-    const historyPath = this.resolveHistoryPath(this.claudeSessionId);
-    if (!historyPath || !fs.existsSync(historyPath)) {
-      return [];
-    }
-    try {
-      const ids: string[] = [];
-      const content = fs.readFileSync(historyPath, "utf8");
-      for (const line of content.split(/\n+/)) {
-        const trimmed = line.trim();
-        if (!trimmed) continue;
-        try {
-          const entry = JSON.parse(trimmed);
-          if (entry?.type === "user" && typeof entry.uuid === "string") {
-            ids.push(entry.uuid);
-          }
-        } catch {
-          // ignore malformed lines
-        }
-      }
-      return ids;
-    } catch {
-      return [];
+  private rebindConversationSession(sessionId: string): void {
+    const oldSessionId = this.claudeSessionId;
+    this.claudeSessionId = sessionId;
+    this.pendingFreshSessionId = null;
+    this.persistence = null;
+    this.cachedRuntimeInfo = null;
+    this.queryRestartNeeded = true;
+    this.persistedHistory = [];
+    this.historyPending = false;
+    this.userMessageIds = [];
+    this.emittedUserMessageIds.clear();
+    this.rewindTurnAnchors.length = 0;
+    this.loadPersistedHistory(sessionId);
+    if (oldSessionId && oldSessionId !== sessionId) {
+      this.dispatchEvents([
+        {
+          type: "timeline",
+          provider: "claude",
+          item: this.createClaudeSessionChangedNotice(oldSessionId, sessionId),
+        },
+        {
+          type: "thread_started",
+          provider: "claude",
+          sessionId,
+        },
+      ]);
     }
   }
 
+  private startFreshConversationSession(): void {
+    const sessionId = randomUUID();
+    this.claudeSessionId = sessionId;
+    this.pendingFreshSessionId = sessionId;
+    this.persistence = null;
+    this.cachedRuntimeInfo = null;
+    this.queryRestartNeeded = true;
+    this.persistedHistory = [];
+    this.historyPending = false;
+    this.userMessageIds = [];
+    this.emittedUserMessageIds.clear();
+    this.rewindTurnAnchors.length = 0;
+  }
+
   private rememberUserMessageId(messageId: string | null | undefined): void {
     if (typeof messageId !== "string" || messageId.length === 0) {
       return;
@@ -2207,6 +2299,92 @@ class ClaudeAgentSession implements AgentSession {
     this.userMessageIds.push(messageId);
   }
 
+  private rememberEmittedUserMessageId(messageId: string | null | undefined): void {
+    if (typeof messageId !== "string" || messageId.length === 0) {
+      return;
+    }
+    this.emittedUserMessageIds.add(messageId);
+  }
+
+  private rememberRewindUserAnchor(userMessageId: string | null | undefined): void {
+    if (typeof userMessageId !== "string" || userMessageId.length === 0) {
+      return;
+    }
+    if (this.rewindTurnAnchors.some((anchor) => anchor.userMessageId === userMessageId)) {
+      return;
+    }
+    this.rewindTurnAnchors.push({
+      userMessageId,
+      assistantMessageId: null,
+    });
+  }
+
+  private rememberRewindAssistantAnchor(assistantMessageId: string | null | undefined): void {
+    if (typeof assistantMessageId !== "string" || assistantMessageId.length === 0) {
+      return;
+    }
+    for (let index = this.rewindTurnAnchors.length - 1; index >= 0; index -= 1) {
+      const anchor = this.rewindTurnAnchors[index];
+      if (!anchor) {
+        continue;
+      }
+      anchor.assistantMessageId = assistantMessageId;
+      return;
+    }
+  }
+
+  private rememberTranscriptProgress(message: SDKMessage, messageId: string | null): void {
+    if (!messageId) {
+      return;
+    }
+    if (
+      message.type === "user" &&
+      !isSyntheticUserEntry(message) &&
+      !isToolResultUserEntry(message)
+    ) {
+      this.rememberRewindUserAnchor(messageId);
+      return;
+    }
+    if (message.type === "assistant") {
+      this.rememberRewindAssistantAnchor(messageId);
+      return;
+    }
+    if (message.type === "stream_event") {
+      const event = toObjectRecord(message.event) ?? {};
+      const eventType = readTrimmedString(event.type);
+      if (eventType === "message_start") {
+        this.rememberRewindAssistantAnchor(messageId);
+      }
+      return;
+    }
+  }
+
+  private resolveClaudeMessageId(messageId: string): string {
+    return messageId;
+  }
+
+  private resolveConversationRewindTarget(messageId: string): ClaudeConversationRewindTarget {
+    const targetUserMessageId = this.resolveClaudeMessageId(messageId);
+    const index = this.rewindTurnAnchors.findIndex(
+      (anchor) => anchor.userMessageId === targetUserMessageId,
+    );
+    if (index < 0) {
+      throw new Error(`Claude rewind target ${messageId} is not in the tracked conversation`);
+    }
+
+    if (index === 0) {
+      return { kind: "fresh-session" };
+    }
+
+    const previousTurn = this.rewindTurnAnchors[index - 1];
+    if (!previousTurn?.assistantMessageId) {
+      throw new Error(
+        `Claude rewind cannot preserve turn ${index} because its assistant response id was not observed`,
+      );
+    }
+    return { kind: "fork", messageId: previousTurn.assistantMessageId };
+  }
+
   private async ensureQuery(): Promise<Query> {
     if (this.query && !this.queryRestartNeeded) {
       return this.query;
@@ -2353,6 +2531,13 @@ class ClaudeAgentSession implements AgentSession {
       },
       "Resolved Claude executable",
     );
+    const sessionBinding: Pick<ClaudeOptions, "resume" | "sessionId"> = {};
+    if (this.pendingFreshSessionId) {
+      sessionBinding.sessionId = this.pendingFreshSessionId;
+    } else if (this.claudeSessionId) {
+      sessionBinding.resume = this.claudeSessionId;
+    }
+
     const base: ClaudeOptions = {
       cwd: this.config.cwd,
       includePartialMessages: true,
@@ -2380,7 +2565,7 @@ class ClaudeAgentSession implements AgentSession {
       enableFileCheckpointing: true,
       // If we have a session ID from a previous query (e.g., after interrupt),
       // resume that session to continue the conversation history.
-      ...(this.claudeSessionId ? { resume: this.claudeSessionId } : {}),
+      ...sessionBinding,
       ...(thinking ? { thinking } : {}),
       ...(effort ? { effort } : {}),
       ...extraClaudeOptions,
@@ -2396,7 +2581,7 @@ class ClaudeAgentSession implements AgentSession {
       base.model = this.config.model;
     }
     this.lastOptionsModel = base.model ?? null;
-    if (this.claudeSessionId) {
+    if (this.claudeSessionId && !this.pendingFreshSessionId) {
       base.resume = this.claudeSessionId;
     }
     if (this.runtimeSettings?.disallowedTools?.length) {
@@ -2559,16 +2744,6 @@ class ClaudeAgentSession implements AgentSession {
     );
   }
 
-  private extractPromptText(prompt: AgentPromptInput): string | null {
-    if (typeof prompt === "string") {
-      return prompt;
-    }
-    const textParts = prompt
-      .filter((block): block is { type: "text"; text: string } => block.type === "text")
-      .map((block) => block.text);
-    return textParts.length > 0 ? textParts.join("\n") : null;
-  }
-
   private async executeRewindTurn(
     _turnId: string,
     invocation: SlashCommandInvocation,
@@ -2630,7 +2805,6 @@ class ClaudeAgentSession implements AgentSession {
     }
     this.notifySubscribers(event);
     this.activeForegroundTurnId = null;
-    this.lastForegroundPromptText = null;
     this.cancelCurrentTurn = null;
     this.activeTurnHasAssistantText = false;
     this.syncTurnState("foreground turn terminal");
@@ -2646,7 +2820,6 @@ class ClaudeAgentSession implements AgentSession {
     if (terminalSeen) {
       if (this.activeForegroundTurnId) {
         this.activeForegroundTurnId = null;
-        this.lastForegroundPromptText = null;
         this.cancelCurrentTurn = null;
         this.activeTurnHasAssistantText = false;
         this.syncTurnState("foreground turn terminal");
@@ -2808,18 +2981,6 @@ class ClaudeAgentSession implements AgentSession {
     }
   }
 
-  private isEchoedForegroundUserMessage(event: AgentStreamEvent): boolean {
-    if (
-      event.type !== "timeline" ||
-      event.item.type !== "user_message" ||
-      !this.activeForegroundTurnId ||
-      !this.lastForegroundPromptText
-    ) {
-      return false;
-    }
-    return event.item.text.trim() === this.lastForegroundPromptText.trim();
-  }
-
   private shouldSuppressStaleResult(message: SDKMessage): boolean {
     // Suppress stale results from interrupted requests. The cancel path already
     // emitted the terminal event; this result is leftover from the killed API
@@ -2862,6 +3023,7 @@ class ClaudeAgentSession implements AgentSession {
 
     const turnId = this.activeForegroundTurnId ?? this.autonomousTurn?.id ?? null;
     const identifiers = readEventIdentifiers(message);
+    this.rememberTranscriptProgress(message, readTranscriptUuid(message));
 
     this.logger.trace(
       {
@@ -2895,12 +3057,7 @@ class ClaudeAgentSession implements AgentSession {
           }) satisfies AgentStreamEvent,
       );
 
-    // User message dedup: suppress echoed user messages that match the foreground prompt
-    const filteredMessageEvents = messageEvents.filter(
-      (event) => !this.isEchoedForegroundUserMessage(event),
-    );
-
-    const events = [...filteredMessageEvents, ...assistantTimelineEvents];
+    const events = [...messageEvents, ...assistantTimelineEvents];
 
     if (events.length === 0) {
       return;
@@ -3013,20 +3170,22 @@ class ClaudeAgentSession implements AgentSession {
     }
 
     const events: AgentStreamEvent[] = [];
-    const sessionCapture = this.captureSessionIdFromMessage(message);
-    if (sessionCapture.notice) {
-      events.push({
-        type: "timeline",
-        provider: "claude",
-        item: sessionCapture.notice,
-      });
-    }
-    if (sessionCapture.threadStartedSessionId) {
-      events.push({
-        type: "thread_started",
-        provider: "claude",
-        sessionId: sessionCapture.threadStartedSessionId,
-      });
+    if (message.type !== "system") {
+      const sessionCapture = this.captureSessionIdFromMessage(message);
+      if (sessionCapture.notice) {
+        events.push({
+          type: "timeline",
+          provider: "claude",
+          item: sessionCapture.notice,
+        });
+      }
+      if (sessionCapture.threadStartedSessionId) {
+        events.push({
+          type: "thread_started",
+          provider: "claude",
+          sessionId: sessionCapture.threadStartedSessionId,
+        });
+      }
     }
 
     switch (message.type) {
@@ -3059,6 +3218,25 @@ class ClaudeAgentSession implements AgentSession {
     return events;
   }
 
+  private emitSubmittedUserMessage(
+    message: Extract<SDKMessage, { type: "user" }>,
+    turnId: string,
+  ): void {
+    const events: AgentStreamEvent[] = [];
+    this.appendUserMessageEvents(message, events);
+    if (events.length === 0) {
+      return;
+    }
+    this.foregroundHasVisibleActivity = true;
+    for (const event of events) {
+      if (event.type === "timeline") {
+        this.notifySubscribers({ ...event, turnId });
+      } else {
+        this.notifySubscribers(event);
+      }
+    }
+  }
+
   private appendSystemMessageEvents(
     message: Extract<SDKMessage, { type: "system" }>,
     events: AgentStreamEvent[],
@@ -3162,7 +3340,11 @@ class ClaudeAgentSession implements AgentSession {
     }
     const messageId =
       typeof message.uuid === "string" && message.uuid.length > 0 ? message.uuid : undefined;
+    if (messageId && this.emittedUserMessageIds.has(messageId)) {
+      return;
+    }
     this.rememberUserMessageId(messageId);
+    this.rememberEmittedUserMessageId(messageId);
     const content = message.message?.content;
     const taskNotificationItem = mapTaskNotificationUserContentToToolCall({
       content,
@@ -3293,10 +3475,12 @@ class ClaudeAgentSession implements AgentSession {
     }
     if (this.claudeSessionId === null) {
       this.claudeSessionId = sessionId;
+      this.pendingFreshSessionId = null;
       this.persistence = null;
       return { threadStartedSessionId: sessionId, notice: null };
     }
     if (this.claudeSessionId === sessionId) {
+      this.pendingFreshSessionId = null;
       return { threadStartedSessionId: null, notice: null };
     }
     const oldSessionId = this.claudeSessionId;
@@ -3308,6 +3492,7 @@ class ClaudeAgentSession implements AgentSession {
       "Claude session ID changed in message; accepting new session",
     );
     this.claudeSessionId = sessionId;
+    this.pendingFreshSessionId = null;
     this.persistence = null;
     return {
       threadStartedSessionId: sessionId,
@@ -3338,9 +3523,11 @@ class ClaudeAgentSession implements AgentSession {
 
     if (existingSessionId === null) {
       this.claudeSessionId = newSessionId;
+      this.pendingFreshSessionId = null;
       threadStartedSessionId = newSessionId;
       this.logger.debug({ sessionId: newSessionId }, "Claude session ID set for the first time");
     } else if (existingSessionId === newSessionId) {
+      this.pendingFreshSessionId = null;
       this.logger.debug({ sessionId: newSessionId }, "Claude session ID unchanged (same value)");
     } else {
       // Session ID changed in an init message (e.g. a hook restarted Claude
@@ -3350,6 +3537,7 @@ class ClaudeAgentSession implements AgentSession {
         "Claude session ID changed in init message; accepting new session",
       );
       this.claudeSessionId = newSessionId;
+      this.pendingFreshSessionId = null;
       threadStartedSessionId = newSessionId;
       notice = this.createClaudeSessionChangedNotice(existingSessionId, newSessionId);
     }
@@ -3703,12 +3891,22 @@ class ClaudeAgentSession implements AgentSession {
     if (entry.isSidechain) {
       return;
     }
-    if (entry.type === "user" && typeof entry.uuid === "string") {
-      this.rememberUserMessageId(entry.uuid);
-    }
 
     const historyTimestamp = normalizeProviderReplayTimestamp(entry.timestamp);
     const items = this.convertHistoryEntry(entry);
+    const isVisibleUserEntry =
+      entry.type === "user" &&
+      typeof entry.uuid === "string" &&
+      !isSyntheticHistoryUserEntry(entry) &&
+      !isToolResultUserEntry(entry);
+    if (isVisibleUserEntry && typeof entry.uuid === "string") {
+      this.rememberUserMessageId(entry.uuid);
+      this.rememberRewindUserAnchor(entry.uuid);
+    }
+    if (entry.type === "assistant" && typeof entry.uuid === "string") {
+      this.rememberRewindAssistantAnchor(entry.uuid);
+    }
+
     if (items.length > 0) {
       timeline.push(
         ...items.map((item) => ({
@@ -3722,10 +3920,25 @@ class ClaudeAgentSession implements AgentSession {
   private resolveHistoryPath(sessionId: string): string | null {
     const cwd = this.config.cwd;
     if (!cwd) return null;
-    const sanitized = sanitizeClaudeProjectPath(cwd);
     const configDir = process.env.CLAUDE_CONFIG_DIR ?? path.join(os.homedir(), ".claude");
-    const dir = path.join(configDir, "projects", sanitized);
-    return path.join(dir, `${sessionId}.jsonl`);
+    const candidates = [cwd];
+    try {
+      const realCwd = fs.realpathSync(cwd);
+      if (realCwd !== cwd) {
+        candidates.push(realCwd);
+      }
+    } catch {
+      // Fall back to the configured cwd when the path has already disappeared.
+    }
+    for (const candidate of candidates) {
+      const sanitized = sanitizeClaudeProjectPath(candidate);
+      const historyPath = path.join(configDir, "projects", sanitized, `${sessionId}.jsonl`);
+      if (fs.existsSync(historyPath)) {
+        return historyPath;
+      }
+    }
+    const sanitized = sanitizeClaudeProjectPath(cwd);
+    return path.join(configDir, "projects", sanitized, `${sessionId}.jsonl`);
   }
 
   private convertHistoryEntry(entry: ClaudeHistoryEntry): AgentTimelineItem[] {
@@ -4409,6 +4622,25 @@ interface ClaudeHistoryEntry {
   [key: string]: unknown;
 }
 
+function mapAssistantHistoryBlocksWithMessageId(
+  entry: ClaudeHistoryEntry,
+  content: string | ClaudeContentChunk[],
+  mapBlocks: (content: string | ClaudeContentChunk[]) => AgentTimelineItem[],
+): AgentTimelineItem[] {
+  const items = mapBlocks(content);
+  const assistantMessageId =
+    typeof entry.uuid === "string" && entry.uuid.length > 0 ? entry.uuid : null;
+  if (!assistantMessageId) {
+    return items;
+  }
+  for (const item of items) {
+    if (item.type === "assistant_message" && !item.messageId) {
+      item.messageId = assistantMessageId;
+    }
+  }
+  return items;
+}
+
 function convertClaudeHistoryEntryPreamble(
   entry: ClaudeHistoryEntry,
 ): { shortCircuit: AgentTimelineItem[] } | { proceed: { content: unknown } } {
@@ -4504,7 +4736,7 @@ export function convertClaudeHistoryEntry(
   }
 
   if (entry.type === "assistant" && contentValue) {
-    return mapBlocks(contentValue);
+    return mapAssistantHistoryBlocksWithMessageId(entry, contentValue, mapBlocks);
   }
 
   return timeline;

packages/server/src/server/agent/providers/claude/rewind.test.ts

@@ -0,0 +1,89 @@
+import { describe, expect, test } from "vitest";
+import type { Query } from "@anthropic-ai/claude-agent-sdk";
+
+import {
+  revertClaudeConversation,
+  revertClaudeConversationAndFiles,
+  revertClaudeFiles,
+} from "./rewind.js";
+import { FakeClaudeSdk } from "./test-rewind-claude-sdk.js";
+
+describe("Claude rewind", () => {
+  test("forks the conversation up to the user message", async () => {
+    const claude = new FakeClaudeSdk();
+    let sessionId = "original-session";
+
+    await revertClaudeConversation({
+      sdk: claude,
+      sessionId,
+      messageId: "user-message-1",
+      setSessionId: (nextSessionId) => {
+        sessionId = nextSessionId;
+      },
+    });
+
+    expect(claude.recordedForks).toEqual([{ upToMessageId: "user-message-1" }]);
+    expect(sessionId).toBe("forked-session-1");
+  });
+
+  test("translates Paseo timeline message ids before forking", async () => {
+    const claude = new FakeClaudeSdk();
+    let sessionId = "original-session";
+
+    await revertClaudeConversation({
+      sdk: claude,
+      sessionId,
+      messageId: "timeline-message-1",
+      resolveMessageId: () => "claude-jsonl-message-1",
+      setSessionId: (nextSessionId) => {
+        sessionId = nextSessionId;
+      },
+    });
+
+    expect(claude.recordedForks).toEqual([{ upToMessageId: "claude-jsonl-message-1" }]);
+    expect(sessionId).toBe("forked-session-1");
+  });
+
+  test("rewinds tracked files to the user message", async () => {
+    const claude = new FakeClaudeSdk();
+
+    await revertClaudeFiles({
+      query: claude.createQuery() as Query,
+      messageId: "user-message-1",
+    });
+
+    expect(claude.recordedFileRewinds).toEqual([{ userMessageId: "user-message-1" }]);
+  });
+
+  test("translates Paseo timeline message ids before rewinding files", async () => {
+    const claude = new FakeClaudeSdk();
+
+    await revertClaudeFiles({
+      query: claude.createQuery() as Query,
+      messageId: "timeline-message-1",
+      resolveMessageId: () => "claude-jsonl-message-1",
+    });
+
+    expect(claude.recordedFileRewinds).toEqual([{ userMessageId: "claude-jsonl-message-1" }]);
+  });
+
+  test("rebinds the Claude session before composed rewind returns for rehydrate", async () => {
+    const claude = new FakeClaudeSdk();
+    claude.setNextSessionId("forked-before-rehydrate");
+    let sessionId = "original-session";
+
+    await revertClaudeConversationAndFiles({
+      sdk: claude,
+      query: claude.createQuery() as Query,
+      sessionId,
+      messageId: "user-message-1",
+      setSessionId: (nextSessionId) => {
+        sessionId = nextSessionId;
+      },
+    });
+
+    expect(claude.recordedFileRewinds).toEqual([{ userMessageId: "user-message-1" }]);
+    expect(claude.recordedForks).toEqual([{ upToMessageId: "user-message-1" }]);
+    expect(sessionId).toBe("forked-before-rehydrate");
+  });
+});

packages/server/src/server/agent/providers/claude/rewind.ts

@@ -0,0 +1,57 @@
+import { forkSession as claudeForkSession, type Query } from "@anthropic-ai/claude-agent-sdk";
+
+export interface ClaudeRewindSdk {
+  forkSession(
+    sessionId: string,
+    options: { upToMessageId: string },
+  ): Promise<{ sessionId: string }>;
+}
+
+export const realClaudeRewindSdk: ClaudeRewindSdk = {
+  forkSession: claudeForkSession,
+};
+
+export async function revertClaudeConversation(input: {
+  sdk: ClaudeRewindSdk;
+  sessionId: string | null;
+  messageId: string;
+  resolveMessageId?: (messageId: string) => string | Promise<string>;
+  setSessionId: (sessionId: string) => void;
+}): Promise<void> {
+  if (!input.sessionId) {
+    throw new Error("Claude session is not ready for rewind");
+  }
+  const messageId = (await input.resolveMessageId?.(input.messageId)) ?? input.messageId;
+  const fork = await input.sdk.forkSession(input.sessionId, {
+    upToMessageId: messageId,
+  });
+  input.setSessionId(fork.sessionId);
+}
+
+export async function revertClaudeFiles(input: {
+  query: Query;
+  messageId: string;
+  resolveMessageId?: (messageId: string) => string | Promise<string>;
+}): Promise<void> {
+  const messageId = (await input.resolveMessageId?.(input.messageId)) ?? input.messageId;
+  const result = await input.query.rewindFiles(messageId, { dryRun: false });
+  if (!result.canRewind) {
+    throw new Error(result.error ?? `No file checkpoint found for message ${messageId}`);
+  }
+}
+
+export async function revertClaudeConversationAndFiles(input: {
+  sdk: ClaudeRewindSdk;
+  query: Query;
+  sessionId: string | null;
+  messageId: string;
+  resolveMessageId?: (messageId: string) => string | Promise<string>;
+  setSessionId: (sessionId: string) => void;
+}): Promise<void> {
+  await revertClaudeFiles({
+    query: input.query,
+    messageId: input.messageId,
+    resolveMessageId: input.resolveMessageId,
+  });
+  await revertClaudeConversation(input);
+}

packages/server/src/server/agent/providers/claude/test-rewind-claude-sdk.ts

@@ -0,0 +1,36 @@
+import type { ClaudeRewindSdk } from "./rewind.js";
+
+export class FakeClaudeSdk implements ClaudeRewindSdk {
+  readonly recordedForks: Array<{ upToMessageId: string }> = [];
+  readonly recordedFileRewinds: Array<{ userMessageId: string }> = [];
+
+  private nextSessionId = "forked-session-1";
+
+  setNextSessionId(sessionId: string): void {
+    this.nextSessionId = sessionId;
+  }
+
+  async forkSession(
+    _sessionId: string,
+    options: { upToMessageId: string },
+  ): Promise<{ sessionId: string }> {
+    this.recordedForks.push({ upToMessageId: options.upToMessageId });
+    return { sessionId: this.nextSessionId };
+  }
+
+  createQuery(): {
+    rewindFiles: (
+      userMessageId: string,
+      options?: { dryRun?: boolean },
+    ) => Promise<{
+      canRewind: boolean;
+    }>;
+  } {
+    return {
+      rewindFiles: async (userMessageId: string) => {
+        this.recordedFileRewinds.push({ userMessageId });
+        return { canRewind: true };
+      },
+    };
+  }
+}

packages/server/src/server/agent/providers/codex-app-server-agent.features.test.ts

@@ -2,7 +2,7 @@ import pino from "pino";
 import { describe, expect, test } from "vitest";
 
 import type { AgentSession, AgentSessionConfig } from "../agent-sdk-types.js";
-import { __codexAppServerInternals } from "./codex-app-server-agent.js";
+import { CodexAppServerAgentSession } from "./codex-app-server-agent.js";
 import {
   createFakeCodexAppServer,
   type FakeCodexAppServer,
@@ -74,7 +74,7 @@ function createSessionHarness(
   const appServer = createFakeCodexAppServer({
     "collaborationMode/list": () => ({ data: TEST_COLLABORATION_MODES }),
   });
-  const session = new __codexAppServerInternals.CodexAppServerAgentSession(
+  const session = new CodexAppServerAgentSession(
     { ...config, provider: CODEX_PROVIDER },
     null,
     options.logger ?? createTestLogger(),

packages/server/src/server/agent/providers/codex-app-server-agent.test.ts

@@ -15,12 +15,20 @@ import type {
   AgentStreamEvent,
 } from "../agent-sdk-types.js";
 import {
-  __codexAppServerInternals,
+  buildCodexAppServerEnv,
   CodexAppServerAgentClient,
+  CodexAppServerAgentSession,
   codexAppServerTurnInputFromPrompt,
+  listCodexSkills,
+  mapCodexPatchNotificationToToolCall,
+  mapCodexPlanToToolCall,
+  normalizeCodexOutputSchema,
+  toAgentUsage,
 } from "./codex-app-server-agent.js";
+import { CodexAppServerClient } from "./codex/app-server-transport.js";
 import {
   createFakeCodexAppServer,
+  type FakeCodexAppServer,
   waitForNextPermission,
 } from "./codex/test-utils/fake-app-server.js";
 import { createTestLogger } from "../../../test-utils/test-logger.js";
@@ -76,7 +84,7 @@ function createSession(
   configOverrides: Partial<AgentSessionConfig> = {},
   options: { goalsEnabled?: boolean; autoReviewEnabled?: boolean } = {},
 ): CodexTestSession {
-  const session = new __codexAppServerInternals.CodexAppServerAgentSession(
+  const session = new CodexAppServerAgentSession(
     createConfig(configOverrides),
     null,
     createTestLogger(),
@@ -106,6 +114,25 @@ function markdownImageSource(markdown: string): string {
   return match[1].replace(/\\\)/g, ")");
 }
 
+function emitCodexUserMessage(
+  appServer: FakeCodexAppServer,
+  input: { id: string; text: string; threadId?: string },
+): void {
+  appServer.child.stdout.write(
+    `${JSON.stringify({
+      method: "item/started",
+      params: {
+        threadId: input.threadId ?? "thread-1",
+        item: {
+          type: "userMessage",
+          id: input.id,
+          content: [{ type: "text", text: input.text }],
+        },
+      },
+    })}\n`,
+  );
+}
+
 type CapturedFakeCodexRecord = Record<string, unknown>;
 
 async function runCustomCodexProviderTurn(
@@ -380,7 +407,7 @@ describe("Codex app-server provider", () => {
       },
     };
 
-    const session = new __codexAppServerInternals.CodexAppServerAgentSession(
+    const session = new CodexAppServerAgentSession(
       createConfig({ thinkingOptionId: "medium" }),
       null,
       createTestLogger(),
@@ -411,7 +438,7 @@ describe("Codex app-server provider", () => {
       },
     };
 
-    const session = new __codexAppServerInternals.CodexAppServerAgentSession(
+    const session = new CodexAppServerAgentSession(
       createConfig({ thinkingOptionId: "medium" }),
       null,
       createTestLogger(),
@@ -437,7 +464,7 @@ describe("Codex app-server provider", () => {
     child.exitCode = null;
     child.signalCode = null;
     child.kill = vi.fn(() => true) as ChildProcessWithoutNullStreams["kill"];
-    const client = new __codexAppServerInternals.CodexAppServerClient(child, createTestLogger());
+    const client = new CodexAppServerClient(child, createTestLogger());
 
     try {
       const disposePromise = client.dispose();
@@ -459,7 +486,7 @@ describe("Codex app-server provider", () => {
       "collaborationMode/list": () => ({ data: [] }),
       "skills/list": () => ({ data: [] }),
     });
-    const session = new __codexAppServerInternals.CodexAppServerAgentSession(
+    const session = new CodexAppServerAgentSession(
       createConfig({ cwd: "/workspace/project" }),
       null,
       createTestLogger(),
@@ -507,6 +534,32 @@ describe("Codex app-server provider", () => {
     await session.close();
   });
 
+  test("rewinds the conversation to a freshly emitted Codex user message id", async () => {
+    const appServer = createFakeCodexAppServer();
+    const session = new CodexAppServerAgentSession(
+      createConfig({ cwd: "/workspace/project" }),
+      null,
+      createTestLogger(),
+      async () => appServer.child,
+    );
+
+    await session.startTurn("remember first");
+    emitCodexUserMessage(appServer, { id: "codex-first", text: "remember first" });
+    appServer.completeTurn();
+    await session.startTurn("remember second");
+    emitCodexUserMessage(appServer, { id: "codex-second", text: "remember second" });
+    appServer.completeTurn();
+
+    await session.revertConversation({ messageId: "codex-first" });
+
+    expect(appServer.recordedRollbacks).toEqual([{ threadId: "forked-thread", numTurns: 2 }]);
+    await expect(session.getRuntimeInfo()).resolves.toMatchObject({
+      sessionId: "forked-thread",
+    });
+    appServer.assertNoErrors();
+    await session.close();
+  });
+
   test("configures Codex app-server to use a custom provider base URL", async () => {
     const capturedRequests = await runCustomCodexProviderTurn(
       "codex-iisb",
@@ -557,7 +610,7 @@ describe("Codex app-server provider", () => {
       },
       "thread/resume": () => {
         threadRequests.push("thread/resume");
-        return Promise.reject(new Error("no rollout found for thread id archived-thread-id"));
+        return Promise.reject(new Error("no tool-call found for thread id archived-thread-id"));
       },
       "thread/start": () => {
         threadRequests.push("thread/start");
@@ -604,7 +657,7 @@ describe("Codex app-server provider", () => {
           (error) => {
             expect(error).toBeInstanceOf(Error);
             expect((error as Error).message).toContain(
-              "no rollout found for thread id archived-thread-id",
+              "no tool-call found for thread id archived-thread-id",
             );
             return "rejected" as const;
           },
@@ -637,9 +690,7 @@ describe("Codex app-server provider", () => {
     };
 
     try {
-      await expect(
-        __codexAppServerInternals.listCodexSkills(cwd, workspaceGitService),
-      ).resolves.toContainEqual({
+      await expect(listCodexSkills(cwd, workspaceGitService)).resolves.toContainEqual({
         name: "shipper",
         description: "Ship changes carefully.",
         argumentHint: "",
@@ -654,7 +705,7 @@ describe("Codex app-server provider", () => {
 
   test("extracts context window usage from snake_case token payloads", () => {
     expect(
-      __codexAppServerInternals.toAgentUsage({
+      toAgentUsage({
         model_context_window: 200000,
         last: {
           total_tokens: 50000,
@@ -674,7 +725,7 @@ describe("Codex app-server provider", () => {
 
   test("extracts context window usage from camelCase token payloads", () => {
     expect(
-      __codexAppServerInternals.toAgentUsage({
+      toAgentUsage({
         modelContextWindow: 200000,
         last: {
           totalTokens: 50000,
@@ -694,7 +745,7 @@ describe("Codex app-server provider", () => {
 
   test("keeps existing usage behavior when context window fields are missing", () => {
     expect(
-      __codexAppServerInternals.toAgentUsage({
+      toAgentUsage({
         last: {
           inputTokens: 30000,
           cachedInputTokens: 5000,
@@ -710,7 +761,7 @@ describe("Codex app-server provider", () => {
 
   test("excludes invalid context window values", () => {
     expect(
-      __codexAppServerInternals.toAgentUsage({
+      toAgentUsage({
         model_context_window: Number.NaN,
         modelContextWindow: "200000",
         last: {
@@ -748,7 +799,7 @@ describe("Codex app-server provider", () => {
       required: ["overall"],
     };
 
-    const normalized = __codexAppServerInternals.normalizeCodexOutputSchema(input);
+    const normalized = normalizeCodexOutputSchema(input);
 
     expect(normalized).toEqual({
       type: "object",
@@ -1013,7 +1064,7 @@ describe("Codex app-server provider", () => {
   });
 
   test("maps patch notifications with array-style changes and alias diff keys", () => {
-    const item = __codexAppServerInternals.mapCodexPatchNotificationToToolCall({
+    const item = mapCodexPatchNotificationToToolCall({
       callId: "patch-array-alias",
       changes: [
         {
@@ -1036,7 +1087,7 @@ describe("Codex app-server provider", () => {
   });
 
   test("maps Codex plan markdown to a synthetic plan tool call", () => {
-    const item = __codexAppServerInternals.mapCodexPlanToToolCall({
+    const item = mapCodexPlanToToolCall({
       callId: "plan-turn-1",
       text: "### Login Screen\n- Build layout\n- Add validation",
     });
@@ -1055,7 +1106,7 @@ describe("Codex app-server provider", () => {
   });
 
   test("maps patch notifications with object-style single change payloads", () => {
-    const item = __codexAppServerInternals.mapCodexPatchNotificationToToolCall({
+    const item = mapCodexPatchNotificationToToolCall({
       callId: "patch-object-single",
       changes: {
         path: "/tmp/repo/src/object-single.ts",
@@ -1076,7 +1127,7 @@ describe("Codex app-server provider", () => {
   });
 
   test("maps patch notifications with file_path aliases in array-style changes", () => {
-    const item = __codexAppServerInternals.mapCodexPatchNotificationToToolCall({
+    const item = mapCodexPatchNotificationToToolCall({
       callId: "patch-array-file-path",
       changes: [
         {
@@ -1105,7 +1156,7 @@ describe("Codex app-server provider", () => {
         PASEO_TEST_FLAG: "codex-launch-value",
       },
     };
-    const env = __codexAppServerInternals.buildCodexAppServerEnv(
+    const env = buildCodexAppServerEnv(
       {
         env: {
           PASEO_AGENT_ID: "runtime-value",
@@ -1499,6 +1550,7 @@ describe("Codex app-server provider", () => {
         item: {
           type: "user_message",
           text: "Check OpenCode timestamps.",
+          messageId: "user-history",
         },
       },
       {
@@ -1573,6 +1625,40 @@ describe("Codex app-server provider", () => {
     ]);
   });
 
+  test("captures live Codex user message ids from item events", () => {
+    const session = createSession();
+    const events: AgentStreamEvent[] = [];
+    session.subscribe((event) => events.push(event));
+
+    const userMessageItem = {
+      type: "userMessage",
+      id: "codex-user-live-1",
+      content: [{ type: "text", text: "Use the native Codex id." }],
+    };
+
+    asInternals(session).handleNotification("item/started", {
+      threadId: "test-thread",
+      item: userMessageItem,
+    });
+    asInternals(session).handleNotification("item/completed", {
+      threadId: "test-thread",
+      item: userMessageItem,
+    });
+
+    expect(events).toEqual([
+      {
+        type: "timeline",
+        provider: "codex",
+        turnId: "test-turn",
+        item: {
+          type: "user_message",
+          text: "Use the native Codex id.",
+          messageId: "codex-user-live-1",
+        },
+      },
+    ]);
+  });
+
   test("emits Codex context compaction markers from live thread items", () => {
     const session = createSession();
     const events: AgentStreamEvent[] = [];
@@ -1694,7 +1780,7 @@ describe("Codex app-server provider", () => {
           return { data: [] };
         }
         if (method === "thread/resume") {
-          throw new Error("no rollout found for thread id archived-thread-id");
+          throw new Error("no tool-call found for thread id archived-thread-id");
         }
         if (method === "thread/start") {
           return { thread: { id: "replacement-empty-thread-id" } };
@@ -1704,7 +1790,7 @@ describe("Codex app-server provider", () => {
     };
 
     await expect(asInternals(session).ensureThreadLoaded()).rejects.toThrow(
-      "no rollout found for thread id archived-thread-id",
+      "no tool-call found for thread id archived-thread-id",
     );
 
     expect(session.currentThreadId).toBe("archived-thread-id");

packages/server/src/server/agent/providers/codex-app-server-agent.ts

@@ -44,7 +44,7 @@ import { renderPromptAttachmentAsText } from "../prompt-attachments.js";
 import { composeSystemPromptParts } from "../system-prompt.js";
 import { curateAgentActivity } from "../activity-curator.js";
 import {
-  mapCodexRolloutToolCall,
+  mapCodexToolCallEnvelope,
   mapCodexToolCallFromThreadItem,
 } from "./codex/tool-call-mapper.js";
 import {
@@ -60,8 +60,15 @@ import { extractCodexTerminalSessionId, nonEmptyString } from "./tool-call-mappe
 import { buildCodexFeatures, codexModelSupportsFastMode } from "./codex-feature-definitions.js";
 import {
   CodexAppServerClient,
+  parseCodexThreadForkResponse,
+  parseCodexThreadRollbackResponse,
+  type CodexThreadForkParams,
+  type CodexThreadForkResponse,
+  type CodexThreadRollbackParams,
+  type CodexThreadRollbackResponse,
   type CodexAppServerTraceContext,
 } from "./codex/app-server-transport.js";
+import { type CodexUserMessageTurnIndex, revertCodexConversation } from "./codex/rewind.js";
 import {
   renderProviderImageOutputAsAssistantMarkdown,
   type ProviderImageOutput,
@@ -158,6 +165,9 @@ const CODEX_APP_SERVER_CAPABILITIES: AgentCapabilityFlags = {
   supportsMcpServers: true,
   supportsReasoningStream: true,
   supportsToolInvocations: true,
+  supportsRewindConversation: true,
+  supportsRewindFiles: false,
+  supportsRewindBoth: false,
 };
 
 const CODEX_MODES: AgentMode[] = [
@@ -183,6 +193,8 @@ const DEFAULT_CODEX_MODE_ID = "auto";
 
 interface CodexAppServerClientLike {
   request(method: string, params?: unknown): Promise<unknown>;
+  forkThread?(params: CodexThreadForkParams): Promise<CodexThreadForkResponse>;
+  rollbackThread?(params: CodexThreadRollbackParams): Promise<CodexThreadRollbackResponse>;
   notify(method: string, params?: unknown): void;
   dispose(): Promise<void>;
 }
@@ -343,7 +355,7 @@ function normalizeCodexOutputSchemaNode(schema: unknown, schemaPath: string): un
   return normalized;
 }
 
-function normalizeCodexOutputSchema(schema: unknown): Record<string, unknown> {
+export function normalizeCodexOutputSchema(schema: unknown): Record<string, unknown> {
   if (!isSchemaRecord(schema)) {
     throw new Error("Codex structured outputs require a JSON object schema.");
   }
@@ -384,7 +396,7 @@ function codexMicrosoftStorePackageRoot(): string | null {
   return path.join(localAppData, "Packages");
 }
 
-async function findCodexMicrosoftStoreBinary(): Promise<string | null> {
+export async function findCodexMicrosoftStoreBinary(): Promise<string | null> {
   if (process.platform !== "win32") {
     return null;
   }
@@ -425,7 +437,7 @@ async function findCodexMicrosoftStoreBinary(): Promise<string | null> {
   return null;
 }
 
-async function findDefaultCodexBinary(): Promise<string | null> {
+export async function findDefaultCodexBinary(): Promise<string | null> {
   return (await findExecutable("codex")) ?? (await findCodexMicrosoftStoreBinary());
 }
 
@@ -597,7 +609,7 @@ async function listCodexCustomPrompts(): Promise<AgentSlashCommand[]> {
   return commands.sort((a, b) => a.name.localeCompare(b.name));
 }
 
-async function listCodexSkills(
+export async function listCodexSkills(
   cwd: string,
   workspaceGitService?: Pick<WorkspaceGitService, "resolveRepoRoot">,
 ): Promise<AgentSlashCommand[]> {
@@ -796,7 +808,7 @@ function filterCodexThreadsByCwd(
   return threads.filter((thread) => typeof thread.cwd === "string" && matchesCwd(thread.cwd));
 }
 
-function toAgentUsage(tokenUsage: unknown): AgentUsage | undefined {
+export function toAgentUsage(tokenUsage: unknown): AgentUsage | undefined {
   const usage = toObjectRecord(tokenUsage);
   if (!usage) return undefined;
   const last = toObjectRecord(usage.last);
@@ -838,7 +850,7 @@ function normalizePlanMarkdown(text: string): string {
     .trim();
 }
 
-function planStepsToMarkdown(steps: Array<{ step: string; status: string }>): string {
+export function planStepsToMarkdown(steps: Array<{ step: string; status: string }>): string {
   const lines = steps
     .map((entry) => entry.step.trim())
     .filter((step) => step.length > 0)
@@ -851,7 +863,7 @@ function planStepsToMarkdown(steps: Array<{ step: string; status: string }>): st
   return normalizePlanMarkdown(lines.join("\n"));
 }
 
-function mapCodexPlanToToolCall(params: {
+export function mapCodexPlanToToolCall(params: {
   callId: string;
   text: string;
 }): ToolCallTimelineItem | null {
@@ -935,7 +947,7 @@ interface CodexQuestionPrompt {
   isSecret?: boolean;
 }
 
-function normalizeCodexQuestionPrompts(raw: unknown): CodexQuestionPrompt[] {
+export function normalizeCodexQuestionPrompts(raw: unknown): CodexQuestionPrompt[] {
   if (!Array.isArray(raw)) {
     return [];
   }
@@ -985,7 +997,7 @@ function normalizeCodexQuestionPrompts(raw: unknown): CodexQuestionPrompt[] {
   return questions;
 }
 
-function formatCodexQuestionPrompts(questions: CodexQuestionPrompt[]): string {
+export function formatCodexQuestionPrompts(questions: CodexQuestionPrompt[]): string {
   return questions
     .map((question) => {
       const lines = [`${question.header}: ${question.question}`];
@@ -998,7 +1010,7 @@ function formatCodexQuestionPrompts(questions: CodexQuestionPrompt[]): string {
     .trim();
 }
 
-function mapCodexQuestionRequestToToolCall(params: {
+export function mapCodexQuestionRequestToToolCall(params: {
   callId: string;
   questions: CodexQuestionPrompt[];
   status: ToolCallTimelineItem["status"];
@@ -1360,7 +1372,7 @@ function mapCodexExecNotificationToToolCall(params: {
           ? { exitCode: params.exitCode }
           : {}),
       };
-  const mapped = mapCodexRolloutToolCall({
+  const mapped = mapCodexToolCallEnvelope({
     callId: params.callId ?? null,
     name: "shell",
     input: {
@@ -1377,7 +1389,7 @@ function mapCodexExecNotificationToToolCall(params: {
   return params.running ? toRunningToolCall(mapped) : mapped;
 }
 
-function mapCodexPatchNotificationToToolCall(params: {
+export function mapCodexPatchNotificationToToolCall(params: {
   callId?: string | null;
   changes: unknown;
   cwd?: string | null;
@@ -1393,7 +1405,7 @@ function mapCodexPatchNotificationToToolCall(params: {
     .find((value): value is string => typeof value === "string" && value.length > 0);
   const patchText = firstPatchText;
   const patchFields = codexPatchTextFields(patchText);
-  const mapped = mapCodexRolloutToolCall({
+  const mapped = mapCodexToolCallEnvelope({
     callId: params.callId ?? null,
     name: "apply_patch",
     input: firstPath
@@ -1490,7 +1502,12 @@ function mapCodexThreadUserMessageItem(
     return null;
   }
   const text = extractUserText(normalizedItem.content) ?? "";
-  return { type: "user_message", text };
+  const messageId = nonEmptyString(normalizedItem.id);
+  return {
+    type: "user_message",
+    text,
+    ...(messageId ? { messageId } : {}),
+  };
 }
 
 function firstStringField(
@@ -1605,7 +1622,7 @@ function mapCodexThreadImageItem(
   );
 }
 
-function threadItemToTimeline(
+export function threadItemToTimeline(
   item: unknown,
   options?: { includeUserMessage?: boolean; cwd?: string | null },
 ): AgentTimelineItem | null {
@@ -1713,6 +1730,26 @@ function readCodexThread(client: CodexAppServerClientLike, threadId: string): Pr
   });
 }
 
+export async function forkCodexThread(
+  client: CodexAppServerClientLike,
+  params: CodexThreadForkParams,
+): Promise<CodexThreadForkResponse> {
+  if (client.forkThread) {
+    return client.forkThread(params);
+  }
+  return parseCodexThreadForkResponse(await client.request("thread/fork", params));
+}
+
+export async function rollbackCodexThread(
+  client: CodexAppServerClientLike,
+  params: CodexThreadRollbackParams,
+): Promise<CodexThreadRollbackResponse> {
+  if (client.rollbackThread) {
+    return client.rollbackThread(params);
+  }
+  return parseCodexThreadRollbackResponse(await client.request("thread/rollback", params));
+}
+
 function toSandboxPolicy(type: string, networkAccess?: boolean): Record<string, unknown> {
   switch (type) {
     case "read-only":
@@ -1999,6 +2036,18 @@ const CodexEventTurnDiffNotificationSchema = z
   })
   .passthrough();
 
+const CodexEventThreadRolledBackNotificationSchema = z
+  .object({
+    msg: z
+      .object({
+        type: z.literal("thread_rolled_back"),
+        num_turns: z.number().int().nonnegative().optional(),
+        numTurns: z.number().int().nonnegative().optional(),
+      })
+      .passthrough(),
+  })
+  .passthrough();
+
 type ParsedCodexNotification =
   | { kind: "thread_started"; threadId: string }
   | { kind: "turn_started"; turnId: string; threadId: string | null }
@@ -2072,10 +2121,33 @@ type ParsedCodexNotification =
       itemId: string;
       delta: string | null;
     }
+  | { kind: "thread_rolled_back"; numTurns: number }
   | { kind: "context_compacted"; threadId: string; turnId: string | null }
   | { kind: "invalid_payload"; method: string; params: unknown }
   | { kind: "unknown_method"; method: string; params: unknown };
 
+type CodexDeltaNotification = Extract<
+  ParsedCodexNotification,
+  {
+    kind:
+      | "agent_message_delta"
+      | "reasoning_delta"
+      | "exec_command_output_delta"
+      | "file_change_output_delta";
+  }
+>;
+
+function isCodexDeltaNotification(
+  parsed: ParsedCodexNotification,
+): parsed is CodexDeltaNotification {
+  return (
+    parsed.kind === "agent_message_delta" ||
+    parsed.kind === "reasoning_delta" ||
+    parsed.kind === "exec_command_output_delta" ||
+    parsed.kind === "file_change_output_delta"
+  );
+}
+
 const CodexNotificationSchema = z.union([
   z
     .object({ method: z.literal("thread/started"), params: ThreadStartedNotificationSchema })
@@ -2548,6 +2620,24 @@ const CodexNotificationSchema = z.union([
       params,
     }),
   ),
+  z
+    .object({
+      method: z.literal("codex/event/thread_rolled_back"),
+      params: CodexEventThreadRolledBackNotificationSchema,
+    })
+    .transform(
+      ({ params }): ParsedCodexNotification => ({
+        kind: "thread_rolled_back",
+        numTurns: params.msg.num_turns ?? params.msg.numTurns ?? 0,
+      }),
+    ),
+  z.object({ method: z.literal("codex/event/thread_rolled_back"), params: z.unknown() }).transform(
+    ({ method, params }): ParsedCodexNotification => ({
+      kind: "invalid_payload",
+      method,
+      params,
+    }),
+  ),
   z
     .object({ method: z.string(), params: z.unknown() })
     .transform(
@@ -2685,7 +2775,7 @@ function toCodexTextInput(text: string): Extract<CodexAppServerUserInput, { type
   };
 }
 
-function buildCodexAppServerEnv(
+export function buildCodexAppServerEnv(
   runtimeSettings?: ProviderRuntimeSettings,
   launchEnv?: Record<string, string>,
 ): NodeJS.ProcessEnv {
@@ -2762,7 +2852,7 @@ interface CodexSubAgentCallState {
   childItems: Map<string, AgentTimelineItem>;
 }
 
-class CodexAppServerAgentSession implements AgentSession {
+export class CodexAppServerAgentSession implements AgentSession {
   readonly provider = CODEX_PROVIDER;
   readonly capabilities = CODEX_APP_SERVER_CAPABILITIES;
 
@@ -2810,6 +2900,8 @@ class CodexAppServerAgentSession implements AgentSession {
   private warnedIncompleteEditToolCallIds = new Set<string>();
   private latestUsage: AgentUsage | undefined;
   private latestPlanResult: { callId: string; text: string; turnId: string | null } | null = null;
+  private readonly userMessageTurnIndexes = new Map<string, number>();
+  private readonly userMessageTurnIds: string[] = [];
   private pendingManualCompactionStarts = 0;
   private compactionTriggerByItemId = new Map<string, "auto" | "manual">();
   // Codex can report one completed compaction through both channels:
@@ -3135,20 +3227,22 @@ class CodexAppServerAgentSession implements AgentSession {
     const client = this.client;
     const threadId = this.currentThreadId;
 
-    try {
-      const timeline = await loadCodexThreadHistoryTimeline({
-        threadId,
-        cwd: this.config.cwd ?? null,
-        requestThread: (threadIdToRead) => {
-          return readCodexThread(client, threadIdToRead);
-        },
-      });
-      if (timeline.length > 0) {
-        this.persistedHistory = timeline;
-        this.historyPending = true;
+    const timeline = await loadCodexThreadHistoryTimeline({
+      threadId,
+      cwd: this.config.cwd ?? null,
+      requestThread: (threadIdToRead) => {
+        return readCodexThread(client, threadIdToRead);
+      },
+    });
+    this.resetCodexUserMessageTurns();
+    for (const entry of timeline) {
+      if (entry.item.type === "user_message") {
+        this.rememberCodexUserMessageTurn(entry.item.messageId);
       }
-    } catch (error) {
-      this.logger.warn({ error }, "Failed to load Codex thread history");
+    }
+    if (timeline.length > 0) {
+      this.persistedHistory = timeline;
+      this.historyPending = true;
     }
   }
 
@@ -3431,6 +3525,41 @@ class CodexAppServerAgentSession implements AgentSession {
     return { turnId };
   }
 
+  private rememberCodexUserMessageTurn(messageId: string | null | undefined): boolean {
+    if (typeof messageId !== "string" || messageId.length === 0) {
+      return false;
+    }
+    if (this.userMessageTurnIndexes.has(messageId)) {
+      return false;
+    }
+    this.userMessageTurnIndexes.set(messageId, this.userMessageTurnIds.length);
+    this.userMessageTurnIds.push(messageId);
+    return true;
+  }
+
+  private resetCodexUserMessageTurns(): void {
+    this.userMessageTurnIndexes.clear();
+    this.userMessageTurnIds.length = 0;
+  }
+
+  private truncateCodexUserMessageTurns(numTurns: number): void {
+    if (numTurns <= 0) {
+      return;
+    }
+    this.userMessageTurnIds.length = Math.max(0, this.userMessageTurnIds.length - numTurns);
+    this.userMessageTurnIndexes.clear();
+    this.userMessageTurnIds.forEach((messageId, index) => {
+      this.userMessageTurnIndexes.set(messageId, index);
+    });
+  }
+
+  private codexUserMessageTurns(): CodexUserMessageTurnIndex {
+    return {
+      resolve: (messageId) => this.userMessageTurnIndexes.get(messageId) ?? null,
+      count: () => this.userMessageTurnIds.length,
+    };
+  }
+
   subscribe(callback: (event: AgentStreamEvent) => void): () => void {
     this.subscribers.add(callback);
     return () => {
@@ -3714,6 +3843,35 @@ class CodexAppServerAgentSession implements AgentSession {
     };
   }
 
+  async revertConversation(input: { messageId: string }): Promise<void> {
+    await this.connect();
+    if (!this.client) {
+      throw new Error("Codex client is not initialized");
+    }
+    if (this.currentThreadId) {
+      await this.ensureThreadLoaded();
+    } else {
+      await this.ensureThread();
+    }
+
+    await revertCodexConversation({
+      client: this.client,
+      threadId: this.currentThreadId,
+      messageId: input.messageId,
+      cwd: this.config.cwd ?? null,
+      model: this.config.model ?? null,
+      serviceTier: this.serviceTier,
+      userMessageTurns: this.codexUserMessageTurns(),
+      setThreadId: async (threadId) => {
+        this.currentThreadId = threadId;
+        this.cachedRuntimeInfo = null;
+        this.persistedHistory = [];
+        this.historyPending = false;
+        await this.loadPersistedHistory();
+      },
+    });
+  }
+
   async interrupt(): Promise<void> {
     if (!this.client || !this.currentThreadId || !this.currentTurnId) return;
     try {
@@ -4059,6 +4217,13 @@ class CodexAppServerAgentSession implements AgentSession {
   private handleNotification(method: string, params: unknown): void {
     const parsed = CodexNotificationSchema.parse({ method, params });
     this.traceParsedNotification(method, params, parsed);
+    if (isCodexDeltaNotification(parsed)) {
+      this.handleCodexDeltaNotification(parsed);
+      return;
+    }
+    if (this.handleThreadStateNotification(parsed)) {
+      return;
+    }
     switch (parsed.kind) {
       case "thread_started":
         this.handleThreadStartedNotification(parsed);
@@ -4080,15 +4245,6 @@ class CodexAppServerAgentSession implements AgentSession {
       case "token_usage_updated":
         this.handleTokenUsageUpdatedNotification(parsed);
         return;
-      case "context_compacted":
-        this.handleContextCompactedNotification(parsed);
-        return;
-      case "agent_message_delta":
-      case "reasoning_delta":
-      case "exec_command_output_delta":
-      case "file_change_output_delta":
-        this.handleCodexDeltaNotification(parsed);
-        return;
       case "exec_command_started":
         this.handleExecCommandStartedNotification(parsed);
         return;
@@ -4113,8 +4269,24 @@ class CodexAppServerAgentSession implements AgentSession {
       case "invalid_payload":
         this.warnInvalidNotificationPayload(parsed.method, parsed.params);
         return;
-      default:
+      case "unknown_method":
         this.warnUnknownNotificationMethod(parsed.method, parsed.params);
+        return;
+      default:
+        return;
+    }
+  }
+
+  private handleThreadStateNotification(parsed: ParsedCodexNotification): boolean {
+    switch (parsed.kind) {
+      case "context_compacted":
+        this.handleContextCompactedNotification(parsed);
+        return true;
+      case "thread_rolled_back":
+        this.handleThreadRolledBackNotification(parsed);
+        return true;
+      default:
+        return false;
     }
   }
 
@@ -4264,18 +4436,7 @@ class CodexAppServerAgentSession implements AgentSession {
     return Boolean(itemId && this.emittedItemCompletedIds.has(itemId));
   }
 
-  private handleCodexDeltaNotification(
-    parsed: Extract<
-      ParsedCodexNotification,
-      {
-        kind:
-          | "agent_message_delta"
-          | "reasoning_delta"
-          | "exec_command_output_delta"
-          | "file_change_output_delta";
-      }
-    >,
-  ): void {
+  private handleCodexDeltaNotification(parsed: CodexDeltaNotification): void {
     if (parsed.kind === "agent_message_delta") {
       const prev = this.pendingAgentMessages.get(parsed.itemId) ?? "";
       const text = prev + parsed.delta;
@@ -4490,6 +4651,19 @@ class CodexAppServerAgentSession implements AgentSession {
     );
   }
 
+  private isUserMessageItem(item: { type?: string; [key: string]: unknown }): boolean {
+    return (
+      normalizeCodexThreadItemType(typeof item.type === "string" ? item.type : undefined) ===
+      "userMessage"
+    );
+  }
+
+  private handleThreadRolledBackNotification(
+    parsed: Extract<ParsedCodexNotification, { kind: "thread_rolled_back" }>,
+  ): void {
+    this.truncateCodexUserMessageTurns(parsed.numTurns);
+  }
+
   private handleContextCompactedNotification(
     parsed: Extract<ParsedCodexNotification, { kind: "context_compacted" }>,
   ): void {
@@ -4626,6 +4800,10 @@ class CodexAppServerAgentSession implements AgentSession {
     if (parsed.source === "codex_event") {
       return;
     }
+    if (this.isUserMessageItem(parsed.item)) {
+      this.handleUserMessageItem(parsed);
+      return;
+    }
     if (this.isContextCompactionItem(parsed.item)) {
       if (this.unpairedCompactionNotificationCompletions > 0) {
         this.unpairedCompactionNotificationCompletions -= 1;
@@ -4769,6 +4947,10 @@ class CodexAppServerAgentSession implements AgentSession {
     if (parsed.source === "codex_event") {
       return;
     }
+    if (this.isUserMessageItem(parsed.item)) {
+      this.handleUserMessageItem(parsed);
+      return;
+    }
     if (this.isContextCompactionItem(parsed.item)) {
       this.emitEvent({
         type: "timeline",
@@ -4815,6 +4997,31 @@ class CodexAppServerAgentSession implements AgentSession {
     }
   }
 
+  private handleUserMessageItem(
+    parsed: Extract<ParsedCodexNotification, { kind: "item_started" | "item_completed" }>,
+  ): void {
+    const itemId = parsed.item.id;
+    const timelineItem = threadItemToTimeline(parsed.item, {
+      includeUserMessage: true,
+      cwd: this.config.cwd ?? null,
+    });
+    if (!timelineItem || timelineItem.type !== "user_message") {
+      return;
+    }
+    const childSubAgentCallId = this.getSubAgentCallIdForThread(parsed.threadId);
+    if (childSubAgentCallId) {
+      if (itemId) {
+        this.upsertSubAgentChildItem(childSubAgentCallId, itemId, timelineItem);
+      }
+      this.emitSubAgentActivityUpdate(childSubAgentCallId, "running");
+      return;
+    }
+    if (!this.rememberCodexUserMessageTurn(timelineItem.messageId)) {
+      return;
+    }
+    this.emitEvent({ type: "timeline", provider: CODEX_PROVIDER, item: timelineItem });
+  }
+
   private warnUnknownNotificationMethod(method: string, params: unknown): void {
     if (this.warnedUnknownNotificationMethods.has(method)) {
       return;
@@ -5510,22 +5717,3 @@ function resolveSkillDescription(skill: Record<string, unknown>): string {
   }
   return "Skill";
 }
-
-export const __codexAppServerInternals = {
-  buildCodexAppServerEnv,
-  CodexAppServerClient,
-  codexModelSupportsFastMode,
-  CodexAppServerAgentSession,
-  findCodexMicrosoftStoreBinary,
-  findDefaultCodexBinary,
-  formatCodexQuestionPrompts,
-  mapCodexQuestionRequestToToolCall,
-  mapCodexPatchNotificationToToolCall,
-  planStepsToMarkdown,
-  mapCodexPlanToToolCall,
-  listCodexSkills,
-  normalizeCodexOutputSchema,
-  normalizeCodexQuestionPrompts,
-  toAgentUsage,
-  threadItemToTimeline,
-};

packages/server/src/server/agent/providers/codex-rollout-parsing.test.ts

@@ -1,547 +0,0 @@
-import { describe, test, expect, beforeEach, afterEach } from "vitest";
-import { rmSync, mkdtempSync, writeFileSync } from "node:fs";
-import { tmpdir } from "node:os";
-import { join } from "node:path";
-import { parseRolloutFile } from "./codex-rollout-timeline.js";
-
-let tmpDir: string;
-
-beforeEach(() => {
-  tmpDir = mkdtempSync(join(tmpdir(), "rollout-test-"));
-});
-
-afterEach(() => {
-  rmSync(tmpDir, { recursive: true, force: true });
-});
-
-describe("exec_command parsing", () => {
-  test("parses exec_command as Bash tool call with command", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:09:01.348Z",
-        type: "response_item",
-        payload: {
-          type: "function_call",
-          name: "exec_command",
-          arguments: '{"cmd":"task show cc4ea7d1"}',
-          call_id: "call_MhTWDF2mpM4dhbNmHNt6ikDF",
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-
-    const toolCalls = timeline.filter((i) => i.type === "tool_call");
-    expect(toolCalls.length).toBe(1);
-    expect(toolCalls[0]).toMatchObject({
-      type: "tool_call",
-      name: "Bash",
-      callId: "call_MhTWDF2mpM4dhbNmHNt6ikDF",
-      detail: { type: "shell", command: "task show cc4ea7d1" },
-    });
-  });
-
-  test("includes function_call_output as tool call output", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:09:01.348Z",
-        type: "response_item",
-        payload: {
-          type: "function_call",
-          name: "exec_command",
-          arguments: '{"cmd":"echo hello"}',
-          call_id: "call_abc123",
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:09:01.785Z",
-        type: "response_item",
-        payload: {
-          type: "function_call_output",
-          call_id: "call_abc123",
-          output:
-            "Chunk ID: 13d232\nWall time: 0.2667 seconds\nProcess exited with code 0\nOriginal token count: 10\nOutput:\nhello",
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-
-    const toolCalls = timeline.filter((i) => i.type === "tool_call");
-    expect(toolCalls.length).toBe(1);
-    expect(toolCalls[0]).toMatchObject({
-      type: "tool_call",
-      name: "Bash",
-      callId: "call_abc123",
-      detail: {
-        type: "shell",
-        command: "echo hello",
-        output: "hello",
-      },
-    });
-  });
-
-  test("maps write_stdin polling calls into terminal interaction tool calls", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:09:01.348Z",
-        type: "response_item",
-        payload: {
-          type: "function_call",
-          name: "exec_command",
-          arguments: '{"cmd":"npm test"}',
-          call_id: "call_real",
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:09:01.785Z",
-        type: "response_item",
-        payload: {
-          type: "function_call_output",
-          call_id: "call_real",
-          output:
-            "Chunk ID: 13d232\nWall time: 0.2667 seconds\nProcess exited with code 0\nOriginal token count: 10\nOutput:\nProcess running with session ID 7144",
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:28:16.497Z",
-        type: "response_item",
-        payload: {
-          type: "function_call",
-          name: "write_stdin",
-          arguments: '{"session_id":7144,"chars":"","yield_time_ms":1000,"max_output_tokens":6000}',
-          call_id: "call_polling",
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-
-    const toolCalls = timeline.filter((i) => i.type === "tool_call");
-    expect(toolCalls.length).toBe(2);
-    expect(toolCalls[0]).toMatchObject({
-      type: "tool_call",
-      name: "Bash",
-    });
-    expect(toolCalls[1]).toMatchObject({
-      type: "tool_call",
-      name: "terminal",
-      callId: "terminal-session-7144",
-      detail: {
-        type: "plain_text",
-        icon: "square_terminal",
-      },
-      metadata: {
-        processId: "7144",
-      },
-    });
-  });
-
-  test("falls back to generic terminal interaction label when command cannot be resolved", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:28:16.497Z",
-        type: "response_item",
-        payload: {
-          type: "function_call",
-          name: "write_stdin",
-          arguments: '{"session_id":7144,"chars":"","yield_time_ms":1000,"max_output_tokens":6000}',
-          call_id: "call_polling",
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-    const toolCalls = timeline.filter((i) => i.type === "tool_call");
-    expect(toolCalls).toHaveLength(1);
-    expect(toolCalls[0]).toMatchObject({
-      type: "tool_call",
-      name: "terminal",
-      callId: "terminal-session-7144",
-      detail: {
-        type: "plain_text",
-        icon: "square_terminal",
-      },
-    });
-  });
-});
-
-describe("older shell format", () => {
-  test("parses shell command as Bash tool call", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2025-11-03T14:37:50.400Z",
-        type: "response_item",
-        payload: {
-          type: "function_call",
-          name: "shell",
-          arguments: '{"command":["bash","-lc","ls -la"],"workdir":"/Users/test/project"}',
-          call_id: "call_shell123",
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-
-    const toolCalls = timeline.filter((i) => i.type === "tool_call");
-    expect(toolCalls.length).toBe(1);
-    expect(toolCalls[0]).toMatchObject({
-      type: "tool_call",
-      name: "Bash",
-      callId: "call_shell123",
-      detail: { type: "shell", command: "ls -la" },
-    });
-  });
-});
-
-describe("real rollout file structure", () => {
-  test("parses user message correctly", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.378Z",
-        type: "response_item",
-        payload: {
-          type: "message",
-          role: "user",
-          content: [{ type: "input_text", text: "Fix the bug in auth.ts" }],
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-
-    expect(timeline).toContainEqual({
-      type: "user_message",
-      text: "Fix the bug in auth.ts",
-    });
-  });
-
-  test("parses assistant message correctly", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.378Z",
-        type: "response_item",
-        payload: {
-          type: "message",
-          role: "assistant",
-          content: [{ type: "output_text", text: "I'll fix that for you." }],
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-
-    expect(timeline).toContainEqual({
-      type: "assistant_message",
-      text: "I'll fix that for you.",
-    });
-  });
-
-  test("parses reasoning correctly", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.378Z",
-        type: "response_item",
-        payload: {
-          type: "reasoning",
-          content: [{ type: "reasoning_text", text: "Let me think about this." }],
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-
-    expect(timeline).toContainEqual({
-      type: "reasoning",
-      text: "Let me think about this.",
-    });
-  });
-
-  test("parses legacy response_item shape using item", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.378Z",
-        type: "response_item",
-        item: {
-          type: "function_call",
-          name: "exec_command",
-          arguments: '{"cmd":"echo hello"}',
-          call_id: "call_legacy_1",
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:09:01.785Z",
-        type: "response_item",
-        item: {
-          type: "function_call_output",
-          call_id: "call_legacy_1",
-          output: "hello",
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-    const toolCalls = timeline.filter((i) => i.type === "tool_call");
-    expect(toolCalls.length).toBe(1);
-    expect(toolCalls[0]).toMatchObject({
-      type: "tool_call",
-      name: "Bash",
-      callId: "call_legacy_1",
-      detail: { type: "shell", command: "echo hello", output: "hello" },
-    });
-  });
-
-  test("parses custom_tool_call apply_patch with input/output into editable tool detail", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const patch = [
-      "*** Begin Patch",
-      "*** Add File: src/new-file.ts",
-      "+export const value = 1;",
-      "*** End Patch",
-    ].join("\n");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-02-09T10:00:00.000Z",
-        type: "response_item",
-        payload: {
-          type: "custom_tool_call",
-          name: "apply_patch",
-          call_id: "call_patch_custom_1",
-          input: patch,
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-02-09T10:00:01.000Z",
-        type: "response_item",
-        payload: {
-          type: "custom_tool_call_output",
-          call_id: "call_patch_custom_1",
-          output:
-            '{"output":"Success. Updated the following files:\\nA src/new-file.ts\\n","metadata":{"exit_code":0}}',
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-    const toolCalls = timeline.filter((i) => i.type === "tool_call");
-    expect(toolCalls.length).toBe(1);
-
-    const patchCall = toolCalls[0];
-    expect(patchCall).toMatchObject({
-      type: "tool_call",
-      name: "apply_patch",
-      callId: "call_patch_custom_1",
-      status: "completed",
-    });
-    expect(patchCall.detail.type).toBe("edit");
-    if (patchCall.detail.type === "edit") {
-      expect(patchCall.detail.filePath).toBe("src/new-file.ts");
-      expect(patchCall.detail.unifiedDiff).toContain("diff --git");
-      expect(patchCall.detail.unifiedDiff).toContain("+export const value = 1;");
-      expect(patchCall.detail.unifiedDiff).not.toContain("*** Begin Patch");
-    }
-  });
-
-  test("parses legacy event_msg shape using msg", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.378Z",
-        type: "event_msg",
-        msg: {
-          type: "agent_reasoning",
-          text: "thinking",
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.378Z",
-        type: "event_msg",
-        msg: {
-          type: "agent_message",
-          message: { role: "assistant", message: "done" },
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.378Z",
-        type: "event_msg",
-        msg: {
-          type: "user_message",
-          message: { role: "user", message: "question" },
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-    expect(timeline).toContainEqual({ type: "reasoning", text: "thinking" });
-    expect(timeline).toContainEqual({ type: "assistant_message", text: "done" });
-    expect(timeline).toContainEqual({ type: "user_message", text: "question" });
-  });
-
-  test("deduplicates mirrored response_item and event_msg text records", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.000Z",
-        type: "response_item",
-        payload: {
-          type: "message",
-          role: "user",
-          content: [{ type: "input_text", text: "question" }],
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.001Z",
-        type: "event_msg",
-        payload: {
-          type: "user_message",
-          message: "question",
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.010Z",
-        type: "response_item",
-        payload: {
-          type: "reasoning",
-          content: [{ type: "reasoning_text", text: "thinking" }],
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.011Z",
-        type: "event_msg",
-        payload: {
-          type: "agent_reasoning",
-          text: "thinking",
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.020Z",
-        type: "response_item",
-        payload: {
-          type: "message",
-          role: "assistant",
-          content: [{ type: "output_text", text: "answer" }],
-        },
-      }),
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.021Z",
-        type: "event_msg",
-        payload: {
-          type: "agent_message",
-          message: "answer",
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-    expect(timeline).toEqual([
-      { type: "user_message", text: "question" },
-      { type: "reasoning", text: "thinking" },
-      { type: "assistant_message", text: "answer" },
-    ]);
-  });
-});
-
-describe("complex conversation", () => {
-  test("parses a full conversation with commands and outputs", async () => {
-    const rolloutPath = join(tmpDir, "rollout.jsonl");
-    const lines = [
-      // User message
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:54.378Z",
-        type: "response_item",
-        payload: {
-          type: "message",
-          role: "user",
-          content: [{ type: "input_text", text: "Run npm test" }],
-        },
-      }),
-      // Reasoning
-      JSON.stringify({
-        timestamp: "2026-01-22T07:08:55.000Z",
-        type: "response_item",
-        payload: {
-          type: "reasoning",
-          content: [{ type: "reasoning_text", text: "I need to run the tests." }],
-        },
-      }),
-      // Command
-      JSON.stringify({
-        timestamp: "2026-01-22T07:09:01.348Z",
-        type: "response_item",
-        payload: {
-          type: "function_call",
-          name: "exec_command",
-          arguments: '{"cmd":"npm test"}',
-          call_id: "call_test",
-        },
-      }),
-      // Command output
-      JSON.stringify({
-        timestamp: "2026-01-22T07:09:05.000Z",
-        type: "response_item",
-        payload: {
-          type: "function_call_output",
-          call_id: "call_test",
-          output:
-            "Chunk ID: abc\nWall time: 3.5 seconds\nProcess exited with code 0\nOutput:\nAll tests passed!",
-        },
-      }),
-      // Assistant response
-      JSON.stringify({
-        timestamp: "2026-01-22T07:09:06.000Z",
-        type: "response_item",
-        payload: {
-          type: "message",
-          role: "assistant",
-          content: [{ type: "output_text", text: "All tests passed!" }],
-        },
-      }),
-    ];
-    writeFileSync(rolloutPath, lines.join("\n") + "\n");
-
-    const timeline = await parseRolloutFile(rolloutPath);
-
-    // Should have: user_message, reasoning, tool_call (with output), assistant_message
-    expect(timeline.length).toBe(4);
-
-    expect(timeline[0]).toMatchObject({ type: "user_message", text: "Run npm test" });
-    expect(timeline[1]).toMatchObject({
-      type: "reasoning",
-      text: "I need to run the tests.",
-    });
-    expect(timeline[2]).toMatchObject({
-      type: "tool_call",
-      name: "Bash",
-      detail: {
-        type: "shell",
-        command: "npm test",
-        output: "All tests passed!",
-      },
-    });
-    expect(timeline[3]).toMatchObject({
-      type: "assistant_message",
-      text: "All tests passed!",
-    });
-  });
-});

packages/server/src/server/agent/providers/codex-rollout-timeline.ts

@@ -1,641 +0,0 @@
-import { promises as fs, type Dirent } from "node:fs";
-import os from "node:os";
-import path from "node:path";
-
-import { z } from "zod";
-import type { Logger } from "pino";
-
-import type { AgentTimelineItem } from "../agent-sdk-types.js";
-import { mapCodexRolloutToolCall } from "./codex/tool-call-mapper.js";
-import { extractCodexTerminalSessionId, nonEmptyString } from "./tool-call-mapper-utils.js";
-
-const MAX_ROLLOUT_SEARCH_DEPTH = 4;
-
-function resolveCodexSessionRoot(): string | null {
-  if (process.env.CODEX_SESSION_DIR) {
-    return process.env.CODEX_SESSION_DIR;
-  }
-  const codexHome = process.env.CODEX_HOME ?? path.join(os.homedir(), ".codex");
-  return path.join(codexHome, "sessions");
-}
-
-async function findRolloutFile(threadId: string, root: string): Promise<string | null> {
-  let currentLevel: { dir: string; depth: number }[] = [{ dir: root, depth: 0 }];
-  while (currentLevel.length > 0) {
-    const readings = await Promise.all(
-      currentLevel.map(async ({ dir, depth }) => {
-        let entries: Dirent[];
-        try {
-          entries = await fs.readdir(dir, { withFileTypes: true });
-        } catch {
-          return { match: null as string | null, next: [] as { dir: string; depth: number }[] };
-        }
-        let match: string | null = null;
-        const next: { dir: string; depth: number }[] = [];
-        for (const entry of entries) {
-          const entryPath = path.join(dir, entry.name);
-          if (entry.isFile()) {
-            const matchesThread = entry.name.includes(threadId);
-            const matchesPrefix = entry.name.startsWith("rollout-");
-            const matchesExtension = entry.name.endsWith(".json") || entry.name.endsWith(".jsonl");
-            if (matchesThread && matchesPrefix && matchesExtension && match === null) {
-              match = entryPath;
-            }
-          } else if (entry.isDirectory() && depth < MAX_ROLLOUT_SEARCH_DEPTH) {
-            next.push({ dir: entryPath, depth: depth + 1 });
-          }
-        }
-        return { match, next };
-      }),
-    );
-    const firstMatch = readings.find((reading) => reading.match !== null);
-    if (firstMatch?.match) {
-      return firstMatch.match;
-    }
-    currentLevel = readings.flatMap((reading) => reading.next);
-  }
-  return null;
-}
-
-const RolloutContentItemSchema = z.union([
-  z.object({ type: z.literal("input_text"), text: z.string() }),
-  z.object({ type: z.literal("output_text"), text: z.string() }),
-  z.object({ type: z.literal("reasoning_text"), text: z.string() }),
-  z.object({ type: z.literal("text"), text: z.string() }),
-  z
-    .object({
-      type: z.string(),
-      text: z.string().optional(),
-      message: z.string().optional(),
-    })
-    .passthrough(),
-]);
-
-const RolloutContentArraySchema = z.array(RolloutContentItemSchema);
-
-function extractContentTextByType(content: unknown, itemType: string): string {
-  const parsed = RolloutContentArraySchema.safeParse(content);
-  if (!parsed.success) {
-    return "";
-  }
-  return parsed.data
-    .filter((item) => item.type === itemType)
-    .map((item) => item.text)
-    .join("\n")
-    .trim();
-}
-
-const RolloutResponseMessagePayloadSchema = z.object({
-  type: z.literal("message"),
-  role: z.enum(["user", "assistant"]).optional(),
-  content: z.unknown().optional(),
-});
-
-const RolloutResponseReasoningPayloadSchema = z.object({
-  type: z.literal("reasoning"),
-  content: z.unknown().optional(),
-  summary: z.array(z.object({ text: z.string().optional() })).optional(),
-  text: z.string().optional(),
-});
-
-const RolloutResponseFunctionCallPayloadSchema = z.object({
-  type: z.literal("function_call"),
-  name: z.string().optional(),
-  call_id: z.string().optional(),
-  arguments: z.unknown().optional(),
-});
-
-const RolloutResponseCustomToolCallPayloadSchema = z
-  .object({
-    type: z.literal("custom_tool_call"),
-    name: z.string().optional(),
-    call_id: z.string().optional(),
-    arguments: z.unknown().optional(),
-    input: z.unknown().optional(),
-  })
-  .passthrough();
-
-const RolloutResponseFunctionCallOutputPayloadSchema = z
-  .object({
-    type: z.literal("function_call_output"),
-    call_id: z.string().optional(),
-    output: z.unknown().optional(),
-  })
-  .passthrough();
-
-const RolloutResponseCustomToolCallOutputPayloadSchema = z
-  .object({
-    type: z.literal("custom_tool_call_output"),
-    call_id: z.string().optional(),
-    output: z.unknown().optional(),
-  })
-  .passthrough();
-
-const RolloutEventAgentReasoningPayloadSchema = z.object({
-  type: z.literal("agent_reasoning"),
-  text: z.string().optional(),
-});
-
-const RolloutEventAgentMessagePayloadSchema = z.object({
-  type: z.literal("agent_message"),
-  message: z
-    .union([
-      z.string(),
-      z
-        .object({
-          role: z.string().optional(),
-          message: z.string().optional(),
-          text: z.string().optional(),
-        })
-        .passthrough(),
-    ])
-    .optional(),
-});
-
-const RolloutEventUserMessagePayloadSchema = z.object({
-  type: z.literal("user_message"),
-  message: z
-    .union([
-      z.string(),
-      z
-        .object({
-          role: z.string().optional(),
-          message: z.string().optional(),
-          text: z.string().optional(),
-        })
-        .passthrough(),
-    ])
-    .optional(),
-});
-
-type RolloutResponseReasoningPayload = z.infer<typeof RolloutResponseReasoningPayloadSchema>;
-type ParsedRolloutRecord =
-  | { kind: "timeline"; item: AgentTimelineItem }
-  | { kind: "call"; name: string; callId?: string; input?: unknown }
-  | { kind: "output"; callId: string; output: unknown }
-  | { kind: "ignore" };
-
-const RolloutMessageContentSchema = z.union([
-  z.string().transform((content) => content.trim()),
-  z
-    .array(
-      z
-        .object({
-          text: z.string().optional(),
-          message: z.string().optional(),
-        })
-        .passthrough(),
-    )
-    .transform((content) =>
-      content
-        .map((block) => block.text ?? block.message ?? "")
-        .map((text) => text.trim())
-        .filter(Boolean)
-        .join("\n")
-        .trim(),
-    ),
-]);
-
-function extractMessageText(content: unknown): string {
-  const parsed = RolloutMessageContentSchema.safeParse(content);
-  if (!parsed.success) {
-    return "";
-  }
-  return parsed.data;
-}
-
-const RolloutEventMessageTextSchema = z.union([
-  z.string(),
-  z
-    .object({
-      message: z.string().optional(),
-      text: z.string().optional(),
-    })
-    .passthrough()
-    .transform((message) => message.message ?? message.text ?? ""),
-]);
-
-function extractEventMessageText(message: unknown): string {
-  const parsed = RolloutEventMessageTextSchema.safeParse(message);
-  if (!parsed.success) {
-    return "";
-  }
-  return parsed.data;
-}
-
-function isSyntheticRolloutUserMessage(text: string): boolean {
-  const normalized = text.trim();
-  if (!normalized) {
-    return false;
-  }
-  const lower = normalized.toLowerCase();
-  if (lower.startsWith("# agents.md instructions for") && lower.includes("<instructions>")) {
-    return true;
-  }
-  if (lower.startsWith("<environment_context>")) {
-    return true;
-  }
-  return false;
-}
-
-function extractReasoningText(payload: RolloutResponseReasoningPayload): string {
-  if (Array.isArray(payload.summary)) {
-    const text = payload.summary
-      .map((item) => item.text ?? "")
-      .filter(Boolean)
-      .join("\n")
-      .trim();
-    if (text) {
-      return text;
-    }
-  }
-  const contentText = extractContentTextByType(payload.content, "reasoning_text");
-  if (contentText) {
-    return contentText;
-  }
-  if (typeof payload.text === "string") {
-    return payload.text;
-  }
-  return "";
-}
-
-function parseJsonLikeString(value: string): unknown {
-  try {
-    return JSON.parse(value);
-  } catch {
-    return value;
-  }
-}
-
-function parseJsonLikeValue(value: unknown): unknown {
-  if (typeof value === "string") {
-    return parseJsonLikeString(value);
-  }
-  return value;
-}
-
-function readTerminalSessionId(value: unknown): string | undefined {
-  if (typeof value === "number" && Number.isFinite(value)) {
-    return String(value);
-  }
-  if (typeof value === "string") {
-    return nonEmptyString(value.trim());
-  }
-  return undefined;
-}
-
-function mapCodexTerminalInteractionToToolCall(params: {
-  processId?: string | undefined;
-  fallbackCallId?: string | undefined;
-  command?: string | undefined;
-}): Extract<AgentTimelineItem, { type: "tool_call" }> {
-  const processId = nonEmptyString(params.processId);
-  const callId = processId
-    ? `terminal-session-${processId}`
-    : (nonEmptyString(params.fallbackCallId) ?? "terminal-interaction");
-  const label = nonEmptyString(params.command);
-  return {
-    type: "tool_call",
-    callId,
-    name: "terminal",
-    status: "completed",
-    error: null,
-    detail: {
-      type: "plain_text",
-      ...(label ? { label } : {}),
-      icon: "square_terminal",
-    },
-    metadata: processId ? { processId } : undefined,
-  };
-}
-
-function buildTerminalCommandBySessionId(
-  parsedRecords: ParsedRolloutRecord[],
-): Map<string, string> {
-  const outputsByCallId = parsedRecords
-    .filter(
-      (record): record is Extract<ParsedRolloutRecord, { kind: "output" }> =>
-        record.kind === "output",
-    )
-    .reduce((map, record) => map.set(record.callId, record.output), new Map<string, unknown>());
-
-  const commandsBySessionId = new Map<string, string>();
-  for (const record of parsedRecords) {
-    if (record.kind !== "call" || record.name === "write_stdin") {
-      continue;
-    }
-
-    const mapped = mapCodexRolloutToolCall({
-      callId: record.callId ?? null,
-      name: record.name,
-      input: record.input ?? null,
-      output: record.callId ? (outputsByCallId.get(record.callId) ?? null) : null,
-    });
-    if (!mapped || mapped.detail.type !== "shell") {
-      continue;
-    }
-
-    const sessionId = extractCodexTerminalSessionId(mapped.detail.output);
-    if (!sessionId) {
-      continue;
-    }
-    commandsBySessionId.set(sessionId, mapped.detail.command);
-  }
-
-  return commandsBySessionId;
-}
-
-function readOutputPayloadValue(payload: Record<string, unknown>): unknown {
-  if (payload.output !== undefined) {
-    return parseJsonLikeValue(payload.output);
-  }
-
-  const { type: _type, call_id: _callId, ...rest } = payload;
-  return Object.keys(rest).length > 0 ? rest : undefined;
-}
-
-const FunctionCallInputNormalizationSchema = z.union([
-  z
-    .object({ cmd: z.string() })
-    .transform((input) => ({ name: "Bash", input: { command: input.cmd } })),
-  z
-    .object({ command: z.array(z.string()) })
-    .transform((input) => ({ name: "Bash", input: { command: input.command[2] ?? "" } })),
-  z.unknown().transform((input) => ({ name: "unknown", input })),
-]);
-
-const RolloutResponseRecordSchema = z.union([
-  RolloutResponseMessagePayloadSchema.transform((payload): ParsedRolloutRecord => {
-    const text = extractMessageText(payload.content);
-    const itemType = payload.role === "assistant" ? "assistant_message" : "user_message";
-    const shouldEmit =
-      text.length > 0 && (itemType !== "user_message" || !isSyntheticRolloutUserMessage(text));
-    return shouldEmit ? { kind: "timeline", item: { type: itemType, text } } : { kind: "ignore" };
-  }),
-  RolloutResponseReasoningPayloadSchema.transform((payload): ParsedRolloutRecord => {
-    const text = extractReasoningText(payload);
-    return text.length > 0
-      ? { kind: "timeline", item: { type: "reasoning", text } }
-      : { kind: "ignore" };
-  }),
-  z
-    .union([RolloutResponseFunctionCallPayloadSchema, RolloutResponseCustomToolCallPayloadSchema])
-    .transform((payload): ParsedRolloutRecord => {
-      const rawName = payload.name ?? "unknown";
-      const rawInput = payload.arguments ?? ("input" in payload ? payload.input : undefined);
-      const parsedArguments = parseJsonLikeValue(rawInput);
-      const normalized =
-        rawName === "exec_command" || rawName === "shell"
-          ? FunctionCallInputNormalizationSchema.parse(parsedArguments)
-          : { name: rawName, input: parsedArguments };
-      return {
-        kind: "call",
-        name: normalized.name,
-        callId: payload.call_id,
-        input: normalized.input,
-      };
-    }),
-  z
-    .union([
-      RolloutResponseFunctionCallOutputPayloadSchema,
-      RolloutResponseCustomToolCallOutputPayloadSchema,
-    ])
-    .transform((payload): ParsedRolloutRecord => {
-      if (!payload.call_id) {
-        return { kind: "ignore" };
-      }
-      const output = readOutputPayloadValue(payload);
-      return output !== undefined
-        ? { kind: "output", callId: payload.call_id, output }
-        : { kind: "ignore" };
-    }),
-  z.unknown().transform((): ParsedRolloutRecord => ({ kind: "ignore" })),
-]);
-
-const RolloutEventRecordSchema = z.union([
-  RolloutEventAgentReasoningPayloadSchema.transform(
-    (payload): ParsedRolloutRecord =>
-      payload.text
-        ? { kind: "timeline", item: { type: "reasoning", text: payload.text } }
-        : { kind: "ignore" },
-  ),
-  RolloutEventAgentMessagePayloadSchema.transform((payload): ParsedRolloutRecord => {
-    const text = extractEventMessageText(payload.message);
-    return text.length > 0
-      ? { kind: "timeline", item: { type: "assistant_message", text } }
-      : { kind: "ignore" };
-  }),
-  RolloutEventUserMessagePayloadSchema.transform((payload): ParsedRolloutRecord => {
-    const text = extractEventMessageText(payload.message);
-    const shouldEmit = text.length > 0 && !isSyntheticRolloutUserMessage(text);
-    return shouldEmit
-      ? { kind: "timeline", item: { type: "user_message", text } }
-      : { kind: "ignore" };
-  }),
-  z.unknown().transform((): ParsedRolloutRecord => ({ kind: "ignore" })),
-]);
-
-const RolloutRecordSchema = z
-  .object({
-    type: z.enum(["response_item", "event_msg"]),
-    payload: z.unknown().optional(),
-    item: z.unknown().optional(),
-    msg: z.unknown().optional(),
-  })
-  .transform((entry) =>
-    entry.type === "response_item"
-      ? RolloutResponseRecordSchema.parse(entry.payload ?? entry.item)
-      : RolloutEventRecordSchema.parse(entry.payload ?? entry.msg),
-  );
-
-function parseJsonRolloutTimeline(parsed: unknown): AgentTimelineItem[] | null {
-  if (!parsed || typeof parsed !== "object") {
-    return null;
-  }
-  const items = (parsed as { items?: unknown }).items;
-  if (!Array.isArray(items)) {
-    return null;
-  }
-  const timeline: AgentTimelineItem[] = [];
-  for (const entry of items) {
-    if (!entry || typeof entry !== "object") {
-      continue;
-    }
-    const messagePayloadResult = RolloutResponseMessagePayloadSchema.safeParse(entry);
-    if (messagePayloadResult.success) {
-      const payload = messagePayloadResult.data;
-      const text = extractMessageText(payload.content);
-      if (!text) {
-        continue;
-      }
-      if (payload.role === "assistant") {
-        timeline.push({ type: "assistant_message", text });
-      } else if (payload.role === "user") {
-        if (!isSyntheticRolloutUserMessage(text)) {
-          timeline.push({ type: "user_message", text });
-        }
-      }
-      continue;
-    }
-
-    const reasoningPayloadResult = RolloutResponseReasoningPayloadSchema.safeParse(entry);
-    if (reasoningPayloadResult.success) {
-      const text = extractReasoningText(reasoningPayloadResult.data);
-      if (text) {
-        timeline.push({ type: "reasoning", text });
-      }
-      continue;
-    }
-  }
-  return timeline;
-}
-
-function timelineTextFingerprint(item: AgentTimelineItem): string | null {
-  switch (item.type) {
-    case "user_message":
-    case "assistant_message":
-    case "reasoning":
-      return `${item.type}\u0000${item.text}`;
-    default:
-      return null;
-  }
-}
-
-function dedupeMirroredTextTimelineItems(timeline: AgentTimelineItem[]): AgentTimelineItem[] {
-  const deduped: AgentTimelineItem[] = [];
-  for (const item of timeline) {
-    const prev = deduped[deduped.length - 1];
-    if (!prev) {
-      deduped.push(item);
-      continue;
-    }
-    const currentFingerprint = timelineTextFingerprint(item);
-    const previousFingerprint = timelineTextFingerprint(prev);
-    if (currentFingerprint && previousFingerprint && currentFingerprint === previousFingerprint) {
-      continue;
-    }
-    deduped.push(item);
-  }
-  return deduped;
-}
-
-export async function parseRolloutFile(filePath: string): Promise<AgentTimelineItem[]> {
-  const content = await fs.readFile(filePath, "utf8");
-  const trimmed = content.trim();
-  if (!trimmed) {
-    return [];
-  }
-  try {
-    const parsed = JSON.parse(trimmed);
-    const jsonTimeline = parseJsonRolloutTimeline(parsed);
-    if (jsonTimeline) {
-      return dedupeMirroredTextTimelineItems(jsonTimeline);
-    }
-  } catch {
-    // Fall back to JSONL parsing.
-  }
-  const lines = trimmed
-    .split(/\r?\n/)
-    .map((line) => line.trim())
-    .filter(Boolean);
-
-  const parsedRecords = lines
-    .map((line) => {
-      try {
-        return JSON.parse(line);
-      } catch {
-        return null;
-      }
-    })
-    .filter((record): record is unknown => record !== null)
-    .map((record) => RolloutRecordSchema.safeParse(record))
-    .filter((result): result is { success: true; data: ParsedRolloutRecord } => result.success)
-    .map((result) => result.data);
-
-  const outputsByCallId = parsedRecords
-    .filter(
-      (record): record is Extract<ParsedRolloutRecord, { kind: "output" }> =>
-        record.kind === "output",
-    )
-    .reduce((map, record) => map.set(record.callId, record.output), new Map<string, unknown>());
-  const terminalCommandsBySessionId = buildTerminalCommandBySessionId(parsedRecords);
-
-  const timeline = parsedRecords.flatMap((record): AgentTimelineItem[] => {
-    if (record.kind === "timeline") {
-      return [record.item];
-    }
-    if (record.kind !== "call") {
-      return [];
-    }
-    if (record.name === "write_stdin") {
-      const input =
-        record.input && typeof record.input === "object"
-          ? (record.input as { session_id?: unknown; sessionId?: unknown })
-          : null;
-      const sessionId =
-        readTerminalSessionId(input?.session_id) ?? readTerminalSessionId(input?.sessionId);
-      return [
-        mapCodexTerminalInteractionToToolCall({
-          processId: sessionId,
-          fallbackCallId: record.callId,
-          command: sessionId ? terminalCommandsBySessionId.get(sessionId) : undefined,
-        }),
-      ];
-    }
-    const mapped = mapCodexRolloutToolCall({
-      callId: record.callId ?? null,
-      name: record.name,
-      input: record.input ?? null,
-      output: record.callId ? (outputsByCallId.get(record.callId) ?? null) : null,
-    });
-    return mapped ? [mapped] : [];
-  });
-  return dedupeMirroredTextTimelineItems(timeline);
-}
-
-export interface CodexPersistedTimelineOptions {
-  sessionRoot?: string | null;
-  rolloutPath?: string | null;
-}
-
-export async function loadCodexPersistedTimeline(
-  sessionId: string,
-  options?: CodexPersistedTimelineOptions,
-  logger?: Logger,
-): Promise<AgentTimelineItem[]> {
-  const rolloutPath = options?.rolloutPath ?? null;
-  if (rolloutPath) {
-    try {
-      const stat = await fs.stat(rolloutPath);
-      if (stat.isFile()) {
-        const timeline = await parseRolloutFile(rolloutPath);
-        if (timeline.length > 0) {
-          return timeline;
-        }
-      }
-    } catch {
-      // Fall back to session root scan.
-    }
-  }
-
-  try {
-    const preferredRoot = options?.sessionRoot ?? resolveCodexSessionRoot();
-    const fallbackRoot = resolveCodexSessionRoot();
-    let rolloutFile: string | null = null;
-
-    if (preferredRoot) {
-      rolloutFile = await findRolloutFile(sessionId, preferredRoot);
-    }
-    if (!rolloutFile && fallbackRoot && fallbackRoot !== preferredRoot) {
-      rolloutFile = await findRolloutFile(sessionId, fallbackRoot);
-    }
-    if (!rolloutFile) {
-      return [];
-    }
-
-    return await parseRolloutFile(rolloutFile);
-  } catch (error) {
-    logger?.warn({ err: error, sessionId }, "Failed to load persisted timeline");
-    return [];
-  }
-}

packages/server/src/server/agent/providers/codex/app-server-transport.test.ts

@@ -1,7 +1,10 @@
 import { describe, expect, test } from "vitest";
 
 import { createTestLogger } from "../../../../test-utils/test-logger.js";
-import { createCodexAppServerChildProcess } from "./test-utils/fake-app-server.js";
+import {
+  createCodexAppServerChildProcess,
+  createFakeCodexAppServer,
+} from "./test-utils/fake-app-server.js";
 import { CodexAppServerClient } from "./app-server-transport.js";
 
 describe("Codex app-server transport", () => {
@@ -25,23 +28,87 @@ describe("Codex app-server transport", () => {
     "item/tool/requestUserInput",
     "tool/requestUserInput",
   ])("answers server-initiated %s requests through registered handlers", async (method) => {
-    const child = createCodexAppServerChildProcess();
-    const client = new CodexAppServerClient(child, createTestLogger());
+    const codex = createFakeCodexAppServer();
+    const client = new CodexAppServerClient(codex.child, createTestLogger());
     const handlerCalls: unknown[] = [];
     client.setRequestHandler(method, async (params) => {
       handlerCalls.push(params);
       return { ok: true };
     });
 
-    const response = new Promise<string>((resolve) => {
-      child.stdin.once("data", (chunk) => resolve(chunk.toString()));
-    });
-    child.stdout.write(`${JSON.stringify({ jsonrpc: "2.0", id: 7, method, params: {} })}\n`);
+    const response = codex.nextResponse();
+    codex.child.stdout.write(`${JSON.stringify({ jsonrpc: "2.0", id: 7, method, params: {} })}\n`);
 
     await expect(response).resolves.toBe('{"id":7,"result":{"ok":true}}\n');
     expect(handlerCalls).toEqual([{}]);
-    child.stdout.end();
-    child.stderr.end();
-    child.stdin.end();
+    codex.child.stdout.end();
+    codex.child.stderr.end();
+    codex.child.stdin.end();
+  });
+
+  test("forks a Codex thread through thread/fork", async () => {
+    const codex = createFakeCodexAppServer({
+      "thread/fork": (params) => ({
+        thread: {
+          id: "forked-thread",
+          sessionId: "forked-session",
+          forkedFromId: (params as { threadId?: string }).threadId,
+          turns: [],
+        },
+        model: "gpt-5.4",
+        modelProvider: "openai",
+        serviceTier: null,
+        cwd: "/workspace/project",
+        runtimeWorkspaceRoots: [],
+        instructionSources: [],
+        approvalPolicy: "on-request",
+        approvalsReviewer: null,
+        sandbox: { type: "workspaceWrite", networkAccess: false },
+        activePermissionProfile: null,
+        reasoningEffort: null,
+      }),
+    });
+    const client = new CodexAppServerClient(codex.child, createTestLogger());
+
+    const forked = await client.forkThread({
+      threadId: "source-thread",
+      cwd: "/workspace/project",
+      excludeTurns: true,
+    });
+
+    expect(forked.thread.id).toBe("forked-thread");
+    expect(forked.thread.forkedFromId).toBe("source-thread");
+    codex.assertNoErrors();
+    codex.child.stdout.end();
+    codex.child.stderr.end();
+    codex.child.stdin.end();
+  });
+
+  test("rolls back a Codex thread by N turns", async () => {
+    const codex = createFakeCodexAppServer({
+      "thread/rollback": (params) => {
+        expect(params).toEqual({ threadId: "forked-thread", numTurns: 2 });
+        return {
+          thread: {
+            id: "forked-thread",
+            sessionId: "forked-session",
+            turns: [{ id: "remaining-turn" }],
+          },
+        };
+      },
+    });
+    const client = new CodexAppServerClient(codex.child, createTestLogger());
+
+    const rolledBack = await client.rollbackThread({
+      threadId: "forked-thread",
+      numTurns: 2,
+    });
+
+    expect(rolledBack.thread.id).toBe("forked-thread");
+    expect(rolledBack.thread.turns).toEqual([{ id: "remaining-turn" }]);
+    codex.assertNoErrors();
+    codex.child.stdout.end();
+    codex.child.stderr.end();
+    codex.child.stdin.end();
   });
 });

packages/server/src/server/agent/providers/codex/app-server-transport.ts

@@ -1,6 +1,7 @@
 import type { ChildProcessWithoutNullStreams } from "node:child_process";
 import readline from "node:readline";
 import type { Logger } from "pino";
+import { z } from "zod";
 
 import { terminateWithTreeKill } from "../../../../utils/tree-kill.js";
 
@@ -35,6 +36,81 @@ interface PendingRequest {
 type RequestHandler = (params: unknown) => unknown;
 type NotificationHandler = (method: string, params: unknown) => void;
 
+export interface CodexThreadForkParams {
+  threadId: string;
+  path?: string | null;
+  model?: string | null;
+  modelProvider?: string | null;
+  serviceTier?: string | null;
+  cwd?: string | null;
+  runtimeWorkspaceRoots?: string[] | null;
+  approvalPolicy?: unknown;
+  approvalsReviewer?: unknown;
+  sandbox?: unknown;
+  permissions?: string | null;
+  config?: Record<string, unknown> | null;
+  baseInstructions?: string | null;
+  developerInstructions?: string | null;
+  ephemeral?: boolean;
+  threadSource?: unknown;
+  excludeTurns?: boolean;
+  persistExtendedHistory?: boolean;
+}
+
+const CodexThreadForkResponseSchema = z
+  .object({
+    thread: z
+      .object({
+        id: z.string(),
+        sessionId: z.string().optional(),
+        forkedFromId: z.string().nullable().optional(),
+        turns: z.array(z.unknown()).optional(),
+      })
+      .passthrough(),
+    model: z.string(),
+    modelProvider: z.string(),
+    serviceTier: z.string().nullable(),
+    cwd: z.string(),
+    runtimeWorkspaceRoots: z.array(z.string()).optional().default([]),
+    instructionSources: z.array(z.string()).optional().default([]),
+    approvalPolicy: z.unknown(),
+    approvalsReviewer: z.unknown(),
+    sandbox: z.unknown(),
+    activePermissionProfile: z.unknown().optional(),
+    reasoningEffort: z.string().nullable().optional(),
+  })
+  .passthrough();
+
+export type CodexThreadForkResponse = z.infer<typeof CodexThreadForkResponseSchema>;
+
+export function parseCodexThreadForkResponse(response: unknown): CodexThreadForkResponse {
+  return CodexThreadForkResponseSchema.parse(response);
+}
+
+export interface CodexThreadRollbackParams {
+  threadId: string;
+  numTurns: number;
+}
+
+const CodexThreadRollbackResponseSchema = z
+  .object({
+    thread: z
+      .object({
+        id: z.string(),
+        sessionId: z.string().optional(),
+        forkedFromId: z.string().nullable().optional(),
+        turns: z.array(z.unknown()).optional(),
+      })
+      .passthrough(),
+  })
+  .passthrough();
+
+export type CodexThreadRollbackResponse = z.infer<typeof CodexThreadRollbackResponseSchema>;
+
+export function parseCodexThreadRollbackResponse(response: unknown): CodexThreadRollbackResponse {
+  return CodexThreadRollbackResponseSchema.parse(response);
+}
+
 export interface CodexAppServerTraceContext {
   agentId?: string;
   sessionId?: string;
@@ -156,6 +232,14 @@ export class CodexAppServerClient {
     });
   }
 
+  async forkThread(params: CodexThreadForkParams): Promise<CodexThreadForkResponse> {
+    return parseCodexThreadForkResponse(await this.request("thread/fork", params));
+  }
+
+  async rollbackThread(params: CodexThreadRollbackParams): Promise<CodexThreadRollbackResponse> {
+    return parseCodexThreadRollbackResponse(await this.request("thread/rollback", params));
+  }
+
   notify(method: string, params?: unknown): void {
     if (this.disposed) {
       return;

packages/server/src/server/agent/providers/codex/rewind.test.ts

@@ -0,0 +1,150 @@
+import { describe, expect, test } from "vitest";
+
+import type {
+  CodexThreadForkParams,
+  CodexThreadForkResponse,
+  CodexThreadRollbackParams,
+  CodexThreadRollbackResponse,
+} from "./app-server-transport.js";
+import {
+  type CodexUserMessageTurnIndex,
+  type CodexRewindClient,
+  revertCodexConversation,
+} from "./rewind.js";
+
+class FakeCodex implements CodexRewindClient {
+  readonly recordedForks: CodexThreadForkParams[] = [];
+  readonly recordedRollbacks: CodexThreadRollbackParams[] = [];
+
+  async forkThread(params: CodexThreadForkParams): Promise<CodexThreadForkResponse> {
+    this.recordedForks.push(params);
+    return {
+      thread: {
+        id: "forked-thread",
+        sessionId: "forked-session",
+        forkedFromId: params.threadId,
+        turns: [],
+      },
+      model: "gpt-5.4-mini",
+      modelProvider: "openai",
+      serviceTier: null,
+      cwd: "/workspace/project",
+      runtimeWorkspaceRoots: [],
+      instructionSources: [],
+      approvalPolicy: "on-request",
+      approvalsReviewer: null,
+      sandbox: { type: "workspaceWrite", networkAccess: false },
+      activePermissionProfile: null,
+      reasoningEffort: null,
+    };
+  }
+
+  async rollbackThread(params: CodexThreadRollbackParams): Promise<CodexThreadRollbackResponse> {
+    this.recordedRollbacks.push(params);
+    return {
+      thread: {
+        id: params.threadId,
+        sessionId: "forked-session",
+        forkedFromId: "source-thread",
+        turns: [],
+      },
+    };
+  }
+
+  request(): Promise<unknown> {
+    throw new Error("FakeCodex uses typed thread methods");
+  }
+}
+
+class CodexMessageTurns implements CodexUserMessageTurnIndex {
+  constructor(private readonly indexesByMessageId: Map<string, number>) {}
+
+  resolve(messageId: string): number | null {
+    return this.indexesByMessageId.get(messageId) ?? null;
+  }
+
+  count(): number {
+    return this.indexesByMessageId.size;
+  }
+}
+
+describe("Codex Rewind", () => {
+  test("rewinds the conversation by forking the thread and rolling back past the native user message", async () => {
+    const codex = new FakeCodex();
+    const userMessageTurns = new CodexMessageTurns(
+      new Map([
+        ["codex-first", 0],
+        ["codex-second", 1],
+      ]),
+    );
+    let reboundThreadId: string | null = null;
+
+    await revertCodexConversation({
+      client: codex,
+      threadId: "source-thread",
+      messageId: "codex-first",
+      cwd: "/workspace/project",
+      model: "gpt-5.4-mini",
+      serviceTier: null,
+      userMessageTurns,
+      setThreadId: (threadId) => {
+        reboundThreadId = threadId;
+      },
+    });
+
+    expect(codex.recordedForks).toEqual([
+      {
+        threadId: "source-thread",
+        cwd: "/workspace/project",
+        model: "gpt-5.4-mini",
+        serviceTier: null,
+        excludeTurns: false,
+        persistExtendedHistory: true,
+      },
+    ]);
+    expect(codex.recordedRollbacks).toEqual([{ threadId: "forked-thread", numTurns: 2 }]);
+    expect(reboundThreadId).toBe("forked-thread");
+  });
+
+  test("rewinds the conversation using native user message ids hydrated from app-server history", async () => {
+    const codex = new FakeCodex();
+    const userMessageTurns = new CodexMessageTurns(
+      new Map([
+        ["codex-first", 0],
+        ["codex-second", 1],
+        ["codex-third", 2],
+      ]),
+    );
+    let reboundThreadId: string | null = null;
+
+    await revertCodexConversation({
+      client: codex,
+      threadId: "source-thread",
+      messageId: "codex-second",
+      userMessageTurns,
+      setThreadId: (threadId) => {
+        reboundThreadId = threadId;
+      },
+    });
+
+    expect(codex.recordedRollbacks).toEqual([{ threadId: "forked-thread", numTurns: 2 }]);
+    expect(reboundThreadId).toBe("forked-thread");
+  });
+
+  test("declines to rewind when the user message is not in the Codex thread", async () => {
+    const codex = new FakeCodex();
+    const userMessageTurns = new CodexMessageTurns(new Map([["codex-first", 0]]));
+
+    await expect(
+      revertCodexConversation({
+        client: codex,
+        threadId: "source-thread",
+        messageId: "missing-message",
+        userMessageTurns,
+        setThreadId: () => undefined,
+      }),
+    ).rejects.toThrow("Codex could not find user message missing-message");
+    expect(codex.recordedForks).toEqual([]);
+    expect(codex.recordedRollbacks).toEqual([]);
+  });
+});

packages/server/src/server/agent/providers/codex/rewind.ts

@@ -0,0 +1,87 @@
+import type {
+  CodexThreadForkParams,
+  CodexThreadForkResponse,
+  CodexThreadRollbackParams,
+  CodexThreadRollbackResponse,
+} from "./app-server-transport.js";
+import {
+  parseCodexThreadForkResponse,
+  parseCodexThreadRollbackResponse,
+} from "./app-server-transport.js";
+
+export interface CodexRewindClient {
+  forkThread?(params: CodexThreadForkParams): Promise<CodexThreadForkResponse>;
+  rollbackThread?(params: CodexThreadRollbackParams): Promise<CodexThreadRollbackResponse>;
+  request(method: string, params?: unknown, timeoutMs?: number): Promise<unknown>;
+}
+
+export interface CodexUserMessageTurnIndex {
+  resolve(messageId: string): number | null;
+  count(): number;
+}
+
+async function forkCodexThread(
+  client: CodexRewindClient,
+  params: CodexThreadForkParams,
+): Promise<CodexThreadForkResponse> {
+  if (client.forkThread) {
+    return client.forkThread(params);
+  }
+  return parseCodexThreadForkResponse(await client.request("thread/fork", params));
+}
+
+async function rollbackCodexThread(
+  client: CodexRewindClient,
+  params: CodexThreadRollbackParams,
+): Promise<CodexThreadRollbackResponse> {
+  if (client.rollbackThread) {
+    return client.rollbackThread(params);
+  }
+  return parseCodexThreadRollbackResponse(await client.request("thread/rollback", params));
+}
+
+export async function revertCodexConversation(input: {
+  client: CodexRewindClient;
+  threadId: string | null;
+  messageId: string;
+  cwd?: string | null;
+  model?: string | null;
+  serviceTier?: string | null;
+  userMessageTurns: CodexUserMessageTurnIndex;
+  setThreadId: (threadId: string) => void | Promise<void>;
+}): Promise<void> {
+  if (!input.threadId) {
+    throw new Error("Codex thread is not ready for rewind");
+  }
+
+  const targetTurnIndex = input.userMessageTurns.resolve(input.messageId);
+  if (targetTurnIndex === null) {
+    throw new Error(`Codex could not find user message ${input.messageId} in the current thread`);
+  }
+
+  const currentUserTurnCount = input.userMessageTurns.count();
+  const numTurns = currentUserTurnCount - targetTurnIndex;
+  if (numTurns < 0) {
+    throw new Error(`Codex user message ${input.messageId} is outside the current thread`);
+  }
+
+  // Fork is non-destructive: the old thread file stays on disk and remains
+  // recoverable with `codex resume <old-uuid>` if the rewind target was wrong.
+  const forked = await forkCodexThread(input.client, {
+    threadId: input.threadId,
+    cwd: input.cwd ?? null,
+    model: input.model ?? null,
+    serviceTier: input.serviceTier ?? null,
+    excludeTurns: false,
+    persistExtendedHistory: true,
+  });
+  const forkedThreadId = forked.thread.id;
+
+  // Codex rollback is chat-only by design. File edits from rewound turns stay
+  // on disk; a future file primitive would be a separate capability.
+  const rolledBack = await rollbackCodexThread(input.client, {
+    threadId: forkedThreadId,
+    numTurns,
+  });
+  await input.setThreadId(rolledBack.thread.id);
+}

packages/server/src/server/agent/providers/codex/test-utils/fake-app-server.ts

@@ -14,8 +14,11 @@ type CodexAppServerChildProcess = ChildProcessWithoutNullStreams & {
 
 export interface FakeCodexAppServer {
   readonly child: CodexAppServerChildProcess;
+  readonly recordedRollbacks: JsonObject[];
   assertNoErrors(): void;
   waitForTurnStart(): Promise<JsonObject>;
+  nextResponse(): Promise<string>;
+  completeTurn(params?: { threadId?: string }): void;
   requestCommandApproval(params: {
     itemId: string;
     threadId: string;
@@ -46,6 +49,7 @@ export function createFakeCodexAppServer(
   handlers: Record<string, FakeCodexAppServerHandler> = {},
 ): FakeCodexAppServer {
   const child = createCodexAppServerChildProcess();
+  const recordedRollbacks: JsonObject[] = [];
   const responseHandlers: Record<string, FakeCodexAppServerHandler> = {
     initialize: () => ({}),
     "collaborationMode/list": () => ({ data: [] }),
@@ -65,6 +69,38 @@ export function createFakeCodexAppServer(
     "thread/loaded/list": () => ({ data: [] }),
     "thread/resume": () => ({}),
     "turn/start": () => ({}),
+    "thread/fork": (params) => ({
+      thread: {
+        id: "forked-thread",
+        sessionId: "forked-session",
+        forkedFromId: toJsonObject(params).threadId,
+        turns: [],
+      },
+      model: "gpt-5.4",
+      modelProvider: "openai",
+      serviceTier: null,
+      cwd: "/workspace/project",
+      runtimeWorkspaceRoots: [],
+      instructionSources: [],
+      approvalPolicy: "on-request",
+      approvalsReviewer: null,
+      sandbox: { type: "workspaceWrite", networkAccess: false },
+      activePermissionProfile: null,
+      reasoningEffort: null,
+    }),
+    "thread/rollback": (params) => {
+      const rollback = toJsonObject(params);
+      recordedRollbacks.push(rollback);
+      return {
+        thread: {
+          id: typeof rollback.threadId === "string" ? rollback.threadId : "forked-thread",
+          sessionId: "forked-session",
+          forkedFromId: "thread-1",
+          turns: [],
+        },
+      };
+    },
+    "thread/read": () => ({ thread: { turns: [] } }),
     ...handlers,
   };
   const messages: JsonObject[] = [];
@@ -161,6 +197,7 @@ export function createFakeCodexAppServer(
 
   return {
     child,
+    recordedRollbacks,
     assertNoErrors() {
       if (errors.length > 0) {
         throw errors[0];
@@ -173,6 +210,19 @@ export function createFakeCodexAppServer(
       );
       return toJsonObject(message.params);
     },
+    nextResponse() {
+      return new Promise<string>((resolve) => {
+        child.stdin.once("data", (chunk) => resolve(chunk.toString()));
+      });
+    },
+    completeTurn(params = {}) {
+      child.stdout.write(
+        `${JSON.stringify({
+          method: "turn/completed",
+          params: { threadId: params.threadId ?? "thread-1", turn: { status: "completed" } },
+        })}\n`,
+      );
+    },
     requestCommandApproval(params) {
       const requestId = nextServerRequestId;
       nextServerRequestId += 1;

packages/server/src/server/agent/providers/codex/tool-call-mapper.ts

@@ -18,7 +18,7 @@ const CodexCommandValueSchema = z.union([z.string(), z.array(z.string())]);
 const CodexToolCallStatusSchema = z.enum(["running", "completed", "failed", "canceled"]);
 type CodexToolCallStatus = z.infer<typeof CodexToolCallStatusSchema>;
 
-const CodexRolloutToolCallParamsSchema = z
+const CodexToolCallEnvelopeParamsSchema = z
   .object({
     callId: z.string().optional().nullable(),
     name: z.string().min(1),
@@ -432,7 +432,7 @@ function asEditTextFields(text: string | undefined): { unifiedDiff?: string; new
   return { newString: text };
 }
 
-function findRolloutEditPatchText(input: Record<string, unknown>): string | undefined {
+function findToolCallEditPatchText(input: Record<string, unknown>): string | undefined {
   return (
     (typeof input.patch === "string" && input.patch) ||
     (typeof input.diff === "string" && input.diff) ||
@@ -443,7 +443,7 @@ function findRolloutEditPatchText(input: Record<string, unknown>): string | unde
   );
 }
 
-function findRolloutEditInputPath(
+function findToolCallEditInputPath(
   input: Record<string, unknown>,
   patchText: string,
 ): string | undefined {
@@ -459,14 +459,14 @@ function findRolloutEditInputPath(
   );
 }
 
-function normalizeRolloutEditRecordInput(input: Record<string, unknown>): unknown {
-  const candidatePatchText = findRolloutEditPatchText(input);
+function normalizeToolCallEditRecordInput(input: Record<string, unknown>): unknown {
+  const candidatePatchText = findToolCallEditPatchText(input);
   if (!candidatePatchText) {
     return input;
   }
 
   const textFields = asEditTextFields(candidatePatchText);
-  const rawPath = findRolloutEditInputPath(input, candidatePatchText);
+  const rawPath = findToolCallEditInputPath(input, candidatePatchText);
 
   const {
     patch: _patch,
@@ -490,7 +490,7 @@ function normalizeRolloutEditRecordInput(input: Record<string, unknown>): unknow
   return normalized;
 }
 
-function normalizeRolloutEditInput(input: unknown): unknown {
+function normalizeToolCallEditInput(input: unknown): unknown {
   if (typeof input === "string") {
     const textFields = asEditTextFields(input);
     const path = extractPatchPrimaryFilePath(input);
@@ -503,7 +503,7 @@ function normalizeRolloutEditInput(input: unknown): unknown {
   if (!isRecord(input)) {
     return input;
   }
-  return normalizeRolloutEditRecordInput(input);
+  return normalizeToolCallEditRecordInput(input);
 }
 
 function asEditFileOutputFields(text: string | undefined): { patch?: string; content?: string } {
@@ -965,7 +965,7 @@ export function mapCodexToolCallFromThreadItem(
   return toToolCallFromNormalizedEnvelope(envelope);
 }
 
-export function mapCodexRolloutToolCall(params: {
+export function mapCodexToolCallEnvelope(params: {
   callId?: string | null;
   name: string;
   input?: unknown;
@@ -973,7 +973,7 @@ export function mapCodexRolloutToolCall(params: {
   error?: unknown;
   cwd?: string | null;
 }): ToolCallTimelineItem | null {
-  const parsed = CodexRolloutToolCallParamsSchema.safeParse(params);
+  const parsed = CodexToolCallEnvelopeParamsSchema.safeParse(params);
   if (!parsed.success) {
     return null;
   }
@@ -988,7 +988,7 @@ export function mapCodexRolloutToolCall(params: {
   }
   const normalizedInput =
     normalizedName === "apply_patch" || normalizedName === "apply_diff"
-      ? normalizeRolloutEditInput(parsed.data.input ?? null)
+      ? normalizeToolCallEditInput(parsed.data.input ?? null)
       : (parsed.data.input ?? null);
 
   return toToolCallFromNormalizedEnvelope({

packages/server/src/server/agent/providers/copilot-acp-agent.ts

@@ -27,6 +27,9 @@ const COPILOT_CAPABILITIES: AgentCapabilityFlags = {
   supportsMcpServers: true,
   supportsReasoningStream: true,
   supportsToolInvocations: true,
+  supportsRewindConversation: false,
+  supportsRewindFiles: false,
+  supportsRewindBoth: false,
 };
 
 const COPILOT_AGENT_MODE_ID = "https://agentclientprotocol.com/protocol/session-modes#agent";

packages/server/src/server/agent/providers/mock-load-test-agent.ts

@@ -42,6 +42,9 @@ const CAPABILITIES: AgentCapabilityFlags = {
   supportsMcpServers: false,
   supportsReasoningStream: true,
   supportsToolInvocations: true,
+  supportsRewindConversation: true,
+  supportsRewindFiles: true,
+  supportsRewindBoth: true,
 };
 
 const MODELS: AgentModelDefinition[] = [
@@ -449,12 +452,17 @@ export class MockLoadTestAgentSession implements AgentSession {
   private pendingPermissions = new Map<string, AgentPermissionRequest>();
   private modeId: string | null;
   private modelId: string | null;
+  private readonly rewindError: string | null;
 
   constructor(options: { config: AgentSessionConfig; sessionId: string; logger?: Logger }) {
     this.id = options.sessionId;
     this.logger = options.logger;
     this.modeId = options.config.modeId ?? MOCK_LOAD_TEST_MODE_ID;
     this.modelId = options.config.model ?? MOCK_LOAD_TEST_DEFAULT_MODEL_ID;
+    this.rewindError =
+      typeof options.config.featureValues?.mockRewindError === "string"
+        ? options.config.featureValues.mockRewindError
+        : null;
   }
 
   async run(prompt: AgentPromptInput, options?: AgentRunOptions): Promise<AgentRunResult> {
@@ -495,6 +503,22 @@ export class MockLoadTestAgentSession implements AgentSession {
       turnStarted: false,
     };
     this.activeTurn = turn;
+    const userMessageId = randomUUID();
+    setTimeout(() => {
+      if (this.activeTurn?.turnId !== turnId) {
+        return;
+      }
+      this.emit({
+        type: "timeline",
+        provider: this.provider,
+        turnId,
+        item: {
+          type: "user_message",
+          text: promptToText(prompt),
+          messageId: userMessageId,
+        },
+      });
+    }, 0);
 
     const largePayload = parseLargeAgentStreamPayloadPrompt(prompt);
     const stress = parseAgentStreamStressPrompt(prompt);
@@ -609,6 +633,21 @@ export class MockLoadTestAgentSession implements AgentSession {
     this.listeners.clear();
   }
 
+  async revertConversation(_input: { messageId: string }): Promise<void> {
+    this.failConfiguredRewind();
+    this.keepFirstUserMessageHistory();
+  }
+
+  async revertFiles(_input: { messageId: string }): Promise<void> {
+    this.failConfiguredRewind();
+    this.keepFirstUserMessageHistory();
+  }
+
+  async revertBoth(_input: { messageId: string }): Promise<void> {
+    this.failConfiguredRewind();
+    this.keepFirstUserMessageHistory();
+  }
+
   async setModel(modelId: string | null): Promise<void> {
     this.modelId = modelId ?? MOCK_LOAD_TEST_DEFAULT_MODEL_ID;
   }
@@ -620,6 +659,12 @@ export class MockLoadTestAgentSession implements AgentSession {
     turn.timer.unref?.();
   }
 
+  private failConfiguredRewind(): void {
+    if (this.rewindError) {
+      throw new Error(this.rewindError);
+    }
+  }
+
   private scheduleLargePayloadTurn(
     turn: ActiveTurn,
     largePayload: LargeAgentStreamPayloadRequest,
@@ -941,7 +986,7 @@ export class MockLoadTestAgentSession implements AgentSession {
   }
 
   private emit(event: AgentStreamEvent): void {
-    this.history.push(event);
+    this.remember(event);
     for (const listener of this.listeners) {
       try {
         listener(event);
@@ -951,6 +996,22 @@ export class MockLoadTestAgentSession implements AgentSession {
     }
   }
 
+  private remember(event: AgentStreamEvent): void {
+    this.history.push(event);
+  }
+
+  private keepFirstUserMessageHistory(): void {
+    const nextHistory: AgentStreamEvent[] = [];
+    for (const event of this.history) {
+      if (event.type === "timeline" && event.item.type === "user_message") {
+        nextHistory.push(event);
+        break;
+      }
+    }
+    this.history.length = 0;
+    this.history.push(...nextHistory);
+  }
+
   private clearTurnTimer(turn: ActiveTurn): void {
     if (!turn.timer) {
       return;

packages/server/src/server/agent/providers/opencode-agent.test.ts

@@ -937,6 +937,10 @@ describe("OpenCode adapter startTurn error handling", () => {
   test("streamHistory preserves OpenCode replay timestamps from message and part times", async () => {
     const fakeClient = {
       session: {
+        get: vi.fn().mockResolvedValue({
+          data: { revert: undefined },
+          error: undefined,
+        }),
         messages: vi.fn().mockResolvedValue({
           data: [
             {
@@ -1029,6 +1033,10 @@ describe("OpenCode adapter startTurn error handling", () => {
   test("streamHistory omits replay timestamps when OpenCode omits times", async () => {
     const fakeClient = {
       session: {
+        get: vi.fn().mockResolvedValue({
+          data: { revert: undefined },
+          error: undefined,
+        }),
         messages: vi.fn().mockResolvedValue({
           data: [
             {

packages/server/src/server/agent/providers/opencode-agent.ts

@@ -67,6 +67,7 @@ import {
   type OpenCodeServerAcquisition,
 } from "./opencode/runtime.js";
 import { normalizeProviderReplayTimestamp } from "../provider-history-timestamps.js";
+import { revertOpenCodeConversationAndFiles } from "./opencode/rewind.js";
 
 const OPENCODE_CAPABILITIES: AgentCapabilityFlags = {
   supportsStreaming: true,
@@ -75,6 +76,9 @@ const OPENCODE_CAPABILITIES: AgentCapabilityFlags = {
   supportsMcpServers: true,
   supportsReasoningStream: true,
   supportsToolInvocations: true,
+  supportsRewindConversation: false,
+  supportsRewindFiles: false,
+  supportsRewindBoth: true,
 };
 
 const OPENCODE_BUILD_MODE_ID = "build";
@@ -700,6 +704,24 @@ function buildOpenCodePromptParts(
   return output;
 }
 
+function buildOpenCodeUserTimelineText(prompt: AgentPromptInput): string {
+  if (typeof prompt === "string") {
+    return prompt;
+  }
+  return prompt
+    .map((part) => {
+      if (part.type === "text") {
+        return part.text;
+      }
+      if (part.type === "image") {
+        return "[Image]";
+      }
+      return renderPromptAttachmentAsText(part);
+    })
+    .filter((text) => text.trim().length > 0)
+    .join("\n");
+}
+
 async function collectOpenCodePersistedAgentsFromSdk(
   client: Pick<OpencodeClient, "experimental" | "session">,
   options?: ListPersistedAgentsOptions,
@@ -845,7 +867,7 @@ async function readOpenCodeSessionMessagesFromSdk(
     return [];
   }
 
-  return response.data;
+  return filterOpenCodeRevertedMessages(response.data, session.revert);
 }
 
 function buildOpenCodeSessionTimeline(
@@ -856,6 +878,20 @@ function buildOpenCodeSessionTimeline(
   );
 }
 
+function filterOpenCodeRevertedMessages(
+  messages: ReadonlyArray<OpenCodeSessionMessage>,
+  revert: OpenCodePersistedSession["revert"] | null | undefined,
+): OpenCodeSessionMessage[] {
+  if (!revert?.messageID || revert.partID) {
+    return [...messages];
+  }
+  const revertIndex = messages.findIndex((message) => message.info.id === revert.messageID);
+  if (revertIndex < 0) {
+    return [...messages];
+  }
+  return messages.slice(0, revertIndex);
+}
+
 function resolveOpenCodePersistedSessionModeId(
   session: OpenCodePersistedSession,
   messages: ReadonlyArray<OpenCodeSessionMessage>,
@@ -1352,6 +1388,8 @@ export interface OpenCodeEventTranslationState {
   sessionId: string;
   cwd?: string;
   messageRoles: Map<string, OpenCodeMessageRole>;
+  pendingUserMessageText?: string | null;
+  emittedUserMessageIds?: Set<string>;
   accumulatedUsage: AgentUsage;
   sessionTotalCostUsd?: number;
   streamedPartKeys: Set<string>;
@@ -1969,6 +2007,10 @@ function appendOpenCodeMessageUpdated(
     return;
   }
   state.messageRoles.set(info.id, info.role);
+  if (info.role === "user") {
+    appendOpenCodeUserMessageUpdated(info, state, events);
+    return;
+  }
   if (info.role !== "assistant") {
     return;
   }
@@ -1994,6 +2036,23 @@ function appendOpenCodeMessageUpdated(
   });
 }
 
+function appendOpenCodeUserMessageUpdated(
+  info: Extract<OpenCodeMessage, { role: "user" }>,
+  state: OpenCodeEventTranslationState,
+  events: AgentStreamEvent[],
+): void {
+  const text = state.pendingUserMessageText;
+  if (!text || text.trim().length === 0 || state.emittedUserMessageIds?.has(info.id)) {
+    return;
+  }
+  state.emittedUserMessageIds?.add(info.id);
+  events.push({
+    type: "timeline",
+    provider: "opencode",
+    item: { type: "user_message", text, messageId: info.id },
+  });
+}
+
 function appendOpenCodeMessagePartUpdated(
   event: Extract<OpenCodeEvent, { type: "message.part.updated" }>,
   state: OpenCodeEventTranslationState,
@@ -2322,6 +2381,8 @@ class OpenCodeAgentSession implements AgentSession {
   private mcpSetupPromise: Promise<void> | null = null;
   /** Tracks the role of each message by ID to distinguish user from assistant messages */
   private messageRoles = new Map<string, OpenCodeMessageRole>();
+  private pendingUserMessageText: string | null = null;
+  private emittedUserMessageIds = new Set<string>();
   /** Tracks streamed textual part IDs to suppress final full-text echoes from OpenCode. */
   private streamedPartKeys = new Set<string>();
   /** Tracks assistant messages already emitted from structured payloads. */
@@ -2432,6 +2493,15 @@ class OpenCodeAgentSession implements AgentSession {
     }
   }
 
+  async revertBoth(input: { messageId: string }): Promise<void> {
+    await revertOpenCodeConversationAndFiles({
+      client: this.client,
+      sessionId: this.sessionId,
+      cwd: this.config.cwd,
+      messageId: input.messageId,
+    });
+  }
+
   private beginSessionAbort(turnId: string | null, reason: string): Promise<void> {
     const abortPromise = this.client.session
       .abort({
@@ -2492,6 +2562,7 @@ class OpenCodeAgentSession implements AgentSession {
     this.accumulatedUsage = contextWindowMaxTokens !== undefined ? { contextWindowMaxTokens } : {};
 
     const parts = buildOpenCodePromptParts(prompt);
+    this.pendingUserMessageText = buildOpenCodeUserTimelineText(prompt);
     const model = this.parseModel(this.config.model);
     const thinkingOptionId = this.config.thinkingOptionId;
     const effectiveVariant = thinkingOptionId ?? undefined;
@@ -2856,6 +2927,7 @@ class OpenCodeAgentSession implements AgentSession {
     } else {
       this.runningToolCalls.clear();
     }
+    this.pendingUserMessageText = null;
     this.activeForegroundTurnId = null;
     this.abortController = null;
     this.notifySubscribers(event, turnId);
@@ -2934,6 +3006,10 @@ class OpenCodeAgentSession implements AgentSession {
   }
 
   async *streamHistory(): AsyncGenerator<AgentStreamEvent> {
+    const sessionResponse = await this.client.session.get({
+      sessionID: this.sessionId,
+      directory: this.config.cwd,
+    });
     const response = await this.client.session.messages({
       sessionID: this.sessionId,
       directory: this.config.cwd,
@@ -2943,7 +3019,11 @@ class OpenCodeAgentSession implements AgentSession {
       return;
     }
 
-    for (const message of response.data) {
+    const messages = filterOpenCodeRevertedMessages(
+      response.data,
+      sessionResponse.error ? null : sessionResponse.data?.revert,
+    );
+    for (const message of messages) {
       for (const event of buildOpenCodeReplayTimelineEvents(message)) {
         yield event;
       }
@@ -3215,6 +3295,8 @@ class OpenCodeAgentSession implements AgentSession {
       sessionId: this.sessionId,
       cwd: this.config.cwd,
       messageRoles: this.messageRoles,
+      pendingUserMessageText: this.pendingUserMessageText,
+      emittedUserMessageIds: this.emittedUserMessageIds,
       accumulatedUsage: this.accumulatedUsage,
       sessionTotalCostUsd: this.sessionTotalCostUsd,
       streamedPartKeys: this.streamedPartKeys,

packages/server/src/server/agent/providers/opencode/rewind.test.ts

@@ -0,0 +1,69 @@
+import { describe, expect, test } from "vitest";
+
+import { createTestLogger } from "../../../../test-utils/test-logger.js";
+import { OpenCodeAgentClient } from "../opencode-agent.js";
+import { revertOpenCodeConversationAndFiles, type OpenCodeRewindClient } from "./rewind.js";
+
+function rewindCapabilities(capabilities: OpenCodeAgentClient["capabilities"]) {
+  return {
+    supportsRewindConversation: capabilities.supportsRewindConversation,
+    supportsRewindFiles: capabilities.supportsRewindFiles,
+    supportsRewindBoth: capabilities.supportsRewindBoth,
+  };
+}
+
+class FakeOpencodeClient implements OpenCodeRewindClient {
+  readonly recordedReverts: Array<{ sessionID: string; directory: string; messageID: string }> = [];
+  revertResponse: Awaited<ReturnType<OpenCodeRewindClient["session"]["revert"]>> = {};
+
+  readonly session = {
+    revert: async (input: { sessionID: string; directory: string; messageID: string }) => {
+      this.recordedReverts.push(input);
+      return this.revertResponse;
+    },
+  };
+}
+
+describe("OpenCode rewind", () => {
+  test("rewinds conversation and files to the OpenCode user message", async () => {
+    const opencode = new FakeOpencodeClient();
+
+    await revertOpenCodeConversationAndFiles({
+      client: opencode,
+      sessionId: "session-1",
+      cwd: "/workspace/project",
+      messageId: "user-message-1",
+    });
+
+    expect(opencode.recordedReverts).toEqual([
+      { sessionID: "session-1", directory: "/workspace/project", messageID: "user-message-1" },
+    ]);
+  });
+
+  test("surfaces OpenCode revert errors", async () => {
+    const opencode = new FakeOpencodeClient();
+    opencode.revertResponse = { error: { name: "NotFoundError", message: "missing message" } };
+
+    await expect(
+      revertOpenCodeConversationAndFiles({
+        client: opencode,
+        sessionId: "session-1",
+        cwd: "/workspace/project",
+        messageId: "missing-message",
+      }),
+    ).rejects.toThrow("missing message");
+    expect(opencode.recordedReverts).toEqual([
+      { sessionID: "session-1", directory: "/workspace/project", messageID: "missing-message" },
+    ]);
+  });
+
+  test("declares only combined rewind capability", () => {
+    const client = new OpenCodeAgentClient(createTestLogger());
+
+    expect(rewindCapabilities(client.capabilities)).toEqual({
+      supportsRewindConversation: false,
+      supportsRewindFiles: false,
+      supportsRewindBoth: true,
+    });
+  });
+});

packages/server/src/server/agent/providers/opencode/rewind.ts

@@ -0,0 +1,29 @@
+import { toDiagnosticErrorMessage } from "../diagnostic-utils.js";
+
+export interface OpenCodeRewindClient {
+  session: {
+    revert(input: {
+      sessionID: string;
+      directory: string;
+      messageID: string;
+    }): Promise<{ error?: unknown }>;
+  };
+}
+
+export async function revertOpenCodeConversationAndFiles(input: {
+  client: OpenCodeRewindClient;
+  sessionId: string;
+  cwd: string;
+  messageId: string;
+}): Promise<void> {
+  // OpenCode keeps unrevert available only until a later prompt triggers its cleanup,
+  // which permanently drops reverted messages. Paseo v1 only exposes revert.
+  const response = await input.client.session.revert({
+    sessionID: input.sessionId,
+    directory: input.cwd,
+    messageID: input.messageId,
+  });
+  if (response.error) {
+    throw new Error(toDiagnosticErrorMessage(response.error));
+  }
+}

packages/server/src/server/agent/providers/pi/agent.test.ts

@@ -1,6 +1,4 @@
-import { existsSync, mkdirSync, mkdtempSync, readFileSync, writeFileSync } from "node:fs";
-import { tmpdir } from "node:os";
-import path from "node:path";
+import { closeSync, existsSync, fstatSync, openSync, readSync } from "node:fs";
 import pino from "pino";
 import { describe, expect, test } from "vitest";
 
@@ -15,12 +13,12 @@ function createClient(pi = new FakePi()): PiRpcAgentClient {
   });
 }
 
-function createClientWithPiAgentDir(agentDir: string): PiRpcAgentClient {
-  return new PiRpcAgentClient({
-    logger: pino({ level: "silent" }),
-    runtime: new FakePi(),
-    runtimeSettings: { env: { PI_CODING_AGENT_DIR: agentDir } },
-  });
+function rewindCapabilities(capabilities: PiRpcAgentSession["capabilities"]) {
+  return {
+    supportsRewindConversation: capabilities.supportsRewindConversation,
+    supportsRewindFiles: capabilities.supportsRewindFiles,
+    supportsRewindBoth: capabilities.supportsRewindBoth,
+  };
 }
 
 function createConfig(overrides: Partial<AgentSessionConfig> = {}): AgentSessionConfig {
@@ -31,6 +29,17 @@ function createConfig(overrides: Partial<AgentSessionConfig> = {}): AgentSession
   };
 }
 
+function readUtf8File(pathname: string): string {
+  const fd = openSync(pathname, "r");
+  try {
+    const buffer = Buffer.alloc(fstatSync(fd).size);
+    const bytesRead = readSync(fd, buffer, 0, buffer.length, 0);
+    return buffer.subarray(0, bytesRead).toString("utf8");
+  } finally {
+    closeSync(fd);
+  }
+}
+
 async function createSession(pi = new FakePi()): Promise<{
   pi: FakePi;
   session: PiRpcAgentSession;
@@ -116,6 +125,13 @@ class SessionEvents {
     );
   }
 
+  nextTimelineEvent(): Promise<Extract<AgentStreamEvent, { type: "timeline" }>> {
+    return this.nextEvent(
+      (event): event is Extract<AgentStreamEvent, { type: "timeline" }> =>
+        event.type === "timeline",
+    );
+  }
+
   private nextEvent<T extends AgentStreamEvent>(
     predicate: (event: AgentStreamEvent) => event is T,
   ): Promise<T> {
@@ -306,6 +322,50 @@ describe("PiRpcAgentSession", () => {
     ]);
   });
 
+  test("emits live user messages with captured Pi tree entry ids", async () => {
+    const { pi, session, events } = await createSession();
+    const fakeSession = pi.latestSession();
+
+    fakeSession.capturedUserEntries = [{ id: "entry-user-1", parentId: null, text: "hello" }];
+    await session.startTurn("hello");
+    fakeSession.emit({
+      type: "message_end",
+      message: { role: "user", content: "hello" },
+    });
+
+    await events.nextTimelineEvent();
+
+    expect(events.timelineItems()).toEqual([
+      { type: "user_message", text: "hello", messageId: "entry-user-1" },
+    ]);
+  });
+
+  test("adds Pi assistant context to generic provider finish errors", async () => {
+    const { pi, session, events } = await createSession();
+
+    await session.startTurn("write qa");
+    pi.latestSession().finishTurn({
+      role: "assistant",
+      provider: "openrouter",
+      model: "google/gemini-2.5-flash-lite",
+      responseId: "gen-test",
+      stopReason: "error",
+      errorMessage: "Provider finish_reason: error",
+      content: [
+        {
+          type: "thinking",
+          thinking: "I will use the write tool for qa.txt.",
+        },
+      ],
+    });
+
+    await expect(events.nextTurnFailure()).resolves.toMatchObject({
+      error: expect.stringContaining(
+        'Provider finish_reason: error (stopReason=error, model=openrouter/google/gemini-2.5-flash-lite, responseId=gen-test, partial="I will use the write tool for qa.txt.")',
+      ),
+    });
+  });
+
   test("resumes by launching Pi with the persisted session file and cwd metadata", async () => {
     const pi = new FakePi();
     const client = createClient(pi);
@@ -314,7 +374,7 @@ describe("PiRpcAgentSession", () => {
       {
         provider: "pi",
         sessionId: "pi-session-1",
-        nativeHandle: "/tmp/native-pi-session.jsonl",
+        nativeHandle: "/tmp/native-pi-session",
         metadata: {
           cwd: "/workspace/project",
           model: "openrouter/model-a",
@@ -324,22 +384,25 @@ describe("PiRpcAgentSession", () => {
       {},
     );
 
-    expect(pi.recordedLaunches).toEqual([
-      expect.objectContaining({
-        cwd: "/workspace/project",
-        session: "/tmp/native-pi-session.jsonl",
-        argv: [
-          "pi",
-          "--mode",
-          "rpc",
-          "--model",
-          "openrouter/model-a",
-          "--thinking",
-          "high",
-          "--session",
-          "/tmp/native-pi-session.jsonl",
-        ],
-      }),
+    expect(pi.recordedLaunches).toHaveLength(1);
+    const actualLaunch = pi.recordedLaunches[0]!;
+    expect(actualLaunch).toMatchObject({
+      cwd: "/workspace/project",
+      session: "/tmp/native-pi-session",
+    });
+    expect(actualLaunch.extensionPaths).toHaveLength(1);
+    expect(actualLaunch.argv).toEqual([
+      "pi",
+      "--mode",
+      "rpc",
+      "--model",
+      "openrouter/model-a",
+      "--thinking",
+      "high",
+      "--session",
+      "/tmp/native-pi-session",
+      "--extension",
+      actualLaunch.extensionPaths[0],
     ]);
   });
 
@@ -354,21 +417,23 @@ describe("PiRpcAgentSession", () => {
       }),
     );
 
-    expect(pi.recordedLaunches[0]).toEqual(
-      expect.objectContaining({
-        cwd: "/tmp/paseo-pi-rpc-test",
-        systemPrompt: "Agent prompt\n\nDaemon prompt",
-        argv: [
-          "pi",
-          "--mode",
-          "rpc",
-          "--thinking",
-          "medium",
-          "--append-system-prompt",
-          "Agent prompt\n\nDaemon prompt",
-        ],
-      }),
-    );
+    const actualLaunch = pi.recordedLaunches[0]!;
+    expect(actualLaunch).toMatchObject({
+      cwd: "/tmp/paseo-pi-rpc-test",
+      systemPrompt: "Agent prompt\n\nDaemon prompt",
+    });
+    expect(actualLaunch.extensionPaths).toHaveLength(1);
+    expect(actualLaunch.argv).toEqual([
+      "pi",
+      "--mode",
+      "rpc",
+      "--thinking",
+      "medium",
+      "--append-system-prompt",
+      "Agent prompt\n\nDaemon prompt",
+      "--extension",
+      actualLaunch.extensionPaths[0],
+    ]);
   });
 
   test("resumes Pi sessions with daemon system prompts appended", async () => {
@@ -379,7 +444,7 @@ describe("PiRpcAgentSession", () => {
       {
         provider: "pi",
         sessionId: "pi-session-1",
-        nativeHandle: "/tmp/native-pi-session.jsonl",
+        nativeHandle: "/tmp/native-pi-session",
         metadata: {
           cwd: "/workspace/project",
           model: "openrouter/model-a",
@@ -392,25 +457,28 @@ describe("PiRpcAgentSession", () => {
       },
     );
 
-    expect(pi.recordedLaunches).toEqual([
-      expect.objectContaining({
-        cwd: "/workspace/project",
-        session: "/tmp/native-pi-session.jsonl",
-        systemPrompt: "Agent prompt\n\nDaemon prompt",
-        argv: [
-          "pi",
-          "--mode",
-          "rpc",
-          "--model",
-          "openrouter/model-a",
-          "--thinking",
-          "high",
-          "--session",
-          "/tmp/native-pi-session.jsonl",
-          "--append-system-prompt",
-          "Agent prompt\n\nDaemon prompt",
-        ],
-      }),
+    expect(pi.recordedLaunches).toHaveLength(1);
+    const actualLaunch = pi.recordedLaunches[0]!;
+    expect(actualLaunch).toMatchObject({
+      cwd: "/workspace/project",
+      session: "/tmp/native-pi-session",
+      systemPrompt: "Agent prompt\n\nDaemon prompt",
+    });
+    expect(actualLaunch.extensionPaths).toHaveLength(1);
+    expect(actualLaunch.argv).toEqual([
+      "pi",
+      "--mode",
+      "rpc",
+      "--model",
+      "openrouter/model-a",
+      "--thinking",
+      "high",
+      "--session",
+      "/tmp/native-pi-session",
+      "--append-system-prompt",
+      "Agent prompt\n\nDaemon prompt",
+      "--extension",
+      actualLaunch.extensionPaths[0],
     ]);
   });
 
@@ -478,6 +546,27 @@ describe("PiRpcAgentClient", () => {
     ]);
   });
 
+  test("rewinds conversation through the Pi tree navigation bridge", async () => {
+    const { pi, session, events } = await createSession();
+    pi.latestSession().capturedUserEntries = [
+      { id: "entry-1", parentId: null, text: "first prompt" },
+      { id: "entry-3", parentId: "entry-2", text: "second prompt" },
+    ];
+
+    await session.startTurn("first prompt");
+    pi.latestSession().finishTurn({ role: "assistant", content: [] });
+    await events.nextTurnCompletion();
+
+    await session.revertConversation?.({ messageId: "entry-1" });
+
+    expect(rewindCapabilities(session.capabilities)).toEqual({
+      supportsRewindConversation: true,
+      supportsRewindFiles: false,
+      supportsRewindBoth: false,
+    });
+    expect(pi.latestSession().treeNavigationRequests).toEqual(["entry-1"]);
+  });
+
   test("injects MCP servers through pi-mcp-adapter when the extension is loaded", async () => {
     const pi = new FakePi();
     pi.queueCommands([
@@ -512,7 +601,8 @@ describe("PiRpcAgentClient", () => {
       cwd: "/tmp/paseo-pi-rpc-test",
       argv: ["pi", "--mode", "rpc"],
     });
-    const actualLaunch = pi.recordedLaunches[1];
+    const actualLaunch = pi.recordedLaunches[1]!;
+    expect(actualLaunch.extensionPaths).toHaveLength(1);
     expect(actualLaunch.argv).toEqual([
       "pi",
       "--mode",
@@ -521,12 +611,14 @@ describe("PiRpcAgentClient", () => {
       "medium",
       "--mcp-config",
       actualLaunch.mcpConfigPath,
+      "--extension",
+      actualLaunch.extensionPaths[0],
     ]);
     expect(session.capabilities.supportsMcpServers).toBe(true);
 
     const configPath = actualLaunch.mcpConfigPath;
     expect(configPath).toEqual(expect.any(String));
-    const injectedConfig = JSON.parse(readFileSync(configPath!, "utf8")) as {
+    const injectedConfig = JSON.parse(readUtf8File(configPath!)) as {
       mcpServers: Record<string, unknown>;
     };
     expect(injectedConfig).toEqual({
@@ -565,54 +657,19 @@ describe("PiRpcAgentClient", () => {
     );
 
     expect(pi.recordedLaunches).toHaveLength(2);
-    expect(pi.recordedLaunches[1]?.argv).toEqual(["pi", "--mode", "rpc", "--thinking", "medium"]);
-    expect(pi.recordedLaunches[1]?.mcpConfigPath).toBeUndefined();
-    expect(session.capabilities.supportsMcpServers).toBe(false);
-  });
-
-  test("lists persisted Pi sessions from the configured Pi agent directory", async () => {
-    const root = mkdtempSync(path.join(tmpdir(), "paseo-pi-client-"));
-    const cwd = path.join(root, "workspace");
-    const agentDir = path.join(root, "agent");
-    const sessionsDir = path.join(agentDir, "sessions", "--workspace--");
-    mkdirSync(sessionsDir, { recursive: true });
-    const sessionFile = path.join(sessionsDir, "20260101_session.jsonl");
-    writeFileSync(
-      sessionFile,
-      [
-        JSON.stringify({
-          type: "session",
-          version: 3,
-          id: "pi-session",
-          timestamp: "2026-01-01T00:00:00.000Z",
-          cwd,
-        }),
-        JSON.stringify({
-          type: "message",
-          id: "entry-1",
-          parentId: null,
-          timestamp: "2026-01-01T00:00:01.000Z",
-          message: { role: "user", content: "remember this" },
-        }),
-      ].join("\n") + "\n",
-      "utf8",
-    );
-    const client = createClientWithPiAgentDir(agentDir);
-
-    await expect(client.listPersistedAgents({ cwd })).resolves.toMatchObject([
-      {
-        provider: "pi",
-        sessionId: "pi-session",
-        cwd,
-        persistence: {
-          provider: "pi",
-          sessionId: "pi-session",
-          nativeHandle: sessionFile,
-          metadata: { provider: "pi", cwd },
-        },
-        timeline: [{ type: "user_message", text: "remember this" }],
-      },
+    const actualLaunch = pi.recordedLaunches[1]!;
+    expect(actualLaunch.extensionPaths).toHaveLength(1);
+    expect(actualLaunch.argv).toEqual([
+      "pi",
+      "--mode",
+      "rpc",
+      "--thinking",
+      "medium",
+      "--extension",
+      actualLaunch.extensionPaths[0],
     ]);
+    expect(actualLaunch.mcpConfigPath).toBeUndefined();
+    expect(session.capabilities.supportsMcpServers).toBe(false);
   });
 });
 

packages/server/src/server/agent/providers/pi/agent.ts

@@ -41,9 +41,13 @@ import {
   resolveBinaryVersion,
   toDiagnosticErrorMessage,
 } from "../diagnostic-utils.js";
-import { streamPiHistory } from "./history-mapper.js";
+import {
+  getUserMessageText,
+  streamPiHistory,
+  type PiCapturedUserMessageEntry,
+} from "./history-mapper.js";
 import { PiCliRuntime } from "./cli-runtime.js";
-import { listPiPersistedAgents } from "./session-descriptor.js";
+import { revertPiConversation } from "./rewind.js";
 import type { PiRuntime, PiRuntimeSession } from "./runtime.js";
 import type {
   PiAgentSessionEvent,
@@ -68,6 +72,11 @@ import {
 const PI_PROVIDER = "pi";
 const DEFAULT_PI_THINKING_LEVEL: PiThinkingLevel = "medium";
 const PI_BINARY_COMMAND = process.env.PI_COMMAND ?? process.env.PI_ACP_PI_COMMAND ?? "pi";
+const PASEO_PI_TREE_EXTENSION_COMMAND = "paseo_tree";
+const PASEO_PI_CAPTURE_EXTENSION_COMMAND = "paseo_capture_entries";
+const PASEO_PI_ENTRY_CAPTURE_MARKER = "PASEO_ENTRY_CAPTURE";
+const PASEO_PI_COMMAND_RESULT_MARKER = "PASEO_COMMAND_RESULT";
+const PASEO_PI_EXTENSION_RESULT_TIMEOUT_MS = 10_000;
 
 const PI_CAPABILITIES: AgentCapabilityFlags = {
   supportsStreaming: true,
@@ -76,6 +85,9 @@ const PI_CAPABILITIES: AgentCapabilityFlags = {
   supportsMcpServers: false,
   supportsReasoningStream: true,
   supportsToolInvocations: true,
+  supportsRewindConversation: true,
+  supportsRewindFiles: false,
+  supportsRewindBoth: false,
 };
 
 const PI_THINKING_OPTIONS: ReadonlyArray<{
@@ -149,6 +161,26 @@ interface PiMcpConfigFile {
   cleanup: () => void;
 }
 
+interface PiTempFile {
+  path: string;
+  cleanup: () => void;
+}
+
+interface PiCapturedEntry extends PiCapturedUserMessageEntry {
+  parentId: string | null;
+}
+
+interface PendingPiUserMessage {
+  text: string;
+  turnId: string | undefined;
+}
+
+interface PendingExtensionResult {
+  resolve: (value: unknown) => void;
+  reject: (error: Error) => void;
+  timer: NodeJS.Timeout;
+}
+
 function normalizePiModelLabel(label: string): string {
   return label.trim().replace(/[_\s]+/g, " ");
 }
@@ -359,6 +391,109 @@ function createPiMcpConfigFile(servers: Record<string, McpServerConfig>): PiMcpC
   };
 }
 
+function createPiPaseoExtensionFile(): PiTempFile {
+  const dir = mkdtempSync(join(tmpdir(), "paseo-pi-extension-"));
+  const filePath = join(dir, "paseo-integration.mjs");
+  writeFileSync(
+    filePath,
+    `
+	function decodePayload(encoded) {
+	  return JSON.parse(Buffer.from(encoded, "base64url").toString("utf8"));
+	}
+
+	function readTextContent(content) {
+	  if (typeof content === "string") {
+	    return content;
+	  }
+	  if (!Array.isArray(content)) {
+	    return "";
+	  }
+	  return content
+	    .filter((part) => part && part.type === "text" && typeof part.text === "string")
+	    .map((part) => part.text)
+	    .join("\\n\\n");
+	}
+
+	function getCapturedUserEntries(ctx) {
+	  return ctx.sessionManager
+	    .getEntries()
+	    .filter((entry) => entry.type === "message" && entry.message?.role === "user")
+	    .map((entry) => ({
+	      id: entry.id,
+	      parentId: entry.parentId ?? null,
+	      text: readTextContent(entry.message.content),
+	    }));
+	}
+
+	function emitEntryCapture(ctx, reason, requestId) {
+	  ctx.ui.notify(
+	    "${PASEO_PI_ENTRY_CAPTURE_MARKER} " +
+	      JSON.stringify({ reason, requestId, entries: getCapturedUserEntries(ctx) }),
+	    "info",
+	  );
+	}
+
+	function emitCommandResult(ctx, requestId, result) {
+	  ctx.ui.notify(
+	    "${PASEO_PI_COMMAND_RESULT_MARKER} " + JSON.stringify({ requestId, ...result }),
+	    result.ok ? "info" : "error",
+	  );
+	}
+	
+	export default function paseoIntegration(pi) {
+	  pi.on("session_start", async (_event, ctx) => {
+	    emitEntryCapture(ctx, "session_start");
+	  });
+
+	  pi.on("turn_end", async (_event, ctx) => {
+	    emitEntryCapture(ctx, "turn_end");
+	  });
+
+	  pi.registerCommand("${PASEO_PI_CAPTURE_EXTENSION_COMMAND}", {
+	    description: "Internal Paseo entry capture bridge",
+	    handler: async (args, ctx) => {
+	      const payload = decodePayload(args.trim());
+	      emitEntryCapture(ctx, "command", payload.requestId);
+	    },
+	  });
+
+	  pi.registerCommand("${PASEO_PI_TREE_EXTENSION_COMMAND}", {
+	    description: "Internal Paseo tree navigation bridge",
+	    handler: async (args, ctx) => {
+	      const payload = decodePayload(args.trim());
+	      try {
+	        const result = await ctx.navigateTree(payload.targetId, { summarize: false });
+	        emitEntryCapture(ctx, "tree_navigation");
+	        emitCommandResult(ctx, payload.requestId, { ok: true, result });
+	      } catch (error) {
+	        const message = error instanceof Error ? error.message : String(error);
+	        emitCommandResult(ctx, payload.requestId, { ok: false, error: message });
+	        throw error;
+	      }
+	    },
+	  });
+	}
+`.trimStart(),
+    "utf8",
+  );
+  return {
+    path: filePath,
+    cleanup: () => rmSync(dir, { recursive: true, force: true }),
+  };
+}
+
+function combineCleanup(cleanups: Array<(() => void) | undefined>): (() => void) | undefined {
+  const activeCleanups = cleanups.filter((cleanup): cleanup is () => void => Boolean(cleanup));
+  if (activeCleanups.length === 0) {
+    return undefined;
+  }
+  return () => {
+    for (const cleanup of activeCleanups) {
+      cleanup();
+    }
+  };
+}
+
 function isPiMcpAdapterCommand(command: PiRpcSlashCommand): boolean {
   if (command.source !== "extension" || !/^mcp(?::\d+)?$/.test(command.name)) {
     return false;
@@ -396,11 +531,43 @@ function modelToId(model: PiModel | null | undefined): string | null {
   return model?.provider && model.id ? `${model.provider}/${model.id}` : null;
 }
 
+function piAssistantText(message: Extract<PiAgentMessage, { role: "assistant" }>): string | null {
+  const text = message.content
+    .flatMap((part) => {
+      if (part.type === "text") {
+        return [part.text];
+      }
+      if (part.type === "thinking") {
+        return [part.thinking];
+      }
+      return [];
+    })
+    .join("\n\n")
+    .trim();
+  return text.length > 0 ? text : null;
+}
+
+function formatPiErrorMessage(message: Extract<PiAgentMessage, { role: "assistant" }>): string {
+  const headline = message.errorMessage?.trim() || "Pi turn failed";
+  const details = [
+    message.stopReason ? `stopReason=${message.stopReason}` : null,
+    message.provider && message.model ? `model=${message.provider}/${message.model}` : null,
+    message.responseModel ? `responseModel=${message.responseModel}` : null,
+    message.responseId ? `responseId=${message.responseId}` : null,
+  ].filter((detail): detail is string => detail !== null);
+  const partialText = piAssistantText(message);
+  if (partialText) {
+    details.push(`partial=${JSON.stringify(partialText.slice(0, 500))}`);
+  }
+  return details.length > 0 ? `${headline} (${details.join(", ")})` : headline;
+}
+
 function latestPiErrorMessage(messages: PiAgentMessage[]): string | null {
   const latestAssistant = messages.findLast((message) => message.role === "assistant");
-  return latestAssistant && "errorMessage" in latestAssistant
-    ? (latestAssistant.errorMessage ?? null)
-    : null;
+  if (!latestAssistant || !latestAssistant.errorMessage?.trim()) {
+    return null;
+  }
+  return formatPiErrorMessage(latestAssistant);
 }
 
 function isRecord(value: unknown): value is Record<string, unknown> {
@@ -411,6 +578,46 @@ function optionalString(value: unknown): string | undefined {
   return typeof value === "string" ? value : undefined;
 }
 
+function parseExtensionMarkerPayload(
+  message: string,
+  marker: string,
+): Record<string, unknown> | null {
+  const prefix = `${marker} `;
+  if (!message.startsWith(prefix)) {
+    return null;
+  }
+  try {
+    const parsed = JSON.parse(message.slice(prefix.length)) as unknown;
+    return isRecord(parsed) ? parsed : null;
+  } catch {
+    return null;
+  }
+}
+
+function parseCapturedEntries(value: unknown): PiCapturedEntry[] {
+  if (!Array.isArray(value)) {
+    return [];
+  }
+  return value.flatMap((entry): PiCapturedEntry[] => {
+    if (!isRecord(entry)) {
+      return [];
+    }
+    const id = optionalString(entry.id)?.trim();
+    const text = optionalString(entry.text);
+    if (!id || text === undefined) {
+      return [];
+    }
+    const parentId = entry.parentId === null ? null : optionalString(entry.parentId)?.trim();
+    return [
+      {
+        id,
+        parentId: parentId || null,
+        text,
+      },
+    ];
+  });
+}
+
 function mapExtensionUiRequestToPermission(
   event: Extract<PiRuntimeEvent, { type: "extension_ui_request" }>,
 ): AgentPermissionRequest | null {
@@ -533,6 +740,12 @@ export class PiRpcAgentSession implements AgentSession {
   private readonly pendingExtensionUiRequests = new Map<string, AgentPermissionRequest>();
   private activeTurnId: string | null = null;
   private lastKnownThinkingOptionId: string | null;
+  currentLeafOverrideId: string | null | undefined;
+  private readonly capturedUserEntries: PiCapturedEntry[] = [];
+  private readonly capturedUserEntriesById = new Map<string, PiCapturedEntry>();
+  private readonly seenUserEntryIds = new Set<string>();
+  private readonly pendingUserMessages: PendingPiUserMessage[] = [];
+  private readonly pendingExtensionResults = new Map<string, PendingExtensionResult>();
   private state: PiSessionState;
   private closed = false;
 
@@ -612,7 +825,12 @@ export class PiRpcAgentSession implements AgentSession {
   }
 
   async *streamHistory(): AsyncGenerator<AgentStreamEvent> {
-    yield* streamPiHistory(PI_PROVIDER, await this.runtimeSession.getMessages());
+    await this.requestEntryCapture("history");
+    yield* streamPiHistory(
+      PI_PROVIDER,
+      await this.runtimeSession.getMessages(),
+      this.capturedUserEntries,
+    );
   }
 
   async getRuntimeInfo(): Promise<AgentRuntimeInfo> {
@@ -683,6 +901,35 @@ export class PiRpcAgentSession implements AgentSession {
     await this.runtimeSession.abort();
   }
 
+  async revertConversation(input: { messageId: string }): Promise<void> {
+    if (this.activeTurnId) {
+      throw new Error("Cannot rewind the Pi conversation while a Pi turn is active");
+    }
+    await this.refreshState().catch(() => undefined);
+    await this.requestEntryCapture("rewind");
+    const targetEntry = this.capturedUserEntriesById.get(input.messageId);
+    if (!targetEntry) {
+      throw new Error(`Pi rewind target ${input.messageId} was not found in captured tree entries`);
+    }
+    await revertPiConversation({
+      messageId: input.messageId,
+      navigator: {
+        navigateTree: (treeEntryId) => this.runPiTreeExtensionCommand(treeEntryId),
+      },
+    });
+    // Pi keeps all tree nodes, so selecting the previous leaf later reverses this rewind.
+    this.currentLeafOverrideId = targetEntry.parentId;
+    this.activeToolCalls.clear();
+  }
+
+  private async runPiTreeExtensionCommand(targetId: string): Promise<unknown> {
+    const requestId = randomUUID();
+    const resultPromise = this.waitForExtensionResult(requestId);
+    const payload = Buffer.from(JSON.stringify({ targetId, requestId })).toString("base64url");
+    await this.runtimeSession.prompt(`/${PASEO_PI_TREE_EXTENSION_COMMAND} ${payload}`);
+    return await resultPromise;
+  }
+
   async close(): Promise<void> {
     if (this.closed) {
       return;
@@ -691,6 +938,7 @@ export class PiRpcAgentSession implements AgentSession {
     try {
       await this.runtimeSession.close();
     } finally {
+      this.rejectAllExtensionResults(new Error("Pi session closed"));
       this.cleanup?.();
     }
   }
@@ -742,9 +990,128 @@ export class PiRpcAgentSession implements AgentSession {
     return this.activeTurnId ?? undefined;
   }
 
+  private async requestEntryCapture(reason: string): Promise<void> {
+    const requestId = randomUUID();
+    const resultPromise = this.waitForExtensionResult(requestId);
+    const payload = Buffer.from(JSON.stringify({ requestId, reason })).toString("base64url");
+    await this.runtimeSession.prompt(`/${PASEO_PI_CAPTURE_EXTENSION_COMMAND} ${payload}`);
+    await resultPromise;
+  }
+
+  private waitForExtensionResult(requestId: string): Promise<unknown> {
+    return new Promise((resolve, reject) => {
+      const timer = setTimeout(() => {
+        this.pendingExtensionResults.delete(requestId);
+        reject(new Error(`Pi extension result timed out for request ${requestId}`));
+      }, PASEO_PI_EXTENSION_RESULT_TIMEOUT_MS);
+      this.pendingExtensionResults.set(requestId, { resolve, reject, timer });
+    });
+  }
+
+  private resolveExtensionResult(requestId: string, result: unknown): void {
+    const pending = this.pendingExtensionResults.get(requestId);
+    if (!pending) {
+      return;
+    }
+    clearTimeout(pending.timer);
+    this.pendingExtensionResults.delete(requestId);
+    pending.resolve(result);
+  }
+
+  private rejectExtensionResult(requestId: string, error: Error): void {
+    const pending = this.pendingExtensionResults.get(requestId);
+    if (!pending) {
+      return;
+    }
+    clearTimeout(pending.timer);
+    this.pendingExtensionResults.delete(requestId);
+    pending.reject(error);
+  }
+
+  private rejectAllExtensionResults(error: Error): void {
+    for (const requestId of this.pendingExtensionResults.keys()) {
+      this.rejectExtensionResult(requestId, error);
+    }
+  }
+
+  private recordCapturedUserEntries(entries: PiCapturedEntry[]): void {
+    const previouslySeenEntryIds = new Set(this.seenUserEntryIds);
+    this.capturedUserEntries.splice(0, this.capturedUserEntries.length, ...entries);
+    this.capturedUserEntriesById.clear();
+    for (const entry of entries) {
+      this.capturedUserEntriesById.set(entry.id, entry);
+    }
+    this.flushPendingUserMessages(previouslySeenEntryIds);
+    for (const entry of entries) {
+      this.seenUserEntryIds.add(entry.id);
+    }
+  }
+
+  private flushPendingUserMessages(previouslySeenEntryIds: Set<string>): void {
+    for (let index = 0; index < this.pendingUserMessages.length; index += 1) {
+      const pending = this.pendingUserMessages[index]!;
+      const entry = this.capturedUserEntries.find(
+        (candidate) => !previouslySeenEntryIds.has(candidate.id),
+      );
+      if (!entry) {
+        continue;
+      }
+      previouslySeenEntryIds.add(entry.id);
+      this.pendingUserMessages.splice(index, 1);
+      index -= 1;
+      this.emit({
+        type: "timeline",
+        provider: PI_PROVIDER,
+        turnId: pending.turnId,
+        item: {
+          type: "user_message",
+          text: pending.text,
+          messageId: entry.id,
+        },
+      });
+    }
+  }
+
+  private handleEntryCaptureMarker(message: string): boolean {
+    const payload = parseExtensionMarkerPayload(message, PASEO_PI_ENTRY_CAPTURE_MARKER);
+    if (!payload) {
+      return false;
+    }
+    const entries = parseCapturedEntries(payload.entries);
+    this.recordCapturedUserEntries(entries);
+    if (typeof payload.requestId === "string") {
+      this.resolveExtensionResult(payload.requestId, entries);
+    }
+    return true;
+  }
+
+  private handleCommandResultMarker(message: string): boolean {
+    const payload = parseExtensionMarkerPayload(message, PASEO_PI_COMMAND_RESULT_MARKER);
+    if (!payload) {
+      return false;
+    }
+    if (typeof payload.requestId !== "string") {
+      return true;
+    }
+    if (payload.ok === true) {
+      this.resolveExtensionResult(payload.requestId, payload.result);
+      return true;
+    }
+    const error = typeof payload.error === "string" ? payload.error : "Pi extension command failed";
+    this.rejectExtensionResult(payload.requestId, new Error(error));
+    return true;
+  }
+
   private handleExtensionUiRequest(
     event: Extract<PiRuntimeEvent, { type: "extension_ui_request" }>,
   ): void {
+    const message = optionalString(event.message);
+    if (event.method === "notify" && message) {
+      if (this.handleEntryCaptureMarker(message) || this.handleCommandResultMarker(message)) {
+        return;
+      }
+    }
+
     const request = mapExtensionUiRequestToPermission(event);
     if (!request) {
       return;
@@ -772,6 +1139,7 @@ export class PiRpcAgentSession implements AgentSession {
   }
 
   private handleProcessExit(error: string): void {
+    this.rejectAllExtensionResults(new Error(error));
     if (!this.activeTurnId) {
       return;
     }
@@ -803,6 +1171,11 @@ export class PiRpcAgentSession implements AgentSession {
           turnId,
         });
         return;
+      case "message_start":
+        return;
+      case "message_end":
+        this.handleMessageEnd(event, turnId);
+        return;
       case "message_update":
         this.handleMessageUpdate(event, turnId);
         return;
@@ -896,6 +1269,29 @@ export class PiRpcAgentSession implements AgentSession {
     }
   }
 
+  private handleMessageEnd(
+    event: Extract<PiAgentSessionEvent, { type: "message_end" }>,
+    turnId: string | undefined,
+  ): void {
+    if (event.message.role !== "user") {
+      return;
+    }
+    const text = getUserMessageText(event.message.content);
+    if (!text) {
+      return;
+    }
+    this.pendingUserMessages.push({ text, turnId });
+    void this.requestEntryCapture("message_end").catch((error: unknown) => {
+      const message = error instanceof Error ? error.message : String(error);
+      this.emit({
+        type: "turn_failed",
+        provider: PI_PROVIDER,
+        turnId,
+        error: message,
+      });
+    });
+  }
+
   private emitToolCallEvent(
     toolCallId: string,
     toolCall: PiTrackedToolCall,
@@ -981,6 +1377,7 @@ export class PiRpcAgentClient implements AgentClient {
     launchContext?: AgentLaunchContext,
   ): Promise<AgentSession> {
     const mcpConfig = await this.prepareMcpConfig(config.cwd, config.mcpServers);
+    const paseoExtension = createPiPaseoExtensionFile();
     let runtimeSession: PiRuntimeSession;
     try {
       runtimeSession = await this.runtime.startSession({
@@ -994,9 +1391,11 @@ export class PiRpcAgentClient implements AgentClient {
         ),
         env: launchContext?.env,
         mcpConfigPath: mcpConfig?.path,
+        extensionPaths: [paseoExtension.path],
       });
     } catch (error) {
       mcpConfig?.cleanup();
+      paseoExtension.cleanup();
       throw error;
     }
     try {
@@ -1005,11 +1404,12 @@ export class PiRpcAgentClient implements AgentClient {
         config,
         initialState: await runtimeSession.getState(),
         capabilities: withPiMcpCapability(mcpConfig !== null),
-        cleanup: mcpConfig?.cleanup,
+        cleanup: combineCleanup([mcpConfig?.cleanup, paseoExtension.cleanup]),
       });
     } catch (error) {
       await runtimeSession.close().catch(() => undefined);
       mcpConfig?.cleanup();
+      paseoExtension.cleanup();
       throw error;
     }
   }
@@ -1028,6 +1428,7 @@ export class PiRpcAgentClient implements AgentClient {
     const resumeConfig = buildResumeConfig(persistenceMetadata, overrides);
 
     const mcpConfig = await this.prepareMcpConfig(resumeConfig.cwd, resumeConfig.config.mcpServers);
+    const paseoExtension = createPiPaseoExtensionFile();
     let runtimeSession: PiRuntimeSession;
     try {
       runtimeSession = await this.runtime.startSession({
@@ -1040,9 +1441,11 @@ export class PiRpcAgentClient implements AgentClient {
           resumeConfig.config.daemonAppendSystemPrompt,
         ),
         mcpConfigPath: mcpConfig?.path,
+        extensionPaths: [paseoExtension.path],
       });
     } catch (error) {
       mcpConfig?.cleanup();
+      paseoExtension.cleanup();
       throw error;
     }
     try {
@@ -1051,11 +1454,12 @@ export class PiRpcAgentClient implements AgentClient {
         config: resumeConfig.config,
         initialState: await runtimeSession.getState(),
         capabilities: withPiMcpCapability(mcpConfig !== null),
-        cleanup: mcpConfig?.cleanup,
+        cleanup: combineCleanup([mcpConfig?.cleanup, paseoExtension.cleanup]),
       });
     } catch (error) {
       await runtimeSession.close().catch(() => undefined);
       mcpConfig?.cleanup();
+      paseoExtension.cleanup();
       throw error;
     }
   }
@@ -1074,12 +1478,9 @@ export class PiRpcAgentClient implements AgentClient {
   }
 
   async listPersistedAgents(
-    options?: ListPersistedAgentsOptions,
+    _options?: ListPersistedAgentsOptions,
   ): Promise<PersistedAgentDescriptor[]> {
-    return await listPiPersistedAgents({
-      ...options,
-      runtimeSettings: this.runtimeSettings,
-    });
+    return [];
   }
 
   async isAvailable(): Promise<boolean> {

packages/server/src/server/agent/providers/pi/history-mapper.test.ts

@@ -2,11 +2,14 @@ import { describe, expect, test } from "vitest";
 
 import type { AgentStreamEvent } from "../../agent-sdk-types.js";
 import type { PiAgentMessage } from "./rpc-types.js";
-import { streamPiHistory } from "./history-mapper.js";
+import { streamPiHistory, type PiCapturedUserMessageEntry } from "./history-mapper.js";
 
-async function collectHistory(messages: PiAgentMessage[]): Promise<AgentStreamEvent[]> {
+async function collectHistory(
+  messages: PiAgentMessage[],
+  userEntries: PiCapturedUserMessageEntry[] = [],
+): Promise<AgentStreamEvent[]> {
   const events: AgentStreamEvent[] = [];
-  for await (const event of streamPiHistory("pi", messages)) {
+  for await (const event of streamPiHistory("pi", messages, userEntries)) {
     events.push(event);
   }
   return events;
@@ -46,7 +49,6 @@ describe("Pi history mapper", () => {
         item: {
           type: "user_message",
           text: "read this\n\nthen answer",
-          messageId: "pi-user-0",
         },
       },
       {
@@ -124,4 +126,44 @@ describe("Pi history mapper", () => {
       },
     ]);
   });
+
+  test("uses Pi tree entry ids for replayed user messages", async () => {
+    await expect(
+      collectHistory(
+        [
+          { role: "user", content: "first prompt" },
+          { role: "assistant", content: [{ type: "text", text: "first answer" }] },
+          { role: "user", content: "second prompt" },
+        ],
+        [
+          { id: "entry-user-1", text: "first prompt" },
+          { id: "entry-user-2", text: "second prompt" },
+        ],
+      ),
+    ).resolves.toEqual([
+      {
+        type: "timeline",
+        provider: "pi",
+        item: {
+          type: "user_message",
+          text: "first prompt",
+          messageId: "entry-user-1",
+        },
+      },
+      {
+        type: "timeline",
+        provider: "pi",
+        item: { type: "assistant_message", text: "first answer" },
+      },
+      {
+        type: "timeline",
+        provider: "pi",
+        item: {
+          type: "user_message",
+          text: "second prompt",
+          messageId: "entry-user-2",
+        },
+      },
+    ]);
+  });
 });

packages/server/src/server/agent/providers/pi/history-mapper.ts

@@ -8,6 +8,11 @@ import {
   type PiTrackedToolCall,
 } from "./tool-call-mapper.js";
 
+export interface PiCapturedUserMessageEntry {
+  id: string;
+  text: string;
+}
+
 function isTextContentBlock(block: unknown): block is PiTextContent {
   return (
     typeof block === "object" &&
@@ -35,6 +40,7 @@ export function getUserMessageText(content: string | (PiTextContent | PiImageCon
 export async function* streamPiHistory(
   provider: string,
   messages: PiAgentMessage[],
+  userEntries: readonly PiCapturedUserMessageEntry[] = [],
 ): AsyncGenerator<AgentStreamEvent> {
   const pendingToolCalls = new Map<string, PiTrackedToolCall>();
   let userIndex = 0;
@@ -43,13 +49,14 @@ export async function* streamPiHistory(
     if (message.role === "user") {
       const text = getUserMessageText(message.content);
       if (text) {
+        const userEntry = userEntries[userIndex];
         yield {
           type: "timeline",
           provider,
           item: {
             type: "user_message",
             text,
-            messageId: `pi-user-${userIndex}`,
+            ...(userEntry ? { messageId: userEntry.id } : {}),
           },
         };
       }

packages/server/src/server/agent/providers/pi/rewind.ts

@@ -0,0 +1,14 @@
+export interface PiRewindNavigator {
+  navigateTree(targetId: string): Promise<unknown>;
+}
+
+export async function revertPiConversation(input: {
+  messageId: string;
+  navigator: PiRewindNavigator;
+}): Promise<void> {
+  const targetId = input.messageId.trim();
+  if (!targetId) {
+    throw new Error("Pi rewind requires a user message id");
+  }
+  await input.navigator.navigateTree(targetId);
+}

packages/server/src/server/agent/providers/pi/rpc-types.ts

@@ -33,6 +33,10 @@ export type PiAgentMessage =
   | {
       role: "assistant";
       content: PiAssistantContent[];
+      provider?: string;
+      model?: string;
+      responseId?: string;
+      responseModel?: string;
       errorMessage?: string | null;
       stopReason?: string;
     }
@@ -129,6 +133,8 @@ export type PiAssistantMessageEvent =
 export type PiAgentSessionEvent =
   | { type: "agent_start" }
   | { type: "turn_start" }
+  | { type: "message_start"; message: PiAgentMessage }
+  | { type: "message_end"; message: PiAgentMessage }
   | {
       type: "message_update";
       message: PiAgentMessage;

packages/server/src/server/agent/providers/pi/runtime.ts

@@ -17,6 +17,7 @@ export interface PiRuntimeLaunch {
   session?: string;
   systemPrompt?: string;
   mcpConfigPath?: string;
+  extensionPaths?: string[];
 }
 
 export interface PiStartSessionInput {
@@ -27,6 +28,7 @@ export interface PiStartSessionInput {
   session?: string;
   systemPrompt?: string;
   mcpConfigPath?: string;
+  extensionPaths?: string[];
 }
 
 export interface PiRuntimeSession {
@@ -85,6 +87,9 @@ export function buildPiLaunch(input: {
   if (input.session.mcpConfigPath) {
     argv.push("--mcp-config", input.session.mcpConfigPath);
   }
+  for (const extensionPath of input.session.extensionPaths ?? []) {
+    argv.push("--extension", extensionPath);
+  }
 
   return {
     cwd: input.session.cwd,
@@ -101,6 +106,7 @@ export function buildPiLaunch(input: {
     session: input.session.session,
     systemPrompt,
     mcpConfigPath: input.session.mcpConfigPath,
+    extensionPaths: input.session.extensionPaths,
   };
 }
 

packages/server/src/server/agent/providers/pi/session-descriptor.test.ts

@@ -1,297 +0,0 @@
-import { mkdirSync, mkdtempSync, realpathSync, symlinkSync, writeFileSync } from "node:fs";
-import { tmpdir } from "node:os";
-import path from "node:path";
-import { describe, expect, test } from "vitest";
-
-import { listPiPersistedAgents } from "./session-descriptor.js";
-
-const directorySymlinkType = process.platform === "win32" ? "junction" : "dir";
-
-function tempRoot(): string {
-  return mkdtempSync(path.join(tmpdir(), "paseo-pi-sessions-"));
-}
-
-function writeJsonl(filePath: string, entries: unknown[]): string {
-  mkdirSync(path.dirname(filePath), { recursive: true });
-  writeFileSync(filePath, `${entries.map((entry) => JSON.stringify(entry)).join("\n")}\n`, "utf8");
-  return filePath;
-}
-
-function piSession(overrides: {
-  id: string;
-  cwd: string;
-  timestamp?: string;
-  entries?: unknown[];
-}): unknown[] {
-  return [
-    {
-      type: "session",
-      version: 3,
-      id: overrides.id,
-      timestamp: overrides.timestamp ?? "2026-01-01T00:00:00.000Z",
-      cwd: overrides.cwd,
-    },
-    ...(overrides.entries ?? []),
-  ];
-}
-
-function message(input: {
-  role: "user" | "assistant";
-  content: unknown;
-  timestamp: string;
-}): unknown {
-  return {
-    type: "message",
-    id: `entry-${input.timestamp}`,
-    parentId: null,
-    timestamp: input.timestamp,
-    message: {
-      role: input.role,
-      content: input.content,
-    },
-  };
-}
-
-function sessionInfo(name: string, timestamp: string): unknown {
-  return {
-    type: "session_info",
-    id: `info-${timestamp}`,
-    parentId: null,
-    timestamp,
-    name,
-  };
-}
-
-describe("listPiPersistedAgents", () => {
-  test("lists Pi sessions from the configured agent dir", async () => {
-    const root = tempRoot();
-    const cwd = path.join(root, "project");
-    const sessionsDir = path.join(root, "agent", "sessions", "--project--");
-    const sessionFile = writeJsonl(
-      path.join(sessionsDir, "20260101_session-a.jsonl"),
-      piSession({
-        id: "session-a",
-        cwd,
-        entries: [
-          message({
-            role: "user",
-            content: "first prompt",
-            timestamp: "2026-01-01T00:00:01.000Z",
-          }),
-          message({
-            role: "assistant",
-            content: [{ type: "text", text: "answer" }],
-            timestamp: "2026-01-01T00:00:02.000Z",
-          }),
-          message({
-            role: "user",
-            content: [{ type: "text", text: "last prompt" }],
-            timestamp: "2026-01-01T00:00:03.000Z",
-          }),
-          sessionInfo("Named Pi Session", "2026-01-01T00:00:10.000Z"),
-        ],
-      }),
-    );
-
-    const descriptors = await listPiPersistedAgents({
-      cwd,
-      env: { PI_CODING_AGENT_DIR: path.join(root, "agent") },
-      homeDir: root,
-    });
-
-    expect(descriptors).toEqual([
-      {
-        provider: "pi",
-        sessionId: "session-a",
-        cwd,
-        title: "Named Pi Session",
-        lastActivityAt: new Date("2026-01-01T00:00:03.000Z"),
-        persistence: {
-          provider: "pi",
-          sessionId: "session-a",
-          nativeHandle: sessionFile,
-          metadata: {
-            provider: "pi",
-            cwd,
-          },
-        },
-        timeline: [
-          { type: "user_message", text: "first prompt" },
-          { type: "user_message", text: "last prompt" },
-        ],
-      },
-    ]);
-  });
-
-  test("uses the runtime session-dir override before Pi settings", async () => {
-    const root = tempRoot();
-    const cwd = path.join(root, "project");
-    const agentDir = path.join(root, "agent");
-    const runtimeSessionsDir = path.join(root, "runtime-sessions");
-    const settingsSessionsDir = path.join(root, "settings-sessions");
-    mkdirSync(agentDir, { recursive: true });
-    writeFileSync(
-      path.join(agentDir, "settings.json"),
-      JSON.stringify({ sessionDir: settingsSessionsDir }),
-      "utf8",
-    );
-    writeJsonl(
-      path.join(settingsSessionsDir, "ignored.jsonl"),
-      piSession({ id: "settings-session", cwd }),
-    );
-    writeJsonl(
-      path.join(runtimeSessionsDir, "selected.jsonl"),
-      piSession({
-        id: "runtime-session",
-        cwd,
-        entries: [
-          message({
-            role: "user",
-            content: "from runtime dir",
-            timestamp: "2026-01-01T00:00:01.000Z",
-          }),
-        ],
-      }),
-    );
-
-    const descriptors = await listPiPersistedAgents({
-      cwd,
-      runtimeSettings: {
-        env: {
-          PI_CODING_AGENT_DIR: agentDir,
-          PI_CODING_AGENT_SESSION_DIR: runtimeSessionsDir,
-        },
-      },
-      env: {},
-      homeDir: root,
-    });
-
-    expect(descriptors.map((descriptor) => descriptor.sessionId)).toEqual(["runtime-session"]);
-  });
-
-  test("resolves project settings sessionDir relative to the requested cwd", async () => {
-    const root = tempRoot();
-    const cwd = path.join(root, "project");
-    const projectSettingsDir = path.join(cwd, ".pi");
-    const sessionsDir = path.join(cwd, "relative-sessions");
-    mkdirSync(projectSettingsDir, { recursive: true });
-    writeFileSync(
-      path.join(projectSettingsDir, "settings.json"),
-      JSON.stringify({ sessionDir: "relative-sessions" }),
-      "utf8",
-    );
-    writeJsonl(
-      path.join(sessionsDir, "relative.jsonl"),
-      piSession({
-        id: "relative-session",
-        cwd,
-        entries: [
-          message({
-            role: "user",
-            content: "relative settings",
-            timestamp: "2026-01-01T00:00:01.000Z",
-          }),
-        ],
-      }),
-    );
-
-    const descriptors = await listPiPersistedAgents({
-      cwd,
-      env: { PI_CODING_AGENT_DIR: path.join(root, "agent") },
-      homeDir: root,
-    });
-
-    expect(descriptors.map((descriptor) => descriptor.sessionId)).toEqual(["relative-session"]);
-  });
-
-  test("matches sessions stored with the real cwd when the requested cwd is symlinked", async () => {
-    const root = tempRoot();
-    const realCwd = path.join(root, "real-project");
-    const linkedCwd = path.join(root, "linked-project");
-    mkdirSync(realCwd, { recursive: true });
-    symlinkSync(realCwd, linkedCwd, directorySymlinkType);
-    const persistedCwd = realpathSync(linkedCwd);
-    const sessionsDir = path.join(root, "agent", "sessions");
-    writeJsonl(
-      path.join(sessionsDir, "symlinked.jsonl"),
-      piSession({
-        id: "symlinked-session",
-        cwd: persistedCwd,
-        entries: [
-          message({
-            role: "user",
-            content: "through symlink",
-            timestamp: "2026-01-01T00:00:01.000Z",
-          }),
-        ],
-      }),
-    );
-
-    const descriptors = await listPiPersistedAgents({
-      cwd: linkedCwd,
-      env: { PI_CODING_AGENT_DIR: path.join(root, "agent") },
-      homeDir: root,
-    });
-
-    expect(descriptors.map((descriptor) => descriptor.sessionId)).toEqual(["symlinked-session"]);
-  });
-
-  test("filters by cwd, sorts by activity, and ignores invalid session files", async () => {
-    const root = tempRoot();
-    const cwd = path.join(root, "project");
-    const otherCwd = path.join(root, "other");
-    const sessionsDir = path.join(root, "agent", "sessions");
-    writeJsonl(
-      path.join(sessionsDir, "older.jsonl"),
-      piSession({
-        id: "older",
-        cwd,
-        entries: [
-          message({
-            role: "user",
-            content: "older",
-            timestamp: "2026-01-01T00:00:01.000Z",
-          }),
-        ],
-      }),
-    );
-    writeJsonl(
-      path.join(sessionsDir, "newer.jsonl"),
-      piSession({
-        id: "newer",
-        cwd,
-        entries: [
-          message({
-            role: "user",
-            content: "newer",
-            timestamp: "2026-01-01T00:00:02.000Z",
-          }),
-        ],
-      }),
-    );
-    writeJsonl(
-      path.join(sessionsDir, "outside.jsonl"),
-      piSession({
-        id: "outside",
-        cwd: otherCwd,
-        entries: [
-          message({
-            role: "user",
-            content: "outside",
-            timestamp: "2026-01-01T00:00:03.000Z",
-          }),
-        ],
-      }),
-    );
-    writeFileSync(path.join(sessionsDir, "broken.jsonl"), '{"type":"nope"}\n', "utf8");
-
-    const descriptors = await listPiPersistedAgents({
-      cwd,
-      limit: 1,
-      env: { PI_CODING_AGENT_DIR: path.join(root, "agent") },
-      homeDir: root,
-    });
-
-    expect(descriptors.map((descriptor) => descriptor.sessionId)).toEqual(["newer"]);
-  });
-});

packages/server/src/server/agent/providers/pi/session-descriptor.ts

@@ -1,372 +0,0 @@
-import { open, readdir, readFile, stat } from "node:fs/promises";
-import { homedir } from "node:os";
-import path from "node:path";
-
-import type {
-  AgentPersistenceHandle,
-  AgentTimelineItem,
-  ListPersistedAgentsOptions,
-  PersistedAgentDescriptor,
-} from "../../agent-sdk-types.js";
-import type { ProviderRuntimeSettings } from "../../provider-launch-config.js";
-import { createRealpathAwarePathMatcher } from "../../../../utils/path.js";
-
-const PI_PROVIDER = "pi";
-const PI_CONFIG_DIR_NAME = ".pi";
-const PI_AGENT_DIR_ENV = "PI_CODING_AGENT_DIR";
-const PI_SESSION_DIR_ENV = "PI_CODING_AGENT_SESSION_DIR";
-const HEAD_BYTES = 64 * 1024;
-const TAIL_BYTES = 256 * 1024;
-const FULL_SCAN_LINE_LIMIT = 2_000;
-
-interface PiSessionDescriptorOptions extends ListPersistedAgentsOptions {
-  runtimeSettings?: ProviderRuntimeSettings;
-  env?: NodeJS.ProcessEnv;
-  homeDir?: string;
-}
-
-interface PiSessionHeader {
-  sessionId: string;
-  cwd: string;
-  createdAt: Date | null;
-}
-
-interface PiSessionTail {
-  title: string | null;
-  lastActivityAt: Date | null;
-  lastUserMessage: string | null;
-}
-
-export async function listPiPersistedAgents(
-  options: PiSessionDescriptorOptions = {},
-): Promise<PersistedAgentDescriptor[]> {
-  const sessionsDir = await resolvePiSessionsDir(options);
-  const files = await walkJsonlFiles(sessionsDir);
-  const matchesCwd = options.cwd ? createRealpathAwarePathMatcher(options.cwd) : null;
-  const limit = options.limit ?? 20;
-  const descriptors: PersistedAgentDescriptor[] = [];
-
-  for (const file of files) {
-    const descriptor = await readPiSessionDescriptor(file);
-    if (!descriptor) continue;
-    if (matchesCwd && !matchesCwd(descriptor.cwd)) continue;
-    descriptors.push(descriptor);
-  }
-
-  return descriptors
-    .sort((left, right) => right.lastActivityAt.getTime() - left.lastActivityAt.getTime())
-    .slice(0, limit);
-}
-
-async function resolvePiSessionsDir(options: PiSessionDescriptorOptions): Promise<string> {
-  const env = options.env ?? process.env;
-  const homeDir = options.homeDir ?? homedir();
-  const baseDir = options.cwd ?? process.cwd();
-  const agentDir = resolvePiAgentDir({ runtimeSettings: options.runtimeSettings, env, homeDir });
-
-  const envSessionDir =
-    options.runtimeSettings?.env?.[PI_SESSION_DIR_ENV] ?? env[PI_SESSION_DIR_ENV];
-  if (envSessionDir?.trim()) {
-    return resolveConfigPath(envSessionDir, { baseDir, homeDir });
-  }
-
-  const settingsSessionDir = await readConfiguredSessionDir({
-    agentDir,
-    cwd: options.cwd,
-  });
-  if (settingsSessionDir?.trim()) {
-    return resolveConfigPath(settingsSessionDir, { baseDir, homeDir });
-  }
-
-  return path.join(agentDir, "sessions");
-}
-
-function resolvePiAgentDir(input: {
-  runtimeSettings?: ProviderRuntimeSettings;
-  env: NodeJS.ProcessEnv;
-  homeDir: string;
-}): string {
-  const configured = input.runtimeSettings?.env?.[PI_AGENT_DIR_ENV] ?? input.env[PI_AGENT_DIR_ENV];
-  if (configured?.trim()) {
-    return resolveConfigPath(configured, { baseDir: process.cwd(), homeDir: input.homeDir });
-  }
-  return path.join(input.homeDir, PI_CONFIG_DIR_NAME, "agent");
-}
-
-async function readConfiguredSessionDir(input: {
-  agentDir: string;
-  cwd: string | undefined;
-}): Promise<string | null> {
-  const values = await Promise.all([
-    readSessionDirFromSettings(path.join(input.agentDir, "settings.json")),
-    input.cwd
-      ? readSessionDirFromSettings(path.join(input.cwd, PI_CONFIG_DIR_NAME, "settings.json"))
-      : null,
-  ]);
-  return values[1] ?? values[0] ?? null;
-}
-
-async function readSessionDirFromSettings(settingsPath: string): Promise<string | null> {
-  try {
-    const parsed = JSON.parse(await readFile(settingsPath, "utf8")) as unknown;
-    if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) {
-      return null;
-    }
-    const sessionDir = Reflect.get(parsed, "sessionDir");
-    return typeof sessionDir === "string" && sessionDir.trim() ? sessionDir : null;
-  } catch {
-    return null;
-  }
-}
-
-function resolveConfigPath(value: string, options: { baseDir: string; homeDir: string }): string {
-  if (value === "~") {
-    return options.homeDir;
-  }
-  if (value.startsWith("~/")) {
-    return path.join(options.homeDir, value.slice(2));
-  }
-  return path.isAbsolute(value) ? value : path.resolve(options.baseDir, value);
-}
-
-async function walkJsonlFiles(root: string): Promise<string[]> {
-  let entries: import("node:fs").Dirent[];
-  try {
-    entries = await readdir(root, { withFileTypes: true });
-  } catch {
-    return [];
-  }
-
-  const files = await Promise.all(
-    entries.map(async (entry) => {
-      const entryPath = path.join(root, entry.name);
-      if (entry.isDirectory()) {
-        return await walkJsonlFiles(entryPath);
-      }
-      return entry.isFile() && entry.name.endsWith(".jsonl") ? [entryPath] : [];
-    }),
-  );
-  return files.flat();
-}
-
-async function readPiSessionDescriptor(filePath: string): Promise<PersistedAgentDescriptor | null> {
-  const firstLine = await readFirstLine(filePath);
-  if (!firstLine) return null;
-  const header = parseSessionHeader(firstLine);
-  if (!header) return null;
-
-  const tail = await readTail(filePath).catch(() => "");
-  const tailInfo = parseSessionTail(tail);
-  const headInfo = await scanSessionHead(filePath);
-  const title = tailInfo.title ?? headInfo.title ?? headInfo.firstUserMessage;
-  const lastActivityAt =
-    tailInfo.lastActivityAt ?? (await readFileMtime(filePath)) ?? header.createdAt ?? new Date(0);
-  const timeline = buildPreviewTimeline({
-    firstUserMessage: headInfo.firstUserMessage,
-    lastUserMessage: tailInfo.lastUserMessage,
-  });
-
-  const persistence: AgentPersistenceHandle = {
-    provider: PI_PROVIDER,
-    sessionId: header.sessionId,
-    nativeHandle: filePath,
-    metadata: {
-      provider: PI_PROVIDER,
-      cwd: header.cwd,
-    },
-  };
-
-  return {
-    provider: PI_PROVIDER,
-    sessionId: header.sessionId,
-    cwd: header.cwd,
-    title,
-    lastActivityAt,
-    persistence,
-    timeline,
-  };
-}
-
-async function readFirstLine(filePath: string): Promise<string | null> {
-  const handle = await open(filePath, "r").catch(() => null);
-  if (!handle) return null;
-  try {
-    const buffer = Buffer.alloc(HEAD_BYTES);
-    const { bytesRead } = await handle.read(buffer, 0, buffer.length, 0);
-    if (bytesRead <= 0) return null;
-    const chunk = buffer.subarray(0, bytesRead).toString("utf8");
-    const newlineIndex = chunk.indexOf("\n");
-    return (newlineIndex === -1 ? chunk : chunk.slice(0, newlineIndex)).trim();
-  } finally {
-    await handle.close().catch(() => undefined);
-  }
-}
-
-async function readTail(filePath: string): Promise<string> {
-  const fileStats = await stat(filePath);
-  const start = Math.max(0, fileStats.size - TAIL_BYTES);
-  const length = fileStats.size - start;
-  const handle = await open(filePath, "r");
-  try {
-    const buffer = Buffer.alloc(length);
-    const { bytesRead } = await handle.read(buffer, 0, buffer.length, start);
-    return buffer.subarray(0, bytesRead).toString("utf8");
-  } finally {
-    await handle.close().catch(() => undefined);
-  }
-}
-
-async function readFileMtime(filePath: string): Promise<Date | null> {
-  try {
-    return (await stat(filePath)).mtime;
-  } catch {
-    return null;
-  }
-}
-
-function parseSessionHeader(firstLine: string): PiSessionHeader | null {
-  const entry = parseJsonRecord(firstLine);
-  if (!entry || entry.type !== "session") return null;
-  const sessionId = typeof entry.id === "string" ? entry.id : null;
-  const cwd = typeof entry.cwd === "string" ? entry.cwd : null;
-  if (!sessionId || !cwd) return null;
-  const createdAt = parseDate(entry.timestamp);
-  return { sessionId, cwd, createdAt };
-}
-
-function parseSessionTail(tail: string): PiSessionTail {
-  const lines = tail.split(/\r?\n/);
-  let title: string | null = null;
-  let lastActivityAt: Date | null = null;
-  let fallbackTimestamp: Date | null = null;
-  let lastUserMessage: string | null = null;
-
-  for (let index = lines.length - 1; index >= 0; index -= 1) {
-    const entry = parseJsonRecord(lines[index].trim());
-    if (!entry) continue;
-
-    if (!title && entry.type === "session_info") {
-      title = readNonEmptyString(entry.name);
-    }
-
-    const entryTimestamp = parseDate(entry.timestamp);
-    if (!fallbackTimestamp && entryTimestamp) {
-      fallbackTimestamp = entryTimestamp;
-    }
-
-    if (entry.type !== "message") {
-      continue;
-    }
-
-    if (!lastActivityAt && entryTimestamp) {
-      lastActivityAt = entryTimestamp;
-    }
-
-    if (!lastUserMessage && isRecord(entry.message) && entry.message.role === "user") {
-      lastUserMessage = extractMessageText(entry.message.content);
-    }
-
-    if (title && lastActivityAt && lastUserMessage) {
-      break;
-    }
-  }
-
-  return { title, lastActivityAt: lastActivityAt ?? fallbackTimestamp, lastUserMessage };
-}
-
-async function scanSessionHead(filePath: string): Promise<{
-  title: string | null;
-  firstUserMessage: string | null;
-}> {
-  let content: string;
-  try {
-    content = await readFile(filePath, "utf8");
-  } catch {
-    return { title: null, firstUserMessage: null };
-  }
-
-  let title: string | null = null;
-  let firstUserMessage: string | null = null;
-  let lineCount = 0;
-
-  for (const rawLine of content.split(/\r?\n/)) {
-    lineCount += 1;
-    const entry = parseJsonRecord(rawLine.trim());
-    if (!entry) continue;
-
-    if (entry.type === "session_info") {
-      title = readNonEmptyString(entry.name) ?? title;
-    }
-
-    if (!firstUserMessage && entry.type === "message" && isRecord(entry.message)) {
-      if (entry.message.role === "user") {
-        firstUserMessage = extractMessageText(entry.message.content);
-      }
-    }
-
-    if (title && firstUserMessage) {
-      break;
-    }
-    if (lineCount >= FULL_SCAN_LINE_LIMIT && firstUserMessage) {
-      break;
-    }
-  }
-
-  return { title, firstUserMessage };
-}
-
-function buildPreviewTimeline(input: {
-  firstUserMessage: string | null;
-  lastUserMessage: string | null;
-}): AgentTimelineItem[] {
-  const items: AgentTimelineItem[] = [];
-  if (input.firstUserMessage) {
-    items.push({ type: "user_message", text: input.firstUserMessage });
-  }
-  if (input.lastUserMessage && input.lastUserMessage !== input.firstUserMessage) {
-    items.push({ type: "user_message", text: input.lastUserMessage });
-  }
-  return items;
-}
-
-function parseJsonRecord(line: string): Record<string, unknown> | null {
-  if (!line) return null;
-  try {
-    const parsed = JSON.parse(line) as unknown;
-    return isRecord(parsed) ? parsed : null;
-  } catch {
-    return null;
-  }
-}
-
-function isRecord(value: unknown): value is Record<string, unknown> {
-  return typeof value === "object" && value !== null && !Array.isArray(value);
-}
-
-function readNonEmptyString(value: unknown): string | null {
-  return typeof value === "string" && value.trim() ? value.trim() : null;
-}
-
-function parseDate(value: unknown): Date | null {
-  if (typeof value !== "string" && typeof value !== "number") {
-    return null;
-  }
-  const date = new Date(value);
-  return Number.isNaN(date.getTime()) ? null : date;
-}
-
-function extractMessageText(content: unknown): string | null {
-  if (typeof content === "string") {
-    return content.trim() || null;
-  }
-  if (!Array.isArray(content)) {
-    return null;
-  }
-  const text = content
-    .flatMap((part) =>
-      isRecord(part) && part.type === "text" && typeof part.text === "string" ? [part.text] : [],
-    )
-    .join("\n\n")
-    .trim();
-  return text || null;
-}

packages/server/src/server/agent/providers/pi/test-utils/fake-pi.ts

@@ -53,6 +53,8 @@ export class FakePiSession implements PiRuntimeSession {
   readonly prompts: Array<{ message: string; imageCount: number }> = [];
   readonly setModelRequests: Array<{ provider: string; modelId: string }> = [];
   readonly setThinkingLevelRequests: string[] = [];
+  readonly treeNavigationRequests: string[] = [];
+  capturedUserEntries: Array<{ id: string; parentId: string | null; text: string }> = [];
   abortRequested = false;
   readonly canceledExtensionUiRequests: string[] = [];
   readonly extensionUiResponses: Array<{
@@ -77,7 +79,7 @@ export class FakePiSession implements PiRuntimeSession {
       thinkingLevel: "medium",
       isStreaming: false,
       isCompacting: false,
-      sessionFile: launch.session ?? "/tmp/pi-session.jsonl",
+      sessionFile: launch.session ?? "/tmp/pi-session",
       sessionId: "pi-session-1",
       messageCount: 0,
       pendingMessageCount: 0,
@@ -96,6 +98,8 @@ export class FakePiSession implements PiRuntimeSession {
     images?: Array<{ type: "image"; data: string; mimeType: string }>,
   ): Promise<void> {
     this.prompts.push({ message, imageCount: images?.length ?? 0 });
+    this.handleTreeNavigationCommand(message);
+    this.handleEntryCaptureCommand(message);
   }
 
   async abort(): Promise<void> {
@@ -158,4 +162,62 @@ export class FakePiSession implements PiRuntimeSession {
     this.messages = [...this.messages, message];
     this.emit({ type: "agent_end", messages: this.messages });
   }
+
+  private handleTreeNavigationCommand(message: string): void {
+    const prefix = "/paseo_tree ";
+    if (!message.startsWith(prefix)) {
+      return;
+    }
+    const payload = JSON.parse(
+      Buffer.from(message.slice(prefix.length), "base64url").toString("utf8"),
+    ) as { targetId?: unknown; requestId?: unknown };
+    if (typeof payload.targetId !== "string" || typeof payload.requestId !== "string") {
+      return;
+    }
+    this.treeNavigationRequests.push(payload.targetId);
+    this.emitEntryCapture(undefined, "tree_navigation");
+    this.emitExtensionCommandResult(payload.requestId, { ok: true, result: {} });
+  }
+
+  private handleEntryCaptureCommand(message: string): void {
+    const prefix = "/paseo_capture_entries ";
+    if (!message.startsWith(prefix)) {
+      return;
+    }
+    const payload = JSON.parse(
+      Buffer.from(message.slice(prefix.length), "base64url").toString("utf8"),
+    ) as { requestId?: unknown; reason?: unknown };
+    if (typeof payload.requestId !== "string") {
+      return;
+    }
+    this.emitEntryCapture(
+      payload.requestId,
+      typeof payload.reason === "string" ? payload.reason : "command",
+    );
+  }
+
+  emitEntryCapture(requestId?: string, reason = "test"): void {
+    this.emit({
+      type: "extension_ui_request",
+      id: `capture-${requestId ?? reason}`,
+      method: "notify",
+      message: `PASEO_ENTRY_CAPTURE ${JSON.stringify({
+        reason,
+        requestId,
+        entries: this.capturedUserEntries,
+      })}`,
+    });
+  }
+
+  private emitExtensionCommandResult(
+    requestId: string,
+    result: { ok: true; result: unknown } | { ok: false; error: string },
+  ): void {
+    this.emit({
+      type: "extension_ui_request",
+      id: `command-${requestId}`,
+      method: "notify",
+      message: `PASEO_COMMAND_RESULT ${JSON.stringify({ requestId, ...result })}`,
+    });
+  }
 }

packages/server/src/server/agent/providers/provider-availability.test.ts

@@ -9,7 +9,7 @@ import { AgentManager } from "../agent-manager.js";
 import { AgentStorage } from "../agent-storage.js";
 
 import { ClaudeAgentClient } from "./claude/agent.js";
-import { __codexAppServerInternals, CodexAppServerAgentClient } from "./codex-app-server-agent.js";
+import { CodexAppServerAgentClient, findDefaultCodexBinary } from "./codex-app-server-agent.js";
 import { OpenCodeAgentClient } from "./opencode-agent.js";
 
 const originalEnv = {
@@ -88,7 +88,7 @@ describe("default provider availability", () => {
     try {
       const client = new CodexAppServerAgentClient(createTestLogger());
 
-      await expect(__codexAppServerInternals.findDefaultCodexBinary()).resolves.toBe(codexExe);
+      await expect(findDefaultCodexBinary()).resolves.toBe(codexExe);
       await expect(client.isAvailable()).resolves.toBe(true);
     } finally {
       Object.defineProperty(process, "platform", { value: originalPlatform, writable: true });

packages/server/src/server/agent/rewind/rewind.test.ts

@@ -0,0 +1,118 @@
+import { describe, expect, test } from "vitest";
+
+import { createTestLogger } from "../../../test-utils/test-logger.js";
+import { AgentManager } from "../agent-manager.js";
+import type {
+  AgentClient,
+  AgentSession,
+  AgentSessionConfig,
+  ListModelsOptions,
+} from "../agent-sdk-types.js";
+import { FakeRewindSession, REWIND_TEST_CAPABILITIES } from "./test-rewind-session.js";
+
+class FakeRewindClient implements AgentClient {
+  readonly provider = "claude";
+  readonly capabilities = REWIND_TEST_CAPABILITIES;
+
+  constructor(readonly session: FakeRewindSession) {}
+
+  async createSession(_config: AgentSessionConfig): Promise<AgentSession> {
+    return this.session;
+  }
+
+  async resumeSession(): Promise<AgentSession> {
+    return this.session;
+  }
+
+  async listModels(_options: ListModelsOptions) {
+    return [];
+  }
+
+  async isAvailable() {
+    return true;
+  }
+}
+
+class RewindHistoryGate {
+  private gate: Promise<void> | null = null;
+  private releaseGate: (() => void) | null = null;
+
+  hold(): void {
+    this.gate = new Promise<void>((resolve) => {
+      this.releaseGate = resolve;
+    });
+  }
+
+  release(): void {
+    this.releaseGate?.();
+    this.releaseGate = null;
+    this.gate = null;
+  }
+
+  async wait(): Promise<void> {
+    await this.gate;
+  }
+}
+
+async function createRewindHarness(options: { historyGate?: RewindHistoryGate } = {}) {
+  const session = new FakeRewindSession(options.historyGate?.wait.bind(options.historyGate));
+  const manager = new AgentManager({
+    clients: { claude: new FakeRewindClient(session) },
+    logger: createTestLogger(),
+    idFactory: () => "00000000-0000-4000-8000-000000000901",
+  });
+  const agent = await manager.createAgent({
+    provider: "claude",
+    cwd: process.cwd(),
+  });
+  return { manager, session, agentId: agent.id };
+}
+
+describe("AgentManager rewind", () => {
+  test("rewinds the conversation and rehydrates the timeline", async () => {
+    const { manager, session, agentId } = await createRewindHarness();
+
+    await manager.rewind(agentId, "message-1", "conversation");
+
+    expect(session.recordedRewinds).toEqual([{ mode: "conversation", messageId: "message-1" }]);
+    expect(session.historyReadCount).toBe(1);
+    expect(manager.fetchTimeline(agentId, { limit: 0 }).rows.map((row) => row.item)).toEqual([
+      { type: "user_message", text: "before", messageId: "message-1" },
+    ]);
+  });
+
+  test("rewinds files without rehydrating the conversation timeline", async () => {
+    const { manager, session, agentId } = await createRewindHarness();
+
+    await manager.rewind(agentId, "message-1", "files");
+
+    expect(session.recordedRewinds).toEqual([{ mode: "files", messageId: "message-1" }]);
+    expect(session.historyReadCount).toBe(0);
+  });
+
+  test("aborts an in-flight turn before rewinding", async () => {
+    const { manager, session, agentId } = await createRewindHarness();
+    const run = manager.streamAgent(agentId, "keep working");
+    await run.next();
+
+    await manager.rewind(agentId, "message-1", "files");
+
+    expect(session.aborted).toBe(true);
+    expect(session.recordedRewinds).toEqual([{ mode: "files", messageId: "message-1" }]);
+  });
+
+  test("blocks new prompts until the rehydrate epoch broadcasts", async () => {
+    const historyGate = new RewindHistoryGate();
+    historyGate.hold();
+    const { manager, agentId } = await createRewindHarness({ historyGate });
+
+    const rewind = manager.rewind(agentId, "message-1", "both");
+
+    expect(() => manager.streamAgent(agentId, "too early")).toThrow(
+      "Agent 00000000-0000-4000-8000-000000000901 already has an active run",
+    );
+
+    historyGate.release();
+    await rewind;
+  });
+});

packages/server/src/server/agent/rewind/rewind.ts

@@ -0,0 +1,36 @@
+import type { AgentSession } from "../agent-sdk-types.js";
+
+export type RewindMode = "conversation" | "files" | "both";
+
+export class RewindCapabilityError extends Error {
+  constructor(mode: RewindMode) {
+    super(`Provider does not support rewinding ${mode}`);
+    this.name = "RewindCapabilityError";
+  }
+}
+
+export async function invokeRewindCapability(
+  session: AgentSession,
+  input: { messageId: string; mode: RewindMode },
+): Promise<void> {
+  switch (input.mode) {
+    case "conversation":
+      if (!session.capabilities.supportsRewindConversation || !session.revertConversation) {
+        throw new RewindCapabilityError(input.mode);
+      }
+      await session.revertConversation({ messageId: input.messageId });
+      return;
+    case "files":
+      if (!session.capabilities.supportsRewindFiles || !session.revertFiles) {
+        throw new RewindCapabilityError(input.mode);
+      }
+      await session.revertFiles({ messageId: input.messageId });
+      return;
+    case "both":
+      if (!session.capabilities.supportsRewindBoth || !session.revertBoth) {
+        throw new RewindCapabilityError(input.mode);
+      }
+      await session.revertBoth({ messageId: input.messageId });
+      return;
+  }
+}

packages/server/src/server/agent/rewind/test-rewind-session.ts

@@ -0,0 +1,125 @@
+import type {
+  AgentCapabilityFlags,
+  AgentPermissionRequest,
+  AgentPermissionResponse,
+  AgentPersistenceHandle,
+  AgentProvider,
+  AgentRunResult,
+  AgentSession,
+  AgentStreamEvent,
+  AgentTimelineItem,
+} from "../agent-sdk-types.js";
+
+export const REWIND_TEST_CAPABILITIES: AgentCapabilityFlags = {
+  supportsStreaming: true,
+  supportsSessionPersistence: true,
+  supportsDynamicModes: false,
+  supportsMcpServers: false,
+  supportsReasoningStream: false,
+  supportsToolInvocations: false,
+  supportsRewindConversation: true,
+  supportsRewindFiles: true,
+  supportsRewindBoth: true,
+};
+
+export interface RecordedRewind {
+  mode: "conversation" | "files" | "both";
+  messageId: string;
+}
+
+export class FakeRewindSession implements AgentSession {
+  readonly provider: AgentProvider = "claude";
+  readonly id = "fake-rewind-session";
+  readonly capabilities = REWIND_TEST_CAPABILITIES;
+  readonly recordedRewinds: RecordedRewind[] = [];
+  aborted = false;
+  historyReadCount = 0;
+  history: AgentTimelineItem[] = [{ type: "user_message", text: "before", messageId: "message-1" }];
+
+  private subscribers = new Set<(event: AgentStreamEvent) => void>();
+  private activeTurnId: string | null = null;
+
+  constructor(private readonly waitBeforeHistory?: () => Promise<void>) {}
+
+  async run(): Promise<AgentRunResult> {
+    return { sessionId: this.id, finalText: "", timeline: [] };
+  }
+
+  async startTurn(): Promise<{ turnId: string }> {
+    this.aborted = false;
+    this.activeTurnId = "turn-1";
+    queueMicrotask(() => {
+      this.emit({ type: "turn_started", provider: this.provider, turnId: "turn-1" });
+    });
+    return { turnId: "turn-1" };
+  }
+
+  subscribe(callback: (event: AgentStreamEvent) => void): () => void {
+    this.subscribers.add(callback);
+    return () => this.subscribers.delete(callback);
+  }
+
+  async *streamHistory(): AsyncGenerator<AgentStreamEvent> {
+    this.historyReadCount += 1;
+    await this.waitBeforeHistory?.();
+    for (const item of this.history) {
+      yield { type: "timeline", provider: this.provider, item };
+    }
+  }
+
+  async getRuntimeInfo() {
+    return { provider: this.provider, sessionId: this.id };
+  }
+
+  async getAvailableModes() {
+    return [];
+  }
+
+  async getCurrentMode() {
+    return null;
+  }
+
+  async setMode(): Promise<void> {}
+
+  getPendingPermissions(): AgentPermissionRequest[] {
+    return [];
+  }
+
+  async respondToPermission(
+    _requestId: string,
+    _response: AgentPermissionResponse,
+  ): Promise<void> {}
+
+  describePersistence(): AgentPersistenceHandle {
+    return { provider: this.provider, sessionId: this.id };
+  }
+
+  async interrupt(): Promise<void> {
+    this.aborted = true;
+    if (this.activeTurnId) {
+      const turnId = this.activeTurnId;
+      this.activeTurnId = null;
+      this.emit({ type: "turn_canceled", provider: this.provider, reason: "interrupted", turnId });
+    }
+  }
+
+  async close(): Promise<void> {}
+
+  async revertConversation(input: { messageId: string }): Promise<void> {
+    this.recordedRewinds.push({ mode: "conversation", messageId: input.messageId });
+  }
+
+  async revertFiles(input: { messageId: string }): Promise<void> {
+    this.recordedRewinds.push({ mode: "files", messageId: input.messageId });
+  }
+
+  async revertBoth(input: { messageId: string }): Promise<void> {
+    this.recordedRewinds.push({ mode: "both", messageId: input.messageId });
+  }
+
+  private emit(event: AgentStreamEvent): void {
+    for (const subscriber of this.subscribers) {
+      subscriber(event);
+    }
+  }
+}

packages/server/src/server/daemon-e2e/claude-rewind.real.e2e.test.ts

@@ -0,0 +1,341 @@
+import { readdir, writeFile } from "node:fs/promises";
+import path from "node:path";
+import pino from "pino";
+import { afterAll, beforeAll, describe, expect, test } from "vitest";
+
+import { ClaudeAgentClient } from "../agent/providers/claude/agent.js";
+import type { AgentTimelineItem } from "../agent/agent-sdk-types.js";
+import { DaemonClient } from "../test-utils/daemon-client.js";
+import { createTestPaseoDaemon, type TestPaseoDaemon } from "../test-utils/paseo-daemon.js";
+import { getFullAccessConfig } from "./agent-configs.js";
+import {
+  closeRewindSession,
+  fetchTimelineItems,
+  fileExists,
+  tmpRewindCwd,
+  userMessageIdForToken,
+} from "./test-utils/rewind-helpers.js";
+
+interface ClaudeRewindHarness {
+  client: DaemonClient;
+  daemon: TestPaseoDaemon;
+}
+
+interface ClaudeRewindSession {
+  agentId: string;
+  cwd: string;
+}
+
+interface ClaudeTurnSpec {
+  index: 1 | 2 | 3;
+  promptToken: string;
+  doneToken: string;
+  fileName: string;
+  content: string;
+}
+
+interface RewindCase {
+  name: string;
+  turnCount: 1 | 2 | 3;
+  rewindTurn: 1 | 2 | 3;
+  mode: "both" | "conversation" | "files";
+}
+
+const TURN_TIMEOUT_MS = 180_000;
+
+const MATRIX: RewindCase[] = [
+  {
+    name: "single-turn session, rewind only user message, both",
+    turnCount: 1,
+    rewindTurn: 1,
+    mode: "both",
+  },
+  { name: "two-turn session, rewind user #1, both", turnCount: 2, rewindTurn: 1, mode: "both" },
+  { name: "two-turn session, rewind user #2, both", turnCount: 2, rewindTurn: 2, mode: "both" },
+  { name: "three-turn session, rewind user #1, both", turnCount: 3, rewindTurn: 1, mode: "both" },
+  { name: "three-turn session, rewind user #2, both", turnCount: 3, rewindTurn: 2, mode: "both" },
+  { name: "three-turn session, rewind user #3, both", turnCount: 3, rewindTurn: 3, mode: "both" },
+  {
+    name: "single-turn session, rewind only user message, conversation",
+    turnCount: 1,
+    rewindTurn: 1,
+    mode: "conversation",
+  },
+  {
+    name: "two-turn session, rewind user #1, conversation",
+    turnCount: 2,
+    rewindTurn: 1,
+    mode: "conversation",
+  },
+  {
+    name: "two-turn session, rewind user #2, conversation",
+    turnCount: 2,
+    rewindTurn: 2,
+    mode: "conversation",
+  },
+  {
+    name: "three-turn session, rewind user #1, conversation",
+    turnCount: 3,
+    rewindTurn: 1,
+    mode: "conversation",
+  },
+  {
+    name: "three-turn session, rewind user #2, conversation",
+    turnCount: 3,
+    rewindTurn: 2,
+    mode: "conversation",
+  },
+  {
+    name: "three-turn session, rewind user #3, conversation",
+    turnCount: 3,
+    rewindTurn: 3,
+    mode: "conversation",
+  },
+  {
+    name: "single-turn session, rewind only user message, files",
+    turnCount: 1,
+    rewindTurn: 1,
+    mode: "files",
+  },
+  { name: "two-turn session, rewind user #1, files", turnCount: 2, rewindTurn: 1, mode: "files" },
+  { name: "two-turn session, rewind user #2, files", turnCount: 2, rewindTurn: 2, mode: "files" },
+  { name: "three-turn session, rewind user #1, files", turnCount: 3, rewindTurn: 1, mode: "files" },
+  { name: "three-turn session, rewind user #2, files", turnCount: 3, rewindTurn: 2, mode: "files" },
+  { name: "three-turn session, rewind user #3, files", turnCount: 3, rewindTurn: 3, mode: "files" },
+];
+
+async function launchClaudeRewindSession(
+  harness: ClaudeRewindHarness,
+  title: string,
+): Promise<ClaudeRewindSession> {
+  const cwd = tmpRewindCwd("daemon-real-claude-rewind-");
+  await writeFile(path.join(cwd, "baseline.txt"), "BASE\n", "utf8");
+
+  const agent = await harness.client.createAgent({
+    cwd,
+    title,
+    ...getFullAccessConfig("claude"),
+  });
+
+  return { agentId: agent.id, cwd };
+}
+
+async function closeClaudeRewindSession(session: ClaudeRewindSession): Promise<void> {
+  closeRewindSession(session);
+}
+
+function buildTurns(scenario: RewindCase): ClaudeTurnSpec[] {
+  const prefix = `${scenario.mode.toUpperCase()}_${scenario.turnCount}_${scenario.rewindTurn}`;
+  return Array.from({ length: scenario.turnCount }, (_, offset) => {
+    const index = (offset + 1) as 1 | 2 | 3;
+    return {
+      index,
+      promptToken: `PASEO_RW_${prefix}_T${index}`,
+      doneToken: `PASEO_RW_${prefix}_T${index}_DONE`,
+      fileName: `turn-${index}.txt`,
+      content: `turn ${index} preserved content\n`,
+    };
+  });
+}
+
+function editPrompt(turn: ClaudeTurnSpec): string {
+  return [
+    `${turn.promptToken}.`,
+    `Use the Write tool, not Bash, to create ${turn.fileName} with exactly:`,
+    "```",
+    turn.content.trimEnd(),
+    "```",
+    `When the file is saved, reply exactly: ${turn.doneToken}`,
+  ].join("\n");
+}
+
+async function sendClaudeWriteTurn(
+  harness: ClaudeRewindHarness,
+  session: ClaudeRewindSession,
+  turn: ClaudeTurnSpec,
+): Promise<void> {
+  await harness.client.sendMessage(session.agentId, editPrompt(turn));
+  const finish = await harness.client.waitForFinish(session.agentId, TURN_TIMEOUT_MS);
+  expect(finish.status).toBe("idle");
+  expect(finish.final?.lastError).toBeUndefined();
+  await expect(fileExists(path.join(session.cwd, turn.fileName))).resolves.toBe(true);
+}
+
+async function sendClaudeReplyTurn(
+  harness: ClaudeRewindHarness,
+  session: ClaudeRewindSession,
+  prompt: string,
+): Promise<void> {
+  await harness.client.sendMessage(session.agentId, prompt);
+  const finish = await harness.client.waitForFinish(session.agentId, TURN_TIMEOUT_MS);
+  expect(finish.status).toBe("idle");
+  expect(finish.final?.lastError).toBeUndefined();
+}
+
+async function runtimeSessionId(
+  harness: ClaudeRewindHarness,
+  session: ClaudeRewindSession,
+): Promise<string | null> {
+  const snapshot = await harness.client.fetchAgent(session.agentId);
+  return snapshot?.agent.runtimeInfo?.sessionId ?? snapshot?.agent.persistence?.sessionId ?? null;
+}
+
+function roleItems(items: AgentTimelineItem[], role: "user_message" | "assistant_message") {
+  return items.filter((item) => item.type === role);
+}
+
+function expectSessionId(value: string | null): asserts value is string {
+  expect(value).toMatch(/^[a-f0-9-]{36}$/);
+}
+
+async function createdFilesAtCwd(session: ClaudeRewindSession): Promise<string[]> {
+  const entries = await readdir(session.cwd);
+  return entries.filter((name) => name === "baseline.txt" || /^turn-\d+\.txt$/u.test(name)).sort();
+}
+
+async function assertFiles(
+  session: ClaudeRewindSession,
+  expectedPresent: ClaudeTurnSpec[],
+): Promise<void> {
+  await expect(createdFilesAtCwd(session)).resolves.toEqual(
+    ["baseline.txt", ...expectedPresent.map((turn) => turn.fileName)].sort(),
+  );
+}
+
+function assertTimeline(items: AgentTimelineItem[], expectedKept: ClaudeTurnSpec[]): void {
+  const userItems = roleItems(items, "user_message");
+  const assistantItems = roleItems(items, "assistant_message");
+
+  expect(userItems).toHaveLength(expectedKept.length);
+  expect(userItems.map((item) => item.text)).toEqual(expectedKept.map(editPrompt));
+  expect(assistantItems).toHaveLength(expectedKept.length);
+}
+
+describe("daemon E2E (real claude) - rewind", () => {
+  let harness: ClaudeRewindHarness;
+
+  beforeAll(async () => {
+    const logger = pino({ level: "silent" });
+    const daemon = await createTestPaseoDaemon({
+      agentClients: { claude: new ClaudeAgentClient({ logger }) },
+      logger,
+    });
+    const client = new DaemonClient({
+      url: `ws://127.0.0.1:${daemon.port}/ws`,
+      appVersion: "0.1.70",
+    });
+
+    await client.connect();
+    await client.fetchAgents({ subscribe: { subscriptionId: "claude-rewind-real" } });
+    harness = { client, daemon };
+  }, 30_000);
+
+  afterAll(async () => {
+    await harness?.client.close().catch(() => undefined);
+    await harness?.daemon.close().catch(() => undefined);
+  });
+
+  test.each(MATRIX)(
+    "$name",
+    async (scenario) => {
+      const session = await launchClaudeRewindSession(
+        harness,
+        `claude-rewind-${scenario.mode}-${scenario.turnCount}-${scenario.rewindTurn}`,
+      );
+      const turns = buildTurns(scenario);
+
+      try {
+        for (const turn of turns) {
+          await sendClaudeWriteTurn(harness, session, turn);
+        }
+
+        const beforeTimeline = await fetchTimelineItems(harness.client, session.agentId);
+        const targetTurn = turns[scenario.rewindTurn - 1];
+        const targetMessageId = userMessageIdForToken(beforeTimeline, targetTurn.promptToken);
+        const sessionIdBefore = await runtimeSessionId(harness, session);
+        expectSessionId(sessionIdBefore);
+
+        await harness.client.rewindAgent(session.agentId, targetMessageId, scenario.mode);
+
+        const afterTimeline = await fetchTimelineItems(harness.client, session.agentId);
+        const sessionIdAfter = await runtimeSessionId(harness, session);
+        const expectedKeptConversation =
+          scenario.mode === "files" ? turns : turns.slice(0, scenario.rewindTurn - 1);
+        const expectedKeptFiles =
+          scenario.mode === "conversation" ? turns : turns.slice(0, scenario.rewindTurn - 1);
+
+        assertTimeline(afterTimeline, expectedKeptConversation);
+        await assertFiles(session, expectedKeptFiles);
+
+        if (scenario.mode === "files") {
+          expect(sessionIdAfter).toBe(sessionIdBefore);
+        } else {
+          expectSessionId(sessionIdAfter);
+          expect(sessionIdAfter).not.toBe(sessionIdBefore);
+        }
+
+        const snapshot = await harness.client.fetchAgent(session.agentId);
+        expect(snapshot?.agent.status).toBe("idle");
+        expect(snapshot?.agent.pendingPermissions).toEqual([]);
+      } finally {
+        await closeClaudeRewindSession(session);
+      }
+    },
+    420_000,
+  );
+
+  test("emits only the deliberate fork session switch after conversation rewind and continue", async () => {
+    const session = await launchClaudeRewindSession(harness, "claude-rewind-no-session-roundtrip");
+    const sessionSwitches: string[] = [];
+    const unsubscribe = harness.client.on((event) => {
+      if (event.type !== "agent_stream" || event.agentId !== session.agentId) {
+        return;
+      }
+      if (
+        event.event.type === "timeline" &&
+        event.event.item.type === "assistant_message" &&
+        event.event.item.text.startsWith("Claude switched to a new session:")
+      ) {
+        sessionSwitches.push(event.event.item.text);
+      }
+    });
+
+    try {
+      await sendClaudeReplyTurn(
+        harness,
+        session,
+        "PASEO_RW_NO_ROUNDTRIP_T1. Reply exactly: PASEO_RW_NO_ROUNDTRIP_T1_DONE",
+      );
+      await sendClaudeReplyTurn(
+        harness,
+        session,
+        "PASEO_RW_NO_ROUNDTRIP_T2. Reply exactly: PASEO_RW_NO_ROUNDTRIP_T2_DONE",
+      );
+
+      const beforeTimeline = await fetchTimelineItems(harness.client, session.agentId);
+      const targetMessageId = userMessageIdForToken(beforeTimeline, "PASEO_RW_NO_ROUNDTRIP_T2");
+      const sessionIdBeforeRewind = await runtimeSessionId(harness, session);
+      expectSessionId(sessionIdBeforeRewind);
+
+      await harness.client.rewindAgent(session.agentId, targetMessageId, "conversation");
+      const forkedSessionId = await runtimeSessionId(harness, session);
+      expectSessionId(forkedSessionId);
+      expect(forkedSessionId).not.toBe(sessionIdBeforeRewind);
+
+      await sendClaudeReplyTurn(
+        harness,
+        session,
+        "PASEO_RW_NO_ROUNDTRIP_T3. Reply exactly: PASEO_RW_NO_ROUNDTRIP_T3_DONE",
+      );
+
+      const finalSessionId = await runtimeSessionId(harness, session);
+      expect(finalSessionId).toBe(forkedSessionId);
+      expect(sessionSwitches).toEqual([
+        `Claude switched to a new session: ${sessionIdBeforeRewind} -> ${forkedSessionId}`,
+      ]);
+    } finally {
+      unsubscribe();
+      await closeClaudeRewindSession(session);
+    }
+  }, 420_000);
+});

packages/server/src/server/daemon-e2e/codex-rewind.real.e2e.test.ts

@@ -0,0 +1,251 @@
+import { readdir, writeFile } from "node:fs/promises";
+import path from "node:path";
+import pino from "pino";
+import { afterAll, beforeAll, describe, expect, test } from "vitest";
+
+import { CodexAppServerAgentClient } from "../agent/providers/codex-app-server-agent.js";
+import type { AgentTimelineItem } from "../agent/agent-sdk-types.js";
+import { DaemonClient } from "../test-utils/daemon-client.js";
+import { createTestPaseoDaemon, type TestPaseoDaemon } from "../test-utils/paseo-daemon.js";
+import { getFullAccessConfig } from "./agent-configs.js";
+import {
+  closeRewindSession,
+  fetchTimelineItems,
+  fileExists,
+  readScratchFile,
+  tmpRewindCwd,
+  userMessageIdForToken,
+} from "./test-utils/rewind-helpers.js";
+
+interface CodexRewindHarness {
+  client: DaemonClient;
+  daemon: TestPaseoDaemon;
+}
+
+interface CodexRewindSession {
+  agentId: string;
+  cwd: string;
+  scratchPath: string;
+}
+
+const TURN_TIMEOUT_MS = 180_000;
+
+async function fetchThreadId(client: DaemonClient, agentId: string): Promise<string> {
+  const result = await client.fetchAgent(agentId);
+  const threadId = result?.agent.persistence?.sessionId ?? result?.agent.runtimeInfo?.sessionId;
+  if (!threadId) {
+    throw new Error(`Agent ${agentId} does not have a visible Codex thread id`);
+  }
+  return threadId;
+}
+
+function expectThreadId(value: string): void {
+  expect(value).toMatch(/^[a-f0-9-]{36}$/);
+}
+
+function roleItems(items: AgentTimelineItem[], role: "user_message" | "assistant_message") {
+  return items.filter((item) => item.type === role);
+}
+
+function expectTimeline(
+  items: AgentTimelineItem[],
+  input: { userTexts: string[]; assistantCount: number },
+): void {
+  const userMessages = roleItems(items, "user_message");
+  const assistantMessages = roleItems(items, "assistant_message");
+
+  expect(userMessages).toHaveLength(input.userTexts.length);
+  expect(userMessages.map((message) => message.text)).toEqual(input.userTexts);
+  expect(assistantMessages).toHaveLength(input.assistantCount);
+}
+
+async function createdFilesAtCwd(session: CodexRewindSession): Promise<string[]> {
+  const entries = await readdir(session.cwd);
+  return entries
+    .filter((name) => name === "rewind-scratch.txt" || name === "codex-dummy.txt")
+    .sort();
+}
+
+async function expectCreatedFiles(
+  session: CodexRewindSession,
+  expectedNames: string[],
+): Promise<void> {
+  await expect(createdFilesAtCwd(session)).resolves.toEqual([...expectedNames].sort());
+}
+
+async function launchCodexRewindSession(
+  harness: CodexRewindHarness,
+  title: string,
+): Promise<CodexRewindSession> {
+  const cwd = tmpRewindCwd("daemon-real-codex-rewind-");
+  const scratchPath = path.join(cwd, "rewind-scratch.txt");
+  await writeFile(scratchPath, "BASE\n", "utf8");
+
+  const agent = await harness.client.createAgent({
+    cwd,
+    title,
+    ...getFullAccessConfig("codex"),
+  });
+
+  return { agentId: agent.id, cwd, scratchPath };
+}
+
+async function closeCodexRewindSession(session: CodexRewindSession): Promise<void> {
+  closeRewindSession(session);
+}
+
+function editPrompt(input: {
+  fileName: string;
+  promptToken: string;
+  content: string;
+  doneToken: string;
+}): string {
+  return [
+    `PASEO_CODEX_REWIND_PROMPT_${input.promptToken}.`,
+    `Use apply_patch to make ${input.fileName} contain exactly:`,
+    "```",
+    input.content.trimEnd(),
+    "```",
+    `When the file is saved, reply exactly: ${input.doneToken}`,
+  ].join("\n");
+}
+
+function singleCreatePrompt(): string {
+  return [
+    "PASEO_CODEX_REWIND_PROMPT_SINGLE_CREATE.",
+    "Use apply_patch to create codex-dummy.txt with exactly CODEX_CREATED.",
+    "When the file is saved, reply exactly: CODEX_SINGLE_CREATE_DONE",
+  ].join("\n");
+}
+
+async function askCodexToEditFile(
+  harness: CodexRewindHarness,
+  session: CodexRewindSession,
+  input: {
+    promptToken: string;
+    content: string;
+    doneToken: string;
+  },
+): Promise<void> {
+  await harness.client.sendMessage(
+    session.agentId,
+    editPrompt({
+      fileName: path.basename(session.scratchPath),
+      promptToken: input.promptToken,
+      content: input.content,
+      doneToken: input.doneToken,
+    }),
+  );
+  const finish = await harness.client.waitForFinish(session.agentId, TURN_TIMEOUT_MS);
+  expect(finish.status).toBe("idle");
+  expect(finish.final?.lastError).toBeUndefined();
+}
+
+describe("daemon E2E (real codex) - rewind", () => {
+  let harness: CodexRewindHarness;
+
+  beforeAll(async () => {
+    const logger = pino({ level: "silent" });
+    const daemon = await createTestPaseoDaemon({
+      agentClients: { codex: new CodexAppServerAgentClient(logger) },
+      logger,
+    });
+    const client = new DaemonClient({
+      url: `ws://127.0.0.1:${daemon.port}/ws`,
+      appVersion: "0.1.70",
+    });
+
+    await client.connect();
+    await client.fetchAgents({ subscribe: { subscriptionId: "codex-rewind-real" } });
+    harness = { client, daemon };
+  }, 30_000);
+
+  afterAll(async () => {
+    await harness?.client.close().catch(() => undefined);
+    await harness?.daemon.close().catch(() => undefined);
+  });
+
+  test("rewinds a real Codex conversation after a single edit turn while leaving the file edit on disk", async () => {
+    const session = await launchCodexRewindSession(harness, "codex-rewind-single-edit-real");
+
+    try {
+      await askCodexToEditFile(harness, session, {
+        promptToken: "SINGLE",
+        content: "BASE\nCODEX_SINGLE_MARKER\n",
+        doneToken: "CODEX_SINGLE_DONE",
+      });
+      const timeline = await fetchTimelineItems(harness.client, session.agentId);
+      const messageId = userMessageIdForToken(timeline, "CODEX_REWIND_PROMPT_SINGLE");
+
+      await harness.client.rewindAgent(session.agentId, messageId, "conversation");
+      const rewoundTimeline = await fetchTimelineItems(harness.client, session.agentId);
+      const fileText = await readScratchFile(session);
+
+      expectTimeline(rewoundTimeline, { userTexts: [], assistantCount: 0 });
+      await expectCreatedFiles(session, ["rewind-scratch.txt"]);
+      expect(fileText).toBe("BASE\nCODEX_SINGLE_MARKER\n");
+    } finally {
+      await closeCodexRewindSession(session);
+    }
+  }, 420_000);
+
+  test("rewinds a real Codex conversation after a single file-creation turn while leaving the created file on disk", async () => {
+    const session = await launchCodexRewindSession(harness, "codex-rewind-single-create-real");
+    const dummyPath = path.join(session.cwd, "codex-dummy.txt");
+
+    try {
+      await harness.client.sendMessage(session.agentId, singleCreatePrompt());
+      const finish = await harness.client.waitForFinish(session.agentId, TURN_TIMEOUT_MS);
+      expect(finish.status).toBe("idle");
+      expect(finish.final?.lastError).toBeUndefined();
+      await expect(fileExists(dummyPath)).resolves.toBe(true);
+
+      const timeline = await fetchTimelineItems(harness.client, session.agentId);
+      const messageId = userMessageIdForToken(timeline, "CODEX_REWIND_PROMPT_SINGLE_CREATE");
+
+      await harness.client.rewindAgent(session.agentId, messageId, "conversation");
+      const rewoundTimeline = await fetchTimelineItems(harness.client, session.agentId);
+
+      await expect(fileExists(dummyPath)).resolves.toBe(true);
+      await expectCreatedFiles(session, ["codex-dummy.txt", "rewind-scratch.txt"]);
+      expectTimeline(rewoundTimeline, { userTexts: [], assistantCount: 0 });
+    } finally {
+      await closeCodexRewindSession(session);
+    }
+  }, 420_000);
+
+  test("rewinds a real Codex conversation to a forked thread while leaving file edits on disk", async () => {
+    const session = await launchCodexRewindSession(harness, "codex-rewind-conversation-real");
+
+    try {
+      await askCodexToEditFile(harness, session, {
+        promptToken: "FIRST",
+        content: "BASE\nCODEX_FIRST_MARKER\n",
+        doneToken: "CODEX_FIRST_DONE",
+      });
+      const firstTimeline = await fetchTimelineItems(harness.client, session.agentId);
+      const firstMessageId = userMessageIdForToken(firstTimeline, "CODEX_REWIND_PROMPT_FIRST");
+
+      await askCodexToEditFile(harness, session, {
+        promptToken: "SECOND",
+        content: "BASE\nCODEX_FIRST_MARKER\nCODEX_SECOND_MARKER\n",
+        doneToken: "CODEX_SECOND_DONE",
+      });
+      const oldThreadId = await fetchThreadId(harness.client, session.agentId);
+      expectThreadId(oldThreadId);
+
+      await harness.client.rewindAgent(session.agentId, firstMessageId, "conversation");
+      const newThreadId = await fetchThreadId(harness.client, session.agentId);
+      const rewoundTimeline = await fetchTimelineItems(harness.client, session.agentId);
+      const fileText = await readScratchFile(session);
+
+      expect(newThreadId).not.toBe(oldThreadId);
+      expectThreadId(newThreadId);
+      expectTimeline(rewoundTimeline, { userTexts: [], assistantCount: 0 });
+      await expectCreatedFiles(session, ["rewind-scratch.txt"]);
+      expect(fileText).toBe("BASE\nCODEX_FIRST_MARKER\nCODEX_SECOND_MARKER\n");
+    } finally {
+      await closeCodexRewindSession(session);
+    }
+  }, 420_000);
+});

packages/server/src/server/daemon-e2e/opencode-rewind.real.e2e.test.ts

@@ -0,0 +1,442 @@
+import { execFileSync } from "node:child_process";
+import { readdir, writeFile } from "node:fs/promises";
+import path from "node:path";
+import pino from "pino";
+import { afterAll, beforeAll, describe, expect, test } from "vitest";
+
+import { OpenCodeAgentClient } from "../agent/providers/opencode-agent.js";
+import type { AgentTimelineItem } from "../agent/agent-sdk-types.js";
+import type { AgentLifecycleStatus } from "../../shared/agent-lifecycle.js";
+import { DaemonClient } from "../test-utils/daemon-client.js";
+import { createTestPaseoDaemon, type TestPaseoDaemon } from "../test-utils/paseo-daemon.js";
+import { getFullAccessConfig } from "./agent-configs.js";
+import {
+  closeRewindSession,
+  fetchTimelineItems,
+  fileExists,
+  readScratchFile,
+  tmpRewindCwd,
+  userMessageIdForToken,
+} from "./test-utils/rewind-helpers.js";
+
+interface OpenCodeRewindHarness {
+  client: DaemonClient;
+  daemon: TestPaseoDaemon;
+}
+
+interface OpenCodeRewindSession {
+  agentId: string;
+  cwd: string;
+  scratchPath: string;
+}
+
+interface AgentStatusRecord {
+  at: number;
+  status: AgentLifecycleStatus;
+}
+
+const TURN_TIMEOUT_MS = 180_000;
+
+async function launchOpenCodeRewindSession(
+  harness: OpenCodeRewindHarness,
+  title: string,
+): Promise<OpenCodeRewindSession> {
+  const cwd = tmpRewindCwd("daemon-real-opencode-rewind-", { realpath: true });
+  const scratchPath = path.join(cwd, "rewind-scratch.txt");
+  execFileSync("git", ["init"], { cwd, stdio: "ignore" });
+  execFileSync("git", ["config", "user.email", "paseo-test@example.com"], {
+    cwd,
+    stdio: "ignore",
+  });
+  execFileSync("git", ["config", "user.name", "Paseo Test"], { cwd, stdio: "ignore" });
+  await writeFile(scratchPath, "BASE\n", "utf8");
+  execFileSync("git", ["add", "rewind-scratch.txt"], { cwd, stdio: "ignore" });
+  execFileSync("git", ["commit", "-m", "base"], { cwd, stdio: "ignore" });
+
+  const agent = await harness.client.createAgent({
+    cwd,
+    title,
+    ...getFullAccessConfig("opencode"),
+  });
+
+  return { agentId: agent.id, cwd, scratchPath };
+}
+
+async function runtimeSessionId(
+  harness: OpenCodeRewindHarness,
+  session: OpenCodeRewindSession,
+): Promise<string> {
+  const snapshot = await harness.client.fetchAgent(session.agentId);
+  const sessionId =
+    snapshot?.agent.runtimeInfo?.sessionId ?? snapshot?.agent.persistence?.sessionId;
+  if (!sessionId) {
+    throw new Error(`Agent ${session.agentId} does not have a visible OpenCode session id`);
+  }
+  return sessionId;
+}
+
+function expectOpenCodeSessionId(value: string): void {
+  expect(value).toMatch(/^ses_/);
+}
+
+function roleItems(items: AgentTimelineItem[], role: "user_message" | "assistant_message") {
+  return items.filter((item) => item.type === role);
+}
+
+function expectTimeline(
+  items: AgentTimelineItem[],
+  input: { userTexts: string[]; assistantCount: number },
+): void {
+  const userMessages = roleItems(items, "user_message");
+  const assistantMessages = roleItems(items, "assistant_message");
+
+  expect(userMessages).toHaveLength(input.userTexts.length);
+  expect(userMessages.map((message) => message.text)).toEqual(input.userTexts);
+  expect(assistantMessages).toHaveLength(input.assistantCount);
+}
+
+function expectUserMessageCount(items: AgentTimelineItem[], expected: number): void {
+  expect(roleItems(items, "user_message")).toHaveLength(expected);
+}
+
+async function recordAgentStatusTransitions(
+  harness: OpenCodeRewindHarness,
+  session: OpenCodeRewindSession,
+): Promise<{ records: AgentStatusRecord[]; stop: () => void }> {
+  const records: AgentStatusRecord[] = [];
+  const initial = await harness.client.fetchAgent(session.agentId);
+  if (initial?.agent.status) {
+    records.push({ at: Date.now(), status: initial.agent.status });
+  }
+  const unsubscribe = harness.client.on("agent_update", (message) => {
+    if (message.payload.kind !== "upsert" || message.payload.agent.id !== session.agentId) {
+      return;
+    }
+    records.push({ at: Date.now(), status: message.payload.agent.status });
+  });
+
+  return { records, stop: unsubscribe };
+}
+
+function screenStatusForInvariant(status: AgentLifecycleStatus): "loading" | AgentLifecycleStatus {
+  return status === "initializing" ? "loading" : status;
+}
+
+function expectNoLoadingRegression(records: AgentStatusRecord[]): void {
+  const statuses = records.map((record) => screenStatusForInvariant(record.status));
+  for (let index = 1; index < statuses.length; index += 1) {
+    expect([statuses[index - 1], statuses[index]]).not.toEqual(["running", "loading"]);
+  }
+  for (let index = 2; index < statuses.length; index += 1) {
+    expect([statuses[index - 2], statuses[index - 1], statuses[index]]).not.toEqual([
+      "idle",
+      "loading",
+      "idle",
+    ]);
+  }
+}
+
+async function expectAgentIdle(
+  harness: OpenCodeRewindHarness,
+  session: OpenCodeRewindSession,
+): Promise<void> {
+  const snapshot = await harness.client.fetchAgent(session.agentId);
+  expect(snapshot?.agent.status).toBe("idle");
+}
+
+async function createdFilesAtCwd(session: OpenCodeRewindSession): Promise<string[]> {
+  const entries = await readdir(session.cwd);
+  return entries
+    .filter((name) =>
+      ["rewind-scratch.txt", "opencode-multi-a.txt", "opencode-multi-b.txt"].includes(name),
+    )
+    .sort();
+}
+
+async function expectCreatedFiles(
+  session: OpenCodeRewindSession,
+  expectedNames: string[],
+): Promise<void> {
+  await expect(createdFilesAtCwd(session)).resolves.toEqual([...expectedNames].sort());
+}
+
+async function closeOpenCodeRewindSession(session: OpenCodeRewindSession): Promise<void> {
+  closeRewindSession(session);
+}
+
+function editPrompt(input: {
+  fileName: string;
+  promptToken: string;
+  content: string;
+  doneToken: string;
+}): string {
+  return [
+    `PASEO_OPENCODE_REWIND_PROMPT_${input.promptToken}.`,
+    `Use the edit or write tool, not shell commands, to make ${input.fileName} contain exactly:`,
+    "```",
+    input.content.trimEnd(),
+    "```",
+    `When the file is saved, reply exactly: ${input.doneToken}`,
+  ].join("\n");
+}
+
+async function askOpenCodeToEditFile(
+  harness: OpenCodeRewindHarness,
+  session: OpenCodeRewindSession,
+  input: {
+    promptToken: string;
+    content: string;
+    doneToken: string;
+  },
+): Promise<void> {
+  await harness.client.sendMessage(
+    session.agentId,
+    editPrompt({
+      fileName: path.basename(session.scratchPath),
+      promptToken: input.promptToken,
+      content: input.content,
+      doneToken: input.doneToken,
+    }),
+  );
+  const finish = await harness.client.waitForFinish(session.agentId, TURN_TIMEOUT_MS);
+  expect(finish.status).toBe("idle");
+  expect(finish.final?.lastError).toBeUndefined();
+}
+
+async function rewindOpenCode(
+  harness: OpenCodeRewindHarness,
+  session: OpenCodeRewindSession,
+  messageId: string,
+): Promise<void> {
+  await harness.client.rewindAgent(session.agentId, messageId, "both");
+}
+
+describe("daemon E2E (real opencode) - rewind", () => {
+  let harness: OpenCodeRewindHarness;
+
+  beforeAll(async () => {
+    const logger = pino({ level: "silent" });
+    const daemon = await createTestPaseoDaemon({
+      agentClients: { opencode: new OpenCodeAgentClient(logger) },
+      logger,
+    });
+    const client = new DaemonClient({
+      url: `ws://127.0.0.1:${daemon.port}/ws`,
+      appVersion: "0.1.70",
+    });
+
+    await client.connect();
+    await client.fetchAgents({ subscribe: { subscriptionId: "opencode-rewind-real" } });
+    harness = { client, daemon };
+  }, 30_000);
+
+  afterAll(async () => {
+    await harness?.client.close().catch(() => undefined);
+    await harness?.daemon.close().catch(() => undefined);
+  });
+
+  test("rewinds conversation and files after a single real OpenCode edit turn", async () => {
+    const session = await launchOpenCodeRewindSession(harness, "opencode-rewind-single-edit-real");
+
+    try {
+      await askOpenCodeToEditFile(harness, session, {
+        promptToken: "SINGLE",
+        content: "BASE\nOPENCODE_SINGLE_MARKER\n",
+        doneToken: "OPENCODE_SINGLE_DONE",
+      });
+      const timeline = await fetchTimelineItems(harness.client, session.agentId);
+      expectUserMessageCount(timeline, 1);
+      const messageId = userMessageIdForToken(timeline, "OPENCODE_REWIND_PROMPT_SINGLE");
+      const sessionIdBefore = await runtimeSessionId(harness, session);
+      expectOpenCodeSessionId(sessionIdBefore);
+      const statusTransitions = await recordAgentStatusTransitions(harness, session);
+
+      try {
+        await rewindOpenCode(harness, session, messageId);
+      } finally {
+        statusTransitions.stop();
+      }
+      const sessionIdAfter = await runtimeSessionId(harness, session);
+      const fileText = await readScratchFile(session);
+      const rewoundTimeline = await fetchTimelineItems(harness.client, session.agentId);
+
+      expect(sessionIdAfter).toBe(sessionIdBefore);
+      await expectAgentIdle(harness, session);
+      expectNoLoadingRegression(statusTransitions.records);
+      expect(fileText).toBe("BASE\n");
+      await expectCreatedFiles(session, ["rewind-scratch.txt"]);
+      expectTimeline(rewoundTimeline, { userTexts: [], assistantCount: 0 });
+    } finally {
+      await closeOpenCodeRewindSession(session);
+    }
+  }, 420_000);
+
+  test("records exactly one plain-text user message for a real OpenCode turn", async () => {
+    const session = await launchOpenCodeRewindSession(
+      harness,
+      "opencode-plain-text-user-message-real",
+    );
+    const prompt = "PASEO_OPENCODE_PLAIN_TEXT_DUP_CHECK. Reply exactly: OPENCODE_PLAIN_TEXT_DONE";
+
+    try {
+      await harness.client.sendMessage(session.agentId, prompt);
+      const finish = await harness.client.waitForFinish(session.agentId, TURN_TIMEOUT_MS);
+      expect(finish.status).toBe("idle");
+      expect(finish.final?.lastError).toBeUndefined();
+
+      const timeline = await fetchTimelineItems(harness.client, session.agentId);
+      const userMessages = roleItems(timeline, "user_message");
+      expect(userMessages).toHaveLength(1);
+      expect(userMessages[0]?.text).toBe(prompt);
+    } finally {
+      await closeOpenCodeRewindSession(session);
+    }
+  }, 420_000);
+
+  test("rewinds a real OpenCode read-only turn without changing files", async () => {
+    const session = await launchOpenCodeRewindSession(harness, "opencode-rewind-read-only-real");
+
+    try {
+      await harness.client.sendMessage(
+        session.agentId,
+        [
+          "PASEO_OPENCODE_REWIND_PROMPT_READ_ONLY.",
+          `Inspect ${path.basename(session.scratchPath)} without editing files.`,
+          "Reply exactly: OPENCODE_READ_ONLY_DONE",
+        ].join(" "),
+      );
+      const finish = await harness.client.waitForFinish(session.agentId, TURN_TIMEOUT_MS);
+      expect(finish.status).toBe("idle");
+      expect(finish.final?.lastError).toBeUndefined();
+
+      const timeline = await fetchTimelineItems(harness.client, session.agentId);
+      expectUserMessageCount(timeline, 1);
+      const messageId = userMessageIdForToken(timeline, "OPENCODE_REWIND_PROMPT_READ_ONLY");
+      const sessionIdBefore = await runtimeSessionId(harness, session);
+      expectOpenCodeSessionId(sessionIdBefore);
+      const statusTransitions = await recordAgentStatusTransitions(harness, session);
+
+      try {
+        await rewindOpenCode(harness, session, messageId);
+      } finally {
+        statusTransitions.stop();
+      }
+      const sessionIdAfter = await runtimeSessionId(harness, session);
+      const fileText = await readScratchFile(session);
+      const rewoundTimeline = await fetchTimelineItems(harness.client, session.agentId);
+
+      expect(sessionIdAfter).toBe(sessionIdBefore);
+      await expectAgentIdle(harness, session);
+      expectNoLoadingRegression(statusTransitions.records);
+      expect(fileText).toBe("BASE\n");
+      await expectCreatedFiles(session, ["rewind-scratch.txt"]);
+      expectTimeline(rewoundTimeline, { userTexts: [], assistantCount: 0 });
+    } finally {
+      await closeOpenCodeRewindSession(session);
+    }
+  }, 420_000);
+
+  test("rewinds every file from a single real OpenCode multi-tool edit turn", async () => {
+    const session = await launchOpenCodeRewindSession(harness, "opencode-rewind-multi-edit-real");
+    const firstPath = path.join(session.cwd, "opencode-multi-a.txt");
+    const secondPath = path.join(session.cwd, "opencode-multi-b.txt");
+
+    try {
+      await harness.client.sendMessage(
+        session.agentId,
+        [
+          "PASEO_OPENCODE_REWIND_PROMPT_MULTI_EDIT.",
+          "Create opencode-multi-a.txt with exactly OPENCODE_MULTI_A.",
+          "Create opencode-multi-b.txt with exactly OPENCODE_MULTI_B.",
+          "Do not use shell commands.",
+          "Reply exactly: OPENCODE_MULTI_EDIT_DONE",
+        ].join("\n"),
+      );
+      const finish = await harness.client.waitForFinish(session.agentId, TURN_TIMEOUT_MS);
+      expect(finish.status).toBe("idle");
+      expect(finish.final?.lastError).toBeUndefined();
+      await expect(fileExists(firstPath)).resolves.toBe(true);
+      await expect(fileExists(secondPath)).resolves.toBe(true);
+
+      const timeline = await fetchTimelineItems(harness.client, session.agentId);
+      expectUserMessageCount(timeline, 1);
+      const messageId = userMessageIdForToken(timeline, "OPENCODE_REWIND_PROMPT_MULTI_EDIT");
+      const sessionIdBefore = await runtimeSessionId(harness, session);
+      expectOpenCodeSessionId(sessionIdBefore);
+      const statusTransitions = await recordAgentStatusTransitions(harness, session);
+
+      try {
+        await rewindOpenCode(harness, session, messageId);
+      } finally {
+        statusTransitions.stop();
+      }
+      const sessionIdAfter = await runtimeSessionId(harness, session);
+      const rewoundTimeline = await fetchTimelineItems(harness.client, session.agentId);
+
+      expect(sessionIdAfter).toBe(sessionIdBefore);
+      await expectAgentIdle(harness, session);
+      expectNoLoadingRegression(statusTransitions.records);
+      await expect(fileExists(firstPath)).resolves.toBe(false);
+      await expect(fileExists(secondPath)).resolves.toBe(false);
+      await expectCreatedFiles(session, ["rewind-scratch.txt"]);
+      expectTimeline(rewoundTimeline, { userTexts: [], assistantCount: 0 });
+    } finally {
+      await closeOpenCodeRewindSession(session);
+    }
+  }, 420_000);
+
+  test("rewinds conversation and files together against a real OpenCode session", async () => {
+    const session = await launchOpenCodeRewindSession(harness, "opencode-rewind-both-real");
+
+    try {
+      await askOpenCodeToEditFile(harness, session, {
+        promptToken: "BOTH_FIRST",
+        content: "BASE\nOPENCODE_BOTH_FIRST_MARKER\n",
+        doneToken: "OPENCODE_BOTH_FIRST_DONE",
+      });
+      const fileTextAfterFirstTurn = await readScratchFile(session);
+      const firstTimeline = await fetchTimelineItems(harness.client, session.agentId);
+      expectUserMessageCount(firstTimeline, 1);
+
+      await askOpenCodeToEditFile(harness, session, {
+        promptToken: "BOTH_SECOND",
+        content: "BASE\nOPENCODE_BOTH_FIRST_MARKER\nOPENCODE_BOTH_SECOND_MARKER\n",
+        doneToken: "OPENCODE_BOTH_SECOND_DONE",
+      });
+      const secondTimeline = await fetchTimelineItems(harness.client, session.agentId);
+      expectUserMessageCount(secondTimeline, 2);
+      const secondMessageId = userMessageIdForToken(secondTimeline, "BOTH_SECOND");
+      const sessionIdBefore = await runtimeSessionId(harness, session);
+      expectOpenCodeSessionId(sessionIdBefore);
+      const statusTransitions = await recordAgentStatusTransitions(harness, session);
+
+      try {
+        await rewindOpenCode(harness, session, secondMessageId);
+      } finally {
+        statusTransitions.stop();
+      }
+      const sessionIdAfter = await runtimeSessionId(harness, session);
+      const fileText = await readScratchFile(session);
+      const rewoundTimeline = await fetchTimelineItems(harness.client, session.agentId);
+
+      expect(sessionIdAfter).toBe(sessionIdBefore);
+      await expectAgentIdle(harness, session);
+      expectNoLoadingRegression(statusTransitions.records);
+      expect(fileText).toBe(fileTextAfterFirstTurn);
+      await expectCreatedFiles(session, ["rewind-scratch.txt"]);
+      expectTimeline(rewoundTimeline, {
+        userTexts: [
+          editPrompt({
+            fileName: path.basename(session.scratchPath),
+            promptToken: "BOTH_FIRST",
+            content: "BASE\nOPENCODE_BOTH_FIRST_MARKER\n",
+            doneToken: "OPENCODE_BOTH_FIRST_DONE",
+          }),
+        ],
+        assistantCount: 1,
+      });
+    } finally {
+      await closeOpenCodeRewindSession(session);
+    }
+  }, 420_000);
+});

packages/server/src/server/daemon-e2e/pi-rewind.real.e2e.test.ts

@@ -0,0 +1,195 @@
+import { readdir } from "node:fs/promises";
+import pino from "pino";
+import { afterAll, beforeAll, describe, expect, test } from "vitest";
+
+import { PiRpcAgentClient } from "../agent/providers/pi/agent.js";
+import type { AgentTimelineItem } from "../agent/agent-sdk-types.js";
+import { DaemonClient } from "../test-utils/daemon-client.js";
+import { createTestPaseoDaemon, type TestPaseoDaemon } from "../test-utils/paseo-daemon.js";
+import {
+  closeRewindSession,
+  fetchTimelineItems,
+  tmpRewindCwd,
+  userMessageIdForToken,
+} from "./test-utils/rewind-helpers.js";
+
+interface PiRewindHarness {
+  client: DaemonClient;
+  daemon: TestPaseoDaemon;
+}
+
+interface PiRewindSession {
+  agentId: string;
+  cwd: string;
+}
+
+const TURN_TIMEOUT_MS = 240_000;
+const PI_REAL_TEST_MODEL = "openrouter/google/gemini-2.5-flash-lite";
+
+async function launchPiRewindSession(
+  harness: PiRewindHarness,
+  title: string,
+): Promise<PiRewindSession> {
+  const cwd = tmpRewindCwd("daemon-real-pi-rewind-");
+  const agent = await harness.client.createAgent({
+    cwd,
+    title,
+    provider: "pi",
+    model: PI_REAL_TEST_MODEL,
+    thinkingOptionId: "medium",
+  });
+
+  return { agentId: agent.id, cwd };
+}
+
+async function closePiRewindSession(session: PiRewindSession): Promise<void> {
+  closeRewindSession(session);
+}
+
+async function runtimeSessionId(
+  harness: PiRewindHarness,
+  session: PiRewindSession,
+): Promise<string> {
+  const snapshot = await harness.client.fetchAgent(session.agentId);
+  const sessionId =
+    snapshot?.agent.runtimeInfo?.sessionId ?? snapshot?.agent.persistence?.sessionId;
+  if (!sessionId) {
+    throw new Error(`Agent ${session.agentId} does not have a visible Pi session id`);
+  }
+  return sessionId;
+}
+
+function expectPiSessionId(value: string): void {
+  expect(value.length).toBeGreaterThan(0);
+}
+
+function piPrompt(input: { promptToken: string; doneToken: string }): string {
+  return [
+    `PASEO_PI_REWIND_PROMPT_${input.promptToken}.`,
+    "Remember this marker for the conversation.",
+    `Reply exactly: ${input.doneToken}`,
+  ].join(" ");
+}
+
+function roleItems(items: AgentTimelineItem[], role: "user_message" | "assistant_message") {
+  return items.filter((item) => item.type === role);
+}
+
+function expectTimeline(
+  items: AgentTimelineItem[],
+  input: { userTexts: string[]; assistantCount: number },
+): void {
+  const userMessages = roleItems(items, "user_message");
+  const assistantMessages = roleItems(items, "assistant_message");
+
+  expect(userMessages).toHaveLength(input.userTexts.length);
+  expect(userMessages.map((message) => message.text)).toEqual(input.userTexts);
+  expect(assistantMessages).toHaveLength(input.assistantCount);
+}
+
+async function expectNoCreatedFiles(session: PiRewindSession): Promise<void> {
+  await expect(readdir(session.cwd)).resolves.toEqual([]);
+}
+
+async function askPi(
+  harness: PiRewindHarness,
+  session: PiRewindSession,
+  input: { promptToken: string; doneToken: string },
+): Promise<void> {
+  await harness.client.sendMessage(session.agentId, piPrompt(input));
+  const finish = await harness.client.waitForFinish(session.agentId, TURN_TIMEOUT_MS);
+  expect(finish.status).toBe("idle");
+  expect(finish.final?.lastError).toBeUndefined();
+}
+
+describe("daemon E2E (real pi) - rewind", () => {
+  let harness: PiRewindHarness;
+
+  beforeAll(async () => {
+    const logger = pino({ level: "silent" });
+    const daemon = await createTestPaseoDaemon({
+      agentClients: { pi: new PiRpcAgentClient({ logger }) },
+      logger,
+    });
+    const client = new DaemonClient({
+      url: `ws://127.0.0.1:${daemon.port}/ws`,
+      appVersion: "0.1.70",
+    });
+
+    await client.connect();
+    await client.fetchAgents({ subscribe: { subscriptionId: "pi-rewind-real" } });
+    harness = { client, daemon };
+  }, 30_000);
+
+  afterAll(async () => {
+    await harness?.client.close().catch(() => undefined);
+    await harness?.daemon.close().catch(() => undefined);
+  });
+
+  test("rewinds a real Pi conversation after a single turn and keeps the session usable", async () => {
+    const session = await launchPiRewindSession(harness, "pi-rewind-single-conversation-real");
+
+    try {
+      await askPi(harness, session, {
+        promptToken: "SINGLE",
+        doneToken: "PI_SINGLE_DONE",
+      });
+      const firstTimeline = await fetchTimelineItems(harness.client, session.agentId);
+      const firstMessageId = userMessageIdForToken(firstTimeline, "PI_REWIND_PROMPT_SINGLE");
+      const sessionIdBefore = await runtimeSessionId(harness, session);
+      expectPiSessionId(sessionIdBefore);
+
+      await harness.client.rewindAgent(session.agentId, firstMessageId, "conversation");
+      const sessionIdAfter = await runtimeSessionId(harness, session);
+      const rewoundTimeline = await fetchTimelineItems(harness.client, session.agentId);
+
+      expect(sessionIdAfter).toBe(sessionIdBefore);
+      expectTimeline(rewoundTimeline, { userTexts: [], assistantCount: 0 });
+      await expectNoCreatedFiles(session);
+
+      await askPi(harness, session, {
+        promptToken: "AFTER_SINGLE",
+        doneToken: "PI_AFTER_SINGLE_DONE",
+      });
+      const nextTimeline = await fetchTimelineItems(harness.client, session.agentId);
+
+      expectTimeline(nextTimeline, {
+        userTexts: [piPrompt({ promptToken: "AFTER_SINGLE", doneToken: "PI_AFTER_SINGLE_DONE" })],
+        assistantCount: 1,
+      });
+      await expectNoCreatedFiles(session);
+    } finally {
+      await closePiRewindSession(session);
+    }
+  }, 420_000);
+
+  test("rewinds a real Pi conversation to an earlier user message", async () => {
+    const session = await launchPiRewindSession(harness, "pi-rewind-conversation-real");
+
+    try {
+      await askPi(harness, session, {
+        promptToken: "FIRST",
+        doneToken: "PI_FIRST_DONE",
+      });
+      const firstTimeline = await fetchTimelineItems(harness.client, session.agentId);
+      const firstMessageId = userMessageIdForToken(firstTimeline, "PI_REWIND_PROMPT_FIRST");
+
+      await askPi(harness, session, {
+        promptToken: "SECOND",
+        doneToken: "PI_SECOND_DONE",
+      });
+      const sessionIdBefore = await runtimeSessionId(harness, session);
+      expectPiSessionId(sessionIdBefore);
+
+      await harness.client.rewindAgent(session.agentId, firstMessageId, "conversation");
+      const sessionIdAfter = await runtimeSessionId(harness, session);
+      const rewoundTimeline = await fetchTimelineItems(harness.client, session.agentId);
+
+      expect(sessionIdAfter).toBe(sessionIdBefore);
+      expectTimeline(rewoundTimeline, { userTexts: [], assistantCount: 0 });
+      await expectNoCreatedFiles(session);
+    } finally {
+      await closePiRewindSession(session);
+    }
+  }, 420_000);
+});

packages/server/src/server/daemon-e2e/test-utils/rewind-helpers.ts

@@ -0,0 +1,111 @@
+import { mkdtempSync, realpathSync, rmSync } from "node:fs";
+import { access, readFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import path from "node:path";
+
+import type { AgentTimelineItem } from "../../agent/agent-sdk-types.js";
+import type { DaemonClient } from "../../test-utils/daemon-client.js";
+
+export interface RewindSessionBase {
+  agentId: string;
+  cwd: string;
+  scratchPath?: string;
+}
+
+export function tmpRewindCwd(prefix: string, options?: { realpath?: boolean }): string {
+  const dir = mkdtempSync(path.join(tmpdir(), prefix));
+  return options?.realpath ? realpathSync(dir) : dir;
+}
+
+export function closeRewindSession(session: RewindSessionBase): void {
+  rmSync(session.cwd, { recursive: true, force: true });
+}
+
+export function timelineItems(
+  timeline: Awaited<ReturnType<DaemonClient["fetchAgentTimeline"]>>,
+): AgentTimelineItem[] {
+  return timeline.entries.map((entry) => entry.item);
+}
+
+export function textByRole(
+  items: AgentTimelineItem[],
+  role: "user_message" | "assistant_message",
+): string {
+  return items
+    .filter((item) => item.type === role)
+    .map((item) => item.text)
+    .join("\n");
+}
+
+export function userMessageIdForToken(items: AgentTimelineItem[], token: string): string {
+  const item = items.find(
+    (candidate) => candidate.type === "user_message" && candidate.text.includes(token),
+  );
+  if (!item?.messageId) {
+    throw new Error(`Timeline did not contain a user message id for ${token}`);
+  }
+  return item.messageId;
+}
+
+export async function fetchTimelineItems(
+  client: DaemonClient,
+  agentId: string,
+): Promise<AgentTimelineItem[]> {
+  const timeline = await client.fetchAgentTimeline(agentId, {
+    direction: "tail",
+    limit: 0,
+    projection: "canonical",
+  });
+  return timelineItems(timeline);
+}
+
+export async function readScratchFile(session: { scratchPath: string }): Promise<string> {
+  return await readFile(session.scratchPath, "utf8");
+}
+
+export async function fileExists(filePath: string): Promise<boolean> {
+  try {
+    await access(filePath);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+export async function waitForTimelineItems(
+  client: DaemonClient,
+  agentId: string,
+  predicate: (items: AgentTimelineItem[]) => boolean,
+): Promise<AgentTimelineItem[]> {
+  const existingItems = await fetchTimelineItems(client, agentId);
+  if (predicate(existingItems)) {
+    return existingItems;
+  }
+
+  return await new Promise<AgentTimelineItem[]>((resolve, reject) => {
+    const timeout = setTimeout(() => {
+      unsubscribe();
+      reject(new Error(`Timed out waiting for timeline items for ${agentId}`));
+    }, 60_000);
+    const unsubscribe = client.on("agent_update", (message) => {
+      if (message.payload.kind !== "upsert" || message.payload.agent.id !== agentId) {
+        return;
+      }
+      void (async () => {
+        try {
+          const items = await fetchTimelineItems(client, agentId);
+          if (!predicate(items)) {
+            return;
+          }
+          clearTimeout(timeout);
+          unsubscribe();
+          resolve(items);
+        } catch (error) {
+          clearTimeout(timeout);
+          unsubscribe();
+          reject(error);
+        }
+      })();
+    });
+  });
+}

packages/server/src/server/daemon-e2e/user-message-contract.real.e2e.test.ts

@@ -0,0 +1,170 @@
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import pino from "pino";
+import { afterEach, beforeAll, beforeEach, describe, expect, test } from "vitest";
+
+import { ClaudeAgentClient } from "../agent/providers/claude/agent.js";
+import { CodexAppServerAgentClient } from "../agent/providers/codex-app-server-agent.js";
+import { OpenCodeAgentClient } from "../agent/providers/opencode-agent.js";
+import { PiRpcAgentClient } from "../agent/providers/pi/agent.js";
+import type {
+  AgentClient,
+  AgentProvider,
+  AgentSessionConfig,
+  AgentStreamEvent,
+} from "../agent/agent-sdk-types.js";
+import { DaemonClient } from "../test-utils/daemon-client.js";
+import { createTestPaseoDaemon, type TestPaseoDaemon } from "../test-utils/paseo-daemon.js";
+import { getFullAccessConfig, isProviderAvailable } from "./agent-configs.js";
+import { fetchTimelineItems } from "./test-utils/rewind-helpers.js";
+
+type ContractProvider = Extract<AgentProvider, "claude" | "codex" | "opencode" | "pi">;
+
+interface ProviderContractCase {
+  provider: ContractProvider;
+  title: string;
+  timeoutMs: number;
+  createClient: (logger: pino.Logger) => AgentClient;
+  createConfig: () => AgentSessionConfig;
+}
+
+const PI_REAL_TEST_MODEL = "openrouter/google/gemini-2.5-flash-lite";
+
+const CONTRACT_CASES: ProviderContractCase[] = [
+  {
+    provider: "claude",
+    title: "Claude",
+    timeoutMs: 180_000,
+    createClient: (logger) => new ClaudeAgentClient({ logger }),
+    createConfig: () => getFullAccessConfig("claude"),
+  },
+  {
+    provider: "codex",
+    title: "Codex",
+    timeoutMs: 180_000,
+    createClient: (logger) => new CodexAppServerAgentClient(logger),
+    createConfig: () => getFullAccessConfig("codex"),
+  },
+  {
+    provider: "opencode",
+    title: "OpenCode",
+    timeoutMs: 180_000,
+    createClient: (logger) => new OpenCodeAgentClient(logger),
+    createConfig: () => getFullAccessConfig("opencode"),
+  },
+  {
+    provider: "pi",
+    title: "Pi",
+    timeoutMs: 240_000,
+    createClient: (logger) => new PiRpcAgentClient({ logger }),
+    createConfig: () => ({
+      provider: "pi",
+      model: PI_REAL_TEST_MODEL,
+      thinkingOptionId: "medium",
+    }),
+  },
+];
+
+function tmpCwd(provider: ContractProvider): string {
+  return mkdtempSync(path.join(tmpdir(), `daemon-real-${provider}-user-message-contract-`));
+}
+
+function collectUserMessageEvents(client: DaemonClient, agentId: string): AgentStreamEvent[] {
+  const events: AgentStreamEvent[] = [];
+  client.on("agent_stream", (message) => {
+    if (message.type !== "agent_stream" || message.payload.agentId !== agentId) {
+      return;
+    }
+    if (message.payload.event.type !== "timeline") {
+      return;
+    }
+    if (message.payload.event.item.type !== "user_message") {
+      return;
+    }
+    events.push(message.payload.event);
+  });
+  return events;
+}
+
+describe.each(CONTRACT_CASES)("daemon E2E (real $provider) - user_message contract", (entry) => {
+  let canRun = false;
+  let daemon: TestPaseoDaemon | null = null;
+  let client: DaemonClient | null = null;
+  let cwd: string | null = null;
+
+  beforeAll(async () => {
+    canRun = await isProviderAvailable(entry.provider);
+  });
+
+  beforeEach(async (context) => {
+    if (!canRun) {
+      context.skip();
+      return;
+    }
+
+    cwd = tmpCwd(entry.provider);
+    const logger = pino({ level: "silent" });
+    daemon = await createTestPaseoDaemon({
+      agentClients: { [entry.provider]: entry.createClient(logger) },
+      logger,
+    });
+    client = new DaemonClient({
+      url: `ws://127.0.0.1:${daemon.port}/ws`,
+      appVersion: "0.1.80",
+    });
+    await client.connect();
+    await client.fetchAgents({ subscribe: { subscriptionId: `${entry.provider}-user-contract` } });
+  }, 30_000);
+
+  afterEach(async () => {
+    await client?.close().catch(() => undefined);
+    await daemon?.close().catch(() => undefined);
+    if (cwd) {
+      rmSync(cwd, { recursive: true, force: true });
+    }
+    client = null;
+    daemon = null;
+    cwd = null;
+  });
+
+  test(
+    "submit one prompt emits exactly one provider user_message",
+    async () => {
+      if (!client || !cwd) {
+        throw new Error(`${entry.title} user-message contract test was not initialized`);
+      }
+
+      const prompt = `PASEO_USER_MESSAGE_CONTRACT_${entry.provider.toUpperCase()}. Reply exactly: OK.`;
+      const agent = await client.createAgent({
+        cwd,
+        title: `${entry.provider}-user-message-contract`,
+        ...entry.createConfig(),
+      });
+      const liveUserEvents = collectUserMessageEvents(client, agent.id);
+
+      await client.sendMessage(agent.id, prompt);
+      const finish = await client.waitForFinish(agent.id, entry.timeoutMs);
+      expect(finish.status).toBe("idle");
+      expect(finish.final?.lastError).toBeUndefined();
+
+      const liveUserMessages = liveUserEvents.filter(
+        (event) => event.type === "timeline" && event.item.type === "user_message",
+      );
+      expect(liveUserMessages).toHaveLength(1);
+      const [liveUserMessage] = liveUserMessages;
+      expect(liveUserMessage?.type).toBe("timeline");
+      expect(liveUserMessage?.item.type).toBe("user_message");
+      expect(liveUserMessage?.item.text).toBe(prompt);
+      expect(liveUserMessage?.item.messageId).toEqual(expect.any(String));
+      expect(liveUserMessage?.item.messageId).not.toBe("");
+
+      const timeline = await fetchTimelineItems(client, agent.id);
+      const canonicalUserMessages = timeline.filter((item) => item.type === "user_message");
+      expect(canonicalUserMessages).toHaveLength(1);
+      expect(canonicalUserMessages[0]?.text).toBe(prompt);
+      expect(canonicalUserMessages[0]?.messageId).toBe(liveUserMessage?.item.messageId);
+    },
+    entry.timeoutMs + 60_000,
+  );
+});

packages/server/src/server/session.ts

@@ -1775,6 +1775,7 @@ export class Session {
   private async dispatchInboundMessage(msg: SessionInboundMessage): Promise<void> {
     const promise =
       this.dispatchVoiceAndControlMessage(msg) ??
+      this.dispatchAgentRewindMessage(msg) ??
       this.dispatchAgentLifecycleMessage(msg) ??
       this.dispatchAgentConfigMessage(msg) ??
       this.dispatchCheckoutMessage(msg) ??
@@ -1836,6 +1837,15 @@ export class Session {
     }
   }
 
+  private dispatchAgentRewindMessage(msg: SessionInboundMessage): Promise<void> | undefined {
+    switch (msg.type) {
+      case "agent.rewind.request":
+        return this.handleAgentRewindRequest(msg);
+      default:
+        return undefined;
+    }
+  }
+
   private async handleDictationStreamStart(
     msg: Extract<SessionInboundMessage, { type: "dictation_stream_start" }>,
   ): Promise<void> {
@@ -3522,6 +3532,33 @@ export class Session {
     }
   }
 
+  private async handleAgentRewindRequest(
+    msg: Extract<SessionInboundMessage, { type: "agent.rewind.request" }>,
+  ): Promise<void> {
+    try {
+      await this.agentManager.rewind(msg.agentId, msg.messageId, msg.mode);
+      this.emit({
+        type: "agent.rewind.response",
+        payload: {
+          requestId: msg.requestId,
+          agentId: msg.agentId,
+          ok: true,
+          error: null,
+        },
+      });
+    } catch (error) {
+      this.emit({
+        type: "agent.rewind.response",
+        payload: {
+          requestId: msg.requestId,
+          agentId: msg.agentId,
+          ok: false,
+          error: error instanceof Error ? error.message : "Failed to rewind agent",
+        },
+      });
+    }
+  }
+
   private async buildAgentSessionConfig(
     config: AgentSessionConfig,
     gitOptions?: GitSetupOptions,
@@ -8794,7 +8831,7 @@ export class Session {
             agentId,
             prompt: formatSystemNotificationPrompt(text),
             unarchive: false,
-            recordUserMessage: false,
+            userMessageVisible: false,
             logger: this.sessionLogger,
           });
         },

packages/server/src/server/test-utils/fake-agent-client.ts

@@ -31,6 +31,9 @@ const TEST_CAPABILITIES: AgentCapabilityFlags = {
   supportsMcpServers: false,
   supportsReasoningStream: true,
   supportsToolInvocations: true,
+  supportsRewindConversation: false,
+  supportsRewindFiles: false,
+  supportsRewindBoth: false,
 };
 
 const TEST_FEATURE_ID = "test_feature";

packages/server/src/server/websocket-server.ts

@@ -1083,6 +1083,8 @@ export class VoiceAssistantWebSocketServer {
         daemonStatusRpc: true,
         // COMPAT(terminalRestoreModes): added in v0.1.81, remove gate after 2026-11-23.
         "terminal-restore-modes": true,
+        // COMPAT(rewind): added in v0.1.X, drop the gate when floor >= v0.1.X.
+        rewind: true,
       },
     };
   }

packages/server/src/shared/agent-feature-schemas.test.ts

@@ -143,4 +143,37 @@ describe("agent feature schemas", () => {
     expect(parsed.features).toHaveLength(1);
     expect(parsed.features?.[0]?.id).toBe("fast_mode");
   });
+
+  it("defaults missing rewind capabilities to false", () => {
+    const parsed = AgentSnapshotPayloadSchema.parse({
+      id: "agent-123",
+      provider: "codex",
+      cwd: "/tmp/project",
+      model: "gpt-5",
+      thinkingOptionId: null,
+      effectiveThinkingOptionId: null,
+      createdAt: "2026-04-03T12:00:00.000Z",
+      updatedAt: "2026-04-03T12:00:00.000Z",
+      lastUserMessageAt: null,
+      status: "idle",
+      capabilities: {
+        supportsStreaming: true,
+        supportsSessionPersistence: true,
+        supportsDynamicModes: true,
+        supportsMcpServers: true,
+        supportsReasoningStream: true,
+        supportsToolInvocations: true,
+      },
+      currentModeId: null,
+      availableModes: [],
+      pendingPermissions: [],
+      persistence: null,
+      title: null,
+      labels: {},
+    });
+
+    expect(parsed.capabilities.supportsRewindConversation).toBe(false);
+    expect(parsed.capabilities.supportsRewindFiles).toBe(false);
+    expect(parsed.capabilities.supportsRewindBoth).toBe(false);
+  });
 });

packages/server/src/shared/messages.ts

@@ -232,6 +232,12 @@ const AgentCapabilityFlagsSchema: z.ZodType<AgentCapabilityFlags> = z.object({
   supportsMcpServers: z.boolean(),
   supportsReasoningStream: z.boolean(),
   supportsToolInvocations: z.boolean(),
+  // COMPAT(rewind): added in v0.1.X, drop when floor >= v0.1.X.
+  supportsRewindConversation: z.boolean().optional().default(false),
+  // COMPAT(rewind): added in v0.1.X, drop when floor >= v0.1.X.
+  supportsRewindFiles: z.boolean().optional().default(false),
+  // COMPAT(rewind): added in v0.1.X, drop when floor >= v0.1.X.
+  supportsRewindBoth: z.boolean().optional().default(false),
 });
 
 const AgentUsageSchema: z.ZodType<AgentUsage> = z.object({
@@ -1246,6 +1252,26 @@ export const SetAgentFeatureResponseMessageSchema = z.object({
   payload: AgentActionResponsePayloadSchema,
 });
 
+export const AgentRewindModeSchema = z.enum(["conversation", "files", "both"]);
+
+export const AgentRewindRequestMessageSchema = z.object({
+  type: z.literal("agent.rewind.request"),
+  agentId: z.string(),
+  messageId: z.string(),
+  mode: AgentRewindModeSchema,
+  requestId: z.string(),
+});
+
+export const AgentRewindResponseMessageSchema = z.object({
+  type: z.literal("agent.rewind.response"),
+  payload: z.object({
+    requestId: z.string(),
+    agentId: z.string(),
+    ok: z.boolean(),
+    error: z.string().nullable(),
+  }),
+});
+
 export const UpdateAgentResponseMessageSchema = z.object({
   type: z.literal("update_agent_response"),
   payload: AgentActionResponsePayloadSchema,
@@ -1854,6 +1880,7 @@ export const SessionInboundMessageSchema = z.discriminatedUnion("type", [
   SetAgentModelRequestMessageSchema,
   SetAgentThinkingRequestMessageSchema,
   SetAgentFeatureRequestMessageSchema,
+  AgentRewindRequestMessageSchema,
   AgentPermissionResponseMessageSchema,
   CheckoutStatusRequestSchema,
   SubscribeCheckoutDiffRequestSchema,
@@ -2095,6 +2122,8 @@ export const ServerInfoStatusPayloadSchema = z
         daemonStatusRpc: z.boolean().optional(),
         // COMPAT(terminalRestoreModes): added in v0.1.81, remove gate after 2026-11-23.
         "terminal-restore-modes": z.boolean().optional(),
+        // COMPAT(rewind): added in v0.1.X, drop the gate when floor >= v0.1.X.
+        rewind: z.boolean().optional(),
       })
       .optional(),
   })
@@ -3624,6 +3653,7 @@ export const SessionOutboundMessageSchema = z.discriminatedUnion("type", [
   SetAgentModelResponseMessageSchema,
   SetAgentThinkingResponseMessageSchema,
   SetAgentFeatureResponseMessageSchema,
+  AgentRewindResponseMessageSchema,
   UpdateAgentResponseMessageSchema,
   ProjectRenameResponseSchema,
   WaitForFinishResponseMessageSchema,
@@ -3763,6 +3793,7 @@ export type SetAgentModeResponseMessage = z.infer<typeof SetAgentModeResponseMes
 export type SetAgentModelResponseMessage = z.infer<typeof SetAgentModelResponseMessageSchema>;
 export type SetAgentThinkingResponseMessage = z.infer<typeof SetAgentThinkingResponseMessageSchema>;
 export type SetAgentFeatureResponseMessage = z.infer<typeof SetAgentFeatureResponseMessageSchema>;
+export type AgentRewindResponseMessage = z.infer<typeof AgentRewindResponseMessageSchema>;
 export type UpdateAgentResponseMessage = z.infer<typeof UpdateAgentResponseMessageSchema>;
 export type ProjectRenameResponse = z.infer<typeof ProjectRenameResponseSchema>;
 export type ProjectRenameResponsePayload = z.infer<typeof ProjectRenameResponsePayloadSchema>;

packages/server/src/shared/wire-compat.test.ts

@@ -1,9 +1,10 @@
 import pino from "pino";
 import { z } from "zod";
-import { describe, expect, test, vi } from "vitest";
+import { describe, expect, test } from "vitest";
 
 import { CLIENT_CAPS } from "./client-capabilities.js";
 import {
+  AgentSnapshotPayloadSchema,
   AgentTimelineItemPayloadSchema,
   FetchAgentTimelineResponseMessageSchema,
   SessionInboundMessageSchema,
@@ -58,8 +59,20 @@ const LegacySubAgentToolCallSchema = z.object({
   }),
 });
 
+const LegacyAgentCapabilityFlagsSchema = z.object({
+  supportsStreaming: z.boolean(),
+  supportsSessionPersistence: z.boolean(),
+  supportsDynamicModes: z.boolean(),
+  supportsMcpServers: z.boolean(),
+  supportsReasoningStream: z.boolean(),
+  supportsToolInvocations: z.boolean(),
+});
+
+const LegacyAgentSnapshotPayloadSchema = AgentSnapshotPayloadSchema.extend({
+  capabilities: LegacyAgentCapabilityFlagsSchema,
+});
+
 interface SessionInternals {
-  buildAgentPayload: (snapshot: unknown) => Promise<null>;
   handleFetchAgentTimelineRequest: (
     message: Extract<
       z.infer<typeof SessionInboundMessageSchema>,
@@ -68,12 +81,140 @@ interface SessionInternals {
   ) => Promise<void>;
 }
 
+class InMemoryAgentManager {
+  constructor(private readonly rows: AgentTimelineRow[]) {}
+
+  getAgent() {
+    return {
+      id: "agent-1",
+      provider: "codex",
+      cwd: "/tmp/project",
+      model: null,
+      thinkingOptionId: null,
+      effectiveThinkingOptionId: null,
+      createdAt: new Date("2026-05-02T00:00:00.000Z"),
+      updatedAt: new Date("2026-05-02T00:00:00.000Z"),
+      lastUserMessageAt: null,
+      lifecycle: "idle",
+      capabilities: {
+        supportsStreaming: true,
+        supportsSessionPersistence: true,
+        supportsDynamicModes: true,
+        supportsMcpServers: true,
+        supportsReasoningStream: true,
+        supportsToolInvocations: true,
+        supportsRewindConversation: false,
+        supportsRewindFiles: false,
+        supportsRewindBoth: false,
+      },
+      config: { provider: "codex", cwd: "/tmp/project" },
+      currentModeId: null,
+      availableModes: [],
+      pendingPermissions: new Map(),
+      bufferedPermissionResolutions: new Map(),
+      inFlightPermissionResponses: new Set(),
+      pendingReplacement: false,
+      persistence: null,
+      historyPrimed: true,
+      lastUsage: undefined,
+      lastError: undefined,
+      attention: { requiresAttention: false, attentionReason: null, attentionTimestamp: null },
+      foregroundTurnWaiters: new Set(),
+      finalizedForegroundTurnIds: new Set(),
+      unsubscribeSession: null,
+      session: null,
+      activeForegroundTurnId: null,
+      labels: {},
+    };
+  }
+
+  fetchTimeline() {
+    return {
+      epoch: "epoch-1",
+      reset: false,
+      staleCursor: false,
+      gap: false,
+      window: { minSeq: 1, maxSeq: 3, nextSeq: 4 },
+      rows: this.rows,
+      hasOlder: false,
+      hasNewer: false,
+    };
+  }
+
+  listAgents() {
+    return [];
+  }
+
+  subscribe() {
+    return () => {};
+  }
+}
+
+class EmptyAgentStorage {
+  async list() {
+    return [];
+  }
+
+  async get() {
+    return null;
+  }
+}
+
+class EmptyProjectRegistry {
+  async list() {
+    return [];
+  }
+
+  async get() {
+    return null;
+  }
+
+  async upsert() {}
+  async archive() {}
+  async remove() {}
+  async initialize() {}
+  async existsOnDisk() {
+    return false;
+  }
+}
+
+class EmptyWorkspaceRegistry {
+  get() {
+    return null;
+  }
+
+  list() {
+    return [];
+  }
+}
+
+class EmptyDaemonConfigStore {
+  get() {
+    return {
+      mcp: { injectIntoAgents: false },
+      providers: {},
+    };
+  }
+
+  onChange() {
+    return () => {};
+  }
+}
+
+class InMemoryWorktreeWorkflow {
+  readonly capturedInputs: unknown[] = [];
+
+  async create(input: unknown) {
+    this.capturedInputs.push(input);
+    return {} as never;
+  }
+}
+
 function createSessionForWireCompatTest(options?: {
   clientCapabilities?: Record<string, unknown> | null;
   messages?: SessionOutboundMessage[];
 }): Session {
   const messages = options?.messages ?? [];
-  const snapshot = { id: "agent-1", provider: "codex" };
   const rows: AgentTimelineRow[] = [
     {
       seq: 1,
@@ -100,74 +241,62 @@ function createSessionForWireCompatTest(options?: {
     downloadTokenStore: {} as SessionOptions["downloadTokenStore"],
     pushTokenStore: {} as SessionOptions["pushTokenStore"],
     paseoHome: "/tmp/paseo-home",
-    agentManager: {
-      getAgent: vi.fn(() => snapshot),
-      fetchTimeline: vi.fn(() => ({
-        epoch: "epoch-1",
-        reset: false,
-        staleCursor: false,
-        gap: false,
-        window: { minSeq: 1, maxSeq: 3, nextSeq: 4 },
-        rows,
-        hasOlder: false,
-        hasNewer: false,
-      })),
-      listAgents: vi.fn(() => []),
-      subscribe: vi.fn(() => () => {}),
-    } as unknown as SessionOptions["agentManager"],
-    agentStorage: {
-      list: vi.fn().mockResolvedValue([]),
-      get: vi.fn().mockResolvedValue(null),
-    } as unknown as SessionOptions["agentStorage"],
-    projectRegistry: {
-      list: vi.fn().mockResolvedValue([]),
-      get: vi.fn(),
-      upsert: vi.fn(),
-      archive: vi.fn(),
-      remove: vi.fn(),
-      initialize: vi.fn(),
-      existsOnDisk: vi.fn(),
-    } as unknown as SessionOptions["projectRegistry"],
-    workspaceRegistry: {
-      get: vi.fn(),
-      list: vi.fn().mockResolvedValue([]),
-    } as unknown as SessionOptions["workspaceRegistry"],
+    agentManager: new InMemoryAgentManager(rows) as unknown as SessionOptions["agentManager"],
+    agentStorage: new EmptyAgentStorage() as unknown as SessionOptions["agentStorage"],
+    projectRegistry: new EmptyProjectRegistry() as unknown as SessionOptions["projectRegistry"],
+    workspaceRegistry:
+      new EmptyWorkspaceRegistry() as unknown as SessionOptions["workspaceRegistry"],
     chatService: {} as SessionOptions["chatService"],
     scheduleService: {} as SessionOptions["scheduleService"],
     loopService: {} as SessionOptions["loopService"],
     checkoutDiffManager: {
-      scheduleRefreshForCwd: vi.fn(),
+      scheduleRefreshForCwd() {},
     } as unknown as SessionOptions["checkoutDiffManager"],
     github: {
-      invalidate: vi.fn(),
-      searchIssuesAndPrs: vi.fn(),
-      createPullRequest: vi.fn(),
+      invalidate() {},
+      async searchIssuesAndPrs() {
+        return [];
+      },
+      async createPullRequest() {
+        return null;
+      },
     } as unknown as SessionOptions["github"],
     workspaceGitService: {
-      getCheckoutDiff: vi.fn(),
-      getSnapshot: vi.fn(),
-      suggestBranchesForCwd: vi.fn(),
-      listStashes: vi.fn(),
-      peekSnapshot: vi.fn(),
-      validateBranchRef: vi.fn(),
-      hasLocalBranch: vi.fn(),
-      resolveRepoRemoteUrl: vi.fn(),
-      getWorkspaceGitMetadata: vi.fn(),
+      async getCheckoutDiff() {
+        return null;
+      },
+      async getSnapshot() {
+        return null;
+      },
+      async suggestBranchesForCwd() {
+        return [];
+      },
+      async listStashes() {
+        return [];
+      },
+      peekSnapshot() {
+        return null;
+      },
+      async validateBranchRef() {
+        return { ok: false, error: "not found" };
+      },
+      async hasLocalBranch() {
+        return false;
+      },
+      async resolveRepoRemoteUrl() {
+        return null;
+      },
+      async getWorkspaceGitMetadata() {
+        return null;
+      },
     } as unknown as SessionOptions["workspaceGitService"],
-    daemonConfigStore: {
-      get: vi.fn(() => ({
-        mcp: { injectIntoAgents: false },
-        providers: {},
-      })),
-      onChange: vi.fn(() => () => {}),
-    } as unknown as SessionOptions["daemonConfigStore"],
+    daemonConfigStore:
+      new EmptyDaemonConfigStore() as unknown as SessionOptions["daemonConfigStore"],
     stt: null,
     tts: null,
     terminalManager: null,
   });
 
-  const internals = session as unknown as SessionInternals;
-  internals.buildAgentPayload = vi.fn(async () => null);
   return session;
 }
 
@@ -256,8 +385,82 @@ describe("wire compatibility", () => {
     expect(parsed.detail.actions).toEqual([]);
   });
 
+  test("old clients parse agent snapshots with rewind capabilities", () => {
+    const parsed = LegacyAgentSnapshotPayloadSchema.parse({
+      id: "agent-1",
+      provider: "claude",
+      cwd: "/tmp/project",
+      model: null,
+      thinkingOptionId: null,
+      effectiveThinkingOptionId: null,
+      createdAt: "2026-05-23T00:00:00.000Z",
+      updatedAt: "2026-05-23T00:00:00.000Z",
+      lastUserMessageAt: null,
+      status: "idle",
+      capabilities: {
+        supportsStreaming: true,
+        supportsSessionPersistence: true,
+        supportsDynamicModes: true,
+        supportsMcpServers: true,
+        supportsReasoningStream: true,
+        supportsToolInvocations: true,
+        supportsRewindConversation: true,
+        supportsRewindFiles: true,
+        supportsRewindBoth: true,
+      },
+      currentModeId: null,
+      availableModes: [],
+      pendingPermissions: [],
+      persistence: null,
+      title: null,
+      labels: {},
+    });
+
+    expect(parsed.capabilities).toEqual({
+      supportsStreaming: true,
+      supportsSessionPersistence: true,
+      supportsDynamicModes: true,
+      supportsMcpServers: true,
+      supportsReasoningStream: true,
+      supportsToolInvocations: true,
+    });
+  });
+
+  test("new clients parse agent snapshots without rewind capabilities", () => {
+    const parsed = AgentSnapshotPayloadSchema.parse({
+      id: "agent-1",
+      provider: "claude",
+      cwd: "/tmp/project",
+      model: null,
+      thinkingOptionId: null,
+      effectiveThinkingOptionId: null,
+      createdAt: "2026-05-23T00:00:00.000Z",
+      updatedAt: "2026-05-23T00:00:00.000Z",
+      lastUserMessageAt: null,
+      status: "idle",
+      capabilities: {
+        supportsStreaming: true,
+        supportsSessionPersistence: true,
+        supportsDynamicModes: true,
+        supportsMcpServers: true,
+        supportsReasoningStream: true,
+        supportsToolInvocations: true,
+      },
+      currentModeId: null,
+      availableModes: [],
+      pendingPermissions: [],
+      persistence: null,
+      title: null,
+      labels: {},
+    });
+
+    expect(parsed.capabilities.supportsRewindConversation).toBe(false);
+    expect(parsed.capabilities.supportsRewindFiles).toBe(false);
+    expect(parsed.capabilities.supportsRewindBoth).toBe(false);
+  });
+
   test("legacy worktree request shape normalizes to the same internal input as the new shape", async () => {
-    const captured: unknown[] = [];
+    const workflow = new InMemoryWorktreeWorkflow();
 
     const dependencies = {
       paseoHome: "/tmp/paseo-home",
@@ -275,12 +478,9 @@ describe("wire compatibility", () => {
           activityAt: null,
           scripts: [],
         }) as never,
-      emit: vi.fn(),
+      emit() {},
       sessionLogger: pino({ level: "silent" }),
-      createPaseoWorktreeWorkflow: async (input: unknown) => {
-        captured.push(input);
-        return {} as never;
-      },
+      createPaseoWorktreeWorkflow: workflow.create.bind(workflow),
     };
 
     const legacyRequest = SessionInboundMessageSchema.parse({
@@ -329,9 +529,9 @@ describe("wire compatibility", () => {
     await handleCreatePaseoWorktreeRequest(dependencies, legacyRequest);
     await handleCreatePaseoWorktreeRequest(dependencies, newRequest);
 
-    expect(captured).toHaveLength(2);
-    expect(captured[0]).toEqual(captured[1]);
-    expect(captured[0]).toEqual({
+    expect(workflow.capturedInputs).toHaveLength(2);
+    expect(workflow.capturedInputs[0]).toEqual(workflow.capturedInputs[1]);
+    expect(workflow.capturedInputs[0]).toEqual({
       cwd: "/tmp/repo",
       worktreeSlug: "legacy-worktree",
       firstAgentContext: {