Stop completed turns from appearing stuck (#2484)

* fix(app): stop completed turns from appearing stuck

Turn activity was inferred from a user-message row flag, so a stale duplicate row could keep the working footer active after the turn ended. Track submission lifecycle separately and route every send path through the shared submission flow.

* fix(app): guard pending message identity

* test(app): measure submission layout independent of scroll

* fix(app): keep submitted messages consistent through reconnects

Track each in-flight send until its own RPC establishes acceptance, and keep canonical timeline placement authoritative. Restore legacy cached rewind IDs during cache deserialization.

* fix(app): close canonical submission races

* test(app): cover canonical submission races in browser

* fix(app): keep replacement submissions authoritative

Keep current pending rows out of legacy cache migration and leave ambiguous terminal lifecycle events to the daemon snapshot. This prevents fabricated rewind identities and stale completion events from marking replacement turns idle.

* fix(app): keep submitted messages stable across sync

Give submission transport and canonical timeline ingestion separate authority. Preserve every unresolved local send across replacement, reconcile provider identity once, and bridge RPC acceptance to authoritative running state without deriving lifecycle from timeline rows.

* fix(app): settle submissions in either acknowledgement order

Complete submission transactions when RPC and provider acknowledgement arrive in either order. Cache only transaction-owned local rows as transient data, preserve canonical ID-less prompts, and invalidate ambiguous legacy display caches instead of inventing provider identity.

* fix(app): keep agent visible during history handoff

Running and terminal updates could clear create continuity before the initial authoritative timeline arrived, leaving a streaming agent behind the loading screen. End the handoff only when authoritative history is applied.

* fix(app): settle attachment-only submissions

Canonical providers can acknowledge image-only prompts with empty text. Reconcile those events by client identity without rendering a blank canonical row.

* fix(agent): settle out-of-band message submissions

Accepted commands that do not allocate a foreground turn previously had no canonical user acknowledgement. Record the command before its handler runs so submission state and reconnect history converge through the normal timeline producer.

* fix(app): settle out-of-band submissions compatibly

* fix(app): preserve canonical prompt order

* test(app): keep workspace status check timing-independent

The workspace-status scenario asserted footer settlement before initial agent creation had necessarily completed. The dedicated draft-handoff coverage owns that lifecycle contract.

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

@@ -1,15 +1,15 @@
 import type { AgentStreamEventPayload } from "@getpaseo/protocol/messages";
-import type { AgentLifecycleStatus } from "@getpaseo/protocol/agent-lifecycle";
-import type { Agent } from "@/stores/session-store";
 import { useSessionStore } from "@/stores/session-store";
-import type { AssistantMessageItem, StreamItem, UserMessageItem } from "@/types/stream";
+import type { AssistantMessageItem, StreamItem } from "@/types/stream";
 import {
   applyStreamEvent,
   flushHeadToTail,
   hydrateStreamState,
   isAgentToolCallItem,
   mergeAgentToolCallItem,
+  replaceWithCanonicalStream,
   reduceStreamUpdate,
+  upsertUserMessageAcrossStream,
 } from "@/types/stream";
 
 const AGENT_STREAM_REDUCER_FLUSH_DELAY_MS = 16 * 3;
@@ -88,6 +88,7 @@ export interface ProcessTimelineResponseInput {
   isInitializing: boolean;
   hasActiveInitDeferred: boolean;
   initRequestDirection: InitRequestDirection;
+  sendingClientMessageIds: readonly string[];
 }
 
 export interface ProcessTimelineResponseOutput {
@@ -99,6 +100,7 @@ export interface ProcessTimelineResponseOutput {
   clearInitializing: boolean;
   error: string | null;
   sideEffects: TimelineReducerSideEffect[];
+  acknowledgedClientMessageIds: string[];
 }
 
 interface TimelineUnit {
@@ -115,6 +117,7 @@ interface TimelinePathResult {
   cursor: TimelineCursor | null | undefined;
   cursorChanged: boolean;
   sideEffects: TimelineReducerSideEffect[];
+  acknowledgedClientMessageIds: string[];
 }
 
 function classifySessionTimelineSeq({
@@ -201,76 +204,35 @@ function shouldResolveTimelineInit({
   return responseDirection === initRequestDirection;
 }
 
-function deriveOptimisticLifecycleStatus(
-  currentStatus: AgentLifecycleStatus,
-  event: AgentStreamEventPayload,
-): AgentLifecycleStatus | null {
-  if (currentStatus !== "running") {
-    return null;
-  }
-  switch (event.type) {
-    case "turn_completed":
-      return "idle";
-    case "turn_failed":
-      return "error";
-    case "turn_canceled":
-      // A canceled turn can be either a final user cancel or an interrupt before
-      // a replacement turn starts. The daemon snapshot is authoritative here.
-      return null;
-    default:
-      return null;
-  }
-}
-
-function preserveReplacePathAssistantHead(params: {
-  tail: StreamItem[];
-  currentHead: StreamItem[];
-}): {
-  tail: StreamItem[];
-  head: StreamItem[];
-} {
-  const { tail, currentHead } = params;
-  const liveAssistant = currentHead.findLast(
-    (item): item is Extract<StreamItem, { kind: "assistant_message" }> =>
-      item.kind === "assistant_message",
-  );
-  if (!liveAssistant) {
-    return { tail, head: [] };
-  }
-  const tailAssistant = tail.at(-1);
-  if (!tailAssistant || tailAssistant.kind !== "assistant_message") {
-    return { tail, head: currentHead };
-  }
-  if (!liveAssistant.text.startsWith(tailAssistant.text)) {
-    return { tail, head: [] };
-  }
-  return {
-    tail: tail.slice(0, -1),
-    head: [{ ...liveAssistant, text: tailAssistant.text }],
-  };
-}
-
 function applyTimelineReplacePath(args: {
   timelineUnits: TimelineUnit[];
   payload: ProcessTimelineResponseInput["payload"];
   bootstrapPolicy: ReturnType<typeof deriveBootstrapTailTimelinePolicy>;
   currentTail: StreamItem[];
   currentHead: StreamItem[];
+  sendingClientMessageIds: readonly string[];
+  preserveLiveHead: boolean;
   toHydratedEvents: (
     units: TimelineUnit[],
   ) => Array<{ event: AgentStreamEventPayload; timestamp: Date }>;
 }): TimelinePathResult {
-  const { timelineUnits, payload, bootstrapPolicy, currentTail, currentHead, toHydratedEvents } =
-    args;
+  const {
+    timelineUnits,
+    payload,
+    bootstrapPolicy,
+    currentTail,
+    currentHead,
+    sendingClientMessageIds,
+    preserveLiveHead,
+    toHydratedEvents,
+  } = args;
   const hydratedTail = hydrateStreamState(toHydratedEvents(timelineUnits), { source: "canonical" });
-  const reconciledTail = reconcileLocalUserPresentationAfterReplace({
-    canonicalTail: hydratedTail,
+  const { tail, head, acknowledgedClientMessageIds } = replaceWithCanonicalStream({
+    canonical: hydratedTail,
     previousTail: currentTail,
     previousHead: currentHead,
-  });
-  const { tail, head } = preserveReplacePathAssistantHead({
-    tail: reconciledTail,
-    currentHead,
+    sendingClientMessageIds,
+    preserveLiveHead,
   });
   const cursor: TimelineCursor | null =
     payload.startCursor && payload.endCursor
@@ -284,136 +246,16 @@ function applyTimelineReplacePath(args: {
   if (bootstrapPolicy.catchUpCursor) {
     sideEffects.push({ type: "catch_up", cursor: bootstrapPolicy.catchUpCursor });
   }
-  return { tail, head, cursor, cursorChanged: true, sideEffects };
-}
-
-function collectLocallyPresentedUserMessages(items: StreamItem[]): Array<{
-  ordinal: number;
-  item: UserMessageItem;
-}> {
-  const localUsers: Array<{ ordinal: number; item: UserMessageItem }> = [];
-  let ordinal = 0;
-  for (const item of items) {
-    if (item.kind !== "user_message") {
-      continue;
-    }
-    if (item.optimistic || item.images?.length || item.attachments?.length) {
-      localUsers.push({ ordinal, item });
-    }
-    ordinal += 1;
-  }
-  return localUsers;
-}
-
-function mergeCanonicalUserWithLocalPresentation(
-  canonical: UserMessageItem,
-  local: UserMessageItem,
-): UserMessageItem {
   return {
-    kind: "user_message",
-    id: canonical.id,
-    ...(canonical.clientMessageId ? { clientMessageId: canonical.clientMessageId } : {}),
-    text: local.text,
-    timestamp: local.timestamp,
-    ...(local.images && local.images.length > 0 ? { images: local.images } : {}),
-    ...(local.attachments && local.attachments.length > 0
-      ? { attachments: local.attachments }
-      : {}),
+    tail,
+    head,
+    cursor,
+    cursorChanged: true,
+    sideEffects,
+    acknowledgedClientMessageIds,
   };
 }
 
-interface CanonicalUserMessageIdentity {
-  messageId?: string;
-  clientMessageId?: string;
-  text: string;
-}
-
-function matchesLocalUserMessageIdentity(
-  canonical: CanonicalUserMessageIdentity,
-  optimistic: UserMessageItem,
-): boolean {
-  if (canonical.clientMessageId !== undefined) {
-    return canonical.clientMessageId === optimistic.id;
-  }
-  if (canonical.messageId === optimistic.id) {
-    return true;
-  }
-  // COMPAT(userMessageClientId): added in v0.2.0, remove after 2027-01-20 once
-  // the supported daemon floor emits clientMessageId on submitted user messages.
-  return canonical.text.length > 0 && canonical.text === optimistic.text;
-}
-
-function reconcileLocalUserPresentationAfterReplace(params: {
-  canonicalTail: StreamItem[];
-  previousTail: StreamItem[];
-  previousHead: StreamItem[];
-}): StreamItem[] {
-  const localUsers = collectLocallyPresentedUserMessages([
-    ...params.previousTail,
-    ...params.previousHead,
-  ]);
-  if (localUsers.length === 0) {
-    return params.canonicalTail;
-  }
-
-  const canonicalUserIndexes: number[] = [];
-  params.canonicalTail.forEach((item, index) => {
-    if (item.kind === "user_message") {
-      canonicalUserIndexes.push(index);
-    }
-  });
-
-  const nextTail = [...params.canonicalTail];
-  const claimedCanonicalIndexes = new Set<number>();
-  const unmatched: UserMessageItem[] = [];
-
-  for (const local of localUsers) {
-    const exactIndex = canonicalUserIndexes.find((index) => {
-      if (claimedCanonicalIndexes.has(index)) return false;
-      const canonical = params.canonicalTail[index];
-      return (
-        canonical?.kind === "user_message" &&
-        matchesLocalUserMessageIdentity(
-          {
-            messageId: canonical.id,
-            clientMessageId: canonical.clientMessageId,
-            text: canonical.text,
-          },
-          local.item,
-        )
-      );
-    });
-    const ordinalIndex = canonicalUserIndexes[local.ordinal];
-    const ordinalItem = ordinalIndex === undefined ? undefined : params.canonicalTail[ordinalIndex];
-    const canonicalIndex =
-      exactIndex ??
-      (ordinalIndex !== undefined &&
-      !claimedCanonicalIndexes.has(ordinalIndex) &&
-      ordinalItem?.kind === "user_message" &&
-      ordinalItem.clientMessageId === undefined
-        ? ordinalIndex
-        : undefined);
-    const canonicalItem = canonicalIndex === undefined ? undefined : nextTail[canonicalIndex];
-    if (canonicalIndex === undefined || !canonicalItem || canonicalItem.kind !== "user_message") {
-      if (local.item.optimistic) {
-        unmatched.push(local.item);
-      }
-      continue;
-    }
-    nextTail[canonicalIndex] = mergeCanonicalUserWithLocalPresentation(canonicalItem, local.item);
-    claimedCanonicalIndexes.add(canonicalIndex);
-  }
-
-  for (const item of unmatched) {
-    const insertionIndex = nextTail.findIndex(
-      (canonical) => canonical.timestamp.getTime() > item.timestamp.getTime(),
-    );
-    nextTail.splice(insertionIndex < 0 ? nextTail.length : insertionIndex, 0, item);
-  }
-
-  return nextTail;
-}
-
 interface IncrementalAcceptResult {
   acceptedUnits: TimelineUnit[];
   cursor: TimelineCursor | undefined;
@@ -515,6 +357,34 @@ function mergePrependedCanonicalTail(olderTail: StreamItem[], currentTail: Strea
     return olderTail;
   }
 
+  const remainingOlder: StreamItem[] = [];
+  let reconciledCurrent = currentTail;
+  for (const item of olderTail) {
+    if (item.kind !== "user_message") {
+      remainingOlder.push(item);
+      continue;
+    }
+    const result = upsertUserMessageAcrossStream({
+      tail: reconciledCurrent,
+      head: [],
+      message: item,
+      insert: "prepend-tail",
+      presentation: "existing",
+    });
+    if (result.location?.matched) {
+      remainingOlder.push(result.location.message);
+      reconciledCurrent = [
+        ...result.tail.slice(0, result.location.index),
+        ...result.tail.slice(result.location.index + 1),
+      ];
+    } else {
+      remainingOlder.push(item);
+    }
+  }
+  olderTail = remainingOlder;
+  currentTail = reconciledCurrent;
+  if (olderTail.length === 0) return currentTail;
+
   const olderLast = olderTail.at(-1);
   const currentFirst = currentTail[0];
 
@@ -745,9 +615,24 @@ function applyCanonicalForwardUnit(params: {
   head: StreamItem[];
   unit: TimelineUnit;
   epoch: string;
-}): { tail: StreamItem[]; head: StreamItem[] } {
+}): { tail: StreamItem[]; head: StreamItem[]; acknowledgedClientMessageIds: string[] } {
   const { event, timestamp, seqEnd } = params.unit;
   const timelineCursor = { epoch: params.epoch, seq: seqEnd };
+  if (event.type === "timeline" && event.item.type === "user_message") {
+    const applied = applyStreamEvent({
+      tail: params.tail,
+      head: params.head,
+      event,
+      timestamp,
+      source: "canonical",
+      timelineCursor,
+    });
+    return {
+      tail: applied.tail,
+      head: applied.head,
+      acknowledgedClientMessageIds: applied.acknowledgedClientMessageIds ?? [],
+    };
+  }
   if (params.head.length === 0) {
     return {
       tail: reduceStreamUpdate(params.tail, event, timestamp, {
@@ -755,6 +640,7 @@ function applyCanonicalForwardUnit(params: {
         timelineCursor,
       }),
       head: params.head,
+      acknowledgedClientMessageIds: [],
     };
   }
   const replacedHead = replaceLiveAssistantWithProjectedText({
@@ -763,7 +649,9 @@ function applyCanonicalForwardUnit(params: {
     timestamp,
     timelineCursor,
   });
-  if (replacedHead) return { tail: params.tail, head: replacedHead };
+  if (replacedHead) {
+    return { tail: params.tail, head: replacedHead, acknowledgedClientMessageIds: [] };
+  }
 
   const activeAssistant = params.head.findLast(
     (item): item is Extract<StreamItem, { kind: "assistant_message" }> =>
@@ -781,6 +669,7 @@ function applyCanonicalForwardUnit(params: {
         source: "canonical",
         timelineCursor,
       }),
+      acknowledgedClientMessageIds: [],
     };
   }
 
@@ -792,7 +681,11 @@ function applyCanonicalForwardUnit(params: {
     source: "canonical",
     timelineCursor,
   });
-  return { tail: applied.tail, head: applied.head };
+  return {
+    tail: applied.tail,
+    head: applied.head,
+    acknowledgedClientMessageIds: applied.acknowledgedClientMessageIds ?? [],
+  };
 }
 
 function applyAcceptedForwardTimelineUnits(params: {
@@ -801,7 +694,7 @@ function applyAcceptedForwardTimelineUnits(params: {
   currentTail: StreamItem[];
   currentHead: StreamItem[];
   currentEndSeq: number | undefined;
-}): { tail: StreamItem[]; head: StreamItem[] } {
+}): { tail: StreamItem[]; head: StreamItem[]; acknowledgedClientMessageIds: string[] } {
   const reconciled = reconcileOverlappingProjectedStreamItems({
     tail: params.currentTail,
     head: params.currentHead,
@@ -811,15 +704,19 @@ function applyAcceptedForwardTimelineUnits(params: {
   });
   let tail = reconciled.tail;
   let head = reconciled.head;
+  const acknowledgedClientMessageIds = new Set<string>();
 
   for (const unit of params.units) {
     if (reconciled.reconciledUnits.has(unit)) continue;
     const applied = applyCanonicalForwardUnit({ tail, head, unit, epoch: params.epoch });
     tail = applied.tail;
     head = applied.head;
+    for (const clientMessageId of applied.acknowledgedClientMessageIds) {
+      acknowledgedClientMessageIds.add(clientMessageId);
+    }
   }
 
-  return { tail, head };
+  return { tail, head, acknowledgedClientMessageIds: [...acknowledgedClientMessageIds] };
 }
 
 function applyTimelineIncrementalPath(args: {
@@ -835,9 +732,17 @@ function applyTimelineIncrementalPath(args: {
   let nextCursor: TimelineCursor | null | undefined = currentCursor;
   let cursorChanged = false;
   const sideEffects: TimelineReducerSideEffect[] = [];
+  let acknowledgedClientMessageIds: string[] = [];
 
   if (timelineUnits.length === 0) {
-    return { tail: nextTail, head: nextHead, cursor: nextCursor, cursorChanged, sideEffects };
+    return {
+      tail: nextTail,
+      head: nextHead,
+      cursor: nextCursor,
+      cursorChanged,
+      sideEffects,
+      acknowledgedClientMessageIds,
+    };
   }
 
   const { acceptedUnits, cursor, gapCursor } =
@@ -874,6 +779,7 @@ function applyTimelineIncrementalPath(args: {
       });
       nextTail = applied.tail;
       nextHead = applied.head;
+      acknowledgedClientMessageIds = applied.acknowledgedClientMessageIds;
     }
   }
 
@@ -892,7 +798,14 @@ function applyTimelineIncrementalPath(args: {
     sideEffects.push({ type: "catch_up", cursor: gapCursor });
   }
 
-  return { tail: nextTail, head: nextHead, cursor: nextCursor, cursorChanged, sideEffects };
+  return {
+    tail: nextTail,
+    head: nextHead,
+    cursor: nextCursor,
+    cursorChanged,
+    sideEffects,
+    acknowledgedClientMessageIds,
+  };
 }
 
 export function processTimelineResponse(
@@ -906,6 +819,7 @@ export function processTimelineResponse(
     isInitializing,
     hasActiveInitDeferred,
     initRequestDirection,
+    sendingClientMessageIds,
   } = input;
 
   // ------------------------------------------------------------------
@@ -921,6 +835,7 @@ export function processTimelineResponse(
       clearInitializing: isInitializing,
       error: payload.error,
       sideEffects: [],
+      acknowledgedClientMessageIds: [],
     };
   }
 
@@ -967,7 +882,6 @@ export function processTimelineResponse(
     hasActiveInitDeferred,
   });
   const replace = bootstrapPolicy.replace;
-
   const sideEffects: TimelineReducerSideEffect[] = [];
   const timelineResult = replace
     ? applyTimelineReplacePath({
@@ -976,6 +890,8 @@ export function processTimelineResponse(
         bootstrapPolicy,
         currentTail,
         currentHead,
+        sendingClientMessageIds,
+        preserveLiveHead: currentCursor?.epoch === payload.epoch,
         toHydratedEvents,
       })
     : applyTimelineIncrementalPath({
@@ -1024,6 +940,7 @@ export function processTimelineResponse(
     clearInitializing,
     error: null,
     sideEffects,
+    acknowledgedClientMessageIds: timelineResult.acknowledgedClientMessageIds,
   };
 }
 
@@ -1038,20 +955,9 @@ export interface ProcessAgentStreamEventInput {
   currentTail: StreamItem[];
   currentHead: StreamItem[];
   currentCursor: TimelineCursor | undefined;
-  currentAgent: {
-    status: AgentLifecycleStatus;
-    updatedAt: Date;
-    lastActivityAt: Date;
-  } | null;
   timestamp: Date;
 }
 
-export interface AgentPatch {
-  status: AgentLifecycleStatus;
-  updatedAt: Date;
-  lastActivityAt: Date;
-}
-
 export interface ProcessAgentStreamEventOutput {
   tail: StreamItem[];
   head: StreamItem[];
@@ -1059,8 +965,7 @@ export interface ProcessAgentStreamEventOutput {
   changedHead: boolean;
   cursor: TimelineCursor | null;
   cursorChanged: boolean;
-  agent: AgentPatch | null;
-  agentChanged: boolean;
+  acknowledgedClientMessageIds: string[];
   sideEffects: AgentStreamReducerSideEffect[];
 }
 
@@ -1079,18 +984,11 @@ interface TimelineSequencingGateResult {
   sideEffects: AgentStreamReducerSideEffect[];
 }
 
-export interface AgentStreamReducerAgentSnapshot {
-  status: AgentLifecycleStatus;
-  updatedAt: Date;
-  lastActivityAt: Date;
-}
-
 export interface ProcessAgentStreamEventsInput {
   events: AgentStreamReducerEvent[];
   currentTail: StreamItem[];
   currentHead: StreamItem[];
   currentCursor: TimelineCursor | undefined;
-  currentAgent: AgentStreamReducerAgentSnapshot | null;
 }
 
 export type AgentStreamReducerSnapshot = Omit<ProcessAgentStreamEventsInput, "events">;
@@ -1114,20 +1012,6 @@ export interface CreateAgentStreamReducerQueueInput {
   cancelFlush: (id: number) => void;
 }
 
-function applyAgentPatch(
-  currentAgent: AgentStreamReducerAgentSnapshot | null,
-  patch: AgentPatch | null,
-): AgentStreamReducerAgentSnapshot | null {
-  if (!currentAgent || !patch) {
-    return currentAgent;
-  }
-  return {
-    status: patch.status,
-    updatedAt: patch.updatedAt,
-    lastActivityAt: patch.lastActivityAt,
-  };
-}
-
 function processTimelineSequencingGate(input: {
   event: AgentStreamEventPayload;
   seq: number | undefined;
@@ -1201,8 +1085,7 @@ function processTimelineSequencingGate(input: {
 export function processAgentStreamEvent(
   input: ProcessAgentStreamEventInput,
 ): ProcessAgentStreamEventOutput {
-  const { event, seq, epoch, currentTail, currentHead, currentCursor, currentAgent, timestamp } =
-    input;
+  const { event, seq, epoch, currentTail, currentHead, currentCursor, timestamp } = input;
 
   const sequencing = processTimelineSequencingGate({ event, seq, epoch, currentCursor });
   const timelineCursor =
@@ -1213,7 +1096,7 @@ export function processAgentStreamEvent(
   // ------------------------------------------------------------------
   // Apply stream event to tail/head
   // ------------------------------------------------------------------
-  const { tail, head, changedTail, changedHead } = sequencing.shouldApplyStreamEvent
+  const applied = sequencing.shouldApplyStreamEvent
     ? applyStreamEvent({
         tail: sequencing.resetLiveTimeline ? [] : currentTail,
         head: sequencing.resetLiveTimeline ? [] : currentHead,
@@ -1229,43 +1112,14 @@ export function processAgentStreamEvent(
         changedHead: false,
       };
 
-  // ------------------------------------------------------------------
-  // Optimistic lifecycle status
-  // ------------------------------------------------------------------
-  let agentPatch: AgentPatch | null = null;
-  let agentChanged = false;
-
-  if (
-    currentAgent &&
-    (event.type === "turn_completed" ||
-      event.type === "turn_canceled" ||
-      event.type === "turn_failed")
-  ) {
-    const optimisticStatus = deriveOptimisticLifecycleStatus(currentAgent.status, event);
-    if (optimisticStatus) {
-      const nextUpdatedAtMs = Math.max(currentAgent.updatedAt.getTime(), timestamp.getTime());
-      const nextLastActivityAtMs = Math.max(
-        currentAgent.lastActivityAt.getTime(),
-        timestamp.getTime(),
-      );
-      agentPatch = {
-        status: optimisticStatus,
-        updatedAt: new Date(nextUpdatedAtMs),
-        lastActivityAt: new Date(nextLastActivityAtMs),
-      };
-      agentChanged = true;
-    }
-  }
-
   return {
-    tail,
-    head,
-    changedTail,
-    changedHead,
+    tail: applied.tail,
+    head: applied.head,
+    changedTail: applied.changedTail,
+    changedHead: applied.changedHead,
     cursor: sequencing.nextTimelineCursor,
     cursorChanged: sequencing.cursorChanged,
-    agent: agentPatch,
-    agentChanged,
+    acknowledgedClientMessageIds: applied.acknowledgedClientMessageIds ?? [],
     sideEffects: sequencing.sideEffects,
   };
 }
@@ -1276,12 +1130,10 @@ export function processAgentStreamEvents(
   let tail = input.currentTail;
   let head = input.currentHead;
   let cursor = input.currentCursor;
-  let agent = input.currentAgent;
   let changedTail = false;
   let changedHead = false;
   let cursorChanged = false;
-  let agentPatch: AgentPatch | null = null;
-  let agentChanged = false;
+  const acknowledgedClientMessageIds = new Set<string>();
   const sideEffects: AgentStreamReducerSideEffect[] = [];
 
   for (const reducerEvent of input.events) {
@@ -1292,7 +1144,6 @@ export function processAgentStreamEvents(
       currentTail: tail,
       currentHead: head,
       currentCursor: cursor,
-      currentAgent: agent,
       timestamp: reducerEvent.timestamp,
     });
 
@@ -1301,17 +1152,14 @@ export function processAgentStreamEvents(
     changedTail = changedTail || result.changedTail;
     changedHead = changedHead || result.changedHead;
     sideEffects.push(...result.sideEffects);
+    for (const clientMessageId of result.acknowledgedClientMessageIds) {
+      acknowledgedClientMessageIds.add(clientMessageId);
+    }
 
     if (result.cursorChanged) {
       cursor = result.cursor ?? undefined;
       cursorChanged = true;
     }
-
-    if (result.agentChanged) {
-      agentPatch = result.agent;
-      agentChanged = true;
-      agent = applyAgentPatch(agent, result.agent);
-    }
   }
 
   return {
@@ -1321,8 +1169,7 @@ export function processAgentStreamEvents(
     changedHead,
     cursor: cursor ?? null,
     cursorChanged,
-    agent: agentPatch,
-    agentChanged,
+    acknowledgedClientMessageIds: [...acknowledgedClientMessageIds],
     sideEffects,
   };
 }
@@ -1405,6 +1252,7 @@ export function createAgentStreamReducerQueue(
 interface StreamStatePatch {
   tail?: StreamItem[];
   head?: StreamItem[];
+  acknowledgedClientMessageIds?: readonly string[];
 }
 
 export interface CreateSessionAgentStreamReducerQueueInput {
@@ -1414,7 +1262,6 @@ export interface CreateSessionAgentStreamReducerQueueInput {
     serverId: string,
     state: (prev: Map<string, TimelineCursor>) => Map<string, TimelineCursor>,
   ) => void;
-  setAgents: (serverId: string, state: (prev: Map<string, Agent>) => Map<string, Agent>) => void;
   recoverTimelineGap: (agentId: string, cursor: { epoch: string; endSeq: number }) => void;
 }
 
@@ -1429,31 +1276,29 @@ function cancelAgentStreamReducerFlush(id: number) {
 export function createSessionAgentStreamReducerQueue(
   input: CreateSessionAgentStreamReducerQueueInput,
 ): AgentStreamReducerQueue {
-  const { serverId, setAgentStreamState, setAgentTimelineCursor, setAgents, recoverTimelineGap } =
-    input;
+  const { serverId, setAgentStreamState, setAgentTimelineCursor, recoverTimelineGap } = input;
 
   return createAgentStreamReducerQueue({
     getSnapshot: (agentId) => {
       const session = useSessionStore.getState().sessions[serverId];
-      const currentAgentEntry = session?.agents.get(agentId);
       return {
         currentTail: session?.agentStreamTail.get(agentId) ?? [],
         currentHead: session?.agentStreamHead.get(agentId) ?? [],
         currentCursor: session?.agentTimelineCursor.get(agentId),
-        currentAgent: currentAgentEntry
-          ? {
-              status: currentAgentEntry.status,
-              updatedAt: currentAgentEntry.updatedAt,
-              lastActivityAt: currentAgentEntry.lastActivityAt,
-            }
-          : null,
       };
     },
     commit: (agentId, result, events) => {
-      if (result.changedTail || result.changedHead) {
+      if (
+        result.changedTail ||
+        result.changedHead ||
+        result.acknowledgedClientMessageIds.length > 0
+      ) {
         setAgentStreamState(serverId, agentId, {
           ...(result.changedTail ? { tail: result.tail } : {}),
           ...(result.changedHead ? { head: result.head } : {}),
+          ...(result.acknowledgedClientMessageIds.length > 0
+            ? { acknowledgedClientMessageIds: result.acknowledgedClientMessageIds }
+            : {}),
         });
       }
 
@@ -1486,24 +1331,6 @@ export function createSessionAgentStreamReducerQueue(
           return next;
         });
       }
-
-      if (result.agentChanged && result.agent) {
-        const nextAgent = result.agent;
-        setAgents(serverId, (prev) => {
-          const current = prev.get(agentId);
-          if (!current) {
-            return prev;
-          }
-          const next = new Map(prev);
-          next.set(agentId, {
-            ...current,
-            status: nextAgent.status,
-            updatedAt: nextAgent.updatedAt,
-            lastActivityAt: nextAgent.lastActivityAt,
-          });
-          return next;
-        });
-      }
     },
     handleSideEffects: (agentId, sideEffects) => {
       for (const effect of sideEffects) {