fix(server): restore wire compatibility for old clients

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

@@ -237,6 +237,11 @@ export type ToolCallDetail =
       description?: string;
       childSessionId?: string;
       log: string;
+      actions?: Array<{
+        index: number;
+        toolName: string;
+        summary?: string;
+      }>;
     }
   | {
       type: "plain_text";

packages/server/src/server/agent/providers/claude/sidechain-tracker.ts

@@ -99,6 +99,7 @@ export class ClaudeSidechainTracker {
           action.summary ? `[${action.toolName}] ${action.summary}` : `[${action.toolName}]`,
         )
         .join("\n"),
+      actions: [],
     };
 
     return [

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

@@ -851,6 +851,7 @@ function mapCollabAgentToolCallItem(
     subAgentType: "Sub-agent",
     ...(item.prompt ? { description: item.prompt } : {}),
     log: "",
+    actions: [],
   };
 
   if (status === "failed") {

packages/server/src/server/agent/providers/opencode/tool-call-detail-parser.ts

@@ -111,6 +111,7 @@ function deriveOpencodeTaskDetail(
     ...(description ? { description } : {}),
     ...(childSessionId ? { childSessionId } : {}),
     log,
+    actions: [],
   };
 }
 

packages/server/src/server/session.ts

@@ -8,6 +8,11 @@ import { basename, resolve, sep } from "path";
 import { homedir } from "node:os";
 import { z } from "zod";
 import type { ToolSet } from "ai";
+import {
+  CLIENT_CAPS,
+  readDeclaredClientCapabilities,
+  type ClientCapability,
+} from "../shared/client-capabilities.js";
 import {
   isLegacyEditorTargetId,
   serializeAgentStreamEvent,
@@ -552,6 +557,7 @@ interface VoiceTranscriptionResultPayload {
 export interface SessionOptions {
   clientId: string;
   appVersion?: string | null;
+  clientCapabilities?: Record<string, unknown> | null;
   onMessage: (msg: SessionOutboundMessage) => void;
   onBinaryMessage?: (frame: Uint8Array) => void;
   onLifecycleIntent?: (intent: SessionLifecycleIntent) => void;
@@ -725,6 +731,22 @@ function convertPCMToWavBuffer(
   return wavBuffer;
 }
 
+class ClientCapabilities {
+  private readonly supported: ReadonlySet<ClientCapability>;
+
+  constructor(capabilities: Iterable<ClientCapability>) {
+    this.supported = new Set(capabilities);
+  }
+
+  static fromHello(capabilities: Record<string, unknown> | null | undefined): ClientCapabilities {
+    return new ClientCapabilities(readDeclaredClientCapabilities(capabilities));
+  }
+
+  supports(capability: ClientCapability): boolean {
+    return this.supported.has(capability);
+  }
+}
+
 /**
  * Session represents a single connected client session.
  * It owns all state management, orchestration logic, and message processing.
@@ -733,6 +755,7 @@ function convertPCMToWavBuffer(
 export class Session {
   private readonly clientId: string;
   private appVersion: string | null;
+  private clientCapabilities: ClientCapabilities;
   private readonly sessionId: string;
   private readonly onMessage: (msg: SessionOutboundMessage) => void;
   private readonly onBinaryMessage: ((frame: Uint8Array) => void) | null;
@@ -849,6 +872,7 @@ export class Session {
     const {
       clientId,
       appVersion,
+      clientCapabilities,
       onMessage,
       onBinaryMessage,
       onLifecycleIntent,
@@ -888,6 +912,7 @@ export class Session {
     } = options;
     this.clientId = clientId;
     this.appVersion = appVersion ?? null;
+    this.clientCapabilities = ClientCapabilities.fromHello(clientCapabilities);
     this.sessionId = uuidv4();
     this.onMessage = onMessage;
     this.onBinaryMessage = onBinaryMessage ?? null;
@@ -959,6 +984,14 @@ export class Session {
     }
   }
 
+  updateClientCapabilities(capabilities: Record<string, unknown> | null): void {
+    this.clientCapabilities = ClientCapabilities.fromHello(capabilities);
+  }
+
+  supports(capability: ClientCapability): boolean {
+    return this.clientCapabilities.supports(capability);
+  }
+
   async syncWorkspaceGitObserverForWorkspace(workspace: PersistedWorkspaceRecord): Promise<void> {
     const descriptor = await this.describeWorkspaceRecordWithGitData(workspace);
     this.syncWorkspaceGitObservers([descriptor]);
@@ -7204,7 +7237,9 @@ export class Session {
             seqStart: entry.seqStart,
             seqEnd: entry.seqEnd,
             sourceSeqRanges: entry.sourceSeqRanges,
-            collapsed: entry.collapsed,
+            collapsed: this.supports(CLIENT_CAPS.reasoningMergeEnum)
+              ? entry.collapsed
+              : entry.collapsed.filter((value) => value !== "reasoning_merge"),
           })),
           error: null,
         },

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

@@ -264,6 +264,7 @@ interface SessionConnection {
   session: Session;
   clientId: string;
   appVersion: string | null;
+  clientCapabilities: Record<string, unknown> | null;
   connectionLogger: pino.Logger;
   sockets: Set<WebSocketLike>;
   externalDisconnectCleanupTimeout: ReturnType<typeof setTimeout> | null;
@@ -874,14 +875,16 @@ export class VoiceAssistantWebSocketServer {
     ws: WebSocketLike;
     clientId: string;
     appVersion: string | null;
+    clientCapabilities: Record<string, unknown> | null;
     connectionLogger: pino.Logger;
   }): SessionConnection {
-    const { ws, clientId, appVersion, connectionLogger } = params;
+    const { ws, clientId, appVersion, clientCapabilities, connectionLogger } = params;
     let connection: SessionConnection | null = null;
 
     const session = new Session({
       clientId,
       appVersion,
+      clientCapabilities,
       onMessage: (msg) => {
         if (!connection) {
           return;
@@ -958,6 +961,7 @@ export class VoiceAssistantWebSocketServer {
       session,
       clientId,
       appVersion,
+      clientCapabilities,
       connectionLogger,
       sockets: new Set([ws]),
       externalDisconnectCleanupTimeout: null,
@@ -1027,6 +1031,14 @@ export class VoiceAssistantWebSocketServer {
         existing.appVersion = newAppVersion;
         existing.session.updateAppVersion(newAppVersion);
       }
+      const newClientCapabilities = message.capabilities ?? null;
+      if (
+        JSON.stringify(existing.clientCapabilities ?? null) !==
+        JSON.stringify(newClientCapabilities ?? null)
+      ) {
+        existing.clientCapabilities = newClientCapabilities;
+        existing.session.updateClientCapabilities(newClientCapabilities);
+      }
       existing.sockets.add(ws);
       this.sessions.set(ws, existing);
       this.sendToClient(ws, this.createServerInfoMessage());
@@ -1047,6 +1059,7 @@ export class VoiceAssistantWebSocketServer {
       ws,
       clientId,
       appVersion: message.appVersion ?? null,
+      clientCapabilities: message.capabilities ?? null,
       connectionLogger,
     });
     this.sessions.set(ws, connection);

packages/server/src/server/worktree-session.ts

@@ -163,6 +163,23 @@ interface HandleCreatePaseoWorktreeRequestDependencies {
   ) => Promise<CreatePaseoWorktreeWorkflowResult>;
 }
 
+function normalizeFirstAgentContext(
+  request: Extract<SessionInboundMessage, { type: "create_paseo_worktree_request" }>,
+): FirstAgentContext | undefined {
+  if (request.firstAgentContext) {
+    return request.firstAgentContext;
+  }
+
+  if (request.attachments || request.nameContext) {
+    return {
+      attachments: request.attachments ?? [],
+      ...(request.nameContext ? { prompt: request.nameContext } : {}),
+    };
+  }
+
+  return undefined;
+}
+
 export async function buildAgentSessionConfig(
   dependencies: BuildAgentSessionConfigDependencies,
   config: AgentSessionConfig,
@@ -492,7 +509,7 @@ export async function handleCreatePaseoWorktreeRequest(
     const createdWorktree = await dependencies.createPaseoWorktreeWorkflow({
       cwd: request.cwd,
       worktreeSlug: request.worktreeSlug,
-      firstAgentContext: request.firstAgentContext,
+      firstAgentContext: normalizeFirstAgentContext(request),
       refName: request.refName,
       action: request.action,
       githubPrNumber: request.githubPrNumber,

packages/server/src/shared/client-capabilities.ts

@@ -0,0 +1,23 @@
+export const CLIENT_CAPS = {
+  reasoningMergeEnum: "reasoning_merge_enum",
+} as const;
+
+export type ClientCapability = (typeof CLIENT_CAPS)[keyof typeof CLIENT_CAPS];
+
+const CLIENT_CAPABILITY_SET = new Set<string>(Object.values(CLIENT_CAPS));
+
+export function isClientCapability(value: string): value is ClientCapability {
+  return CLIENT_CAPABILITY_SET.has(value);
+}
+
+export function readDeclaredClientCapabilities(
+  capabilities: Record<string, unknown> | null | undefined,
+): ClientCapability[] {
+  if (!capabilities) {
+    return [];
+  }
+
+  return Object.entries(capabilities).flatMap(([key, value]) =>
+    value === true && isClientCapability(key) ? [key] : [],
+  );
+}

packages/server/src/shared/messages.ts

@@ -1,4 +1,5 @@
 import { z } from "zod";
+import { CLIENT_CAPS } from "./client-capabilities.js";
 import { AGENT_LIFECYCLE_STATUSES } from "./agent-lifecycle.js";
 import { MAX_EXPLICIT_AGENT_TITLE_CHARS } from "../server/agent/agent-title-limits.js";
 import { AgentProviderSchema } from "../server/agent/provider-manifest.js";
@@ -414,6 +415,15 @@ const ToolCallDetailPayloadSchema: z.ZodType<ToolCallDetail, z.ZodTypeDef, unkno
       description: z.string().optional(),
       childSessionId: z.string().optional(),
       log: z.string(),
+      actions: z
+        .array(
+          z.object({
+            index: z.number().int().positive(),
+            toolName: z.string(),
+            summary: z.string().optional(),
+          }),
+        )
+        .optional(),
     }),
     z.object({
       type: z.literal("plain_text"),
@@ -1374,6 +1384,8 @@ export const CreatePaseoWorktreeRequestSchema = z.object({
   type: z.literal("create_paseo_worktree_request"),
   cwd: z.string(),
   worktreeSlug: z.string().optional(),
+  nameContext: z.string().optional(),
+  attachments: AgentAttachmentsSchema.optional(),
   firstAgentContext: FirstAgentContextSchema.optional(),
   refName: z.string().min(1).optional(),
   action: z.enum(["branch-off", "checkout"]).optional(),
@@ -3661,6 +3673,7 @@ export const WSHelloMessageSchema = z.object({
     .object({
       voice: z.boolean().optional(),
       pushNotifications: z.boolean().optional(),
+      [CLIENT_CAPS.reasoningMergeEnum]: z.boolean().optional(),
     })
     .passthrough()
     .optional(),