feat: messages API returns parts with accurate running status for active subagents

packages/builtin-tools/src/tools/AgentTool/runAgent.ts

@@ -747,6 +747,21 @@ export async function* runAgent({
     agentType: agentDefinition.agentType,
     ...(worktreePath && { worktreePath }),
     ...(description && { description }),
+    parent_session_id: getSessionId(),
+    prompt: promptMessages
+      .map((m: Message) => {
+        const content = (m as Record<string, unknown>).content
+        if (typeof content === 'string') return content
+        if (Array.isArray(content)) {
+          return content
+            .filter((b: Record<string, unknown>) => b.type === 'text')
+            .map((b: Record<string, unknown>) => b.text)
+            .join('')
+        }
+        return ''
+      })
+      .filter(Boolean)
+      .slice(-1)[0] ?? undefined,
   }).catch(_err => logForDebugging(`Failed to write agent metadata: ${_err}`))
 
   // Track the last recorded message UUID for parent chain continuity
@@ -812,6 +827,7 @@ export async function* runAgent({
           )
           break
         }
+        message.agent_id = agentId
         yield message as Message
         continue
       }
@@ -828,6 +844,7 @@ export async function* runAgent({
         if (message.type !== 'progress') {
           lastRecordedUuid = message.uuid
         }
+        message.agent_id = agentId
         yield message
       }
     }

src/QueryEngine.ts

@@ -789,9 +789,10 @@ export class QueryEngine {
       }
 
       switch (message.type) {
-        case 'tombstone':
+        case 'tombstone': {
-          // Tombstone messages are control signals for removing messages, skip them
+          yield message as SDKMessage
           break
+        }
         case 'assistant': {
           // Capture stop_reason if already set (synthetic messages). For
           // streamed responses, this is null at content_block_stop time;

src/server/routes/message.ts

@@ -4,9 +4,60 @@ import { notFound } from '../errors.js'
 import {
   readSessionMessages,
   readSessionTodos,
+  readSessionTasks,
   readSessionDiff,
   type SessionMessage,
+  type TaskInfo,
+  type MessagePart,
+  decomposeMessageToParts,
 } from '../transcriptReader.js'
+import { getSubagentProgress } from '../sessionMessageRouter.js'
+
+function findParentCwd(sessionManager: SessionManager, id: string): string | undefined {
+  for (const handle of sessionManager.getAllSessions()) {
+    if (handle.activeSubagents.has(id)) {
+      return handle.spawnCwd ?? handle.cwd
+    }
+  }
+  return undefined
+}
+
+function patchActiveSubagentsInMessages(
+  messages: SessionMessage[],
+  activeSubagents: ReadonlyMap<string, { agentId: string; toolUseId?: string }>,
+): void {
+  if (activeSubagents.size === 0) return
+
+  const runningCallIDs = new Set<string>()
+  const progressByCallID = new Map<string, string[]>()
+
+  for (const [, info] of activeSubagents) {
+    if (info.toolUseId) {
+      runningCallIDs.add(info.toolUseId)
+      const progress = getSubagentProgress(info.agentId)
+      if (progress?.progressLines?.length) {
+        progressByCallID.set(info.toolUseId, progress.progressLines)
+      }
+    }
+  }
+
+  if (runningCallIDs.size === 0) return
+
+  for (const msg of messages) {
+    if (!Array.isArray(msg.parts)) continue
+    for (const part of msg.parts) {
+      if (part.type !== 'tool') continue
+      const toolPart = part as MessagePart & { type: 'tool'; callID: string; state: Record<string, unknown> }
+      if (!runningCallIDs.has(toolPart.callID)) continue
+      toolPart.state = {
+        ...toolPart.state,
+        status: 'running',
+        progress: progressByCallID.get(toolPart.callID) ?? [],
+        time: { start: (toolPart.state as any).time?.start ?? Date.now() },
+      } as any
+    }
+  }
+}
 
 function dedupeMessages(disk: SessionMessage[], memory: SessionMessage[]): SessionMessage[] {
   if (disk.length === 0) return memory
@@ -20,6 +71,8 @@ export function createMessageRoutes(sessionManager: SessionManager): Hono {
     .get('/session/:sessionID/message', async c => {
       const id = c.req.param('sessionID')
       const handle = sessionManager.getSession(id)
+      const parentCwd = handle ? undefined : findParentCwd(sessionManager, id)
+      const effectiveCwd = handle?.spawnCwd ?? handle?.cwd ?? parentCwd
 
       const url = new URL(c.req.url)
       const limit = parseInt(url.searchParams.get('limit') ?? '50', 10)
@@ -28,7 +81,7 @@ export function createMessageRoutes(sessionManager: SessionManager): Hono {
 
       const { messages: diskMessages, nextCursor } = await readSessionMessages({
         sessionId: id,
-        cwd: handle?.spawnCwd ?? handle?.cwd,
+        cwd: effectiveCwd,
         limit,
         before,
         includeSystem,
@@ -38,12 +91,25 @@ export function createMessageRoutes(sessionManager: SessionManager): Hono {
         ? dedupeMessages(diskMessages, [...handle.messageBuffer])
         : diskMessages
 
+      const tombstoned = handle?.tombstonedUuids
+      const filtered = tombstoned && tombstoned.size > 0
+        ? messages.filter(m => !tombstoned.has(m.uuid))
+        : messages
+
+      const decomposed = filtered.map(decomposeMessageToParts)
+
+      if (handle) {
+        patchActiveSubagentsInMessages(decomposed, handle.activeSubagents)
+      }
+
+      const result = decomposed
+
       if (nextCursor) {
         c.header('Link', `<${url.pathname}?limit=${limit}&before=${nextCursor}>; rel="prev"`)
         c.header('X-Next-Cursor', nextCursor)
       }
 
-      return c.json({ messages })
+      return c.json({ messages: result })
     })
     .get('/session/:sessionID/todo', async c => {
       const id = c.req.param('sessionID')
@@ -56,6 +122,17 @@ export function createMessageRoutes(sessionManager: SessionManager): Hono {
 
       return c.json({ todos })
     })
+    .get('/session/:sessionID/tasks', async c => {
+      const id = c.req.param('sessionID')
+      const handle = sessionManager.getSession(id)
+
+      const tasks = await readSessionTasks({
+        sessionId: id,
+        cwd: handle?.spawnCwd ?? handle?.cwd,
+      })
+
+      return c.json({ tasks })
+    })
     .get('/session/:sessionID/diff', async c => {
       const id = c.req.param('sessionID')
       const handle = sessionManager.getSession(id)

src/server/routes/session.ts

@@ -528,7 +528,16 @@ export function createSessionRoutes(
     .post('/session/:sessionID/abort', async c => {
       const id = c.req.param('sessionID')
       const handle = sessionManager.getSession(id)
-      if (!handle) return c.json({ aborted: true })
+      if (!handle) {
+        // Even when no in-memory handle exists, emit idle status so that
+        // a prior prompt_async busy event (which fires before the handle
+        // is created) is not left dangling forever.
+        eventBus.publish('session.status', {
+          sessionID: id,
+          status: { type: 'idle' },
+        })
+        return c.json({ aborted: true })
+      }
       await handle.abort()
       return c.json({ aborted: true })
     })

src/server/sessionMessageRouter.ts

@@ -147,6 +147,12 @@ export type MessageRouterCtx = {
   addTombstonedUuid(uuid: string): void
 }
 
+export function getSubagentProgress(agentId: string): { progressLines: string[]; mainToolUseID: string } | undefined {
+  const state = subagentToolState.get(agentId)
+  if (!state) return undefined
+  return { progressLines: state.progressLines, mainToolUseID: state.mainToolUseID }
+}
+
 export function routeMessage(msg: StdoutMessage, ctx: MessageRouterCtx): void {
   if (
     ctx.getStatus() === 'starting' &&

src/utils/sdkEventQueue.ts

@@ -12,6 +12,10 @@ type TaskStartedEvent = {
   task_type?: string
   workflow_name?: string
   prompt?: string
+  /** Explicit agent_id for virtual session mapping in serve mode.
+   * Same value as task_id but named for clarity. Enables the serve layer
+   * to construct virtual child sessions without guessing the relationship. */
+  agent_id?: string
 }
 
 type TaskProgressEvent = {
@@ -27,10 +31,9 @@ type TaskProgressEvent = {
   }
   last_tool_name?: string
   summary?: string
-  // Delta batch of workflow state changes. Clients upsert by
-  // `${type}:${index}` then group by phaseIndex to rebuild the phase tree,
-  // same fold as collectFromEvents + groupByPhase in PhaseProgress.tsx.
   workflow_progress?: SdkWorkflowProgress[]
+  /** Explicit agent_id for virtual session mapping in serve mode. */
+  agent_id?: string
 }
 
 // Emitted when a foreground agent completes without being backgrounded.
@@ -51,6 +54,8 @@ type TaskNotificationSdkEvent = {
     tool_uses: number
     duration_ms: number
   }
+  /** Explicit agent_id for virtual session mapping in serve mode. */
+  agent_id?: string
 }
 
 // SessionStateChangedEvent is now emitted directly by sessionState.ts's
@@ -122,5 +127,6 @@ export function emitTaskTerminatedSdk(
     output_file: opts?.outputFile ?? '',
     summary: opts?.summary ?? '',
     usage: opts?.usage,
+    agent_id: taskId,
   })
 }

src/utils/sessionStorage.ts

@@ -269,6 +269,14 @@ export type AgentMetadata = {
    * resumed agent's notification can show the original description instead
    * of a placeholder. Optional — older metadata files lack this field. */
   description?: string
+  /** Parent session ID for virtual session hierarchy in serve mode.
+   * Enables the serve layer to reconstruct subagent → parent relationships
+   * on restart. Optional — older metadata files lack this field. */
+  parent_session_id?: string
+  /** Agent-specific prompt for the subagent. Persisted so the serve layer
+   * can construct a virtual session with the original prompt context.
+   * Optional — older metadata files lack this field. */
+  prompt?: string
 }
 
 /**

src/utils/task/framework.ts

@@ -113,6 +113,7 @@ export function registerTask(task: TaskState, setAppState: SetAppState): void {
         ? (task.workflowName as string | undefined)
         : undefined,
     prompt: 'prompt' in task ? (task.prompt as string) : undefined,
+    agent_id: task.id,
   })
 }
 

src/utils/task/sdkProgress.ts

@@ -32,5 +32,6 @@ export function emitTaskProgress(params: {
     last_tool_name: params.lastToolName,
     summary: params.summary,
     workflow_progress: params.workflowProgress,
+    agent_id: params.taskId,
   })
 }