fix: prune missing task sessions

dist/server.js

@@ -1144,7 +1144,7 @@ class TaskTracker {
   }
   async refreshLiveChildren(client, parentSessionID) {
     const session = client.session;
-    if (!session.children || !session.status)
+    if (!session.children)
       return;
     let childIDs;
     try {
@@ -1154,7 +1154,8 @@ class TaskTracker {
     } catch {
       return;
     }
-    if (childIDs.length === 0)
+    this.markAbsentRunningChildren(parentSessionID, new Set(childIDs));
+    if (childIDs.length === 0 || !session.status)
       return;
     let statuses;
     try {
@@ -1240,6 +1241,16 @@ class TaskTracker {
         continue;
       this.snapshotIdleHolds.delete(key);
       this.settledSnapshotIdleTasks.add(key);
+      const task = this.tasks.get(hold.taskID);
+      if (task?.parentSessionID === hold.parentSessionID && task.state === "running")
+        this.tasks.delete(hold.taskID);
+    }
+  }
+  markAbsentRunningChildren(parentSessionID, liveChildIDs) {
+    for (const task of this.tasks.values()) {
+      if (task.parentSessionID !== parentSessionID || task.state !== "running" || liveChildIDs.has(task.taskID))
+        continue;
+      this.markSnapshotIdle(parentSessionID, task.taskID);
     }
   }
   snapshotIdleKey(parentSessionID, taskID) {
@@ -1364,6 +1375,8 @@ var server = async ({ client }, options) => {
           await pauseGoalForPlanMode(sessionID);
         return;
       }
+      if (busySessions.has(sessionID))
+        return;
       if (!fromTaskDeferral && taskDeferredSessions.has(sessionID)) {
         scheduleSettledContinuation(sessionID);
         return;

src/server.ts

@@ -438,7 +438,7 @@ class TaskTracker {
       children?: (input: { path: { id: string } }) => Promise<{ data?: unknown } | unknown[]>
       status?: () => Promise<{ data?: unknown } | Record<string, unknown>>
     }
-    if (!session.children || !session.status) return
+    if (!session.children) return
     let childIDs: string[]
     try {
       const result = await session.children({ path: { id: parentSessionID } })
@@ -447,7 +447,8 @@ class TaskTracker {
     } catch {
       return
     }
-    if (childIDs.length === 0) return
+    this.markAbsentRunningChildren(parentSessionID, new Set(childIDs))
+    if (childIDs.length === 0 || !session.status) return
     let statuses: Record<string, unknown>
     try {
       const result = await session.status()
@@ -540,6 +541,15 @@ class TaskTracker {
       if (hold.expiresAt > now) continue
       this.snapshotIdleHolds.delete(key)
       this.settledSnapshotIdleTasks.add(key)
+      const task = this.tasks.get(hold.taskID)
+      if (task?.parentSessionID === hold.parentSessionID && task.state === "running") this.tasks.delete(hold.taskID)
+    }
+  }
+
+  private markAbsentRunningChildren(parentSessionID: string, liveChildIDs: Set<string>) {
+    for (const task of this.tasks.values()) {
+      if (task.parentSessionID !== parentSessionID || task.state !== "running" || liveChildIDs.has(task.taskID)) continue
+      this.markSnapshotIdle(parentSessionID, task.taskID)
     }
   }
 
@@ -662,6 +672,7 @@ const server: Plugin = async ({ client }, options?: Options) => {
         if (current.status === "active") await pauseGoalForPlanMode(sessionID)
         return
       }
+      if (busySessions.has(sessionID)) return
       if (!fromTaskDeferral && taskDeferredSessions.has(sessionID)) {
         scheduleSettledContinuation(sessionID)
         return

test/server.test.ts

@@ -839,6 +839,38 @@ test("idle live child bounded retry does not inject while parent session is busy
   expect(JSON.stringify(calls[0])).toContain("Continue working toward the active session goal")
 })
 
+test("tracked running child absent from live children stops blocking after grace period", async () => {
+  const calls: unknown[] = []
+  let children = [{ id: "task_1" }]
+  const hooks = await plugin.server(
+    {
+      client: {
+        session: {
+          children: async () => ({ data: children }),
+          status: async () => ({ data: { task_1: { type: "busy" } } }),
+          promptAsync: async (input: unknown) => {
+            calls.push(input)
+          },
+        },
+      },
+    } as never,
+    { auto_continue: true, max_auto_turns: 1, min_continue_interval_seconds: 0 },
+  )
+  const tools = hooks.tool
+  if (!tools) throw new Error("expected goal tools to be registered")
+
+  await requireTool(tools.create_goal, "create_goal").execute({ objective: "keep going" }, { sessionID: "ses_1" } as never)
+  await hooks.event!({ event: { type: "session.idle", properties: { sessionID: "ses_1" } } as never })
+  expect(calls).toHaveLength(0)
+
+  children = []
+  await hooks.event!({ event: { type: "session.idle", properties: { sessionID: "ses_1" } } as never })
+
+  expect(calls).toHaveLength(0)
+  await waitForContinuation(calls)
+  expect(JSON.stringify(calls[0])).toContain("Continue working toward the active session goal")
+})
+
 test("task deferral can be disabled with config", async () => {
   const calls: unknown[] = []
   const hooks = await plugin.server(