diff --git a/packages/server/src/server/agent/providers/codex-app-server-agent.test.ts b/packages/server/src/server/agent/providers/codex-app-server-agent.test.ts
index cb8cb2684b..4754942133 100644
--- a/packages/server/src/server/agent/providers/codex-app-server-agent.test.ts
+++ b/packages/server/src/server/agent/providers/codex-app-server-agent.test.ts
@@ -5004,6 +5004,120 @@ describe("Codex app-server provider", () => {
     });
   });
 
+  function collaboration(tool: string, states: Record<string, string>, id = tool) {
+    return {
+      type: "collabAgentToolCall",
+      id,
+      tool,
+      status: "completed",
+      prompt: tool === "spawnAgent" ? "Inspect the regression" : null,
+      receiverThreadIds: Object.keys(states),
+      agentsStates: Object.fromEntries(
+        Object.entries(states).map(([threadId, status]) => [threadId, { status }]),
+      ),
+    };
+  }
+
+  test("replays nullable wait and close results onto the original spawn cards", async () => {
+    const session = createSession();
+    const items = [
+      collaboration("spawnAgent", { first: "pendingInit" }, "spawn-first"),
+      collaboration("spawnAgent", { second: "pendingInit" }, "spawn-second"),
+      collaboration("wait", { first: "completed", second: "running" }, "wait-first"),
+      collaboration("wait", { second: "completed" }, "wait-second"),
+      collaboration("closeAgent", { first: "shutdown", second: "completed" }),
+    ];
+    session.client = {
+      request: vi.fn(async (_method: string, params: unknown) => ({
+        thread: {
+          turns: [
+            { items: (params as { threadId: string }).threadId === "test-thread" ? items : [] },
+          ],
+        },
+      })),
+    };
+
+    const history = await Array.fromAsync(session.streamHistory());
+
+    expect(
+      history.filter((event) => event.type === "timeline").map((event) => event.item),
+    ).toMatchObject([
+      { callId: "spawn-first", status: "completed" },
+      { callId: "spawn-second", status: "completed" },
+    ]);
+    expect(
+      history.flatMap((event) =>
+        event.type === "provider_subagent" && event.event.type === "upsert" ? [event.event] : [],
+      ),
+    ).toMatchObject([
+      { id: "first", toolCallId: "spawn-first", status: "completed" },
+      { id: "second", toolCallId: "spawn-second", status: "completed" },
+    ]);
+  });
+
+  test("updates live children independently and reopens only an explicit follow-up", async () => {
+    const session = createSession();
+    const events: AgentStreamEvent[] = [];
+    session.subscribe((event) => events.push(event));
+    async function notify(tool: string, states: Record<string, string>, id = tool) {
+      await asInternals(session).handleNotification("item/completed", {
+        threadId: "test-thread",
+        item: collaboration(tool, states, id),
+      });
+    }
+    await notify("spawnAgent", { first: "pendingInit" }, "spawn-first");
+    await notify("spawnAgent", { second: "pendingInit" }, "spawn-second");
+    events.length = 0;
+    await notify("wait", { first: "completed", second: "running" });
+
+    expect(
+      events.flatMap((event) =>
+        event.type === "provider_subagent" && event.event.type === "upsert" ? [event.event] : [],
+      ),
+    ).toMatchObject([{ id: "first", toolCallId: "spawn-first", status: "completed" }]);
+    expect(
+      events.filter((event) => event.type === "timeline").map((event) => event.item),
+    ).toMatchObject([{ callId: "spawn-first", status: "completed" }]);
+
+    events.length = 0;
+    await notify("closeAgent", { first: "shutdown" });
+    await notify("wait", { first: "running" }, "stale-wait");
+    await notify("sendInput", { first: "running" });
+    expect(
+      events.filter((event) => event.type === "timeline").map((event) => event.item),
+    ).toMatchObject([{ callId: "spawn-first", status: "running" }]);
+  });
+
+  test.each([
+    ["shutdown", "canceled"],
+    ["notFound", "failed"],
+  ])("replays %s as %s without completing an unfinished child", async (childStatus, expected) => {
+    const session = createSession();
+    const items = [
+      collaboration("spawnAgent", { first: "pendingInit" }, "spawn-first"),
+      collaboration("spawnAgent", { second: "pendingInit" }, "spawn-second"),
+      collaboration("closeAgent", { first: childStatus }),
+      collaboration("wait", {}),
+    ];
+    session.client = {
+      request: vi.fn(async (_method: string, params: unknown) => ({
+        thread: {
+          turns: [
+            { items: (params as { threadId: string }).threadId === "test-thread" ? items : [] },
+          ],
+        },
+      })),
+    };
+    const history = await Array.fromAsync(session.streamHistory());
+    expect(
+      history.flatMap((event) =>
+        event.type === "provider_subagent" && event.event.type === "upsert" ? [event.event] : [],
+      ),
+    ).toMatchObject([
+      { id: "first", status: expected },
+      { id: "second", status: "running" },
+    ]);
+  });
   test("loads mixed legacy and MultiAgentV2 sub-agent history", async () => {
     const session = createSession();
     session.client = {
diff --git a/packages/server/src/server/agent/providers/codex-app-server-agent.ts b/packages/server/src/server/agent/providers/codex-app-server-agent.ts
index f7d4f50215..2095f651de 100644
--- a/packages/server/src/server/agent/providers/codex-app-server-agent.ts
+++ b/packages/server/src/server/agent/providers/codex-app-server-agent.ts
@@ -1857,6 +1857,59 @@ function readCodexSubAgentActivity(item: unknown): CodexSubAgentActivity | null
   };
 }
 
+interface CodexCollabAgentUpdate {
+  threadId: string;
+  status: ToolCallTimelineItem["status"];
+  shutdown: boolean;
+  reopen: boolean;
+}
+
+function readCodexCollabAgentUpdates(item: unknown): CodexCollabAgentUpdate[] {
+  const record = toObjectRecord(item);
+  if (
+    !record ||
+    normalizeCodexThreadItemType(typeof record.type === "string" ? record.type : undefined) !==
+      "collabAgentToolCall" ||
+    record.tool === "spawnAgent"
+  ) {
+    return [];
+  }
+  return Object.entries(toObjectRecord(record.agentsStates) ?? {}).flatMap(([threadId, value]) => {
+    const state = toObjectRecord(value);
+    if (typeof state?.status !== "string") return [];
+    const mapped = mapCodexToolCallFromThreadItem({
+      type: "collabAgentToolCall",
+      id: record.id,
+      tool: record.tool,
+      status: "completed",
+      agentsStates: { [threadId]: state },
+    });
+    return mapped
+      ? [
+          {
+            threadId,
+            status: mapped.status,
+            shutdown: state.status === "shutdown",
+            reopen: record.tool === "sendInput" && record.status === "completed",
+          },
+        ]
+      : [];
+  });
+}
+
+function resolveCodexCollabAgentUpdate(
+  previous: ToolCallTimelineItem["status"],
+  update: CodexCollabAgentUpdate,
+): ToolCallTimelineItem["status"] {
+  if (
+    isTerminalSubAgentStatus(previous) &&
+    (update.shutdown || (update.status === "running" && !update.reopen))
+  ) {
+    return previous;
+  }
+  return update.status;
+}
+
 function shouldIgnoreMirroredLifecycleItem(source: "item" | "codex_event", item: unknown): boolean {
   return source === "codex_event" && !readCodexSubAgentActivity(item);
 }
@@ -2060,6 +2113,27 @@ async function threadItemToTimelineEntries(
   return [timelineItem, ...(await mcpToolResultImagesToTimeline(item))];
 }
 
+function updateHistoricalCollabAgentCalls(
+  timeline: PersistedTimelineEntry[],
+  timelineIndexByThreadId: Map<string, number>,
+  item: unknown,
+): boolean {
+  let updated = false;
+  for (const update of readCodexCollabAgentUpdates(item)) {
+    const existingIndex = timelineIndexByThreadId.get(update.threadId);
+    const existing = existingIndex === undefined ? undefined : timeline[existingIndex];
+    if (existingIndex === undefined || existing?.item.type !== "tool_call") continue;
+    const status = resolveCodexCollabAgentUpdate(existing.item.status, update);
+    const toolCall: ToolCallTimelineItem =
+      status === "failed"
+        ? { ...existing.item, status, error: { message: "Sub-agent failed" } }
+        : { ...existing.item, status, error: null };
+    timeline[existingIndex] = { ...existing, item: toolCall };
+    updated = true;
+  }
+  return updated;
+}
+
 async function loadCodexThreadHistoryTimeline(params: {
   client: CodexAppServerClientLike;
   threadId: string;
@@ -2095,6 +2169,9 @@ async function projectCodexThreadHistory(
   const { timeline, subAgentTimelineIndexByThreadId } = projection;
   for await (const row of readCodexThreadHistory(params.client, params.threadId)) {
     const { item } = row;
+    if (updateHistoricalCollabAgentCalls(timeline, subAgentTimelineIndexByThreadId, item)) {
+      continue;
+    }
     const historicalSubAgentActivity = readCodexSubAgentActivity(item);
     if (historicalSubAgentActivity) {
       const existingIndex = subAgentTimelineIndexByThreadId.get(
@@ -5737,6 +5814,19 @@ export class CodexAppServerAgentSession implements AgentSession {
   }
 
   private handleRegisteredSubAgentActivity(rawItem: { [key: string]: unknown }): boolean {
+    let updatedExistingSubagent = false;
+    for (const update of readCodexCollabAgentUpdates(rawItem)) {
+      const callId = this.subAgentCallIdByChildThreadId.get(update.threadId);
+      if (!callId) continue;
+      const state = this.subAgentCallsByCallId.get(callId);
+      if (!state) continue;
+      const status = resolveCodexCollabAgentUpdate(state.toolCall.status, update);
+      if (status !== state.toolCall.status) {
+        this.emitSubAgentActivityUpdate(callId, status, { reopen: update.reopen });
+      }
+      updatedExistingSubagent = true;
+    }
+    if (updatedExistingSubagent) return true;
     const activity = readCodexSubAgentActivity(rawItem);
     if (!activity) {
       return false;
diff --git a/packages/server/src/server/agent/providers/codex/tool-call-mapper.test.ts b/packages/server/src/server/agent/providers/codex/tool-call-mapper.test.ts
index 566fd10083..32403b6675 100644
--- a/packages/server/src/server/agent/providers/codex/tool-call-mapper.test.ts
+++ b/packages/server/src/server/agent/providers/codex/tool-call-mapper.test.ts
@@ -213,6 +213,20 @@ describe("codex tool-call mapper", () => {
     });
   });
 
+  it("accepts a nullable prompt in completed collaboration control items", () => {
+    expect(
+      mapCodexToolCallFromThreadItem({
+        type: "collabAgentToolCall",
+        id: "wait-child",
+        tool: "wait",
+        prompt: null,
+        status: "completed",
+        receiverThreadIds: ["child"],
+        agentsStates: { child: { status: "completed" } },
+      }),
+    ).toMatchObject({ callId: "wait-child", status: "completed" });
+  });
+
   it("maps collabAgentToolCall into canonical sub-agent detail", () => {
     const item = mapCodexToolCallFromThreadItem({
       type: "collabAgentToolCall",
diff --git a/packages/server/src/server/agent/providers/codex/tool-call-mapper.ts b/packages/server/src/server/agent/providers/codex/tool-call-mapper.ts
index 64629bc5d9..8147dd9de7 100644
--- a/packages/server/src/server/agent/providers/codex/tool-call-mapper.ts
+++ b/packages/server/src/server/agent/providers/codex/tool-call-mapper.ts
@@ -186,7 +186,7 @@ const CodexCollabAgentToolCallItemSchema = z
     id: z.string().min(1),
     status: z.string().optional(),
     error: z.unknown().optional(),
-    prompt: z.string().optional(),
+    prompt: z.string().nullish(),
     tool: z.string().optional(),
     receiverThreadIds: z.array(z.string()).optional(),
     agentsStates: z.record(z.string(), z.unknown()).optional(),