From aab1dd88e0ca8a49d094dffb2942147bc6753107 Mon Sep 17 00:00:00 2001
From: Vincent Koc <25068+vincentkoc@users.noreply.github.com>
Date: Fri, 19 Jun 2026 14:32:17 +0800
Subject: [PATCH] fix(copilot): defer background compaction hooks

---
 extensions/copilot/src/attempt.test.ts      | 32 +++++++++++++++++++++
 extensions/copilot/src/attempt.ts           |  3 +-
 extensions/copilot/src/event-bridge.test.ts |  1 +
 extensions/copilot/src/event-bridge.ts      |  6 ++++
 4 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/extensions/copilot/src/attempt.test.ts b/extensions/copilot/src/attempt.test.ts
index fd9e1848a4e4..8371db5fc270 100644
--- a/extensions/copilot/src/attempt.test.ts
+++ b/extensions/copilot/src/attempt.test.ts
@@ -441,6 +441,38 @@ describe("runCopilotAttempt", () => {
     expect(beforeCompaction.mock.calls[0]?.[0]).not.toHaveProperty("messages");
   });
 
+  it("does not await background compaction hooks before returning a turn", async () => {
+    const releaseBeforeCompaction = createDeferred<void>();
+    const beforeCompaction = vi.fn(async () => releaseBeforeCompaction.promise);
+    initializeGlobalHookRunner(
+      createMockPluginRegistry([{ hookName: "before_compaction", handler: beforeCompaction }]),
+    );
+    let activeSession: FakeSession | undefined;
+    const sdk = makeFakeSdk({
+      onCreateSession: (session) => {
+        activeSession = session;
+        session.sendAndWait.mockImplementationOnce(async () => {
+          session.emit("session.compaction_start", {});
+          return makeAssistantMessageEvent("done");
+        });
+      },
+    });
+
+    const result = await runCopilotAttempt(makeParams(), { pool: makeFakePool(sdk) });
+
+    expect(result.timedOut).toBe(false);
+    await vi.waitFor(() => {
+      expect(beforeCompaction).toHaveBeenCalledTimes(1);
+    });
+    expect(activeSession?.disconnect).not.toHaveBeenCalled();
+
+    releaseBeforeCompaction.resolve();
+    activeSession?.emit("session.compaction_complete", { success: true });
+    await vi.waitFor(() => {
+      expect(activeSession?.disconnect).toHaveBeenCalledTimes(1);
+    });
+  });
+
   it("returns a successful turn while background compaction remains observed", async () => {
     vi.useFakeTimers();
     const sdk = makeFakeSdk({
diff --git a/extensions/copilot/src/attempt.ts b/extensions/copilot/src/attempt.ts
index 32a68e3423f3..a41bd7ae87d9 100644
--- a/extensions/copilot/src/attempt.ts
+++ b/extensions/copilot/src/attempt.ts
@@ -736,7 +736,6 @@ export async function runCopilotAttempt(
       }
       const result = await session.sendAndWait(messageOptions, input.timeoutMs);
       await bridge.awaitDeltaChain();
-      await bridge.awaitCompactionChain();
       if (!bridge.recordSendResult(result) && !aborted) {
         // SDK sendAndWait returning undefined is treated as a timeout by the
         // capability inventory. Do not call session.abort() here: OpenClaw may
@@ -778,7 +777,7 @@ export async function runCopilotAttempt(
     }
   } finally {
     settled = true;
-    if (bridge?.isCompacting() && session && handle) {
+    if (bridge?.hasObservedCompaction() && session && handle) {
       timedOutDuringCompaction ||= timedOut;
       const cleanupAbort = new AbortController();
       const abortCleanup = () => cleanupAbort.abort();
diff --git a/extensions/copilot/src/event-bridge.test.ts b/extensions/copilot/src/event-bridge.test.ts
index dcad8057a793..e7a5fe012032 100644
--- a/extensions/copilot/src/event-bridge.test.ts
+++ b/extensions/copilot/src/event-bridge.test.ts
@@ -650,6 +650,7 @@ describe("attachEventBridge", () => {
     const completion = bridge.awaitCompactionCompletion();
     await flushAsync();
 
+    expect(bridge.hasObservedCompaction()).toBe(true);
     expect(complete).not.toHaveBeenCalled();
     session.emit(
       "session.compaction_complete",
diff --git a/extensions/copilot/src/event-bridge.ts b/extensions/copilot/src/event-bridge.ts
index 04e137144188..d520ffa22238 100644
--- a/extensions/copilot/src/event-bridge.ts
+++ b/extensions/copilot/src/event-bridge.ts
@@ -70,6 +70,7 @@ export interface EventBridgeController {
   awaitCompactionChain(): Promise<void>;
   awaitCompactionCompletion(): Promise<void>;
   awaitDeltaChain(): Promise<void>;
+  hasObservedCompaction(): boolean;
   isCompacting(): boolean;
   snapshot(): EventBridgeSnapshot;
   buildAssistantMessage(args: BuildAssistantMessageArgs): AssistantMessage | undefined;
@@ -96,6 +97,7 @@ export function attachEventBridge(
   let startedCount = 0;
   let completedCount = 0;
   let activeCompactionCount = 0;
+  let observedCompaction = false;
   let deltaQueue = Promise.resolve();
   let deltaChain = Promise.resolve();
   let compactionChain = Promise.resolve();
@@ -182,6 +184,7 @@ export function attachEventBridge(
   });
 
   registerListener(session, unsubscribeFns, "session.compaction_start", () => {
+    observedCompaction = true;
     if (activeCompactionCount === 0) {
       compactionIdle = new Promise<void>((resolve) => {
         resolveCompactionIdle = resolve;
@@ -248,6 +251,9 @@ export function attachEventBridge(
     awaitDeltaChain() {
       return deltaChain;
     },
+    hasObservedCompaction() {
+      return observedCompaction;
+    },
     isCompacting() {
       return activeCompactionCount > 0;
     },