fix(rpc): serialize IRC wake finalization

packages/coding-agent/src/session/agent-session.ts

@@ -504,7 +504,9 @@ export class AgentSession {
 	#asyncDeliveryEpoch = 0;
 
 	readonly #irc: IrcBridge;
-	#ircWakeTurnObserver: ((records: CustomMessage[]) => ((error?: unknown) => void) | undefined) | undefined;
+	#ircWakeTurnObserver:
+		| ((records: CustomMessage[]) => ((error?: unknown) => void | Promise<void>) | undefined)
+		| undefined;
 	// Agent identity (registry id) used for IRC routing and job ownership.
 	#agentId: string | undefined;
 	#agentKind: "main" | "sub" = "main";
@@ -575,7 +577,7 @@ export class AgentSession {
 	// on `agent_end` can fire its next `prompt` before #promptWithMessage's finally
 	#promptGeneration = 0;
 	#pendingAgentEndEmit: AgentSessionEvent | undefined;
-	#inFlightSettledCallbacks: Array<() => void> = [];
+	#inFlightSettledCallbacks: Array<() => void | Promise<void>> = [];
 	#sessionStopContinuationCount = 0;
 	#sessionStopHookActive = false;
 	#obfuscator: SecretObfuscator | undefined;
@@ -641,23 +643,25 @@ export class AgentSession {
 		}
 	}
 
-	#endInFlight(onSettled?: () => void): void {
+	#endInFlight(onSettled?: () => void | Promise<void>): void {
 		if (onSettled) this.#inFlightSettledCallbacks.push(onSettled);
 		this.#promptInFlightCount = Math.max(0, this.#promptInFlightCount - 1);
-		if (this.#promptInFlightCount === 0) {
-			this.#releasePowerAssertion();
-			this.#flushPendingAgentEnd();
-			this.#flushInFlightSettledCallbacks();
+		if (this.#promptInFlightCount !== 0) return;
+		this.#releasePowerAssertion();
+		this.#flushPendingAgentEnd();
+		if (this.#inFlightSettledCallbacks.length === 0) {
 			this.#drainStrandedQueuedMessages();
+			return;
 		}
+		void this.#flushInFlightSettledCallbacks().finally(() => this.#drainStrandedQueuedMessages());
 	}
 
-	#flushInFlightSettledCallbacks(): void {
+	async #flushInFlightSettledCallbacks(): Promise<void> {
 		const callbacks = this.#inFlightSettledCallbacks;
 		this.#inFlightSettledCallbacks = [];
 		for (const callback of callbacks) {
 			try {
-				callback();
+				await callback();
 			} catch (error) {
 				logger.warn("In-flight settle callback failed", { error: String(error) });
 			}
@@ -744,7 +748,7 @@ export class AgentSession {
 		if (parkedFollowUps.length > 0) {
 			this.agent.replaceQueues([...this.agent.peekSteeringQueue()], []);
 		}
-		let finishObservation: ((error?: unknown) => void) | undefined;
+		let finishObservation: ((error?: unknown) => void | Promise<void>) | undefined;
 		try {
 			finishObservation = this.#ircWakeTurnObserver?.(records);
 		} catch (error) {
@@ -779,9 +783,9 @@ export class AgentSession {
 						[...parkedFollowUps, ...this.agent.peekFollowUpQueue()],
 					);
 				}
-				this.#endInFlight(() => {
+				this.#endInFlight(async () => {
 					try {
-						finishObservation?.(turnError);
+						await finishObservation?.(turnError);
 					} catch (error) {
 						logger.warn("IRC wake turn observer failed to finish", { error: String(error) });
 					}
@@ -826,8 +830,11 @@ export class AgentSession {
 		this.#promptInFlightCount = 0;
 		this.#releasePowerAssertion();
 		this.#flushPendingAgentEnd();
-		this.#flushInFlightSettledCallbacks();
-		this.#drainStrandedQueuedMessages();
+		if (this.#inFlightSettledCallbacks.length === 0) {
+			this.#drainStrandedQueuedMessages();
+			return;
+		}
+		void this.#flushInFlightSettledCallbacks().finally(() => this.#drainStrandedQueuedMessages());
 	}
 
 	#flushPendingAgentEnd(): void {
@@ -6953,7 +6960,7 @@ export class AgentSession {
 
 	/** Installs task-executor monitoring around autonomous IRC wake turns. */
 	setIrcWakeTurnObserver(
-		observer: ((records: CustomMessage[]) => ((error?: unknown) => void) | undefined) | undefined,
+		observer: ((records: CustomMessage[]) => ((error?: unknown) => void | Promise<void>) | undefined) | undefined,
 	): void {
 		this.#ircWakeTurnObserver = observer;
 	}

packages/coding-agent/src/task/executor.ts

@@ -2277,7 +2277,7 @@ export function attachIrcWakeTurnMonitor(session: AgentSession, options: IrcWake
 
 		turnMonitor.setActiveSession(session);
 		const unsubscribeTurn = turnMonitor.attach(session);
-		return turnError => {
+		return async turnError => {
 			unsubscribeTurn();
 			const activeSession = turnMonitor.takeActiveSession();
 			if (activeSession) turnMonitor.captureSalvage(activeSession);
@@ -2294,35 +2294,37 @@ export function attachIrcWakeTurnMonitor(session: AgentSession, options: IrcWake
 							: String(turnError)
 						: undefined;
 			turnMonitor.finish();
-			void finalizeRunResult({
-				monitor: turnMonitor,
-				done: {
-					exitCode: aborted || error ? 1 : 0,
-					error,
-					aborted,
-					abortReason: aborted ? turnMonitor.resolveAbortReasonText() : undefined,
-					durationMs: Date.now() - turnStartTime,
-				},
-				index,
-				id,
-				agent,
-				task: ircTask,
-				modelOverride: options.modelOverride,
-				outputSchema: options.outputSchema,
-				outputSchemaMode: options.outputSchemaMode,
-				outputSchemaSource: options.outputSchemaSource,
-				artifactsDir: options.artifactsDir,
-				eventBus: options.eventBus,
-				parentToolCallId: options.parentToolCallId,
-				detached: true,
-				sessionFile,
-				startTime: turnStartTime,
-			}).catch(finalizeError => {
+			try {
+				await finalizeRunResult({
+					monitor: turnMonitor,
+					done: {
+						exitCode: aborted || error ? 1 : 0,
+						error,
+						aborted,
+						abortReason: aborted ? turnMonitor.resolveAbortReasonText() : undefined,
+						durationMs: Date.now() - turnStartTime,
+					},
+					index,
+					id,
+					agent,
+					task: ircTask,
+					modelOverride: options.modelOverride,
+					outputSchema: options.outputSchema,
+					outputSchemaMode: options.outputSchemaMode,
+					outputSchemaSource: options.outputSchemaSource,
+					artifactsDir: options.artifactsDir,
+					eventBus: options.eventBus,
+					parentToolCallId: options.parentToolCallId,
+					detached: true,
+					sessionFile,
+					startTime: turnStartTime,
+				});
+			} catch (finalizeError) {
 				logger.warn("IRC subagent turn finalization failed", {
 					id,
 					error: finalizeError instanceof Error ? finalizeError.message : String(finalizeError),
 				});
-			});
+			}
 		};
 	});
 }

packages/coding-agent/test/task/executor-soft-budget.test.ts

@@ -54,7 +54,9 @@ function createMockSession(
 	let abortCount = 0;
 	let disposeCount = 0;
 	let promptIndex = 0;
-	let ircWakeTurnObserver: ((records: CustomMessage[]) => ((error?: unknown) => void) | undefined) | undefined;
+	let ircWakeTurnObserver:
+		| ((records: CustomMessage[]) => ((error?: unknown) => void | Promise<void>) | undefined)
+		| undefined;
 
 	const emit = (event: AgentSessionEvent) => {
 		for (const listener of [...listeners]) listener(event);
@@ -125,7 +127,7 @@ function createMockSession(
 				isError: false,
 			} as AgentSessionEvent);
 			emit({ type: "agent_end", messages: [yieldMessage] } as unknown as AgentSessionEvent);
-			finishObservation?.();
+			await finishObservation?.();
 			return "woken";
 		},
 		abort: async () => {

packages/coding-agent/test/task/persisted-revive.test.ts

@@ -39,7 +39,7 @@ function createRef(sessionFile: string): AgentRef {
 	};
 }
 
-type IrcWakeObserver = (records: CustomMessage[]) => ((error?: unknown) => void) | undefined;
+type IrcWakeObserver = (records: CustomMessage[]) => ((error?: unknown) => void | Promise<void>) | undefined;
 
 interface RevivedSessionHandle {
 	session: AgentSession;
@@ -223,7 +223,7 @@ describe("persisted subagent revival", () => {
 			timestamp: Date.now(),
 		};
 		const finish = observer?.([record]);
-		finish?.();
+		await finish?.();
 		await terminal.promise;
 
 		expect(frames[0]).toMatchObject({