From a4556a470779d2eda3f258ea8260a3e505cdb4eb Mon Sep 17 00:00:00 2001
From: Matt Pua <matt.p@posthog.com>
Date: Tue, 16 Jun 2026 11:48:54 -0400
Subject: [PATCH] fix(sessions): keep queued messages in queue when cancelling

Stop now cancels only the in-flight turn. Queued messages stay in the
queue (shown as queued cards) instead of being dumped into the input.
A queuePaused flag suppresses the auto-drain triggered by the
cancel-induced turn-end event; it's cleared on the next user send, so
the kept messages resume then.

Generated-By: PostHog Code
Task-Id: 82344ce6-2b72-4bb3-b929-41cd17820f5e
---
 packages/core/src/sessions/sessionService.ts  | 10 ++++--
 packages/shared/src/sessions.ts               |  7 ++++
 .../sessions/hooks/useSessionCallbacks.ts     | 33 ++-----------------
 3 files changed, 18 insertions(+), 32 deletions(-)

diff --git a/packages/core/src/sessions/sessionService.ts b/packages/core/src/sessions/sessionService.ts
index 0eb24e96dc..56c241bd65 100644
--- a/packages/core/src/sessions/sessionService.ts
+++ b/packages/core/src/sessions/sessionService.ts
@@ -1533,7 +1533,8 @@ export class SessionService {
     const hasQueuedMessages =
       freshSession &&
       freshSession.messageQueue.length > 0 &&
-      freshSession.status === "connected";
+      freshSession.status === "connected" &&
+      !freshSession.queuePaused;
 
     if (hasQueuedMessages) {
       setTimeout(() => {
@@ -1667,6 +1668,10 @@ export class SessionService {
       );
     }
 
+    if (session.queuePaused) {
+      this.d.store.updateSession(session.taskRunId, { queuePaused: false });
+    }
+
     if (session.isCloud) {
       return this.sendCloudPrompt(session, prompt);
     }
@@ -1909,6 +1914,7 @@ export class SessionService {
     this.d.store.updateSession(session.taskRunId, {
       isPromptPending: false,
       promptStartedAt: null,
+      queuePaused: true,
     });
 
     if (session.isCloud) {
@@ -2162,7 +2168,7 @@ export class SessionService {
         isTerminal ||
         (session.cloudStatus === "in_progress" &&
           session.status === "connected");
-      if (!canSendNow || session.isPromptPending) return;
+      if (!canSendNow || session.isPromptPending || session.queuePaused) return;
 
       const drained = this.d.store.dequeueMessages(taskId);
       const combined = this.d.h.combineQueuedCloudPrompts(drained);
diff --git a/packages/shared/src/sessions.ts b/packages/shared/src/sessions.ts
index 1c7663ba6b..94eda72497 100644
--- a/packages/shared/src/sessions.ts
+++ b/packages/shared/src/sessions.ts
@@ -68,6 +68,13 @@ export interface AgentSession {
   pendingPermissions: Map<string, PermissionRequest>;
   pausedDurationMs: number;
   messageQueue: QueuedMessage[];
+  /**
+   * Set when the user cancels an in-flight prompt. Keeps queued messages in
+   * `messageQueue` but suppresses the auto-drain that a turn-end event would
+   * otherwise trigger, so a Stop doesn't immediately fire the next queued
+   * message. Cleared on the next user-initiated send (see `sendPrompt`).
+   */
+  queuePaused?: boolean;
   isCloud?: boolean;
   cloudStatus?: TaskRunStatus;
   cloudStage?: string | null;
diff --git a/packages/ui/src/features/sessions/hooks/useSessionCallbacks.ts b/packages/ui/src/features/sessions/hooks/useSessionCallbacks.ts
index 5678edca4c..482750782d 100644
--- a/packages/ui/src/features/sessions/hooks/useSessionCallbacks.ts
+++ b/packages/ui/src/features/sessions/hooks/useSessionCallbacks.ts
@@ -1,7 +1,3 @@
-import {
-  combineQueuedCloudPrompts,
-  promptToQueuedEditorContent,
-} from "@posthog/core/sessions/cloudPrompt";
 import {
   SESSION_SERVICE,
   type SessionService,
@@ -10,10 +6,7 @@ import { useService } from "@posthog/di/react";
 import type { Task } from "@posthog/shared/domain-types";
 import { tryExecuteCodeCommand } from "@posthog/ui/features/message-editor/commands";
 import { useDraftStore } from "@posthog/ui/features/message-editor/draftStore";
-import {
-  type AgentSession,
-  sessionStoreSetters,
-} from "@posthog/ui/features/sessions/sessionStore";
+import type { AgentSession } from "@posthog/ui/features/sessions/sessionStore";
 import { useTaskViewed } from "@posthog/ui/features/sidebar/useTaskViewed";
 import {
   SHELL_CLIENT,
@@ -42,7 +35,7 @@ export function useSessionCallbacks({
   const sessionService = useService<SessionService>(SESSION_SERVICE);
   const shellClient = useService<ShellClient>(SHELL_CLIENT);
   const { markActivity, markAsViewed } = useTaskViewed();
-  const { requestFocus, setPendingContent } = useDraftStore((s) => s.actions);
+  const { requestFocus } = useDraftStore((s) => s.actions);
 
   const sessionRef = useRef(session);
   sessionRef.current = session;
@@ -94,30 +87,10 @@ export function useSessionCallbacks({
   );
 
   const handleCancelPrompt = useCallback(async () => {
-    const queuedMessages = sessionStoreSetters.dequeueMessages(taskId);
     const result = await sessionService.cancelPrompt(taskId);
     log.info("Prompt cancelled", { success: result });
-
-    const queuedPrompt = sessionRef.current?.isCloud
-      ? combineQueuedCloudPrompts(queuedMessages)
-      : queuedMessages.map((message) => message.content).join("\n\n");
-
-    if (queuedPrompt) {
-      const pendingContent = sessionRef.current?.isCloud
-        ? promptToQueuedEditorContent(queuedPrompt)
-        : {
-            segments: [
-              {
-                type: "text" as const,
-                text: typeof queuedPrompt === "string" ? queuedPrompt : "",
-              },
-            ],
-          };
-
-      setPendingContent(taskId, pendingContent);
-    }
     requestFocus(taskId);
-  }, [taskId, setPendingContent, requestFocus, sessionService]);
+  }, [taskId, requestFocus, sessionService]);
 
   const handleRetry = useCallback(async () => {
     try {