feat(code): warn on local task branch mismatch

apps/code/src/renderer/features/message-editor/components/MessageEditor.tsx

@@ -136,6 +136,7 @@ function ModeAndBranchRow({
 interface MessageEditorProps {
   sessionId: string;
   placeholder?: string;
+  onBeforeSubmit?: (text: string) => boolean;
   onSubmit?: (text: string) => void;
   onBashCommand?: (command: string) => void;
   onBashModeChange?: (isBashMode: boolean) => void;
@@ -154,6 +155,7 @@ export const MessageEditor = forwardRef<EditorHandle, MessageEditorProps>(
     {
       sessionId,
       placeholder = "Type a message... @ to mention files, ! for bash mode, / for skills",
+      onBeforeSubmit,
       onSubmit,
       onBashCommand,
       onBashModeChange,
@@ -213,6 +215,7 @@ export const MessageEditor = forwardRef<EditorHandle, MessageEditorProps>(
       context: { taskId, repoPath },
       getPromptHistory,
       capabilities: { bashMode: !isCloud },
+      onBeforeSubmit,
       onSubmit,
       onBashCommand,
       onBashModeChange,

apps/code/src/renderer/features/message-editor/tiptap/useTiptapEditor.ts

@@ -29,6 +29,11 @@ export interface UseTiptapEditorOptions {
   };
   clearOnSubmit?: boolean;
   getPromptHistory?: () => string[];
+  /**
+   * Called before submit with the serialized text. Return `false` to block
+   * the submit — `onSubmit` will not fire and the editor will not clear.
+   */
+  onBeforeSubmit?: (text: string) => boolean;
   onSubmit?: (text: string) => void;
   onBashCommand?: (command: string) => void;
   onBashModeChange?: (isBashMode: boolean) => void;
@@ -84,6 +89,7 @@ export function useTiptapEditor(options: UseTiptapEditorOptions) {
     capabilities = {},
     clearOnSubmit = true,
     getPromptHistory,
+    onBeforeSubmit,
     onSubmit,
     onBashCommand,
     onBashModeChange,
@@ -99,6 +105,7 @@ export function useTiptapEditor(options: UseTiptapEditorOptions) {
   } = capabilities;
 
   const callbackRefs = useRef({
+    onBeforeSubmit,
     onSubmit,
     onBashCommand,
     onBashModeChange,
@@ -107,6 +114,7 @@ export function useTiptapEditor(options: UseTiptapEditorOptions) {
     onBlur,
   });
   callbackRefs.current = {
+    onBeforeSubmit,
     onSubmit,
     onBashCommand,
     onBashModeChange,
@@ -459,8 +467,15 @@ export function useTiptapEditor(options: UseTiptapEditorOptions) {
       const command = text.slice(1).trim();
       if (command) callbackRefs.current.onBashCommand?.(command);
     } else {
+      const serialized = contentToXml(content);
+
+      // Allow callers to block submit (e.g., branch mismatch warning)
+      if (callbackRefs.current.onBeforeSubmit?.(serialized) === false) {
+        return;
+      }
+
       // Normal prompts can be queued when loading
-      callbackRefs.current.onSubmit?.(contentToXml(content));
+      callbackRefs.current.onSubmit?.(serialized);
     }
 
     if (clearOnSubmit) {

apps/code/src/renderer/features/sessions/components/SessionView.tsx

@@ -38,6 +38,7 @@ interface SessionViewProps {
   isRunning: boolean;
   isPromptPending?: boolean | null;
   promptStartedAt?: number | null;
+  onBeforeSubmit?: (text: string) => boolean;
   onSendPrompt: (text: string) => void;
   onBashCommand?: (command: string) => void;
   onCancelPrompt: () => void;
@@ -73,6 +74,7 @@ export function SessionView({
   isRunning,
   isPromptPending = false,
   promptStartedAt,
+  onBeforeSubmit,
   onSendPrompt,
   onBashCommand,
   onCancelPrompt,
@@ -538,6 +540,7 @@ export function SessionView({
                         ref={editorRef}
                         sessionId={sessionId}
                         placeholder="Type a message... @ to mention files, ! for bash mode, / for skills"
+                        onBeforeSubmit={onBeforeSubmit}
                         onSubmit={handleSubmit}
                         onBashCommand={onBashCommand}
                         onCancel={onCancelPrompt}

apps/code/src/renderer/features/task-detail/components/BranchMismatchDialog.tsx

@@ -0,0 +1,122 @@
+import { GitBranch, Warning } from "@phosphor-icons/react";
+import { AlertDialog, Button, Code, Flex, Text } from "@radix-ui/themes";
+
+interface BranchMismatchDialogProps {
+  open: boolean;
+  linkedBranch: string;
+  currentBranch: string;
+  onSwitch: () => void;
+  onContinue: () => void;
+  onCancel: () => void;
+  isSwitching?: boolean;
+}
+
+function BranchLabel({ name }: { name: string }) {
+  return (
+    <Code
+      size="2"
+      variant="ghost"
+      truncate
+      style={{
+        maxWidth: "100%",
+        display: "inline-flex",
+        alignItems: "center",
+        gap: "4px",
+      }}
+    >
+      <GitBranch size={12} style={{ flexShrink: 0 }} />
+      <span
+        style={{
+          overflow: "hidden",
+          textOverflow: "ellipsis",
+          whiteSpace: "nowrap",
+        }}
+      >
+        {name}
+      </span>
+    </Code>
+  );
+}
+
+export function BranchMismatchDialog({
+  open,
+  linkedBranch,
+  currentBranch,
+  onSwitch,
+  onContinue,
+  onCancel,
+  isSwitching,
+}: BranchMismatchDialogProps) {
+  return (
+    <AlertDialog.Root open={open}>
+      <AlertDialog.Content maxWidth="420px" size="2">
+        <AlertDialog.Title size="3">
+          <Flex align="center" gap="2">
+            <Warning size={18} weight="fill" color="var(--orange-9)" />
+            Wrong branch
+          </Flex>
+        </AlertDialog.Title>
+        <AlertDialog.Description size="2">
+          This task is linked to a different branch than the one you're
+          currently on. The agent will make changes on the current branch.
+        </AlertDialog.Description>
+        <Flex direction="column" gap="1" mt="3" style={{ minWidth: 0 }}>
+          <Flex align="center" gap="2" style={{ minWidth: 0 }}>
+            <Text
+              size="1"
+              color="gray"
+              style={{ flexShrink: 0, width: "64px" }}
+            >
+              Linked
+            </Text>
+            <BranchLabel name={linkedBranch} />
+          </Flex>
+          <Flex align="center" gap="2" style={{ minWidth: 0 }}>
+            <Text
+              size="1"
+              color="gray"
+              style={{ flexShrink: 0, width: "64px" }}
+            >
+              Current
+            </Text>
+            <BranchLabel name={currentBranch} />
+          </Flex>
+        </Flex>
+
+        <Flex justify="end" gap="2" mt="4">
+          <AlertDialog.Cancel>
+            <Button
+              variant="soft"
+              color="gray"
+              size="1"
+              onClick={onCancel}
+              disabled={isSwitching}
+            >
+              Cancel
+            </Button>
+          </AlertDialog.Cancel>
+
+          <Button
+            variant="soft"
+            size="1"
+            onClick={onContinue}
+            disabled={isSwitching}
+          >
+            Continue anyway
+          </Button>
+
+          <AlertDialog.Action>
+            <Button
+              variant="solid"
+              size="1"
+              onClick={onSwitch}
+              loading={isSwitching}
+            >
+              Switch branch
+            </Button>
+          </AlertDialog.Action>
+        </Flex>
+      </AlertDialog.Content>
+    </AlertDialog.Root>
+  );
+}

apps/code/src/renderer/features/task-detail/components/TaskLogsPanel.tsx

@@ -15,15 +15,19 @@ import { useSessionConnection } from "@features/sessions/hooks/useSessionConnect
 import { useSessionViewState } from "@features/sessions/hooks/useSessionViewState";
 import { useRestoreTask } from "@features/suspension/hooks/useRestoreTask";
 import { useSuspendedTaskIds } from "@features/suspension/hooks/useSuspendedTaskIds";
+import { BranchMismatchDialog } from "@features/task-detail/components/BranchMismatchDialog";
 import { WorkspaceSetupPrompt } from "@features/task-detail/components/WorkspaceSetupPrompt";
+import { useBranchMismatchGuard } from "@features/workspace/hooks/useBranchMismatch";
 import {
   useCreateWorkspace,
   useWorkspaceLoaded,
 } from "@features/workspace/hooks/useWorkspace";
 import { Box, Flex } from "@radix-ui/themes";
+import { trpcClient } from "@renderer/trpc/client";
 import type { Task } from "@shared/types";
+import { logger } from "@utils/logger";
 import { getTaskRepository } from "@utils/repository";
-import { useCallback, useEffect, useMemo } from "react";
+import { useCallback, useEffect, useMemo, useState } from "react";
 
 interface TaskLogsPanelProps {
   taskId: string;
@@ -81,6 +85,61 @@ export function TaskLogsPanel({ taskId, task, hideInput }: TaskLogsPanelProps) {
     handleBashCommand,
   } = useSessionCallbacks({ taskId, task, session, repoPath });
 
+  // Branch mismatch guard
+  const { shouldWarn, linkedBranch, currentBranch, dismissWarning } =
+    useBranchMismatchGuard(taskId);
+  const [pendingMessage, setPendingMessage] = useState<string | null>(null);
+  const [isSwitchingBranch, setIsSwitchingBranch] = useState(false);
+
+  const handleBeforeSubmit = useCallback(
+    (text: string): boolean => {
+      if (shouldWarn) {
+        setPendingMessage(text);
+        return false;
+      }
+      return true;
+    },
+    [shouldWarn],
+  );
+
+  const handleMismatchSwitch = useCallback(async () => {
+    if (!linkedBranch || !repoPath) return;
+    setIsSwitchingBranch(true);
+    try {
+      await trpcClient.git.checkoutBranch.mutate({
+        directoryPath: repoPath,
+        branchName: linkedBranch,
+      });
+      dismissWarning();
+      if (pendingMessage) {
+        handleSendPrompt(pendingMessage);
+      }
+    } catch (error) {
+      logger.scope("task-logs-panel").error("Failed to switch branch", error);
+    } finally {
+      setIsSwitchingBranch(false);
+      setPendingMessage(null);
+    }
+  }, [
+    linkedBranch,
+    repoPath,
+    dismissWarning,
+    pendingMessage,
+    handleSendPrompt,
+  ]);
+
+  const handleMismatchContinue = useCallback(() => {
+    dismissWarning();
+    if (pendingMessage) {
+      handleSendPrompt(pendingMessage);
+    }
+    setPendingMessage(null);
+  }, [dismissWarning, pendingMessage, handleSendPrompt]);
+
+  const handleMismatchCancel = useCallback(() => {
+    setPendingMessage(null);
+  }, []);
+
   const cloudOutput = session?.cloudOutput ?? null;
   const prUrl =
     isCloud && cloudOutput?.pr_url ? (cloudOutput.pr_url as string) : null;
@@ -147,6 +206,7 @@ export function TaskLogsPanel({ taskId, task, hideInput }: TaskLogsPanelProps) {
               isRestoring={isRestoring}
               isPromptPending={isPromptPending}
               promptStartedAt={promptStartedAt}
+              onBeforeSubmit={handleBeforeSubmit}
               onSendPrompt={handleSendPrompt}
               onBashCommand={isCloud ? undefined : handleBashCommand}
               onCancelPrompt={handleCancelPrompt}
@@ -165,6 +225,18 @@ export function TaskLogsPanel({ taskId, task, hideInput }: TaskLogsPanelProps) {
           </ErrorBoundary>
         </Box>
       </Flex>
+
+      {linkedBranch && currentBranch && (
+        <BranchMismatchDialog
+          open={pendingMessage !== null}
+          linkedBranch={linkedBranch}
+          currentBranch={currentBranch}
+          onSwitch={handleMismatchSwitch}
+          onContinue={handleMismatchContinue}
+          onCancel={handleMismatchCancel}
+          isSwitching={isSwitchingBranch}
+        />
+      )}
     </BackgroundWrapper>
   );
 }