feat: restore previous permission mode when exiting plan mode (#866)

src/cli/App.tsx

@@ -9559,9 +9559,11 @@ ${SYSTEM_REMINDER_CLOSE}
       lastPlanFilePathRef.current = planFilePath;
 
       // Exit plan mode
-      const newMode = acceptEdits ? "acceptEdits" : "default";
-      permissionMode.setMode(newMode);
-      setUiPermissionMode(newMode);
+      const restoreMode = acceptEdits
+        ? "acceptEdits"
+        : (permissionMode.getModeBeforePlan() ?? "default");
+      permissionMode.setMode(restoreMode);
+      setUiPermissionMode(restoreMode);
 
       try {
         // Execute ExitPlanMode tool to get the result

src/permissions/mode.ts

@@ -16,10 +16,12 @@ export type PermissionMode =
 // This prevents Bun's bundler from creating duplicate instances of the mode manager
 const MODE_KEY = Symbol.for("@letta/permissionMode");
 const PLAN_FILE_KEY = Symbol.for("@letta/planFilePath");
+const MODE_BEFORE_PLAN_KEY = Symbol.for("@letta/permissionModeBeforePlan");
 
 type GlobalWithMode = typeof globalThis & {
   [MODE_KEY]: PermissionMode;
   [PLAN_FILE_KEY]: string | null;
+  [MODE_BEFORE_PLAN_KEY]?: PermissionMode | null;
 };
 
 function getGlobalMode(): PermissionMode {
@@ -45,6 +47,16 @@ function setGlobalPlanFilePath(value: string | null): void {
   global[PLAN_FILE_KEY] = value;
 }
 
+function getGlobalModeBeforePlan(): PermissionMode | null {
+  const global = globalThis as GlobalWithMode;
+  return global[MODE_BEFORE_PLAN_KEY] ?? null;
+}
+
+function setGlobalModeBeforePlan(value: PermissionMode | null): void {
+  const global = globalThis as GlobalWithMode;
+  global[MODE_BEFORE_PLAN_KEY] = value;
+}
+
 /**
  * Permission mode state for the current session.
  * Set via CLI --permission-mode flag or settings.json defaultMode.
@@ -62,11 +74,33 @@ class PermissionModeManager {
    * Set the permission mode for this session
    */
   setMode(mode: PermissionMode): void {
+    const prevMode = this.currentMode;
+
+    // If we are entering plan mode, remember what mode we were previously in so
+    // ExitPlanMode can restore it (e.g. YOLO).
+    if (mode === "plan" && prevMode !== "plan") {
+      setGlobalModeBeforePlan(prevMode);
+    }
+
     this.currentMode = mode;
+
     // Clear plan file path when exiting plan mode
     if (mode !== "plan") {
       setGlobalPlanFilePath(null);
     }
+
+    // Once we leave plan mode, the remembered mode has been consumed.
+    if (prevMode === "plan" && mode !== "plan") {
+      setGlobalModeBeforePlan(null);
+    }
+  }
+
+  /**
+   * Get the permission mode that was active before entering plan mode.
+   * Used to restore the user's previous setting (e.g., bypassPermissions).
+   */
+  getModeBeforePlan(): PermissionMode | null {
+    return getGlobalModeBeforePlan();
   }
 
   /**
@@ -261,6 +295,8 @@ class PermissionModeManager {
    */
   reset(): void {
     this.currentMode = "default";
+    setGlobalPlanFilePath(null);
+    setGlobalModeBeforePlan(null);
   }
 }
 

src/tests/permissions-mode.test.ts

@@ -452,3 +452,20 @@ test("Permission mode takes precedence over CLI allowedTools", () => {
   // Clean up
   cliPermissions.clear();
 });
+
+test("plan mode - remembers and restores previous mode", () => {
+  permissionMode.setMode("bypassPermissions");
+  expect(permissionMode.getMode()).toBe("bypassPermissions");
+
+  // Enter plan mode - should remember prior mode.
+  permissionMode.setMode("plan");
+  expect(permissionMode.getMode()).toBe("plan");
+  expect(permissionMode.getModeBeforePlan()).toBe("bypassPermissions");
+
+  // Exit plan mode by restoring previous mode.
+  permissionMode.setMode(permissionMode.getModeBeforePlan() ?? "default");
+  expect(permissionMode.getMode()).toBe("bypassPermissions");
+
+  // Once we leave plan mode, the remembered mode is consumed.
+  expect(permissionMode.getModeBeforePlan()).toBe(null);
+});