Integrate todo list with session management.

This adds the current todo list content into the session save/load payload.

The flag --preserve-todo-list no longer has any effect and is marked as deprecated.

Author: jamwil

aider/args.py

@@ -309,7 +309,10 @@ def get_parser(default_config_files, git_root):
     group.add_argument(
         "--preserve-todo-list",
         action="store_true",
-        help="Preserve the existing .aider.todo.txt file on startup (default: False)",
+        help=(
+            "Deprecated: no longer needed because the todo list is saved and restored with"
+            " sessions. This flag has no effect and will be removed."
+        ),
         default=False,
     )
     group.add_argument(

aider/coders/base_coder.py

@@ -314,6 +314,12 @@ def __init__(
         self.auto_accept_architect = auto_accept_architect
         self.preserve_todo_list = preserve_todo_list
 
+        if self.preserve_todo_list:
+            self.io.tool_warning(
+                "--preserve-todo-list is deprecated; todo lists are now saved and restored with"
+                " sessions. The flag will be removed in a future release."
+            )
+
         self.ignore_mentions = ignore_mentions
         if not self.ignore_mentions:
             self.ignore_mentions = set()
@@ -524,17 +530,16 @@ def __init__(
         self.auto_test = auto_test
         self.test_cmd = test_cmd
 
-        # Clean up todo list file on startup unless preserve_todo_list is True
-        if not getattr(self, "preserve_todo_list", False):
-            todo_file_path = ".aider.todo.txt"
-            abs_path = self.abs_root_path(todo_file_path)
-            if os.path.isfile(abs_path):
-                try:
-                    os.remove(abs_path)
-                    if self.verbose:
-                        self.io.tool_output(f"Removed existing todo list file: {todo_file_path}")
-                except Exception as e:
-                    self.io.tool_warning(f"Could not remove todo list file {todo_file_path}: {e}")
+        # Clean up todo list file on startup; sessions will restore it when needed
+        todo_file_path = ".aider.todo.txt"
+        abs_path = self.abs_root_path(todo_file_path)
+        if os.path.isfile(abs_path):
+            try:
+                os.remove(abs_path)
+                if self.verbose:
+                    self.io.tool_output(f"Removed existing todo list file: {todo_file_path}")
+            except Exception as e:
+                self.io.tool_warning(f"Could not remove todo list file {todo_file_path}: {e}")
 
         # validate the functions jsonschema
         if self.functions:

aider/sessions.py

@@ -126,6 +126,17 @@ def _build_session_data(self, session_name) -> Dict:
             for abs_fname in self.coder.abs_read_only_stubs_fnames
         ]
 
+        # Capture todo list content so it can be restored with the session
+        todo_content = None
+        try:
+            todo_path = self.coder.abs_root_path(".aider.todo.txt")
+            if os.path.isfile(todo_path):
+                todo_content = self.io.read_text(todo_path)
+                if todo_content is None:
+                    todo_content = ""
+        except Exception as e:
+            self.io.tool_warning(f"Could not read todo list file: {e}")
+
         return {
             "version": 1,
             "session_name": session_name,
@@ -148,6 +159,7 @@ def _build_session_data(self, session_name) -> Dict:
                 "auto_lint": self.coder.auto_lint,
                 "auto_test": self.coder.auto_test,
             },
+            "todo_list": todo_content,
         }
 
     def _find_session_file(self, session_identifier: str) -> Optional[Path]:
@@ -232,6 +244,19 @@ def _apply_session_data(self, session_data: Dict, session_file: Path) -> bool:
             if "auto_test" in settings:
                 self.coder.auto_test = settings["auto_test"]
 
+            # Restore todo list content if present in the session
+            if "todo_list" in session_data:
+                todo_path = self.coder.abs_root_path(".aider.todo.txt")
+                todo_content = session_data.get("todo_list")
+                try:
+                    if todo_content is None:
+                        if os.path.exists(todo_path):
+                            os.remove(todo_path)
+                    else:
+                        self.io.write_text(todo_path, todo_content)
+                except Exception as e:
+                    self.io.tool_warning(f"Could not restore todo list: {e}")
+
             self.io.tool_output(
                 f"Session loaded: {session_data.get('session_name', session_file.stem)}"
             )

aider/website/docs/sessions.md

@@ -42,6 +42,7 @@ When `--auto-save` is enabled, aider will automatically save your session as 'au
 - All files in the chat (editable, read-only, and read-only stubs)
 - Current model and edit format settings
 - Auto-commit, auto-lint, and auto-test settings
+- Todo list content from `.aider.todo.txt`
 - Session metadata (timestamp, version)
 
 ### `/load-session <name>`
@@ -56,6 +57,7 @@ Load a previously saved session by name or file path.
 - Restores chat history and file configurations
 - Recreates the exact session state
 - Preserves all settings and model configurations
+- Restores the todo list content saved in the session
 
 ### `/list-sessions`
 List all available saved sessions in `.aider/sessions/`.
@@ -78,10 +80,13 @@ Sessions are stored as JSON files in the `.aider/sessions/` directory within you
 
 ```json
 {
-  "version": "1.0",
+  "version": 1,
   "timestamp": 1700000000,
   "session_name": "my-session",
   "model": "gpt-4",
+  "weak_model": "gpt-4o-mini",
+  "editor_model": "gpt-4o",
+  "editor_edit_format": "diff",
   "edit_format": "diff",
   "chat_history": {
     "done_messages": [...],
@@ -93,11 +98,11 @@ Sessions are stored as JSON files in the `.aider/sessions/` directory within you
     "read_only_stubs": []
   },
   "settings": {
-    "root": "/path/to/project",
     "auto_commits": true,
     "auto_lint": false,
     "auto_test": false
-  }
+  },
+  "todo_list": "- plan feature A\n- write tests\n"
 }
 ```
 
@@ -143,6 +148,7 @@ Sessions are stored as JSON files in the `.aider/sessions/` directory within you
 - Session files include all file paths, so they work best when project structure is stable
 - External files (outside the project root) are stored with absolute paths
 - Missing files are skipped with warnings during loading
+- The todo list file (`.aider.todo.txt`) is cleared on startup; it is restored when you load a session or when you update it during a run
 
 ### Version Control
 - Consider adding `.aider/sessions/` to your `.gitignore` if sessions contain sensitive information
@@ -160,13 +166,17 @@ If files are reported as missing during loading:
 - The files may have been moved or deleted
 - Session files store relative paths, so directory structure changes can affect this
 - External files must exist at their original locations
+- The todo list (`.aider.todo.txt`) is cleared on startup unless restored from a loaded session
 
 ### Corrupted Sessions
 If a session fails to load:
 - Check the session file is valid JSON
 - Verify the session version is compatible
 - Try creating a new session and compare file structures
 
+### Deprecated Options
+- `--preserve-todo-list` is deprecated. The todo list is cleared on startup and restored only when you load a session that contains it.
+
 ## Related Commands
 - `/reset` - Clear chat history and drop files (useful before loading a session)
 

tests/basic/test_sessions.py

@@ -57,6 +57,10 @@ async def test_cmd_save_session_basic(self):
                 {"role": "user", "content": "Can you help me?"},
             ]
 
+            # Add a todo list
+            todo_content = "Task 1\nTask 2"
+            Path(".aider.todo.txt").write_text(todo_content, encoding="utf-8")
+
             # Save session
             session_name = "test_session"
             commands.cmd_save_session(session_name)
@@ -69,7 +73,7 @@ async def test_cmd_save_session_basic(self):
             with open(session_file, "r", encoding="utf-8") as f:
                 session_data = json.load(f)
 
-            self.assertEqual(session_data["version"], "1.0")
+            self.assertEqual(session_data["version"], 1)
             self.assertEqual(session_data["session_name"], session_name)
             self.assertEqual(session_data["model"], self.GPT35.name)
             self.assertEqual(session_data["edit_format"], coder.edit_format)
@@ -87,11 +91,13 @@ async def test_cmd_save_session_basic(self):
 
             # Verify settings
             settings = session_data["settings"]
-            self.assertEqual(settings["root"], coder.root)
             self.assertEqual(settings["auto_commits"], coder.auto_commits)
             self.assertEqual(settings["auto_lint"], coder.auto_lint)
             self.assertEqual(settings["auto_test"], coder.auto_test)
 
+            # Verify todo list persisted
+            self.assertEqual(session_data["todo_list"], todo_content)
+
     async def test_cmd_load_session_basic(self):
         """Test basic session load functionality"""
         with GitTemporaryDirectory() as repo_dir:
@@ -113,7 +119,7 @@ async def test_cmd_load_session_basic(self):
 
             # Create a session file manually
             session_data = {
-                "version": "1.0",
+                "version": 1,
                 "timestamp": time.time(),
                 "session_name": "test_session",
                 "model": self.GPT35.name,
@@ -133,11 +139,11 @@ async def test_cmd_load_session_basic(self):
                     "read_only_stubs": [],
                 },
                 "settings": {
-                    "root": str(repo_dir),
                     "auto_commits": True,
                     "auto_lint": False,
                     "auto_test": False,
                 },
+                "todo_list": "Restored tasks\n- item",
             }
 
             # Save session file
@@ -166,6 +172,11 @@ async def test_cmd_load_session_basic(self):
             self.assertEqual(coder.auto_lint, False)
             self.assertEqual(coder.auto_test, False)
 
+            # Verify todo list restored
+            todo_file = Path(".aider.todo.txt")
+            self.assertTrue(todo_file.exists())
+            self.assertEqual(todo_file.read_text(encoding="utf-8"), session_data["todo_list"])
+
     async def test_cmd_list_sessions_basic(self):
         """Test basic session list functionality"""
         with GitTemporaryDirectory():
@@ -176,7 +187,7 @@ async def test_cmd_list_sessions_basic(self):
             # Create multiple session files
             sessions_data = [
                 {
-                    "version": "1.0",
+                    "version": 1,
                     "timestamp": time.time() - 3600,  # 1 hour ago
                     "session_name": "session1",
                     "model": "gpt-3.5-turbo",
@@ -191,7 +202,7 @@ async def test_cmd_list_sessions_basic(self):
                     },
                 },
                 {
-                    "version": "1.0",
+                    "version": 1,
                     "timestamp": time.time(),  # current time
                     "session_name": "session2",
                     "model": "gpt-4",
@@ -232,3 +243,18 @@ async def test_cmd_list_sessions_basic(self):
                 self.assertIn("session2", output_text)
                 self.assertIn("gpt-3.5-turbo", output_text)
                 self.assertIn("gpt-4", output_text)
+
+    async def test_preserve_todo_list_deprecated(self):
+        """Ensure preserve-todo-list flag is deprecated and todo is cleared on startup"""
+        with GitTemporaryDirectory():
+            todo_path = Path(".aider.todo.txt")
+            todo_path.write_text("keep me", encoding="utf-8")
+
+            io = InputOutput(pretty=False, fancy_input=False, yes=True)
+            with mock.patch.object(io, "tool_warning") as mock_tool_warning:
+                await Coder.create(self.GPT35, None, io, preserve_todo_list=True)
+
+            self.assertFalse(todo_path.exists())
+            self.assertTrue(
+                any("deprecated" in call[0][0] for call in mock_tool_warning.call_args_list)
+            )