[codex] Add lint and typecheck gates

.github/workflows/pr-check.yml

@@ -25,5 +25,11 @@ jobs:
       - name: Install dependencies
         run: uv sync --group dev
 
+      - name: Run lint
+        run: uv run ruff check .
+
+      - name: Run typecheck
+        run: uv run mypy
+
       - name: Run test suite
         run: uv run pytest

README.md

@@ -200,6 +200,16 @@ uv run deep-code-agent --backend-type filesystem --skills-dir .agents/skills
 
 Skills currently require `--backend-type filesystem`; the state backend does not load local skill directories.
 
+## Development Checks
+
+Run the same checks used by CI before opening a pull request:
+
+```bash
+uv run ruff check .
+uv run mypy
+uv run pytest
+```
+
 ### Working with Subagents
 
 The Deep Code Agent includes specialized subagents that can be used independently or as part of the main workflow:

pyproject.toml

@@ -24,10 +24,22 @@ build-backend = "uv_build"
 [tool.pytest.ini_options]
 addopts = "--cov=src/deep_code_agent --cov-report=term-missing --cov-fail-under=40"
 
+[tool.ruff]
+target-version = "py313"
+
+[tool.mypy]
+check_untyped_defs = true
+files = ["src/deep_code_agent"]
+python_version = "3.13"
+show_error_codes = true
+warn_unused_configs = true
+
 [dependency-groups]
 dev = [
     "ipython>=9.8.0",
     "langgraph-cli[inmem]>=0.4.9",
+    "mypy>=2.1.0",
     "pytest>=9.0.2",
     "pytest-cov>=7.1.0",
+    "ruff>=0.15.20",
 ]

src/deep_code_agent/cli.py

@@ -296,7 +296,7 @@ def _run_tui_mode(args) -> None:
     dotenv_path = Path(codebase_dir) / ".env"
     load_dotenv(dotenv_path=dotenv_path if dotenv_path.exists() else None)
 
-    print(f"🚀 Starting Deep Code Agent TUI...")
+    print("🚀 Starting Deep Code Agent TUI...")
     print(f"📁 Codebase: {codebase_dir}")
 
     def agent_factory():

src/deep_code_agent/code_agent.py

@@ -66,6 +66,7 @@ def create_code_agent(
     system_prompt = get_system_prompt().format(codebase_dir=codebase_dir)
     model = model or create_chat_model()
     subagents = create_subagent_configurations()
+    backend: Any
 
     if backend_type == "filesystem":
         from deepagents.backends.filesystem import FilesystemBackend
@@ -75,9 +76,10 @@ def create_code_agent(
     elif backend_type == "state":
         from deepagents.backends.state import StateBackend
 
-        def backend(rt):
+        def create_state_backend(rt: Any) -> Any:
             return StateBackend(rt)
 
+        backend = create_state_backend
         tools = []
     else:
         raise ValueError(f"Unsupported backend_type: {backend_type}")

src/deep_code_agent/models/llms/langchain_chat.py

@@ -11,7 +11,7 @@ def create_chat_model(
     base_url: str | None = None,
 ):
     model_name = model_name or os.getenv("MODEL_NAME")
-    api_key = api_key or os.getenv("OPENAI_API_KEY", "EMPTY")
+    api_key = api_key or os.getenv("OPENAI_API_KEY") or "EMPTY"
     base_url = base_url or os.getenv("OPENAI_API_BASE")
     return init_chat_model(
         model=model_name,

src/deep_code_agent/tui/app.py

@@ -40,8 +40,8 @@ class DeepCodeAgentApp(App):
 
     # Reactive state
     dark = reactive(True)
-    session_info = reactive({})
-    auto_approve_tools = reactive([])
+    session_info: reactive[dict[str, Any]] = reactive({})
+    auto_approve_tools: reactive[list[str]] = reactive(list)
 
     def __init__(
         self,

src/deep_code_agent/tui/bridge/stream_handler.py

@@ -1,6 +1,5 @@
 """Stream handler for processing LangGraph Agent output."""
 
-import asyncio
 import json
 from dataclasses import dataclass
 from enum import Enum, auto
@@ -154,7 +153,8 @@ def add_chunk(item: dict) -> None:
             for item in additional_kwargs.get("tool_calls") or []:
                 if not isinstance(item, dict):
                     continue
-                function = item.get("function") if isinstance(item.get("function"), dict) else {}
+                function_value = item.get("function")
+                function = function_value if isinstance(function_value, dict) else {}
                 add_chunk(
                     {
                         "id": item.get("id"),
@@ -249,7 +249,8 @@ def _normalize_tool_call(self, tc: Any, *, fallback_name: str | None = None) ->
                 pass
 
         if isinstance(tc, dict):
-            function = tc.get("function") if isinstance(tc.get("function"), dict) else {}
+            function_value = tc.get("function")
+            function = function_value if isinstance(function_value, dict) else {}
             tool_name = tc.get("name") or tc.get("tool_name") or function.get("name") or ""
             raw_args = tc.get("args") if "args" in tc else function.get("arguments")
             tool_args = self._coerce_tool_args(raw_args)

src/deep_code_agent/tui/screens/main_screen.py

@@ -5,6 +5,7 @@
 from pathlib import Path
 from typing import TYPE_CHECKING, cast
 
+from textual import work
 from textual.app import ComposeResult
 from textual.binding import Binding
 from textual.containers import Vertical
@@ -113,8 +114,6 @@ def update_session_info(self, session_info: dict) -> None:
         except Exception:
             pass
 
-    from textual import work
-
     @work(exclusive=True, name="agent_request")
     async def process_agent_request(self, content: str) -> None:
         """Process the agent request in a worker."""

src/deep_code_agent/tui/widgets/input_box.py

@@ -1,6 +1,7 @@
 """Input composer widget for user message entry."""
 
 from pathlib import Path
+from typing import Any
 
 from rich.markup import escape
 from textual.binding import Binding
@@ -134,7 +135,7 @@ class InputBox(Vertical):
 
     # Reactive state
     disabled = reactive(False)
-    session_info = reactive({})
+    session_info: reactive[dict[str, Any]] = reactive({})
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)

src/deep_code_agent/tui/widgets/session_header.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 from pathlib import Path
+from typing import Any
 
 from deep_code_agent import __version__
 from textual.reactive import reactive
@@ -22,7 +23,7 @@ class SessionHeader(Static):
     }
     """
 
-    session_info = reactive({})
+    session_info: reactive[dict[str, Any]] = reactive({})
 
     def __init__(self, session_info: dict | None = None, **kwargs) -> None:
         super().__init__("", markup=False, **kwargs)

src/deep_code_agent/tui/widgets/side_panel.py

@@ -1,6 +1,7 @@
 """Side panel widget for session context and recent activity."""
 
 from pathlib import Path
+from typing import Any
 
 from textual.containers import Vertical
 from textual.reactive import reactive
@@ -72,8 +73,8 @@ class SidePanel(Vertical):
     }
     """
 
-    session_info = reactive({})
-    tool_calls = reactive(list)
+    session_info: reactive[dict[str, Any]] = reactive({})
+    tool_calls: reactive[list[dict[str, Any]]] = reactive(list)
 
     def __init__(self, session_info: dict | None = None, **kwargs):
         super().__init__(**kwargs)

src/deep_code_agent/tui/widgets/status_bar.py

@@ -1,8 +1,10 @@
 """Status bar widget for displaying application state."""
 
+from typing import Any
+
+from rich.markup import escape
 from textual.reactive import reactive
 from textual.widgets import Static
-from rich.markup import escape
 
 
 class StatusBar(Static):
@@ -42,7 +44,7 @@ class StatusBar(Static):
     # Reactive state
     status = reactive("ready")
     message = reactive("")
-    session_info = reactive({})
+    session_info: reactive[dict[str, Any]] = reactive({})
 
     def __init__(self, **kwargs):
         super().__init__(**kwargs)

tests/tui/test_app.py

@@ -1,8 +1,5 @@
 """Tests for DeepCodeAgentApp."""
 
-import pytest
-from textual.app import App
-
 
 def test_app_auto_approve_tools():
     """Test that app has auto_approve_tools configuration."""

tests/tui/test_tool_call_view.py

@@ -1,6 +1,4 @@
 """Tests for ToolCallView widget."""
-
-import pytest
 from textual.app import App