chore: use ruff to lint and auto-format

backend/.gitignore

@@ -7,6 +7,7 @@ wheels/
 *.egg-info
 .coverage
 .coverage.*
+.ruff_cache
 agent_history.gif
 static/browser_history/*.gif
 

backend/.vscode/extensions.json

@@ -0,0 +1,3 @@
+{
+  "recommendations": ["charliermarsh.ruff"]
+}

backend/.vscode/settings.json

@@ -0,0 +1,10 @@
+{
+  "[python]": {
+    "editor.formatOnSave": true,
+    "editor.codeActionsOnSave": {
+      "source.fixAll": "explicit",
+      "source.organizeImports": "explicit"
+    },
+    "editor.defaultFormatter": "charliermarsh.ruff"
+  }
+}

backend/pyproject.toml

@@ -15,3 +15,8 @@ dependencies = [
     "readabilipy>=0.3.0",
     "tavily-python>=0.7.17",
 ]
+
+[dependency-groups]
+dev = [
+    "ruff>=0.14.11",
+]

backend/ruff.toml

@@ -0,0 +1,10 @@
+line-length = 240
+target-version = "py312"
+
+[lint]
+select = ["E", "F", "I", "UP"]
+ignore = []
+
+[format]
+quote-style = "double"
+indent-style = "space"

backend/src/agents/lead_agent/agent.py

@@ -1,4 +1,5 @@
 from langchain.agents import create_agent
+
 from src.agents.lead_agent.prompt import apply_prompt_template
 from src.models import create_chat_model
 from src.tools import get_available_tools

backend/src/agents/lead_agent/prompt.py

@@ -71,7 +71,4 @@ All temporary work happens in `{MOUNT_POINT}/user-data/workspace`. Final deliver
 
 
 def apply_prompt_template() -> str:
-    return (
-        SYSTEM_PROMPT
-        + f"\n<current_date>{datetime.now().strftime("%Y-%m-%d, %A")}</current_date>"
-    )
+    return SYSTEM_PROMPT + f"\n<current_date>{datetime.now().strftime('%Y-%m-%d, %A')}</current_date>"

backend/src/config/app_config.py

@@ -13,14 +13,10 @@ from src.config.tool_config import ToolConfig, ToolGroupConfig
 class AppConfig(BaseModel):
     """Config for the DeerFlow application"""
 
-    models: list[ModelConfig] = Field(
-        default_factory=list, description="Available models"
-    )
+    models: list[ModelConfig] = Field(default_factory=list, description="Available models")
     sandbox: SandboxConfig = Field(description="Sandbox configuration")
     tools: list[ToolConfig] = Field(default_factory=list, description="Available tools")
-    tool_groups: list[ToolGroupConfig] = Field(
-        default_factory=list, description="Available tool groups"
-    )
+    tool_groups: list[ToolGroupConfig] = Field(default_factory=list, description="Available tool groups")
     model_config = ConfigDict(extra="allow", frozen=False)
 
     @classmethod
@@ -35,16 +31,12 @@ class AppConfig(BaseModel):
         if config_path:
             path = Path(config_path)
             if not Path.exists(path):
-                raise FileNotFoundError(
-                    f"Config file specified by param `config_path` not found at {path}"
-                )
+                raise FileNotFoundError(f"Config file specified by param `config_path` not found at {path}")
             return path
         elif os.getenv("DEER_FLOW_CONFIG_PATH"):
             path = Path(os.getenv("DEER_FLOW_CONFIG_PATH"))
             if not Path.exists(path):
-                raise FileNotFoundError(
-                    f"Config file specified by environment variable `DEER_FLOW_CONFIG_PATH` not found at {path}"
-                )
+                raise FileNotFoundError(f"Config file specified by environment variable `DEER_FLOW_CONFIG_PATH` not found at {path}")
             return path
         else:
             # Check if the config.yaml is in the parent directory of CWD
@@ -66,7 +58,7 @@ class AppConfig(BaseModel):
             AppConfig: The loaded config.
         """
         resolved_path = cls.resolve_config_path(config_path)
-        with open(resolved_path, "r") as f:
+        with open(resolved_path) as f:
             config_data = yaml.safe_load(f)
         cls.resolve_env_variables(config_data)
         result = cls.model_validate(config_data)

backend/src/reflection/resolvers.py

@@ -1,12 +1,12 @@
 from importlib import import_module
-from typing import Type, TypeVar
+from typing import TypeVar
 
 T = TypeVar("T")
 
 
 def resolve_variable[T](
     variable_path: str,
-    expected_type: Type[T] | tuple[Type, ...] | None = None,
+    expected_type: type[T] | tuple[type, ...] | None = None,
 ) -> T:
     """Resolve a variable from a path.
 
@@ -25,9 +25,7 @@ def resolve_variable[T](
     try:
         module_path, variable_name = variable_path.rsplit(":", 1)
     except ValueError as err:
-        raise ImportError(
-            f"{variable_path} doesn't look like a variable path. Example: parent_package_name.sub_package_name.module_name:variable_name"
-        ) from err
+        raise ImportError(f"{variable_path} doesn't look like a variable path. Example: parent_package_name.sub_package_name.module_name:variable_name") from err
 
     try:
         module = import_module(module_path)
@@ -37,26 +35,18 @@ def resolve_variable[T](
     try:
         variable = getattr(module, variable_name)
     except AttributeError as err:
-        raise ImportError(
-            f"Module {module_path} does not define a {variable_name} attribute/class"
-        ) from err
+        raise ImportError(f"Module {module_path} does not define a {variable_name} attribute/class") from err
 
     # Type validation
     if expected_type is not None:
         if not isinstance(variable, expected_type):
-            type_name = (
-                expected_type.__name__
-                if isinstance(expected_type, type)
-                else " or ".join(t.__name__ for t in expected_type)
-            )
-            raise ValueError(
-                f"{variable_path} is not an instance of {type_name}, got {type(variable).__name__}"
-            )
+            type_name = expected_type.__name__ if isinstance(expected_type, type) else " or ".join(t.__name__ for t in expected_type)
+            raise ValueError(f"{variable_path} is not an instance of {type_name}, got {type(variable).__name__}")
 
     return variable
 
 
-def resolve_class(class_path: str, base_class: Type[T] | None = None) -> Type[T]:
+def resolve_class[T](class_path: str, base_class: type[T] | None = None) -> type[T]:
     """Resolve a class from a module path and class name.
 
     Args:

backend/src/sandbox/local/local_sandbox.py

@@ -29,7 +29,7 @@ class LocalSandbox(Sandbox):
         return list_dir(path, max_depth)
 
     def read_file(self, path: str) -> str:
-        with open(path, "r") as f:
+        with open(path) as f:
             return f.read()
 
     def write_file(self, path: str, content: str, append: bool = False) -> None:

backend/uv.lock

@@ -128,6 +128,11 @@ dependencies = [
     { name = "tavily-python" },
 ]
 
+[package.dev-dependencies]
+dev = [
+    { name = "ruff" },
+]
+
 [package.metadata]
 requires-dist = [
     { name = "langchain", specifier = ">=1.2.3" },
@@ -141,6 +146,9 @@ requires-dist = [
     { name = "tavily-python", specifier = ">=0.7.17" },
 ]
 
+[package.metadata.requires-dev]
+dev = [{ name = "ruff", specifier = ">=0.14.11" }]
+
 [[package]]
 name = "distro"
 version = "1.9.0"
@@ -897,6 +905,32 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/3f/51/d4db610ef29373b879047326cbf6fa98b6c1969d6f6dc423279de2b1be2c/requests_toolbelt-1.0.0-py2.py3-none-any.whl", hash = "sha256:cccfdd665f0a24fcf4726e690f65639d272bb0637b9b92dfd91a5568ccf6bd06", size = 54481, upload-time = "2023-05-01T04:11:28.427Z" },
 ]
 
+[[package]]
+name = "ruff"
+version = "0.14.11"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/d4/77/9a7fe084d268f8855d493e5031ea03fa0af8cc05887f638bf1c4e3363eb8/ruff-0.14.11.tar.gz", hash = "sha256:f6dc463bfa5c07a59b1ff2c3b9767373e541346ea105503b4c0369c520a66958", size = 5993417, upload-time = "2026-01-08T19:11:58.322Z" }
+wheels = [
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+]
+
 [[package]]
 name = "six"
 version = "1.17.0"

deer-flow.code-workspace

@@ -0,0 +1,7 @@
+{
+  "folders": [
+    {
+      "path": "backend"
+    }
+  ]
+}