Add pyright strict mode on the whole project (#1254)

Author: Kludex

.github/workflows/shared.yml

@@ -6,6 +6,9 @@ on:
 permissions:
   contents: read
 
+env:
+  COLUMNS: 150
+
 jobs:
   pre-commit:
     runs-on: ubuntu-latest

README.md

@@ -197,6 +197,7 @@ from contextlib import asynccontextmanager
 from dataclasses import dataclass
 
 from mcp.server.fastmcp import Context, FastMCP
+from mcp.server.session import ServerSession
 
 
 # Mock database class for example
@@ -242,7 +243,7 @@ mcp = FastMCP("My App", lifespan=app_lifespan)
 
 # Access type-safe lifespan context in tools
 @mcp.tool()
-def query_db(ctx: Context) -> str:
+def query_db(ctx: Context[ServerSession, AppContext]) -> str:
     """Tool that uses initialized resources."""
     db = ctx.request_context.lifespan_context.db
     return db.query()
@@ -314,12 +315,13 @@ Tools can optionally receive a Context object by including a parameter with the
 <!-- snippet-source examples/snippets/servers/tool_progress.py -->
 ```python
 from mcp.server.fastmcp import Context, FastMCP
+from mcp.server.session import ServerSession
 
 mcp = FastMCP(name="Progress Example")
 
 
 @mcp.tool()
-async def long_running_task(task_name: str, ctx: Context, steps: int = 5) -> str:
+async def long_running_task(task_name: str, ctx: Context[ServerSession, None], steps: int = 5) -> str:
     """Execute a task with progress updates."""
     await ctx.info(f"Starting: {task_name}")
 
@@ -445,7 +447,7 @@ def get_user(user_id: str) -> UserProfile:
 
 # Classes WITHOUT type hints cannot be used for structured output
 class UntypedConfig:
-    def __init__(self, setting1, setting2):
+    def __init__(self, setting1, setting2):  # type: ignore[reportMissingParameterType]
         self.setting1 = setting1
         self.setting2 = setting2
 
@@ -571,12 +573,13 @@ The Context object provides the following capabilities:
 <!-- snippet-source examples/snippets/servers/tool_progress.py -->
 ```python
 from mcp.server.fastmcp import Context, FastMCP
+from mcp.server.session import ServerSession
 
 mcp = FastMCP(name="Progress Example")
 
 
 @mcp.tool()
-async def long_running_task(task_name: str, ctx: Context, steps: int = 5) -> str:
+async def long_running_task(task_name: str, ctx: Context[ServerSession, None], steps: int = 5) -> str:
     """Execute a task with progress updates."""
     await ctx.info(f"Starting: {task_name}")
 
@@ -694,6 +697,7 @@ Request additional information from users. This example shows an Elicitation dur
 from pydantic import BaseModel, Field
 
 from mcp.server.fastmcp import Context, FastMCP
+from mcp.server.session import ServerSession
 
 mcp = FastMCP(name="Elicitation Example")
 
@@ -709,12 +713,7 @@ class BookingPreferences(BaseModel):
 
 
 @mcp.tool()
-async def book_table(
-    date: str,
-    time: str,
-    party_size: int,
-    ctx: Context,
-) -> str:
+async def book_table(date: str, time: str, party_size: int, ctx: Context[ServerSession, None]) -> str:
     """Book a table with date availability check."""
     # Check if date is available
     if date == "2024-12-25":
@@ -750,13 +749,14 @@ Tools can interact with LLMs through sampling (generating text):
 <!-- snippet-source examples/snippets/servers/sampling.py -->
 ```python
 from mcp.server.fastmcp import Context, FastMCP
+from mcp.server.session import ServerSession
 from mcp.types import SamplingMessage, TextContent
 
 mcp = FastMCP(name="Sampling Example")
 
 
 @mcp.tool()
-async def generate_poem(topic: str, ctx: Context) -> str:
+async def generate_poem(topic: str, ctx: Context[ServerSession, None]) -> str:
     """Generate a poem using LLM sampling."""
     prompt = f"Write a short poem about {topic}"
 
@@ -785,12 +785,13 @@ Tools can send logs and notifications through the context:
 <!-- snippet-source examples/snippets/servers/notifications.py -->
 ```python
 from mcp.server.fastmcp import Context, FastMCP
+from mcp.server.session import ServerSession
 
 mcp = FastMCP(name="Notifications Example")
 
 
 @mcp.tool()
-async def process_data(data: str, ctx: Context) -> str:
+async def process_data(data: str, ctx: Context[ServerSession, None]) -> str:
     """Process data with logging."""
     # Different log levels
     await ctx.debug(f"Debug: Processing '{data}'")
@@ -1244,6 +1245,7 @@ Run from the repository root:
 
 from collections.abc import AsyncIterator
 from contextlib import asynccontextmanager
+from typing import Any
 
 import mcp.server.stdio
 import mcp.types as types
@@ -1272,7 +1274,7 @@ class Database:
 
 
 @asynccontextmanager
-async def server_lifespan(_server: Server) -> AsyncIterator[dict]:
+async def server_lifespan(_server: Server) -> AsyncIterator[dict[str, Any]]:
     """Manage server startup and shutdown lifecycle."""
     # Initialize resources on startup
     db = await Database.connect()
@@ -1304,7 +1306,7 @@ async def handle_list_tools() -> list[types.Tool]:
 
 
 @server.call_tool()
-async def query_db(name: str, arguments: dict) -> list[types.TextContent]:
+async def query_db(name: str, arguments: dict[str, Any]) -> list[types.TextContent]:
     """Handle database query tool call."""
     if name != "query_db":
         raise ValueError(f"Unknown tool: {name}")
@@ -1558,7 +1560,7 @@ server_params = StdioServerParameters(
 
 # Optional: create a sampling callback
 async def handle_sampling_message(
-    context: RequestContext, params: types.CreateMessageRequestParams
+    context: RequestContext[ClientSession, None], params: types.CreateMessageRequestParams
 ) -> types.CreateMessageResult:
     print(f"Sampling request: {params.messages}")
     return types.CreateMessageResult(

examples/clients/simple-auth-client/mcp_simple_auth_client/main.py

@@ -188,9 +188,7 @@ async def _default_redirect_handler(authorization_url: str) -> None:
             # Create OAuth authentication handler using the new interface
             oauth_auth = OAuthClientProvider(
                 server_url=self.server_url.replace("/mcp", ""),
-                client_metadata=OAuthClientMetadata.model_validate(
-                    client_metadata_dict
-                ),
+                client_metadata=OAuthClientMetadata.model_validate(client_metadata_dict),
                 storage=InMemoryTokenStorage(),
                 redirect_handler=_default_redirect_handler,
                 callback_handler=callback_handler,
@@ -322,9 +320,7 @@ async def interactive_loop(self):
                     await self.call_tool(tool_name, arguments)
 
                 else:
-                    print(
-                        "❌ Unknown command. Try 'list', 'call <tool_name>', or 'quit'"
-                    )
+                    print("❌ Unknown command. Try 'list', 'call <tool_name>', or 'quit'")
 
             except KeyboardInterrupt:
                 print("\n\n👋 Goodbye!")

examples/clients/simple-auth-client/pyproject.toml

@@ -39,7 +39,7 @@ select = ["E", "F", "I"]
 ignore = []
 
 [tool.ruff]
-line-length = 88
+line-length = 120
 target-version = "py310"
 
 [tool.uv]

examples/clients/simple-chatbot/mcp_simple_chatbot/main.py

@@ -12,9 +12,7 @@
 from mcp.client.stdio import stdio_client
 
 # Configure logging
-logging.basicConfig(
-    level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s"
-)
+logging.basicConfig(level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s")
 
 
 class Configuration:
@@ -75,29 +73,19 @@ def __init__(self, name: str, config: dict[str, Any]) -> None:
 
     async def initialize(self) -> None:
         """Initialize the server connection."""
-        command = (
-            shutil.which("npx")
-            if self.config["command"] == "npx"
-            else self.config["command"]
-        )
+        command = shutil.which("npx") if self.config["command"] == "npx" else self.config["command"]
         if command is None:
             raise ValueError("The command must be a valid string and cannot be None.")
 
         server_params = StdioServerParameters(
             command=command,
             args=self.config["args"],
-            env={**os.environ, **self.config["env"]}
-            if self.config.get("env")
-            else None,
+            env={**os.environ, **self.config["env"]} if self.config.get("env") else None,
         )
         try:
-            stdio_transport = await self.exit_stack.enter_async_context(
-                stdio_client(server_params)
-            )
+            stdio_transport = await self.exit_stack.enter_async_context(stdio_client(server_params))
             read, write = stdio_transport
-            session = await self.exit_stack.enter_async_context(
-                ClientSession(read, write)
-            )
+            session = await self.exit_stack.enter_async_context(ClientSession(read, write))
             await session.initialize()
             self.session = session
         except Exception as e:
@@ -122,10 +110,7 @@ async def list_tools(self) -> list[Any]:
 
         for item in tools_response:
             if isinstance(item, tuple) and item[0] == "tools":
-                tools.extend(
-                    Tool(tool.name, tool.description, tool.inputSchema, tool.title)
-                    for tool in item[1]
-                )
+                tools.extend(Tool(tool.name, tool.description, tool.inputSchema, tool.title) for tool in item[1])
 
         return tools
 
@@ -164,9 +149,7 @@ async def execute_tool(
 
             except Exception as e:
                 attempt += 1
-                logging.warning(
-                    f"Error executing tool: {e}. Attempt {attempt} of {retries}."
-                )
+                logging.warning(f"Error executing tool: {e}. Attempt {attempt} of {retries}.")
                 if attempt < retries:
                     logging.info(f"Retrying in {delay} seconds...")
                     await asyncio.sleep(delay)
@@ -209,9 +192,7 @@ def format_for_llm(self) -> str:
         args_desc = []
         if "properties" in self.input_schema:
             for param_name, param_info in self.input_schema["properties"].items():
-                arg_desc = (
-                    f"- {param_name}: {param_info.get('description', 'No description')}"
-                )
+                arg_desc = f"- {param_name}: {param_info.get('description', 'No description')}"
                 if param_name in self.input_schema.get("required", []):
                     arg_desc += " (required)"
                 args_desc.append(arg_desc)
@@ -281,10 +262,7 @@ def get_response(self, messages: list[dict[str, str]]) -> str:
                 logging.error(f"Status code: {status_code}")
                 logging.error(f"Response details: {e.response.text}")
 
-            return (
-                f"I encountered an error: {error_message}. "
-                "Please try again or rephrase your request."
-            )
+            return f"I encountered an error: {error_message}. Please try again or rephrase your request."
 
 
 class ChatSession:
@@ -323,17 +301,13 @@ async def process_llm_response(self, llm_response: str) -> str:
                     tools = await server.list_tools()
                     if any(tool.name == tool_call["tool"] for tool in tools):
                         try:
-                            result = await server.execute_tool(
-                                tool_call["tool"], tool_call["arguments"]
-                            )
+                            result = await server.execute_tool(tool_call["tool"], tool_call["arguments"])
 
                             if isinstance(result, dict) and "progress" in result:
                                 progress = result["progress"]
                                 total = result["total"]
                                 percentage = (progress / total) * 100
-                                logging.info(
-                                    f"Progress: {progress}/{total} ({percentage:.1f}%)"
-                                )
+                                logging.info(f"Progress: {progress}/{total} ({percentage:.1f}%)")
 
                             return f"Tool execution result: {result}"
                         except Exception as e:
@@ -408,9 +382,7 @@ async def start(self) -> None:
 
                         final_response = self.llm_client.get_response(messages)
                         logging.info("\nFinal response: %s", final_response)
-                        messages.append(
-                            {"role": "assistant", "content": final_response}
-                        )
+                        messages.append({"role": "assistant", "content": final_response})
                     else:
                         messages.append({"role": "assistant", "content": llm_response})
 
@@ -426,10 +398,7 @@ async def main() -> None:
     """Initialize and run the chat session."""
     config = Configuration()
     server_config = config.load_config("servers_config.json")
-    servers = [
-        Server(name, srv_config)
-        for name, srv_config in server_config["mcpServers"].items()
-    ]
+    servers = [Server(name, srv_config) for name, srv_config in server_config["mcpServers"].items()]
     llm_client = LLMClient(config.llm_api_key)
     chat_session = ChatSession(servers, llm_client)
     await chat_session.start()

examples/clients/simple-chatbot/pyproject.toml

@@ -41,7 +41,7 @@ select = ["E", "F", "I"]
 ignore = []
 
 [tool.ruff]
-line-length = 88
+line-length = 120
 target-version = "py310"
 
 [tool.uv]

examples/servers/simple-auth/mcp_simple_auth/server.py

@@ -45,7 +45,8 @@ class ResourceServerSettings(BaseSettings):
     # RFC 8707 resource validation
     oauth_strict: bool = False
 
-    def __init__(self, **data):
+    # TODO(Marcelo): Is this even needed? I didn't have time to check.
+    def __init__(self, **data: Any):
         """Initialize settings with values from environment variables."""
         super().__init__(**data)
 

examples/servers/simple-auth/mcp_simple_auth/simple_auth_provider.py

@@ -46,7 +46,7 @@ class SimpleAuthSettings(BaseSettings):
     mcp_scope: str = "user"
 
 
-class SimpleOAuthProvider(OAuthAuthorizationServerProvider):
+class SimpleOAuthProvider(OAuthAuthorizationServerProvider[AuthorizationCode, RefreshToken, AccessToken]):
     """
     Simple OAuth provider for demo purposes.
 
@@ -116,7 +116,7 @@ async def get_login_page(self, state: str) -> HTMLResponse:
             <p>This is a simplified authentication demo. Use the demo credentials below:</p>
             <p><strong>Username:</strong> demo_user<br>
             <strong>Password:</strong> demo_password</p>
-            
+
             <form action="{self.server_url.rstrip("/")}/login/callback" method="post">
                 <input type="hidden" name="state" value="{state}">
                 <div class="form-group">
@@ -264,7 +264,8 @@ async def exchange_refresh_token(
         """Exchange refresh token - not supported in this example."""
         raise NotImplementedError("Refresh tokens not supported")
 
-    async def revoke_token(self, token: str, token_type_hint: str | None = None) -> None:
+    # TODO(Marcelo): The type hint is wrong. We need to fix, and test to check if it works.
+    async def revoke_token(self, token: str, token_type_hint: str | None = None) -> None:  # type: ignore
         """Revoke a token."""
         if token in self.tokens:
             del self.tokens[token]

examples/servers/simple-auth/mcp_simple_auth/token_verifier.py

@@ -1,6 +1,7 @@
 """Example token verifier implementation using OAuth 2.0 Token Introspection (RFC 7662)."""
 
 import logging
+from typing import Any
 
 from mcp.server.auth.provider import AccessToken, TokenVerifier
 from mcp.shared.auth_utils import check_resource_allowed, resource_url_from_server_url
@@ -79,13 +80,13 @@ async def verify_token(self, token: str) -> AccessToken | None:
                 logger.warning(f"Token introspection failed: {e}")
                 return None
 
-    def _validate_resource(self, token_data: dict) -> bool:
+    def _validate_resource(self, token_data: dict[str, Any]) -> bool:
         """Validate token was issued for this resource server."""
         if not self.server_url or not self.resource_url:
             return False  # Fail if strict validation requested but URLs missing
 
         # Check 'aud' claim first (standard JWT audience)
-        aud = token_data.get("aud")
+        aud: list[str] | str | None = token_data.get("aud")
         if isinstance(aud, list):
             for audience in aud:
                 if self._is_valid_resource(audience):