Merge branch 'main' into auth-metadata

Author: imfing

README.md

@@ -315,27 +315,42 @@ async def long_task(files: list[str], ctx: Context) -> str:
 Authentication can be used by servers that want to expose tools accessing protected resources.
 
 `mcp.server.auth` implements an OAuth 2.0 server interface, which servers can use by
-providing an implementation of the `OAuthServerProvider` protocol.
+providing an implementation of the `OAuthAuthorizationServerProvider` protocol.
 
-```
-mcp = FastMCP("My App",
-        auth_server_provider=MyOAuthServerProvider(),
-        auth=AuthSettings(
-            issuer_url="https://myapp.com",
-            revocation_options=RevocationOptions(
-                enabled=True,
-            ),
-            client_registration_options=ClientRegistrationOptions(
-                enabled=True,
-                valid_scopes=["myscope", "myotherscope"],
-                default_scopes=["myscope"],
-            ),
-            required_scopes=["myscope"],
+```python
+from mcp import FastMCP
+from mcp.server.auth.provider import OAuthAuthorizationServerProvider
+from mcp.server.auth.settings import (
+    AuthSettings,
+    ClientRegistrationOptions,
+    RevocationOptions,
+)
+
+
+class MyOAuthServerProvider(OAuthAuthorizationServerProvider):
+    # See an example on how to implement at `examples/servers/simple-auth`
+    ...
+
+
+mcp = FastMCP(
+    "My App",
+    auth_server_provider=MyOAuthServerProvider(),
+    auth=AuthSettings(
+        issuer_url="https://myapp.com",
+        revocation_options=RevocationOptions(
+            enabled=True,
+        ),
+        client_registration_options=ClientRegistrationOptions(
+            enabled=True,
+            valid_scopes=["myscope", "myotherscope"],
+            default_scopes=["myscope"],
         ),
+        required_scopes=["myscope"],
+    ),
 )
 ```
 
-See [OAuthServerProvider](src/mcp/server/auth/provider.py) for more details.
+See [OAuthAuthorizationServerProvider](src/mcp/server/auth/provider.py) for more details.
 
 ## Running Your Server
 
@@ -462,15 +477,12 @@ For low level server with Streamable HTTP implementations, see:
 - Stateful server: [`examples/servers/simple-streamablehttp/`](examples/servers/simple-streamablehttp/)
 - Stateless server: [`examples/servers/simple-streamablehttp-stateless/`](examples/servers/simple-streamablehttp-stateless/)
 
-
-
 The streamable HTTP transport supports:
 - Stateful and stateless operation modes
 - Resumability with event stores
-- JSON or SSE response formats  
+- JSON or SSE response formats
 - Better scalability for multi-node deployments
 
-
 ### Mounting to an Existing ASGI Server
 
 > **Note**: SSE transport is being superseded by [Streamable HTTP transport](https://modelcontextprotocol.io/specification/2025-03-26/basic/transports#streamable-http).

src/mcp/client/session.py

@@ -116,12 +116,18 @@ def __init__(
         self._message_handler = message_handler or _default_message_handler
 
     async def initialize(self) -> types.InitializeResult:
-        sampling = types.SamplingCapability()
-        roots = types.RootsCapability(
+        sampling = (
+            types.SamplingCapability()
+            if self._sampling_callback is not _default_sampling_callback
+            else None
+        )
+        roots = (
             # TODO: Should this be based on whether we
             # _will_ send notifications, or only whether
             # they're supported?
-            listChanged=True,
+            types.RootsCapability(listChanged=True)
+            if self._list_roots_callback is not _default_list_roots_callback
+            else None
         )
 
         result = await self.send_request(

src/mcp/client/sse.py

@@ -53,7 +53,7 @@ async def sse_client(
 
     async with anyio.create_task_group() as tg:
         try:
-            logger.info(f"Connecting to SSE endpoint: {remove_request_params(url)}")
+            logger.debug(f"Connecting to SSE endpoint: {remove_request_params(url)}")
             async with httpx_client_factory(headers=headers, auth=auth) as client:
                 async with aconnect_sse(
                     client,
@@ -73,7 +73,7 @@ async def sse_reader(
                                 match sse.event:
                                     case "endpoint":
                                         endpoint_url = urljoin(url, sse.data)
-                                        logger.info(
+                                        logger.debug(
                                             f"Received endpoint URL: {endpoint_url}"
                                         )
 
@@ -146,7 +146,7 @@ async def post_writer(endpoint_url: str):
                             await write_stream.aclose()
 
                     endpoint_url = await tg.start(sse_reader)
-                    logger.info(
+                    logger.debug(
                         f"Starting post writer with endpoint URL: {endpoint_url}"
                     )
                     tg.start_soon(post_writer, endpoint_url)

src/mcp/client/stdio/__init__.py

@@ -108,20 +108,28 @@ async def stdio_client(server: StdioServerParameters, errlog: TextIO = sys.stder
     read_stream_writer, read_stream = anyio.create_memory_object_stream(0)
     write_stream, write_stream_reader = anyio.create_memory_object_stream(0)
 
-    command = _get_executable_command(server.command)
-
-    # Open process with stderr piped for capture
-    process = await _create_platform_compatible_process(
-        command=command,
-        args=server.args,
-        env=(
-            {**get_default_environment(), **server.env}
-            if server.env is not None
-            else get_default_environment()
-        ),
-        errlog=errlog,
-        cwd=server.cwd,
-    )
+    try:
+        command = _get_executable_command(server.command)
+
+        # Open process with stderr piped for capture
+        process = await _create_platform_compatible_process(
+            command=command,
+            args=server.args,
+            env=(
+                {**get_default_environment(), **server.env}
+                if server.env is not None
+                else get_default_environment()
+            ),
+            errlog=errlog,
+            cwd=server.cwd,
+        )
+    except OSError:
+        # Clean up streams if process creation fails
+        await read_stream.aclose()
+        await write_stream.aclose()
+        await read_stream_writer.aclose()
+        await write_stream_reader.aclose()
+        raise
 
     async def stdout_reader():
         assert process.stdout, "Opened process is missing stdout"
@@ -177,12 +185,18 @@ async def stdin_writer():
             yield read_stream, write_stream
         finally:
             # Clean up process to prevent any dangling orphaned processes
-            if sys.platform == "win32":
-                await terminate_windows_process(process)
-            else:
-                process.terminate()
+            try:
+                if sys.platform == "win32":
+                    await terminate_windows_process(process)
+                else:
+                    process.terminate()
+            except ProcessLookupError:
+                # Process already exited, which is fine
+                pass
             await read_stream.aclose()
             await write_stream.aclose()
+            await read_stream_writer.aclose()
+            await write_stream_reader.aclose()
 
 
 def _get_executable_command(command: str) -> str:

src/mcp/client/streamable_http.py

@@ -463,7 +463,7 @@ async def streamablehttp_client(
 
     async with anyio.create_task_group() as tg:
         try:
-            logger.info(f"Connecting to StreamableHTTP endpoint: {url}")
+            logger.debug(f"Connecting to StreamableHTTP endpoint: {url}")
 
             async with httpx_client_factory(
                 headers=transport.request_headers,

src/mcp/server/fastmcp/server.py

@@ -49,7 +49,7 @@
 from mcp.server.stdio import stdio_server
 from mcp.server.streamable_http import EventStore
 from mcp.server.streamable_http_manager import StreamableHTTPSessionManager
-from mcp.shared.context import LifespanContextT, RequestContext
+from mcp.shared.context import LifespanContextT, RequestContext, RequestT
 from mcp.types import (
     AnyFunction,
     EmbeddedResource,
@@ -124,9 +124,11 @@ class Settings(BaseSettings, Generic[LifespanResultT]):
 def lifespan_wrapper(
     app: FastMCP,
     lifespan: Callable[[FastMCP], AbstractAsyncContextManager[LifespanResultT]],
-) -> Callable[[MCPServer[LifespanResultT]], AbstractAsyncContextManager[object]]:
+) -> Callable[
+    [MCPServer[LifespanResultT, Request]], AbstractAsyncContextManager[object]
+]:
     @asynccontextmanager
-    async def wrap(s: MCPServer[LifespanResultT]) -> AsyncIterator[object]:
+    async def wrap(s: MCPServer[LifespanResultT, Request]) -> AsyncIterator[object]:
         async with lifespan(app) as context:
             yield context
 
@@ -260,7 +262,7 @@ async def list_tools(self) -> list[MCPTool]:
             for info in tools
         ]
 
-    def get_context(self) -> Context[ServerSession, object]:
+    def get_context(self) -> Context[ServerSession, object, Request]:
         """
         Returns a Context object. Note that the context will only be valid
         during a request; outside a request, most methods will error.
@@ -917,7 +919,7 @@ def _convert_to_content(
     return [TextContent(type="text", text=result)]
 
 
-class Context(BaseModel, Generic[ServerSessionT, LifespanContextT]):
+class Context(BaseModel, Generic[ServerSessionT, LifespanContextT, RequestT]):
     """Context object providing access to MCP capabilities.
 
     This provides a cleaner interface to MCP's RequestContext functionality.
@@ -951,13 +953,15 @@ def my_tool(x: int, ctx: Context) -> str:
     The context is optional - tools that don't need it can omit the parameter.
     """
 
-    _request_context: RequestContext[ServerSessionT, LifespanContextT] | None
+    _request_context: RequestContext[ServerSessionT, LifespanContextT, RequestT] | None
     _fastmcp: FastMCP | None
 
     def __init__(
         self,
         *,
-        request_context: RequestContext[ServerSessionT, LifespanContextT] | None = None,
+        request_context: (
+            RequestContext[ServerSessionT, LifespanContextT, RequestT] | None
+        ) = None,
         fastmcp: FastMCP | None = None,
         **kwargs: Any,
     ):
@@ -973,7 +977,9 @@ def fastmcp(self) -> FastMCP:
         return self._fastmcp
 
     @property
-    def request_context(self) -> RequestContext[ServerSessionT, LifespanContextT]:
+    def request_context(
+        self,
+    ) -> RequestContext[ServerSessionT, LifespanContextT, RequestT]:
         """Access to the underlying request context."""
         if self._request_context is None:
             raise ValueError("Context is not available outside of a request")

src/mcp/server/fastmcp/tools/base.py

@@ -14,7 +14,7 @@
 if TYPE_CHECKING:
     from mcp.server.fastmcp.server import Context
     from mcp.server.session import ServerSessionT
-    from mcp.shared.context import LifespanContextT
+    from mcp.shared.context import LifespanContextT, RequestT
 
 
 class Tool(BaseModel):
@@ -85,7 +85,7 @@ def from_function(
     async def run(
         self,
         arguments: dict[str, Any],
-        context: Context[ServerSessionT, LifespanContextT] | None = None,
+        context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None,
     ) -> Any:
         """Run the tool with arguments."""
         try:

src/mcp/server/fastmcp/tools/tool_manager.py

@@ -6,7 +6,7 @@
 from mcp.server.fastmcp.exceptions import ToolError
 from mcp.server.fastmcp.tools.base import Tool
 from mcp.server.fastmcp.utilities.logging import get_logger
-from mcp.shared.context import LifespanContextT
+from mcp.shared.context import LifespanContextT, RequestT
 from mcp.types import ToolAnnotations
 
 if TYPE_CHECKING:
@@ -65,7 +65,7 @@ async def call_tool(
         self,
         name: str,
         arguments: dict[str, Any],
-        context: Context[ServerSessionT, LifespanContextT] | None = None,
+        context: Context[ServerSessionT, LifespanContextT, RequestT] | None = None,
     ) -> Any:
         """Call a tool by name with arguments."""
         tool = self.get_tool(name)

src/mcp/server/lowlevel/server.py

@@ -72,11 +72,12 @@ async def main():
 import warnings
 from collections.abc import AsyncIterator, Awaitable, Callable, Iterable
 from contextlib import AbstractAsyncContextManager, AsyncExitStack, asynccontextmanager
-from typing import Any, Generic, TypeVar
+from typing import Any, Generic
 
 import anyio
 from anyio.streams.memory import MemoryObjectReceiveStream, MemoryObjectSendStream
 from pydantic import AnyUrl
+from typing_extensions import TypeVar
 
 import mcp.types as types
 from mcp.server.lowlevel.helper_types import ReadResourceContents
@@ -85,15 +86,16 @@ async def main():
 from mcp.server.stdio import stdio_server as stdio_server
 from mcp.shared.context import RequestContext
 from mcp.shared.exceptions import McpError
-from mcp.shared.message import SessionMessage
+from mcp.shared.message import ServerMessageMetadata, SessionMessage
 from mcp.shared.session import RequestResponder
 
 logger = logging.getLogger(__name__)
 
 LifespanResultT = TypeVar("LifespanResultT")
+RequestT = TypeVar("RequestT", default=Any)
 
 # This will be properly typed in each Server instance's context
-request_ctx: contextvars.ContextVar[RequestContext[ServerSession, Any]] = (
+request_ctx: contextvars.ContextVar[RequestContext[ServerSession, Any, Any]] = (
     contextvars.ContextVar("request_ctx")
 )
 
@@ -111,7 +113,7 @@ def __init__(
 
 
 @asynccontextmanager
-async def lifespan(server: Server[LifespanResultT]) -> AsyncIterator[object]:
+async def lifespan(server: Server[LifespanResultT, RequestT]) -> AsyncIterator[object]:
     """Default lifespan context manager that does nothing.
 
     Args:
@@ -123,14 +125,15 @@ async def lifespan(server: Server[LifespanResultT]) -> AsyncIterator[object]:
     yield {}
 
 
-class Server(Generic[LifespanResultT]):
+class Server(Generic[LifespanResultT, RequestT]):
     def __init__(
         self,
         name: str,
         version: str | None = None,
         instructions: str | None = None,
         lifespan: Callable[
-            [Server[LifespanResultT]], AbstractAsyncContextManager[LifespanResultT]
+            [Server[LifespanResultT, RequestT]],
+            AbstractAsyncContextManager[LifespanResultT],
         ] = lifespan,
     ):
         self.name = name
@@ -215,7 +218,9 @@ def get_capabilities(
         )
 
     @property
-    def request_context(self) -> RequestContext[ServerSession, LifespanResultT]:
+    def request_context(
+        self,
+    ) -> RequestContext[ServerSession, LifespanResultT, RequestT]:
         """If called outside of a request context, this will raise a LookupError."""
         return request_ctx.get()
 
@@ -555,6 +560,13 @@ async def _handle_request(
 
             token = None
             try:
+                # Extract request context from message metadata
+                request_data = None
+                if message.message_metadata is not None and isinstance(
+                    message.message_metadata, ServerMessageMetadata
+                ):
+                    request_data = message.message_metadata.request_context
+
                 # Set our global state that can be retrieved via
                 # app.get_request_context()
                 token = request_ctx.set(
@@ -563,6 +575,7 @@ async def _handle_request(
                         message.request_meta,
                         session,
                         lifespan_context,
+                        request=request_data,
                     )
                 )
                 response = await handler(req)