Fix type-checking error with OAuth

docs/docs.json

@@ -122,7 +122,10 @@
                   {
                     "group": "Essentials",
                     "icon": "cube",
-                    "pages": ["clients/client", "clients/transports"]
+                    "pages": [
+                      "clients/client",
+                      "clients/transports"
+                    ]
                   },
                   {
                     "group": "Core Operations",
@@ -148,7 +151,10 @@
                   {
                     "group": "Authentication",
                     "icon": "user-shield",
-                    "pages": ["clients/auth/oauth", "clients/auth/bearer"]
+                    "pages": [
+                      "clients/auth/oauth",
+                      "clients/auth/bearer"
+                    ]
                   }
                 ]
               },
@@ -194,12 +200,17 @@
           },
           {
             "anchor": "What's New",
-            "pages": ["updates", "changelog"]
+            "pages": [
+              "updates",
+              "changelog"
+            ]
           },
           {
             "anchor": "Community",
             "icon": "users",
-            "pages": ["community/showcase"]
+            "pages": [
+              "community/showcase"
+            ]
           }
         ]
       },

docs/python-sdk/fastmcp-client-auth-oauth.mdx

@@ -7,13 +7,13 @@ sidebarTitle: oauth
 
 ## Functions
 
-### `default_cache_dir` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L34" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+### `default_cache_dir` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L36" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 default_cache_dir() -> Path
 ```
 
-### `check_if_auth_required` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L152" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+### `check_if_auth_required` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L154" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 check_if_auth_required(mcp_url: str, httpx_kwargs: dict[str, Any] | None = None) -> bool
@@ -28,7 +28,7 @@ Check if the MCP endpoint requires authentication by making a test request.
 
 ## Classes
 
-### `FileTokenStorage` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L38" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+### `FileTokenStorage` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L40" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 
 File-based token storage implementation for OAuth credentials and tokens.
@@ -39,7 +39,7 @@ Each instance is tied to a specific server URL for proper token isolation.
 
 **Methods:**
 
-#### `get_base_url` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L53" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `get_base_url` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L55" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 get_base_url(url: str) -> str
@@ -48,7 +48,7 @@ get_base_url(url: str) -> str
 Extract the base URL (scheme + host) from a URL.
 
 
-#### `get_cache_key` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L58" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `get_cache_key` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L60" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 get_cache_key(self) -> str
@@ -57,7 +57,7 @@ get_cache_key(self) -> str
 Generate a safe filesystem key from the server's base URL.
 
 
-#### `get_tokens` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L73" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `get_tokens` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L75" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 get_tokens(self) -> OAuthToken | None
@@ -66,7 +66,7 @@ get_tokens(self) -> OAuthToken | None
 Load tokens from file storage.
 
 
-#### `set_tokens` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L90" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `set_tokens` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L92" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 set_tokens(self, tokens: OAuthToken) -> None
@@ -75,7 +75,7 @@ set_tokens(self, tokens: OAuthToken) -> None
 Save tokens to file storage.
 
 
-#### `get_client_info` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L96" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `get_client_info` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L98" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 get_client_info(self) -> OAuthClientInformationFull | None
@@ -84,7 +84,7 @@ get_client_info(self) -> OAuthClientInformationFull | None
 Load client information from file storage.
 
 
-#### `set_client_info` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L124" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `set_client_info` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L126" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 set_client_info(self, client_info: OAuthClientInformationFull) -> None
@@ -93,7 +93,7 @@ set_client_info(self, client_info: OAuthClientInformationFull) -> None
 Save client information to file storage.
 
 
-#### `clear` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L130" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `clear` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L132" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 clear(self) -> None
@@ -102,7 +102,7 @@ clear(self) -> None
 Clear all cached data for this server.
 
 
-#### `clear_all` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L139" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `clear_all` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L141" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 clear_all(cls, cache_dir: Path | None = None) -> None
@@ -111,7 +111,7 @@ clear_all(cls, cache_dir: Path | None = None) -> None
 Clear all cached data for all servers.
 
 
-### `OAuth` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L182" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+### `OAuth` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L184" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 
 OAuth client provider for MCP servers with browser-based authentication.
@@ -122,7 +122,7 @@ a browser for user authorization and running a local callback server.
 
 **Methods:**
 
-#### `redirect_handler` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L248" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `redirect_handler` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L250" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 redirect_handler(self, authorization_url: str) -> None
@@ -131,7 +131,7 @@ redirect_handler(self, authorization_url: str) -> None
 Open browser for authorization.
 
 
-#### `callback_handler` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L253" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
+#### `callback_handler` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L255" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>
 
 ```python
 callback_handler(self) -> tuple[str, str | None]

src/fastmcp/client/auth/oauth.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import asyncio
 import json
 import webbrowser
+from asyncio import Future
 from pathlib import Path
 from typing import Any, Literal
 from urllib.parse import urlparse
@@ -18,6 +19,7 @@ from mcp.shared.auth import (
     OAuthToken as OAuthToken,
 )
 from pydantic import AnyHttpUrl, ValidationError
+from uvicorn.server import Server
 
 from fastmcp import settings as fastmcp_global_settings
 from fastmcp.client.oauth_callback import (
@@ -253,10 +255,10 @@ class OAuth(OAuthClientProvider):
     async def callback_handler(self) -> tuple[str, str | None]:
         """Handle OAuth callback and return (auth_code, state)."""
         # Create a future to capture the OAuth response
-        response_future = asyncio.get_running_loop().create_future()
+        response_future: Future[Any] = asyncio.get_running_loop().create_future()
 
         # Create server with the future
-        server = create_oauth_callback_server(
+        server: Server = create_oauth_callback_server(
             port=self.redirect_port,
             server_url=self.server_base_url,
             response_future=response_future,
@@ -280,3 +282,5 @@ class OAuth(OAuthClientProvider):
                 server.should_exit = True
                 await asyncio.sleep(0.1)  # Allow server to shutdown gracefully
                 tg.cancel_scope.cancel()
+
+        raise RuntimeError("OAuth callback handler could not be started")