Fix/bearer token usage

CHANGELOG.md

@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.3.2]
+
+### Fixed
+- 🐛 Fix a bug preventing simple setup of [basic token passthrough](docs/03_authentication_and_authorization.md#basic-token-passthrough)
+
 ## [0.3.1]
 
 🚀 FastApiMCP now supports MCP Authorization!

docs/03_authentication_and_authorization.md

@@ -49,6 +49,8 @@ mcp = FastApiMCP(
 mcp.mount()
 ```
 
+For a complete working example of authorization header, check out the [auth_example_token_passthrough.py](/examples/08_auth_example_token_passthrough.py) in the examples folder.
+
 ## OAuth Flow
 
 FastAPI-MCP supports the full OAuth 2 flow, compliant with [MCP Spec 2025-03-26](https://modelcontextprotocol.io/specification/2025-03-26/basic/authorization).
@@ -138,7 +140,7 @@ For this to work, you have to make sure mcp-remote is running [on a fixed port](
 
 ## Working Example with Auth0
 
-For a complete working example of OAuth integration with Auth0, check out the [auth_example_auth0.py](/examples/08_auth_example_auth0.py) in the examples folder. This example demonstrates the simple case of using Auth0 as an OAuth provider, with a working example of the OAuth flow.
+For a complete working example of OAuth integration with Auth0, check out the [auth_example_auth0.py](/examples/09_auth_example_auth0.py) in the examples folder. This example demonstrates the simple case of using Auth0 as an OAuth provider, with a working example of the OAuth flow.
 
 For it to work, you need an .env file in the root of the project with the following variables:
 

examples/08_auth_example_token_passthrough.py

@@ -0,0 +1,58 @@
+"""
+This example shows how to reject any request without a valid token passed in the Authorization header.
+
+In order to configure the auth header, the config file for the MCP server should looks like this:
+```json
+{
+  "mcpServers": {
+    "remote-example": {
+      "command": "npx",
+      "args": [
+        "mcp-remote",
+        "http://localhost:8000/mcp",
+        "--header",
+        "Authorization:${AUTH_HEADER}"
+      ]
+    },
+    "env": {
+      "AUTH_HEADER": "Bearer <your-token>"
+    }
+  }
+}
+```
+"""
+from examples.shared.apps.items import app # The FastAPI app
+from examples.shared.setup import setup_logging
+
+from fastapi import Depends
+from fastapi.security import HTTPBearer
+
+from fastapi_mcp import FastApiMCP, AuthConfig
+
+setup_logging()
+
+# Scheme for the Authorization header
+token_auth_scheme = HTTPBearer()
+
+# Create a private endpoint
+@app.get("/private")
+async def private(token = Depends(token_auth_scheme)):
+    return token.credentials
+
+# Create the MCP server with the token auth scheme
+mcp = FastApiMCP(
+    app,
+    name="Protected MCP",
+    auth_config=AuthConfig(
+        dependencies=[Depends(token_auth_scheme)],
+    ),
+)
+
+# Mount the MCP server
+mcp.mount()
+
+
+if __name__ == "__main__":
+    import uvicorn
+
+    uvicorn.run(app, host="0.0.0.0", port=8000)

fastapi_mcp/types.py

@@ -41,13 +41,13 @@ class OAuthMetadata(BaseType):
     ]
 
     authorization_endpoint: Annotated[
-        StrHttpUrl,
+        Optional[StrHttpUrl],
         Doc(
             """
             URL of the authorization server's authorization endpoint.
             """
         ),
-    ]
+    ] = None
 
     token_endpoint: Annotated[
         StrHttpUrl,
@@ -353,18 +353,15 @@ async def authenticate_request(request: Request, token: str = Depends(oauth2_sch
 
     @model_validator(mode="after")
     def validate_required_fields(self):
-        if self.custom_oauth_metadata is None and self.issuer is None:
-            raise ValueError("'issuer' is required when 'custom_oauth_metadata' is not provided")
+        if self.custom_oauth_metadata is None and self.issuer is None and not self.dependencies:
+            raise ValueError("at least one of 'issuer', 'custom_oauth_metadata' or 'dependencies' is required")
 
         if self.setup_proxies:
             if self.client_id is None:
                 raise ValueError("'client_id' is required when 'setup_proxies' is True")
 
-        if self.setup_fake_dynamic_registration and not self.client_secret:
-            raise ValueError("'client_secret' is required when 'setup_fake_dynamic_registration' is True")
-
-        if self.setup_fake_dynamic_registration and not self.setup_proxies:
-            raise ValueError("'setup_fake_dynamic_registration' can only be True when 'setup_proxies' is True")
+            if self.setup_fake_dynamic_registration and not self.client_secret:
+                raise ValueError("'client_secret' is required when 'setup_fake_dynamic_registration' is True")
 
         return self
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "fastapi-mcp"
-version = "0.3.1"
+version = "0.3.2"
 description = "Automatic MCP server generator for FastAPI applications - converts FastAPI endpoints to MCP tools for LLM integration"
 readme = "README.md"
 requires-python = ">=3.10"

tests/test_types_validation.py

@@ -0,0 +1,111 @@
+import pytest
+from pydantic import ValidationError
+from fastapi import Depends
+
+from fastapi_mcp.types import (
+    OAuthMetadata,
+    AuthConfig,
+)
+
+
+class TestOAuthMetadata:
+    def test_non_empty_lists_validation(self):
+        for field in [
+            "scopes_supported",
+            "response_types_supported",
+            "grant_types_supported",
+            "token_endpoint_auth_methods_supported",
+            "code_challenge_methods_supported",
+        ]:
+            with pytest.raises(ValidationError, match=f"{field} cannot be empty"):
+                OAuthMetadata(
+                    issuer="https://example.com",
+                    authorization_endpoint="https://example.com/auth",
+                    token_endpoint="https://example.com/token",
+                    **{field: []},
+                )
+
+    def test_authorization_endpoint_required_for_authorization_code(self):
+        with pytest.raises(ValidationError) as exc_info:
+            OAuthMetadata(
+                issuer="https://example.com",
+                token_endpoint="https://example.com/token",
+                grant_types_supported=["authorization_code", "client_credentials"],
+            )
+        assert "authorization_endpoint is required when authorization_code grant type is supported" in str(
+            exc_info.value
+        )
+
+        OAuthMetadata(
+            issuer="https://example.com",
+            token_endpoint="https://example.com/token",
+            authorization_endpoint="https://example.com/auth",
+            grant_types_supported=["client_credentials"],
+        )
+
+    def test_model_dump_excludes_none(self):
+        metadata = OAuthMetadata(
+            issuer="https://example.com",
+            authorization_endpoint="https://example.com/auth",
+            token_endpoint="https://example.com/token",
+        )
+
+        dumped = metadata.model_dump()
+
+        assert "registration_endpoint" not in dumped
+
+
+class TestAuthConfig:
+    def test_required_fields_validation(self):
+        with pytest.raises(
+            ValidationError, match="at least one of 'issuer', 'custom_oauth_metadata' or 'dependencies' is required"
+        ):
+            AuthConfig()
+
+        AuthConfig(issuer="https://example.com")
+
+        AuthConfig(
+            custom_oauth_metadata={
+                "issuer": "https://example.com",
+                "authorization_endpoint": "https://example.com/auth",
+                "token_endpoint": "https://example.com/token",
+            },
+        )
+
+        def dummy_dependency():
+            pass
+
+        AuthConfig(dependencies=[Depends(dummy_dependency)])
+
+    def test_client_id_required_for_setup_proxies(self):
+        with pytest.raises(ValidationError, match="'client_id' is required when 'setup_proxies' is True"):
+            AuthConfig(
+                issuer="https://example.com",
+                setup_proxies=True,
+            )
+
+        AuthConfig(
+            issuer="https://example.com",
+            setup_proxies=True,
+            client_id="test-client-id",
+            client_secret="test-client-secret",
+        )
+
+    def test_client_secret_required_for_fake_registration(self):
+        with pytest.raises(
+            ValidationError, match="'client_secret' is required when 'setup_fake_dynamic_registration' is True"
+        ):
+            AuthConfig(
+                issuer="https://example.com",
+                setup_proxies=True,
+                client_id="test-client-id",
+                setup_fake_dynamic_registration=True,
+            )
+
+        AuthConfig(
+            issuer="https://example.com",
+            setup_proxies=True,
+            client_id="test-client-id",
+            client_secret="test-client-secret",
+            setup_fake_dynamic_registration=True,
+        )