"""GitHub OAuth provider for FastMCP. This module provides a complete GitHub OAuth integration that's ready to use with just a client ID and client secret. It handles all the complexity of GitHub's OAuth flow, token validation, and user management. Example: ```python from fastmcp import FastMCP from fastmcp.server.auth.providers.github import GitHubProvider # Simple GitHub OAuth protection auth = GitHubProvider( client_id="your-github-client-id", client_secret="your-github-client-secret" ) mcp = FastMCP("My Protected Server", auth=auth) ``` """ from __future__ import annotations import httpx from key_value.aio.protocols import AsyncKeyValue from pydantic import AnyHttpUrl, SecretStr, field_validator from pydantic_settings import BaseSettings, SettingsConfigDict from fastmcp.server.auth import TokenVerifier from fastmcp.server.auth.auth import AccessToken from fastmcp.server.auth.oauth_proxy import OAuthProxy from fastmcp.settings import ENV_FILE from fastmcp.utilities.auth import parse_scopes from fastmcp.utilities.logging import get_logger from fastmcp.utilities.types import NotSet, NotSetT logger = get_logger(__name__) class GitHubProviderSettings(BaseSettings): """Settings for GitHub OAuth provider.""" model_config = SettingsConfigDict( env_prefix="FASTMCP_SERVER_AUTH_GITHUB_", env_file=ENV_FILE, extra="ignore", ) client_id: str | None = None client_secret: SecretStr | None = None base_url: AnyHttpUrl | str | None = None issuer_url: AnyHttpUrl | str | None = None redirect_path: str | None = None required_scopes: list[str] | None = None timeout_seconds: int | None = None allowed_client_redirect_uris: list[str] | None = None jwt_signing_key: str | None = None @field_validator("required_scopes", mode="before") @classmethod def _parse_scopes(cls, v): return parse_scopes(v) class GitHubTokenVerifier(TokenVerifier): """Token verifier for GitHub OAuth tokens. GitHub OAuth tokens are opaque (not JWTs), so we verify them by calling GitHub's API to check if they're valid and get user info. """ def __init__( self, *, required_scopes: list[str] | None = None, timeout_seconds: int = 10, ): """Initialize the GitHub token verifier. Args: required_scopes: Required OAuth scopes (e.g., ['user:email']) timeout_seconds: HTTP request timeout """ super().__init__(required_scopes=required_scopes) self.timeout_seconds = timeout_seconds async def verify_token(self, token: str) -> AccessToken | None: """Verify GitHub OAuth token by calling GitHub API.""" try: async with httpx.AsyncClient(timeout=self.timeout_seconds) as client: # Get token info from GitHub API response = await client.get( "https://api.github.com/user", headers={ "Authorization": f"Bearer {token}", "Accept": "application/vnd.github.v3+json", "User-Agent": "FastMCP-GitHub-OAuth", }, ) if response.status_code != 200: logger.debug( "GitHub token verification failed: %d - %s", response.status_code, response.text[:200], ) return None user_data = response.json() # Get token scopes from GitHub API # GitHub includes scopes in the X-OAuth-Scopes header scopes_response = await client.get( "https://api.github.com/user/repos", # Any authenticated endpoint headers={ "Authorization": f"Bearer {token}", "Accept": "application/vnd.github.v3+json", "User-Agent": "FastMCP-GitHub-OAuth", }, ) # Extract scopes from X-OAuth-Scopes header if available oauth_scopes_header = scopes_response.headers.get("x-oauth-scopes", "") token_scopes = [ scope.strip() for scope in oauth_scopes_header.split(",") if scope.strip() ] # If no scopes in header, assume basic scopes based on successful user API call if not token_scopes: token_scopes = ["user"] # Basic scope if we can access user info # Check required scopes if self.required_scopes: token_scopes_set = set(token_scopes) required_scopes_set = set(self.required_scopes) if not required_scopes_set.issubset(token_scopes_set): logger.debug( "GitHub token missing required scopes. Has %d, needs %d", len(token_scopes_set), len(required_scopes_set), ) return None # Create AccessToken with GitHub user info return AccessToken( token=token, client_id=str(user_data.get("id", "unknown")), # Use GitHub user ID scopes=token_scopes, expires_at=None, # GitHub tokens don't typically expire claims={ "sub": str(user_data["id"]), "login": user_data.get("login"), "name": user_data.get("name"), "email": user_data.get("email"), "avatar_url": user_data.get("avatar_url"), "github_user_data": user_data, }, ) except httpx.RequestError as e: logger.debug("Failed to verify GitHub token: %s", e) return None except Exception as e: logger.debug("GitHub token verification error: %s", e) return None class GitHubProvider(OAuthProxy): """Complete GitHub OAuth provider for FastMCP. This provider makes it trivial to add GitHub OAuth protection to any FastMCP server. Just provide your GitHub OAuth app credentials and a base URL, and you're ready to go. Features: - Transparent OAuth proxy to GitHub - Automatic token validation via GitHub API - User information extraction - Minimal configuration required Example: ```python from fastmcp import FastMCP from fastmcp.server.auth.providers.github import GitHubProvider auth = GitHubProvider( client_id="Ov23li...", client_secret="abc123...", base_url="https://my-server.com" ) mcp = FastMCP("My App", auth=auth) ``` """ def __init__( self, *, client_id: str | NotSetT = NotSet, client_secret: str | NotSetT = NotSet, base_url: AnyHttpUrl | str | NotSetT = NotSet, issuer_url: AnyHttpUrl | str | NotSetT = NotSet, redirect_path: str | NotSetT = NotSet, required_scopes: list[str] | NotSetT = NotSet, timeout_seconds: int | NotSetT = NotSet, allowed_client_redirect_uris: list[str] | NotSetT = NotSet, client_storage: AsyncKeyValue | None = None, jwt_signing_key: str | bytes | NotSetT = NotSet, require_authorization_consent: bool = True, ): """Initialize GitHub OAuth provider. Args: client_id: GitHub OAuth app client ID (e.g., "Ov23li...") client_secret: GitHub OAuth app client secret base_url: Public URL where OAuth endpoints will be accessible (includes any mount path) issuer_url: Issuer URL for OAuth metadata (defaults to base_url). Use root-level URL to avoid 404s during discovery when mounting under a path. redirect_path: Redirect path configured in GitHub OAuth app (defaults to "/auth/callback") required_scopes: Required GitHub scopes (defaults to ["user"]) timeout_seconds: HTTP request timeout for GitHub API calls allowed_client_redirect_uris: List of allowed redirect URI patterns for MCP clients. If None (default), all URIs are allowed. If empty list, no URIs are allowed. client_storage: Storage backend for OAuth state (client registrations, encrypted tokens). If None, a DiskStore will be created in the data directory (derived from `platformdirs`). The disk store will be encrypted using a key derived from the JWT Signing Key. jwt_signing_key: Secret for signing FastMCP JWT tokens (any string or bytes). If bytes are provided, they will be used as is. If a string is provided, it will be derived into a 32-byte key. If not provided, the upstream client secret will be used to derive a 32-byte key using PBKDF2. require_authorization_consent: Whether to require user consent before authorizing clients (default True). When True, users see a consent screen before being redirected to GitHub. When False, authorization proceeds directly without user confirmation. SECURITY WARNING: Only disable for local development or testing environments. """ settings = GitHubProviderSettings.model_validate( { k: v for k, v in { "client_id": client_id, "client_secret": client_secret, "base_url": base_url, "issuer_url": issuer_url, "redirect_path": redirect_path, "required_scopes": required_scopes, "timeout_seconds": timeout_seconds, "allowed_client_redirect_uris": allowed_client_redirect_uris, "jwt_signing_key": jwt_signing_key, }.items() if v is not NotSet } ) # Validate required settings if not settings.client_id: raise ValueError( "client_id is required - set via parameter or FASTMCP_SERVER_AUTH_GITHUB_CLIENT_ID" ) if not settings.client_secret: raise ValueError( "client_secret is required - set via parameter or FASTMCP_SERVER_AUTH_GITHUB_CLIENT_SECRET" ) # Apply defaults timeout_seconds_final = settings.timeout_seconds or 10 required_scopes_final = settings.required_scopes or ["user"] allowed_client_redirect_uris_final = settings.allowed_client_redirect_uris # Create GitHub token verifier token_verifier = GitHubTokenVerifier( required_scopes=required_scopes_final, timeout_seconds=timeout_seconds_final, ) # Extract secret string from SecretStr client_secret_str = ( settings.client_secret.get_secret_value() if settings.client_secret else "" ) # Initialize OAuth proxy with GitHub endpoints super().__init__( upstream_authorization_endpoint="https://github.com/login/oauth/authorize", upstream_token_endpoint="https://github.com/login/oauth/access_token", upstream_client_id=settings.client_id, upstream_client_secret=client_secret_str, token_verifier=token_verifier, base_url=settings.base_url, redirect_path=settings.redirect_path, issuer_url=settings.issuer_url or settings.base_url, # Default to base_url if not specified allowed_client_redirect_uris=allowed_client_redirect_uris_final, client_storage=client_storage, jwt_signing_key=settings.jwt_signing_key, require_authorization_consent=require_authorization_consent, ) logger.debug( "Initialized GitHub OAuth provider for client %s with scopes: %s", settings.client_id, required_scopes_final, )