"""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 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.utilities.auth import parse_scopes
from fastmcp.utilities.logging import get_logger
from fastmcp.utilities.storage import KVStorage
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",
extra="ignore",
)
client_id: str | None = None
client_secret: SecretStr | None = None
base_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
@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,
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: KVStorage | None = None,
):
"""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 of your FastMCP server (for OAuth callbacks)
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 implementation for OAuth client registrations.
Defaults to file-based storage if not specified.
"""
settings = GitHubProviderSettings.model_validate(
{
k: v
for k, v in {
"client_id": client_id,
"client_secret": client_secret,
"base_url": base_url,
"redirect_path": redirect_path,
"required_scopes": required_scopes,
"timeout_seconds": timeout_seconds,
"allowed_client_redirect_uris": allowed_client_redirect_uris,
}.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.base_url, # We act as the issuer for client registration
allowed_client_redirect_uris=allowed_client_redirect_uris_final,
client_storage=client_storage,
)
logger.info(
"Initialized GitHub OAuth provider for client %s with scopes: %s",
settings.client_id,
required_scopes_final,
)