fastmcp.client.auth.oauth

Functions

check_if_auth_required ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L41" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

check_if_auth_required(mcp_url: str, httpx_kwargs: dict[str, Any] | None = None) -> bool

Check if the MCP endpoint requires authentication by making a test request.

Returns:

• True if auth appears to be required, False otherwise

Classes

ClientNotFoundError ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L37" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Raised when OAuth client credentials are not found on the server.

TokenStorageAdapter ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L71" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Methods:

clear ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L102" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

clear(self) -> None

get_tokens ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L111" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

get_tokens(self) -> OAuthToken | None

set_tokens ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L115" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

set_tokens(self, tokens: OAuthToken) -> None

get_token_expiry ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L135" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

get_token_expiry(self) -> float | None

get_client_info ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L145" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

get_client_info(self) -> OAuthClientInformationFull | None

set_client_info ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L151" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

set_client_info(self, client_info: OAuthClientInformationFull) -> None

OAuth ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L164" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

OAuth client provider for MCP servers with browser-based authentication.

This class provides OAuth authentication for FastMCP clients by opening a browser for user authorization and running a local callback server.

Methods:

redirect_handler ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L320" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

redirect_handler(self, authorization_url: str) -> None

Open browser for authorization, with pre-flight check for invalid client.

callback_handler ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L341" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

callback_handler(self) -> tuple[str, str | None]

Handle OAuth callback and return (auth_code, state).

async_auth_flow ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/auth/oauth.py#L380" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

async_auth_flow(self, request: httpx.Request) -> AsyncGenerator[httpx.Request, httpx.Response]

HTTPX auth flow with automatic retry on stale cached credentials.

If the OAuth flow fails due to invalid/stale client credentials, clears the cache and retries once with fresh registration.