{"issuer": "https://mcp.alphavantage.co", "authorization_endpoint": "https://mcp.alphavantage.co/authorize", "token_endpoint": "https://mcp.alphavantage.co/token", "registration_endpoint": "https://mcp.alphavantage.co/register", "scopes_supported": ["alphavantage:read"], "response_types_supported": ["code"], "grant_types_supported": ["authorization_code", "refresh_token"], "code_challenge_methods_supported": ["S256"], "token_endpoint_auth_methods_supported": ["none", "client_secret_basic", "client_secret_post"], "subject_types_supported": ["public"]}