FastAPI + FastMCP OAuth Authentication with Scalekit

You can validate OAuth 2.1 Bearer tokens in FastAPI middleware by implementing issuer and audience validation. This Skill uses the Scalekit SDK to enforce token authentication and protect endpoints in production deployments.

An OAuth 2.1 protected resource metadata endpoint, located at /.well-known/oauth-protected-resource, enables client discovery. It is needed for clients to automatically find token issuance and validation details when connecting to MCP servers.

Yes, FastMCP supports plug-and-play tool integration with authenticated context. This Skill secures multi-tenant MCP services by applying FastAPI middleware that validates Bearer tokens and enforces scope-based access.

The Scalekit SDK validates issuer and audience claims directly within FastAPI middleware. It intercepts requests, verifies the Bearer token against configured OAuth authorities, and blocks unauthorized access to MCP endpoints.

FastAPI works with FastMCP to provide authenticated context for custom tools via middleware-based enforcement. After validating Bearer tokens, the FastMCP tool registration enables plug-and-play MCP tools with secure token handling.

The best way to secure a multi-tenant MCP server is using FastAPI middleware with Scalekit SDK. This approach validates OAuth 2.1 Bearer tokens, enforces scope-based access, and generates audit-ready traces for production.