auth0-fastify

Adds session-based authentication to Fastify web applications using the @auth0/auth0-fastify SDK. It registers login, logout, and callback routes automatically, and provides helpers to check sessions, get user profiles, and retrieve access tokens. For stateless API-only setups, there's a separate auth0-fastify-api skill. It handles the full OAuth redirect flow, session management, and token refresh in a single Fastify plugin registration, so you don't have to wire up callback routes and cookie encryption yourself.