Adds session-based authentication to Fastify web apps using Auth0's official SDK. You get login, logout, and callback routes out of the box, plus helpers to protect routes and grab user data. The setup is straightforward: register the plugin with your Auth0 credentials and session secret, then use preHandler hooks to lock down routes. One thing to watch: this is for server-rendered apps, not SPAs or stateless APIs. If you're building a JWT-validated REST API, you want auth0-fastify-api instead. The quick start is solid and covers the common gotchas like forgetting callback URLs in the Auth0 dashboard.
npx skills add https://github.com/auth0/agent-skills --skill auth0-fastify