This walks you through implementing OAuth 2.0, OpenID Connect, and JWT authentication from scratch. You get complete server implementations in Node.js, Python, and Java Spring Security, covering authorization code flows, token management, and PKCE for mobile clients. The quick start drops you into a functional Express OAuth server with all the core components. Best practices are solid and opinionated: use PKCE, rotate tokens, never touch implicit flow, keep access tokens short-lived. If you're building authentication for a new app or integrating SSO across microservices, this gives you the security patterns without having to piece together blog posts and RFCs.
npx skills add https://github.com/aj-geddes/useful-ai-prompts --skill oauth-implementation