This is a comprehensive prompt for designing APIs with Claude that covers the fundamentals you'd expect: versioning, REST conventions, error handling, authentication patterns. It pushes you toward OpenAPI documentation and includes specific guidance on pagination, rate limiting, and security headers. The prompt is thorough but reads more like a reference checklist than an opinionated framework. If you're starting an API from scratch or need Claude to maintain consistency across endpoints, it'll keep you from forgetting the basics. The 28 GitHub stars suggest it's relatively new, but it passed all three security audits, so the prompt itself is clean.
npx skills add https://github.com/daffy0208/ai-dev-standards --skill api-designer