- API Design Guide – detailed explanation of API design principles (en).
- HTTP API Design Guide – set of API design principles, extracted from Heroku API (en).
- REST API: Your Guide to Getting Started Quickly – REST tutorial with Docker and Swagger (en).
- REST Resource Naming Guide – big guide on REST API naming. Whole website worth reading (en).
- REST CookBook – set of problems&solutins for REST API (en).
- Microsoft API guidelines – Microsoft's internal company-wide REST API design guidelines (en).
- Design Guidelines – set of API guidelines of different companies (en).
- Zalando RESTful API and Event Scheme Guidelines – API guidelines from Zalando (en).
- Google API Design Guide – Google API guidelines (en).
- NationalBankBelgium/REST-API-Design-Guide – REST API Design Guide of the National Bank of Belgium (en).
- VictorianGovernment/api-design-standards – Design Standards for Whole of Victorian Government Application Programming Interfaces (en).