Summary Why a Haufe API Styleguide Introduction General Guidlines Designing APIs API Design Principles API Design Process API Design Review Process API Documentation Using REST REST Principles Hypermedia and REST Hypermedia Formats Using HTTP URI Components and Versioning Filtering, sorting, field selection and paging Search HTTP Verbs HTTP Status Codes Error handling Caching Respresenting Resources Resources Relationships and Sub-Resources Resource Collections Resource Schema and Postels Law Resource Type Formatting Managing APIs Security and Authentication Authorization API Management Azure API Management Haufe OSS API Management API Management Scenarios API Gateways The Forwarded header API Portals Automating API Deployments Appendix FAQ Further Reading