Look up any part of an HTTP API
Status codes, headers, methods and RFC 9457 problem types, each on its own page that says when to use it and what to use instead.
Sections
8- ErrorsProblem types to use as the type of an RFC 9457 response.25
- Status codesWhen to send each code, and which one to send instead.63
- HeadersRequest and response headers, with an example line for each.46
- MethodsWhether each method is safe, idempotent and cacheable.18
- GuidesLong-form design guides, from the shape of a resource to what a model makes of it.45
- SpecificationsOpenAPI, AsyncAPI, JSON Schema and the other formats that describe an API.21
- ToolsTools for designing, testing, running and watching an API.35
- Problem+JSONHow RFC 9457 problem responses work, field by field.
Start from the problem
- Rate limiting a client
- 429, Retry-After, Rate limit exceeded
- Reporting validation errors
- 422, Validation failed, Problem+JSON
- Making retries safe
- Idempotency-Key, POST, Idempotency guide
