HTTP Reference API
A clean, programmatic reference for HTTP semantics, built on the official IANA registries. Look up any status code with its reason phrase and class (404 → Not Found, Client Error; 503 → Service Unavailable, Server Error), list a whole class (4xx, 5xx…); look up any method with its safe/idempotent flags (GET → safe + idempotent, POST → neither, DELETE → idempotent); or look up / search the 255 registered HTTP header fields (Content-Type, Authorization, …) with their registration status. Ideal for API tooling, HTTP clients, documentation, linters, learning resources and error pages.
api.oanor.com/http-api
