How AI is applied across API Evangelist and APIs.io. Read my AI disclosure →
API Evangelist API Evangelist
Discovery
Learnings
Guidance
Toolbox
Alignment
API Evangelist LLC

RateLimit-Policy

Rate Limiting & Quota de facto — unregistered response 2 spellings

A reference entry. The registry facts and catalog measurements below are complete; the written guidance for this header has not been authored yet.

The RateLimit-Policy HTTP header — rate limiting & quota, declared by 27 providers in the API Evangelist catalog.

RateLimit-Policy is rate limiting & quota — Headers that tell a caller where it stands against a limit. Documented limits give you the ceiling; these tell you your altitude.

The registry

Not registered with IANA. It is a de facto or vendor field — real, widely used, and governed by nothing but convention.

In the catalog

Declared by 27 providers across 5,388 published specification files in the API Evangelist catalog, where it appears as a response header — sent by the server.

It is spelled 2 different ways across those contracts — RateLimit-Policy, ratelimit-policy. HTTP field names are case-insensitive (RFC 9110, §5.1), so every one of these is the same header. They are not the same string, which is why generated clients disagree about it.

Governed by these rules

Machine-enforceable governance rules from rules.apievangelist.com that apply to this header when it appears in an OpenAPI.

OpenAPI Components Headers Error error

Utilizing the headers object in the centralized OpenAPI components library helps make headers reusable across API requests and responses

Guidance: Rate Limits →
OpenAPI Components Headers Info info

Utilizing the headers object in the centralized OpenAPI components library helps make headers reusable across API requests and responses

Guidance: Rate Limits →
OpenAPI Components Headers Rate Limit Error error

Utilizing centralized headers rate limits allows you to reuse headers across all API requests and responses, enabling a more organized approach to handling the transport and rate limits applied consistently across all...

Guidance: Rate Limits →
OpenAPI Components Headers Rate Limit Info info

Utilizing centralized headers rate limits allows you to reuse headers across all API requests and responses, enabling a more organized approach to handling the transport and rate limits applied consistently across all...

Guidance: Rate Limits →
OpenAPI Headers Hyphenated Pascal Case error

HTTP headers should follow Hyphenated-Pascal-Case naming convention for consistency and readability, such as Content-Type, X-Request-Id, or Accept-Language.

Guidance: Naming →
OpenAPI Response RateLimit Headers error

API responses must include the standard rate limit header trio (ratelimit-limit, ratelimit-remaining, ratelimit-reset) to inform consumers of their current usage against rate limits.

Guidance: Errors →