The Repeatability-First-Sent HTTP header — idempotency & reliability, declared by 1 providers in the API Evangelist catalog.
Repeatability-First-Sent
Idempotency & Reliability IANA provisional request 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.
Repeatability-First-Sent is idempotency & reliability — Headers that make a retry safe. Almost entirely a payments-industry invention that the rest of the API economy has not adopted.
The registry
Listed in the IANA HTTP Field Name Registry as a provisional entry — registered, but not through a standards-track document. Defined in Repeatable Requests Version 1.0][OASIS][Chet_Ensign.
In the catalog
Declared by 1 providers across 34 published specification files in the API Evangelist catalog, where it appears as a request header — sent by the client.
It is spelled 2 different ways across those contracts — Repeatability-First-Sent, repeatability-first-sent. 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 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 →