Error reference

When something prevents the middleware from handling an idempotent request, it responds with an RFC 9457 application/problem+json body:

{
  "type": "https://eben-vranken.github.io/idempo-docs/errors/conflict/",
  "title": "Status Conflict",
  "status": 409,
  "detail": "Another request is already handing this request.",
  "instance": "/charge"
}

The fields are:

Field	Meaning
type	A URL identifying the error class. It resolves to the matching page in this reference (one page per error below).
title	A short, human-readable summary of the error class.
status	The HTTP status code, repeated in the body.
detail	A human-readable explanation specific to this occurrence.
instance	The request path that produced the error (r.URL.Path).

The Content-Type of these responses is application/problem+json.

The errors

type path	HTTP status	When it happens
/errors/key-too-long	400 Bad Request	Idempotency-Key header exceeds 255 characters
/errors/content-too-large	413 Content Too Large	request body exceeds MaxBodyBytes
/errors/conflict	409 Conflict	another request with the same key is in flight
/errors/body-mismatch	422 Unprocessable Entity	key reused with a different request
/errors/internal-server-error	500 Internal Server Error	store unavailable / claim failed

About the type URLs

In the current library source the type URLs are https://demo.com/errors/<code> placeholders. They are slated to be swapped to point at this documentation site, so each <code> resolves at /errors/<code>/ here. The HTTP status, title, and detail text on each page are quoted verbatim from the library.