conflict¶


Title	Status Conflict
HTTP status	`409 Conflict`
`type`	`/errors/conflict`

What triggers it¶

Another request with the same Idempotency-Key is still in flight. The first request won the claim and holds the key in a pending state; a concurrent duplicate that claims the same key is told the request is already being handled (StatusPending) and receives 409 instead of blocking. This matches Stripe's behavior — see Concurrency.

Example response¶

HTTP/1.1 409 Conflict
Content-Type: application/problem+json

{
  "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"
}

What the client should do¶

Retry after a short delay. This is a transient condition: the original request is still running. Once it completes, retrying the same key with the same request will replay the stored response (with Idempotency-Replayed: true) rather than running the side effect again. Back off briefly between retries.