Mock JSON endpoint returning HTTP 409

Live demo endpoint

Any method, any path. Returns 409 Conflict with Content-Type: application/json. OPTIONS returns 204 with CORS headers.

Call it with curl

curl -i https://demo-json-409.supercrontab.com/

Call it with fetch

const res = await fetch("https://demo-json-409.supercrontab.com/");
console.log(res.status); // 409
const body = await res.json();

What HTTP 409 Conflict means

When you see it

The request clashes with current state: a duplicate unique key, a stale version number or a concurrent edit.

What a client should do

Reload the current state, resolve the conflict and resend. Blind retries will keep hitting 409.

Retry?

No

Sample response body

{"ok":true,"id":42,"items":["alpha","beta","gamma"]}

The default for REST APIs. Parse it with response.json() and check the ok field.

Questions