Stop an execution

Stop an execution that is still running. Use it when your own process no longer needs the answer — your customer abandoned the journey, the case was closed, a timeout of yours fired. The execution closes as `ABORTED` with `CLIENT_CANCELLED`, which reads as a cancellation and not as a failure anywhere you look at it later. <Note> **Whatever was already retrieved stays readable** until you delete the execution. Aborting also frees the slot immediately, which clears the `409` that blocks a new execution for the same customer and engine. </Note> | Status | Meaning | | :--- | :--- | | `204` | Stopped. No body. | | `304` | It had already closed on its own. Nothing changed — **aborting twice is safe**, and this is the second answer, not an error. | | `404` | No such execution for your application, or it has been deleted. | <Tip> **A paused execution is a good candidate.** One waiting on a challenge your customer will never answer holds nothing useful: abort it rather than letting it reach `ACTION_TIMEOUT` on its own. </Tip> <Note> **Server to server only.** This call is authorised with your application secret: it belongs in your backend, never in a browser, a mobile app or anything your customer can read. </Note>