Higgsfield cancel queued request: 202 or 400, and the Sume match

Higgsfield lets you cancel a request only while it is still queued: POST /requests/{request_id}/cancel returns 202 when the request was canceled and 400 once processing has started. Sume works the same way in spirit. POST /v1/jobs/{id}/cancel succeeds only before generation work starts, and after that it returns 409 job_generation_already_started with details.cancelable: false.

The two cancel contracts side by side

The two APIs agree on the rule and differ on the status codes and the lookup rules. Higgsfield's cancel page also says a request that does not exist or belongs to another account returns 404. Sume scopes jobs to a workspace and to the member whose key created them, and only that member can cancel.

Which state can you still cancel

Higgsfield's lifecycle page calls queued cancellable and in_progress non-cancellable. On Sume the equivalent states are queued (accepted, waiting for a concurrency slot) and processing. For paid generation, queued is a normal accepted state, so a job that is waiting behind your workspace concurrency limit is exactly the kind you can still cancel.

What happens to the money

Higgsfield says a successfully canceled queued request is refunded. Sume's core workflow reserves the cost on submit, captures actual cost on success, and refunds on failure or cancellation before capture. Either way, a cancel that wins the race costs nothing, and a cancel that loses it does not stop the bill.

What to do with the refusal

Treat a 400 from Higgsfield or a 409 from Sume as information, not a failure: the work is running and will finish. Read the job result instead of resubmitting, because a second submit pays for a second clip.

Also remember that a client-side timeout cancels nothing on Sume. The jobs guide says the job keeps running and still bills until you stop it with an explicit cancel.

• Store the job id from the submit response before you do anything else.
• Cancel early: the window closes when generation starts.
• On 409, poll GET /v1/jobs/{id}/status until a terminal state.
• Never resubmit just because a cancel was refused.

curl -X POST https://api.sume.com/v1/jobs/job_123/cancel \
  -H "Authorization: Bearer $SUME_API_KEY"