Which Sume submit errors cost money: 402, queue_full, 429, 503

No submit-time rejection on Sume leaves you with a charge. 402 insufficient_credits fails before provider work starts, 429 queue_full releases the reservation of the failed admission, and 429 rate_limited and 503 mean the job was not accepted. What differs is what you should do next: pay, wait, or back off.

The four errors side by side

The table combines the Generation admission and Errors and rate limits pages.

What the docs say you pay for

Paid generation reserves the estimated amount at submit. A successful completion captures it, and failed jobs or failed queue admission release or refund it. The Format errors page adds that a 4xx at create, an idempotent 200 replay and a skipped run cost nothing, but generation that finished before a later failure is not refunded.

Reading the ledger

If a balance looks lower than expected right after a failed submit, check GET /v1/usage. Reserved rows are holds, not spend, and refunded rows show a hold that was given back. Ask support with the request id from the error body; the docs say it is safe to share, unlike API keys or signed URLs.

• Use the same Idempotency-Key for every retry of one logical job.
• Do not retry a paid submit blindly after a local timeout.
• retry-after is the first thing to obey on a 429.

A small decision rule

You can reduce the table to one rule. If the error is 402, change the money. If it is queue_full, change the pace. If it is rate_limited or 503, wait and retry. None of these needs a new idempotency key, and none of them needs a refund request.

For a batch of 100 jobs on a Pro workspace, expect queue_full after 24 accepted jobs if you submit them all at once. Submitting in waves, using the live generation_limits headroom, avoids the error entirely. The admission page recommends max(0, concurrency_limit - active - queued) as the budget for new in-flight work.

• Poll with exponential backoff, not tight loops.
• Cancel queued jobs you no longer need; cancellation succeeds only before generation starts.
• After generation starts, cancel returns 409 job_generation_already_started.