Balance needed to submit 10 or 50 video jobs: reserve per model

Each POST /v1/videos reserves the job's estimated Sume price from the workspace balance at submit, so a batch needs the sum of its estimates available up front, not at the end. Ten ten-second Wan 3.0 clips at 720p need $12.50 free; fifty need $62.50. The first job whose reserve does not fit fails with 402 insufficient_credits before any provider work starts.

The estimate is provider list price times 1.25, and the numbers below come from the same estimators that perform the reservation.

Balance to cover the batch

What happens when the balance runs short

Submits are checked one by one. If the balance covers 31 of 50 jobs, jobs 1 to 31 are accepted and the 32nd returns 402, so the batch is split rather than refused whole. Completed jobs capture their reserve; a failed job releases its hold.

That is why pre-computing the sum is worth a few lines of code: you can stop before submit instead of discovering the cut-off in the middle of a loop.

Practical rules

• Compute the sum from GET /v1/videos/models pricing before the loop and compare it with your balance.
• Number your idempotency keys by item so a re-run after a top-up resumes at item 32 and skips the 31 already accepted.
• Keep the 25 percent house margin in mind when you compare these prices with a provider's own list.

A pre-flight sketch

Before a large loop, compute the sum for the model, resolution and duration you will send, read the workspace balance from GET /v1/balance, and stop early if the sum does not fit. The estimate is the same number the reservation uses, so the comparison is exact rather than approximate; it only ignores other jobs that submit in the meantime.

• Group the batch by model and resolution so each group has one price.
• Multiply by item count and add the groups.
• Leave a margin for work other members of the workspace are submitting at the same time.
• If the sum does not fit, either top up, move to a cheaper row of the table, or split the batch across days.

Moving a draft pass to a cheaper model and re-rendering only the approved clips on a premium one is the usual way to keep the reserve small. The table shows the spread: the same ten seconds costs several times more on some rows than others.