Bulk Format run, 100 Nano Banana 2.1 4K images: $20.00, 7 rounds

A 100-item Format bulk queue in which each item makes one Nano Banana 2.1 image at 4K costs $20.00 in image generation ($0.20 each) and takes 7 rounds at the maximum concurrency of 16 (100 divided by 16, rounded up). The queue itself has no cap, so each item's generation_spend_cap_usd is your only ceiling.

Image cost and rounds

concurrency is an integer from 1 to 16, items from 1 to 100. The round count is the number of times the window refills.

The queue body

Only concurrency and items sit at the top level, and each item carries its own generation_spend_cap_usd. Send one Idempotency-Key per queue.

{
  "concurrency": 16,
  "items": [
    { "instruction": "4K product shot, blue background", "input": { "sku": "A-001" }, "generation_spend_cap_usd": 1 },
    { "instruction": "4K product shot, blue background", "input": { "sku": "A-002" }, "generation_spend_cap_usd": 1 }
  ]
}

Limits and gotchas

The $20.00 is only the image price. A Format run is an agent turn, so a real item also pays for its other tools, and the item cap bounds the total, not the image alone.

• The queue status completed does not mean success; check counts.failed.
• There is no queue webhook and no cancel-queue endpoint; cancel children one by one.
• Items always run with on_active_run: allow.