Agent Completion cap for ten Nano Banana 2.1 images at 2K: $1.50

Ten Nano Banana 2.1 images at 2K cost $1.50 on Sume ($0.15 each), so a cap of 2 on the completion covers them with $0.50 spare; the same ten at 4K cost exactly $2.00. Because Agent Completions have no default cap, this arithmetic is the sizing step before you send the request.

Ten images at four resolutions

Image price is flat per image, so the total is the unit price times ten.

The request

Name the resolution and count in the instruction. Reuse the same Idempotency-Key on a retry: the same key with the same payload returns the original receipt with idempotency_hit: true, and a different payload returns 409 idempotency_conflict.

curl -sS -X POST https://api.sume.com/v1/agent/completions \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"instruction": "Generate ten Nano Banana 2.1 images at 2K of a ceramic mug in different rooms.", "generation_spend_cap_usd": 2}'

# poll until next_action is no longer poll_status
curl -sS https://api.sume.com/v1/agent-runs/$RUN_ID \
  -H "Authorization: Bearer $SUME_API_KEY"

Limits and gotchas

The completion runs an agent, so it may retry or add images if the instruction is loose. Keep the count explicit.

• Finished media comes back as durable media.sume.com URLs under output.images.
• Send exactly one of instruction or messages; assistant turns are rejected.
• A cap of exactly the expected total leaves no room for a single retry.