Smoke-test 1:4, 4:1, 1:8 and 8:1 on Nano Banana 2.1 for $0.30

The cheapest real check that all four new Nano Banana 2.1 ratios work on your key is four calls at 0.5K: $0.075 each, $0.30 total. The same four at 4K cost $0.20 each, $0.80 total, so keep smoke tests at the small tier.

What each run costs

The script

It prints the status code, the billed usage.cost, and any error object for each ratio.

import os, requests

H = {"Authorization": f"Bearer {os.environ['SUME_API_KEY']}"}
for ratio in ["1:4", "4:1", "1:8", "8:1"]:
    r = requests.post("https://api.sume.com/v1/images", headers=H, timeout=60, json={
        "model": "google/nano-banana-2.1",
        "prompt": "A plain grey gradient with one small red circle",
        "aspect_ratio": ratio,
        "resolution": "0.5K",
    })
    body = r.json()
    print(ratio, r.status_code, body.get("usage", {}).get("cost"), body.get("error"))

Reading the output

Gotchas

• A failed or cancelled generation is not billed; a completed one is billed in full.
• Treat 202 as a pass for the ratio check, then read the job result.
• Do not run the smoke test on every commit. Run the free ratio-list check from GET /v1/images/models there, and the paid test nightly.