GPT Image 2.5 on Sume: no quality means high, auto reserves max

On Sume, leaving quality out of a GPT Image 2.5 request means high. Sending quality: auto is different: the docs say auto reserves max for the estimate. At 1280x720 that is the gap between about $0.0355 and about $0.1420 per image, a factor of 4.

The Sume docs (read 2026-10-06) state both rules: if you omit quality the default is high, and auto quality reserves max.

Three ways to say 'no preference'

Why it matters

A reserve is an amount held before the job runs, so a batch of auto requests ties up more of your balance than it will necessarily spend. It also makes a pre-run estimate look much higher than the image cost you expected.

Auto also removes the one thing you control. Pin the quality you want. Low and medium are enough for drafts, and high is the finish. The xhigh and max post covers when the top tiers pay off.

Check it on your own account

Do not budget from a blog table alone. GET /v1/images/models lists every model with its descriptors, and GET /v1/images/models/{id}/endpoints shows the pricing line for one model. Then run one small request and read usage.cost on the response, which is the billed amount in USD; the token counts in usage are reported as 0 on this route.

Run the test at the quality and size you plan to ship, because both move the price. A single test at low quality costs under a cent for most sizes here, so it is a cheap way to confirm your assumptions before a batch.

Sync, async and failures

The /v1/images route waits up to 30 seconds for the image. If the job finishes in that window you get the result directly; otherwise you get a 202 and an async job to poll. Write your client to branch on the status code, since larger sizes and higher quality are the likely cases for a 202.

Requests are strict. A parameter the chosen model does not list returns 400 unsupported_parameter, stream returns a 400, and provider.only or provider.order accept only sume. Treat a 400 as a bug in the request, not a transient error, and do not retry it unchanged.

Unknowns

The docs describe the reserve, not the final billed amount for an auto job. Check usage.cost on a small run before you rely on a number.