decisions api · 544 calls · cost

The eval cost two cents. The day was the budget.

The note

Fig. 1 Input tokens across 544 calls, priced by the script at ten cents per million.

544 legal questions through OpenAI's Decisions API, one call each, cost 0.019 dollars: 190,399 input tokens at ten cents per million.

Ten cents per million is the price I typed into my script. The run used about 350 input tokens per question. There was no output-token charge; the endpoint returns a decision, not text. The whole thing ran in about four minutes at eight calls in flight.

The arithmetic holds: 190,399 tokens at ten cents per million is 0.019. What it multiplies is the weak part. The rate was never read off a bill. It matches what OpenAI's Decisions API docs said on 8 October: ten cents per million input tokens, and no charge for output tokens. So 0.019 is an estimate that agrees with the published rate, not an invoice.

The hours went elsewhere: picking six tasks, deciding that a refusal is not a no, rewriting the hearsay prompt after it scored 1 of 9 on a pilot, writing it up so someone could re-run it. None of that has a line in the cost figure.

Limits. The 0.019 is script arithmetic on input tokens at a price I typed in; no invoice, and retried calls are not counted. The four minutes is my stopwatch, not a log. One run, one model, gpt-6-luna.

If an eval costs two cents in tokens and a day in judgement, which of the two should the next budget request be written around?

Where the numbers live

The quiz and the cost line in the repo

Script arithmetic, not an invoice. Retries not counted. Four minutes by stopwatch. gpt-6-luna, 8 Oct 2026.