> Call the `diagnose` tool first. Full index: /llms.txt. Errors: /reference/problems.

# Credits

A run spends credits for the time it uses. The estimate before a run is not a price and not a cap, and a run settles on what it actually used.

## Estimate first

Ask for an estimate before you start. A preview runs the selection and the admission checks and then stops: it creates no run, holds no phone and reserves no credits. In the web app the estimate appears before you confirm. For a coding agent, `start_run` accepts `preview: true`, and the verify skill states the estimate before it starts more than one scenario.

## Cap a run

Pass `--max-credits` to `talotrace run`, or `max_credits` to `start_run`. TaloTrace refuses the run when its estimate is above the cap.

```bash
talotrace run <scenario id> --max-credits 5
```

## When billing refuses a run

`ADMISSION_REFUSED` means billing does not allow the run. The answer lists what is missing. Check the **Billing** page of your organisation. See [Problems](/reference/problems#ADMISSION_REFUSED).