# Can Curbi detect a $500 claim when a signed receipt says $50?

The amount-aware checker can flag a dollar amount that contradicts an amount-bearing signed receipt for the claimed operation in the same sentence. The signed amount lab demonstrates this with temporary local keys and sample data. Those keys are not trusted by the public API, and the lab does not prove a real provider action occurred.

- [Run the signed amount lab](https://curbi.io/lab/)
- [Receipt reference](https://curbi.io/developers/#receipts)

Updated 2026-10-27. Public access.

## Try a configured check

This public example checks a reply against a configured price; it does not authorize an action or establish a provider outcome.

```sh
curl -sS https://api.curbi.io/v1/check \
  -H 'Content-Type: application/json' \
  -d '{"policy":{"prices":[{"item":"Starter","amount":49}]},"reply":"Starter is $99."}'
```

Expect `pass: false` with `price:mismatch`.

Next: [install a framework adapter](https://curbi.io/connect/) or [start with a working policy](https://curbi.io/policies/).