# Receipts

Every Zambo tool call returns a verifiable receipt with a UUID, tool name, UTC timestamp, SHA-256 hash of the exact output bytes, execution status, and a public URL.

To verify one, open the URL and compare the SHA-256 value with a fresh hash of the exact returned output bytes. The receipt proves observed execution and byte identity. It does not prove correctness or anything outside the recorded call.

Whole-job receipts use `journal_log` and public run pages for one checkable timeline per job.