What a journal_log receipt records
A journal_log receipt is one AER-1 record (receipt schema version 0.4, hosted profile zambo-hosted-receipt/1) for one call. Read from a real journal_log payload, it records:
- Receipt id: a full UUID. The id is the address of the record: the human page is https://zambo.dev/run/ followed by the id.
- Tool: name
journal_log, version4.0.0, scopepublic. - Timestamps: the record creation time, and inside the step list a started_at and a completed_at for the call itself.
- Step status: one step per call, with the tool name and its status. On the first example below the step status is
success. - The saved output: the exact output object the call returned, kept as canonical bytes. The saved output carries the entry, a status, a verify_url, and two explicit fields, attests and does_not_attest, that state what the record does and does not claim. Its provenance class on the checked example is LOGGED BY AGENT.
- Output digest: output_hash, the SHA-256 digest of those canonical bytes, with the canonical byte length recorded too (1264 bytes on the first example below).
- Caller and provenance: a caller type (
anonymouson the first example) and a provenance class ofLOGGED BY AGENT, which states how the record was produced. - Declared side effects: the record declares its side effects,
state_writeon the first example. - Verification status: the API carries a verification_status field for the record. On the first example below, the verify API reported verification_status
commitment_matches, its wording for a record whose digest still matches the saved bytes.
Live journal_log receipt examples
Each example below is a real journal_log receipt. Open one and you see the saved result, when it was saved, and its digest, the same fields described above.
zambo.dev/run/94a8243e-d4be-4eae-aef8-22a6cf5fbeea
Saved: 2026-10-24T16:55:33.009Z
Output SHA-256 digest: sha256:4f2f581a5dada6cd02ea11cf1ab88831cb8c4a17c629605a8ffc348938dba58d
Checked live on 2026-10-24: this URL returned HTTP 200 with this receipt on the page.
zambo.dev/run/1f56fe3e-b4f3-40b0-8619-5935741c9a73
Saved: 2026-10-24T16:25:40.791Z
Output SHA-256 digest: sha256:44fcf8d38ba476e6026e19d9dc15b4bb78c89940301a480faa15747efab4a9c0
Checked live on 2026-10-24: this URL returned HTTP 200 with this receipt on the page.
zambo.dev/run/57e1cbb2-3dd4-4c9c-91ea-c761faca9b1e
Saved: 2026-10-24T16:04:19.243Z
Output SHA-256 digest: sha256:09ef1597510fdfa179be6c4b710b026387979eb9c7eae05e63482ff6e7af49b2
Checked live on 2026-10-24: this URL returned HTTP 200 with this receipt on the page.
How to verify a journal_log receipt
- Open zambo.dev/verify/ and paste the receipt link or the receipt id. The checker recomputes the SHA-256 digest over the saved bytes and reports whether the record still matches.
- Or call the API directly:
GET https://zambo.dev/api/v2/receipt/{receipt-id}/verifyreturns the record as JSON, including its output_hash and verification_status. - The format is AER-1, an open IETF Internet-Draft: draft-zambo-aer1-26. Anyone can implement the check; it does not need a Zambo account.
Verification answers one question: is this the record that was saved, byte for byte? It does not answer whether the result inside was right.
Get receipts for your own calls
Add Zambo to your AI once, at zambo.dev/add/, and every tool call after that files a receipt like the ones above. Every account starts with 20 free calls per day, and free calls file receipts too. The background is at AI agent receipts, and more worked examples are indexed at receipt examples by tool.