What a handover_accept receipt records
A handover_accept receipt is one AER-1 record (receipt schema version 0.4, hosted profile zambo-hosted-receipt/1) for one call. Read from a real handover_accept 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
handover_accept, 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. One public example saved the acceptance fields handover_id, action and agent. The other carried a private delivery notice, with the fields visibility and message.
- Output digest: output_hash, the SHA-256 digest of those canonical bytes, with the canonical byte length recorded too (579 bytes on the first example below).
- Caller and provenance: a caller type (
api_keyon the first example) and a provenance class ofEXECUTED BY ZAMBO, 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 handover_accept receipt examples
Each example below is a real handover_accept receipt. Open one and you see the saved result, when it was saved, and its digest, the same fields described above.
zambo.dev/run/e592fcf8-6f0a-40f8-8640-83dcbbc88f5d
Saved: 2026-10-24T01:09:28.360Z
Output SHA-256 digest: sha256:c5dbd0c1ea02ca743372e3f03dcd82c37197346dbad71698b560bcb0cb845028
Checked live on 2026-10-24: this URL returned HTTP 200 with this receipt on the page.
zambo.dev/run/3b9fc1e0-d9f0-43bb-a208-dd8f2004214f
Saved: 2026-10-24T01:09:28.019Z
Output SHA-256 digest: sha256:afd7e3fad9a30179b2d73992d6b60d827455bf2990455404484dc13e6f2a5b49
Checked live on 2026-10-24: this URL returned HTTP 200 with this receipt on the page.
How to verify a handover_accept 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.