An AI agent execution receipt is a structured record of one tool call. It identifies the execution, names the tool and time, and commits to exact output bytes so a reviewer can repeat the hash check.
The names below were read from a live receipt verification response. Optional members can be absent from other records.
| Field | Meaning |
|---|---|
id | Stable identifier for this recorded execution. |
output_hash | SHA-256 commitment for the exact canonical bytes. |
hash_algorithm | Hash function named by the response. |
canonical_bytes | Base64 encoding of the exact bytes used for the output hash. |
canonical_byte_length | Length of the decoded canonical byte sequence. |
receipt_schema_version | Version label attached to the receipt record. |
tool | Tool name, version, and scope reported for the call. |
caller | Caller classification and privacy-preserving identifier. |
side_effects | Declared effects plus their schema version and commitment. |
verification_status | Verifier status returned for this record. |
verified | Boolean summary returned by the verifier. |
provenance | Source, request, observation time, and response digest when present. |
anchor | Anchor record and its reported evidence status when present. |
external_evidence | Additional evidence references returned with the record. |
checks | Individual verification checks, results, and details. |
checked_at | Time when this verification response was checked. |
This complete verification response was fetched from the public receipt wall at build time. The linked receipt and every displayed verifier field come from the live record.
{
"id": "bcfc11ee-ed2a-4e45-a014-e3b6dfe4f091",
"output_hash": "sha256:7192f53e4a9445c38bee81dba80972980882d03c45a7c0c73b4ec153e090c367",
"hash_algorithm": "sha256",
"canonical_bytes": "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",
"canonical_byte_length": 652,
"receipt_schema_version": "0.3",
"tool": {
"name": "new_session",
"version": "4.0.0",
"scope": "public"
},
"caller": {
"type": "anonymous",
"id": "sha256:1e977dac556d47de0aac5532e76dc10628e98562dda758e425f3603521816c0e"
},
"side_effects": {
"declared": [
"none"
],
"schema_version": "zambo-side-effects/1",
"declaration_hash": "sha256:45aad38f3aa982b9aafe92ecb416ebe98791eddbaf8ab6df0bd08605b7c1bfee"
},
"verification_status": "commitment_matches",
"provenance": null,
"anchor": {
"event_id": "56e8851642bc9c09b4964e711fa889990d925c0e3cb71a321e8dedfeb188dc10",
"pubkey": "e13475107d30c918ec664adf2ab1141024a22fb35190f82c9e933704fa49af41",
"relays": [
"wss://relay.damus.io",
"wss://nos.lol",
"wss://relay.primal.net"
],
"status": "published",
"published_at": "2026-09-28T19:30:19.912Z",
"schema_version": "zambo-receipt-anchor/1",
"envelope": {
"anchored_at": "2026-09-28T19:30:19.298Z",
"evidence_url": null,
"receipt_uuid": "bcfc11ee-ed2a-4e45-a014-e3b6dfe4f091",
"output_sha256": "sha256:7192f53e4a9445c38bee81dba80972980882d03c45a7c0c73b4ec153e090c367",
"schema_version": "zambo-receipt-anchor/1",
"evidence_sha256": null,
"evidence_byte_length": null
},
"envelope_bytes": "{\"anchored_at\":\"2026-09-28T19:30:19.298Z\",\"evidence_byte_length\":null,\"evidence_sha256\":null,\"evidence_url\":null,\"output_sha256\":\"sha256:7192f53e4a9445c38bee81dba80972980882d03c45a7c0c73b4ec153e090c367\",\"receipt_uuid\":\"bcfc11ee-ed2a-4e45-a014-e3b6dfe4f091\",\"schema_version\":\"zambo-receipt-anchor/1\"}"
},
"external_evidence": [],
"checks": {
"signature_valid": {
"label": "Ed25519 signature (not checked)",
"passed": false,
"status": "not_checked",
"detail": "Compatibility field only. No Ed25519 signature was checked; use API v2 checks.commitment_matches for the SHA-256 commitment."
},
"commitment_matches": {
"label": "SHA-256 commitment",
"passed": true,
"status": "pass",
"detail": "SHA-256 matches the exact decoded canonical receipt bytes."
},
"issued_by_zambo_dev": {
"label": "Issued by zambo.dev",
"passed": true,
"detail": "Receipt is served from the zambo.dev receipt store."
},
"chain_valid": {
"label": "Receipt chain (not checked)",
"passed": false,
"status": "not_checked",
"detail": "This endpoint does not verify an append-only receipt chain."
},
"immutable_log_timestamp": {
"label": "Stored timestamp",
"passed": true,
"timestamp": "2026-09-28T19:30:19.314Z",
"detail": "The receipt store reports 2026-09-28T19:30:19.314Z; external immutability was not checked."
},
"receipt_schema_version": "0.3"
},
"checked_at": "2026-09-28T19:34:19.977Z"
}This compatibility-response excerpt intentionally omits the deprecated v1 verified boolean. It is not a signature or chain verdict; new clients should use API v2. Open this receipt or prefill the browser checker.
The verifier decodes receipt.canonical_bytes from Base64, hashes the exact bytes with SHA-256, and compares the lowercase digest with receipt.output_hash. It does not hash a parsed and reserialized display object.
curl -fsSL https://zambo.dev/api/v2/receipt/bcfc11ee-ed2a-4e45-a014-e3b6dfe4f091/verify -o receipt.json
jq -r '.receipt.canonical_bytes' receipt.json | base64 -d | sha256sum
jq -r '.receipt.output_hash' receipt.jsonThe first command returns a local digest. Compare the part after sha256: in receipt.output_hash with the digest printed by sha256sum.
The core format checks the required receipt members and whether the declared hash matches the exact bytes. The reference-producer profile adds one payload convention: the canonical JSON object carries an inputs member alongside its tool and outputs. The missing-inputs vector is accepted by core and rejected by that profile. This is a producer convention, not an interoperation requirement.
The record's integrity and provenance are useful evidence about what the recording system observed. They do not guarantee that a tool output was correct or that an outside data source was truthful.
The API v2 response separates the hosted receipt from top-level checks: commitment_matches, signature, schema, and chain. It does not return a combined verified verdict. Signature and chain are NOT CHECKED unless a real verifier or proof is supplied.
Decode receipt.canonical_bytes from Base64 and compute SHA-256 over those exact bytes. Compare the lowercase digest with receipt.output_hash. Do not parse and reserialize the payload first.
It is the Base64 representation of the exact UTF-8 byte sequence committed by the output hash. The verifier hashes the decoded bytes, not a later display version.
Fetch API v2, Base64-decode receipt.canonical_bytes, run sha256sum on the decoded bytes, then compare the digest with receipt.output_hash.
The core checks receipt structure and byte integrity. The reference-producer profile adds a payload convention requiring an inputs member. The missing-inputs boundary is core-valid and profile-rejected.
Zambo gives AI work a receipt you can check. For people: add Zambo to your AI app and ask for a job. These technical links are for developers and AI agents.
One hosted MCP at https://zambo.dev/mcp.
Check the proof for recorded tool calls (verify a receipt).
Agents: 24-hour Day Pass, $0.99 USDC on Base via x402, not per call. People: Zambo Pass $29/mo or $290/yr; holder pass $19/mo for verified $ZAMBO holders.