GETMethod GET/passport/01/{gtin}/10/{lot}/proof

You fetch the public proofs of a production batch's passport. When you leave this page, you will know how to request these proofs, how to check by yourself that the batch's version is written on chain, and why no minting was needed.

Full address:

GET https://api.sealtrust.io/v1/passport/01/{gtin}/10/{lot}/proof

#Authorization

None, public endpoint. The response is the same for everyone.

#Rate limit

600 calls per window of 60 seconds, counted per calling IP address, shared by every read (GET) whose address starts with /passport.

#Path and query parameters

This endpoint has no query parameter.

#Request body

None. This request has no body.

#Example request

curl -i "https://api.sealtrust.io/v1/passport/01/03701234567891/10/LOT-26A/proof"

const response = await fetch(
  "https://api.sealtrust.io/v1/passport/01/03701234567891/10/LOT-26A/proof",
);
const proofs = await response.json();
console.log(proofs.level, proofs.batch_code, proofs.passport_anchor);

import requests

response = requests.get(
    "https://api.sealtrust.io/v1/passport/01/03701234567891/10/LOT-26A/proof",
    timeout=30,
)
proofs = response.json()
print(proofs["level"], proofs["batch_code"], proofs.get("passport_anchor"))

#Example response

HTTP code 200, for a version already anchored.

{
  "passport_version": 2,
  "data_hash": "9f2c1e7d4b8a6f0e3d5c2b1a9e8f7d6c5b4a3f2e1d0c9b8a7f6e5d4c3b2a1f0e",
  "passport_anchor": {
    "type": "passport_anchor",
    "chain": "base",
    "chain_id": 8453,
    "tx_hash": "0x5e1f0c2d3b4a59687766554433221100ffeeddccbbaa99887766554433221100",
    "merkle_root": "0x0d1c2b3a49586776655443322110ffeeddccbbaa998877665544332211000f1e",
    "leaf": "0x7a6b5c4d3e2f1a0b9c8d7e6f5a4b3c2d1e0f9a8b7c6d5e4f3a2b1c0d9e8f7a6b",
    "leaf_index": 3,
    "proof": ["0x1122334455667788990011223344556677889900112233445566778899001122"],
    "block_timestamp": "2026-09-26T09:00:02+00:00",
    "passport_version": 2,
    "data_hash_matches": true,
    "anchored": true,
    "proves": "content_existed_at_or_before_tx"
  },
  "seal": {"sealed": true, "linked": true, "chain_link_match": true},
  "vc": {"issued": false},
  "level": "batch",
  "gtin": "03701234567891",
  "batch_code": "LOT-26A"
}

Every value in this example is fictitious, and the real response carries other fields in passport_anchor and seal, described on GET /passport/01/{gtin}/proof.

Two blocks are absent, and their absence is the right answer: anchor, which dates an item, and verifications, which counts the reads of a physical label. A batch is neither. As long as the version has not been taken by the sweep, passport_anchor is absent too, and seal is enough to make any rewrite visible in the meantime.

#Verifying the proof yourself

The leaf is keccak256(abi.encode(uint256 passportId, uint256 passportVersion, bytes32 dataHash)), where passportId is the id field of GET /passport/01/{gtin}/10/{lot}. Walking up from the leaf with each node of proof, two by two and in ascending byte order, you get back merkle_root. The detail is on Trust and proofs.

#Errors

#See also

• GET /passport/01/{gtin}/10/{lot}, the content of the batch's passport.
• Trust and proofs, what each proof establishes and how to cross-check it.