Does IAUon / XAUt match its issuer's published contract?

QED signs a canonical JSON payload. Fetch the public key from /.well-known/qed.json, then check the signature against this payload.

Canonical JSON

{"block":26233118,"chain":"ethereum","checked_at":"2026-10-20T10:12:41Z","dev":false,"expires_at":"2026-10-21T10:12:41Z","issuer":"Ondo","pool":{"base":{"address":"0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","balance":"2056061629764551020","decimals":18,"symbol":"IAUon"},"chain":"ethereum","dex":"uniswap-v3","pool":"0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf","quote":{"address":"0x68749665FF8D2d112Fa859AA293F07A622782F38","balance":"209336","decimals":6,"symbol":"XAUt"}},"quote_share_of_supply":0.000019243769041011162,"reads":[{"block":26233118,"method":"eth_blockNumber","params":[],"result_hash":"38b9d65fcd7ea3d656f62c7003327b70ab33b6abc30efecf257721667d730122","slot":null},{"block":null,"method":"eth_call","params":["0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf","token0()"],"raw_result":"0x4f0ca3df1c2e6b943cf82e649d576ffe7b2fabcf","result_hash":"3a335a3f5abdeeb8012ff0feccdf5b79b9142b1d61a0b3f4e798c3ecfffbe56f","slot":null},{"block":null,"method":"eth_call","params":["0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf","token1()"],"raw_result":"0x68749665ff8d2d112fa859aa293f07a622782f38","result_hash":"7bedceff9faa0f94cec5014000336f8469e05fae1e21ea49a43314379ea647a9","slot":null},{"block":null,"method":"eth_call","params":["0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf","getReserves()"],"raw_result":"false","result_hash":"076de6e730df0b4c3860877a0f619c6ac11f8aefd78313ac793a2a703c026869","slot":null},{"block":null,"method":"eth_call","params":["0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf","slot0()"],"raw_result":"true","result_hash":"18d10c7d2b4b04aaf04254d1ae5d655a5dc0407cbcdd5a8c3986e985370f36ee","slot":null},{"block":null,"method":"eth_call","params":["0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf","factory()"],"raw_result":"0x1f98431c8ad98523631ae4a59f267346ea31f984","result_hash":"24b698329e82b3994906dfbd01281d9a6f12f65aa59de65831657e6e928d4c80","slot":null},{"block":null,"method":"eth_call","params":["0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf","fee()"],"raw_result":"10000","result_hash":"328d48ab2376d2f42d3af5ba69086143c8f5fe883ed195a8280b2154a5711a33","slot":null},{"block":null,"method":"eth_call","params":["0x1F98431c8aD98523631AE4a59f267346ea31F984","getPool","0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","0x68749665FF8D2d112Fa859AA293F07A622782F38","0x2710"],"raw_result":"0xb692a5d05fe23ca1aabf788cac2ac1a60ae44bff","result_hash":"f6b4da2ece906de1537ad5294522ad3e783f8ed69198d4dd63164e0fcd643dd9","slot":null},{"block":null,"method":"eth_call","params":["0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","symbol()"],"raw_result":"Some(\"IAUon\")","result_hash":"f99be27a9eae0c79d37db46fd75b118049e02def9d35686282b0447f1978cac5","slot":null},{"block":null,"method":"eth_call","params":["0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","balanceOf","0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf"],"raw_result":"Some(\"2056061629764551020\")","result_hash":"a3af4064070fc5dc965d2be9450020e0c983e776e6f75e7dc27d436f73dd6c62","slot":null},{"block":null,"method":"eth_call","params":["0x68749665FF8D2d112Fa859AA293F07A622782F38","symbol()"],"raw_result":"Some(\"XAUt\")","result_hash":"c8c25b3d1df8c0b462abb7260f366a4f17338d3d3e946de0fb2721d29f47cec3","slot":null},{"block":null,"method":"eth_call","params":["0x68749665FF8D2d112Fa859AA293F07A622782F38","decimals()"],"raw_result":"Some(6)","result_hash":"c68fe6989b1835302197d0af5be845dfab10ed9f9632205eb4ab5b949b9e1a6a","slot":null},{"block":null,"method":"eth_call","params":["0x68749665FF8D2d112Fa859AA293F07A622782F38","balanceOf","0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf"],"raw_result":"Some(\"209336\")","result_hash":"7113328363f60c4a7fd787076499cac047656f758252aedd13515e49fc7b873c","slot":null},{"block":null,"method":"eth_call","params":["0x68749665FF8D2d112Fa859AA293F07A622782F38","symbol()"],"raw_result":"Some(\"XAUt\")","result_hash":"c8c25b3d1df8c0b462abb7260f366a4f17338d3d3e946de0fb2721d29f47cec3","slot":null},{"block":null,"method":"eth_call","params":["0x68749665FF8D2d112Fa859AA293F07A622782F38","name()"],"raw_result":"Some(\"Tether Gold\")","result_hash":"03658931e0a9db6ba24baca05bcda4448a08913154c9cd64f85b403576633dcb","slot":null},{"block":null,"method":"eth_call","params":["0x68749665FF8D2d112Fa859AA293F07A622782F38","decimals()"],"raw_result":"Some(6)","result_hash":"c68fe6989b1835302197d0af5be845dfab10ed9f9632205eb4ab5b949b9e1a6a","slot":null},{"block":null,"method":"eth_call","params":["0x68749665FF8D2d112Fa859AA293F07A622782F38","totalSupply()"],"raw_result":"Some(\"827417630000\")","result_hash":"88caee7a3395cf5b712e523abfd500f52f518d015e3173600274e83f9897e4d7","slot":null},{"block":null,"method":"eth_call","params":["0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","symbol()"],"raw_result":"Some(\"IAUon\")","result_hash":"f99be27a9eae0c79d37db46fd75b118049e02def9d35686282b0447f1978cac5","slot":null},{"block":null,"method":"eth_call","params":["0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","name()"],"raw_result":"Some(\"iShares Gold Trust (Ondo Tokenized)\")","result_hash":"6595e74843ad2e163ec81ceb8b9c4fa57e63ff94f51037e808521644c7a5d057","slot":null},{"block":null,"method":"eth_call","params":["0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","totalSupply()"],"raw_result":"Some(\"106842979947576598502669\")","result_hash":"1d2b7ad74221fa25c2cf4a8919c32de33754aac21c2069aeef6939b40f985580","slot":null},{"block":null,"method":"eth_getCode","params":["0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","latest"],"result_hash":"8538a8190a64db88a5e0ec4c95f0129f9eecd6f3a3aacb869262b82d01d123ec","slot":null},{"block":null,"method":"eth_getCode","params":["0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","latest"],"result_hash":"8538a8190a64db88a5e0ec4c95f0129f9eecd6f3a3aacb869262b82d01d123ec","slot":null}],"registry_entry":{"chain":"ethereum","contract":"0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","decimals":null,"issuer":"Ondo","last_checked":"2026-10-19T21:40:22Z","name":"iShares Gold Trust (Ondo Tokenized)","official_deployments":[{"address":"0x4f0CA3df1c2e6b943cf82E649d576ffe7B2fABCF","network":"Ethereum"},{"address":"0xcB2a0F46f67dC4c58a316F1c008EDef5c2311795","network":"BNB Chain"},{"address":"M77ZvkZ8zW5udRbuJCbuwSwavRa7bGAZYMTwru8ondo","network":"Solana"},{"address":"0x83b01AC9e2D1632A70Dd1C813c5B8eDF29cd707f","network":"HyperEVM"}],"source":"https://docs.ondo.finance/addresses.md","source_url":"https://www.dropbox.com/scl/fi/qjfxyg748mx0dwi6up86d/EXTERNAL-Ondo-GM-Tokens-Ondo-GM-Tokens.csv?rlkey=n3no1w78wrah3umsl0nr9s77i&e=2&st=spdit2q1&dl=1","ticker":"IAU"},"registry_hash":"af3c37a81cb7944cc1629e1bdb3d7e524e4edd4e0a8725e736cdb69f4867e121","signer":"GJWKkiUd3zj1pJGfeE7JitiPiwDJC6XmNFvpJWJuvvpn","slot":null,"subject":"0xB692A5D05Fe23CA1aABF788CaC2ac1a60Ae44BFf","ticker":"IAU","verdict":{"Verified":{"issuer":"Ondo","ticker":"IAU"}},"version":1}

Signature

4cihCwN7qKgM98SCoMeB1U17toRt0+L/IcxyN0t0FEpRCkRPYGYl6uBIOLEs0F+I8T0PxD8FOQAOkizF7p3IDA==

API call

GET /api/attest/03ca053651738fab916c50b0120781d4d2a050ecb92278598282b7bfca1dfb38

1. Fetch the public key and attestation JSON, then verify the signature with the published key.
2. Canonicalize the payload with sorted object keys and no whitespace, then verify its SHA-256 attestation id.
3. Run the API call above and compare the returned payload, serial, signer, and signature with this certificate.