Does COINon / USDC 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":26233132,"chain":"ethereum","checked_at":"2026-10-20T10:15:23Z","dev":false,"expires_at":"2026-10-21T10:15:23Z","issuer":"Ondo","pool":{"base":{"address":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","balance":"235054","decimals":6,"symbol":"USDC"},"chain":"ethereum","dex":"uniswap-v3","pool":"0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829","quote":{"address":"0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","balance":"17105719043744104","decimals":18,"symbol":"COINon"}},"quote_share_of_supply":1.2763755376543334e-6,"reads":[{"block":26233132,"method":"eth_blockNumber","params":[],"result_hash":"a2985f653c3027755ca4b0411622b3ee8079edd2588cd34deac8117e2212d48b","slot":null},{"block":null,"method":"eth_call","params":["0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829","token0()"],"raw_result":"0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48","result_hash":"6239f262cd1d947b947081c9eba6e8771378942478e1d48654f4f132ebb96021","slot":null},{"block":null,"method":"eth_call","params":["0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829","token1()"],"raw_result":"0xf042cfa86cf1d598a75bdb55c3507a1f39f9493b","result_hash":"22f480edeff6022b0caf8f5fe962bcf5ce577d4753a3c0418c6118e14223179d","slot":null},{"block":null,"method":"eth_call","params":["0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829","getReserves()"],"raw_result":"false","result_hash":"076de6e730df0b4c3860877a0f619c6ac11f8aefd78313ac793a2a703c026869","slot":null},{"block":null,"method":"eth_call","params":["0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829","slot0()"],"raw_result":"true","result_hash":"18d10c7d2b4b04aaf04254d1ae5d655a5dc0407cbcdd5a8c3986e985370f36ee","slot":null},{"block":null,"method":"eth_call","params":["0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829","factory()"],"raw_result":"0x1f98431c8ad98523631ae4a59f267346ea31f984","result_hash":"24b698329e82b3994906dfbd01281d9a6f12f65aa59de65831657e6e928d4c80","slot":null},{"block":null,"method":"eth_call","params":["0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829","fee()"],"raw_result":"10000","result_hash":"328d48ab2376d2f42d3af5ba69086143c8f5fe883ed195a8280b2154a5711a33","slot":null},{"block":null,"method":"eth_call","params":["0x1F98431c8aD98523631AE4a59f267346ea31F984","getPool","0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","0x2710"],"raw_result":"0x6b12d00dbdfc765d57aba9e6e37560ce2ba3d829","result_hash":"fd7fed88f933fc2939907613543f4d4778ed4932daf340aa0d008eb0d7eabde2","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","symbol()"],"raw_result":"Some(\"USDC\")","result_hash":"a3c9e246b0832b52e41efce041d8614251f5e288cdd4b192e85bfd3dfcb748ff","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","decimals()"],"raw_result":"Some(6)","result_hash":"c68fe6989b1835302197d0af5be845dfab10ed9f9632205eb4ab5b949b9e1a6a","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","balanceOf","0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829"],"raw_result":"Some(\"235054\")","result_hash":"33d2c09f48f69c8e96f15d578cf84308be17d4db7ca684964570f4b73a1a6b70","slot":null},{"block":null,"method":"eth_call","params":["0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","symbol()"],"raw_result":"Some(\"COINon\")","result_hash":"b497a864914ac6daa740013199f06c88bb67fc6e814b8326e74cbf572873bc5e","slot":null},{"block":null,"method":"eth_call","params":["0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","balanceOf","0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829"],"raw_result":"Some(\"17105719043744104\")","result_hash":"3562a8263870a17c40d881afff80eaa3d8bfe6f0e4752360c1ef296760f4f1b0","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","symbol()"],"raw_result":"Some(\"USDC\")","result_hash":"a3c9e246b0832b52e41efce041d8614251f5e288cdd4b192e85bfd3dfcb748ff","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","name()"],"raw_result":"Some(\"USD Coin\")","result_hash":"fe94af15dc887a2c9df1fb0d6d276e6c586ca9d430ffeac0d05e4baee0637fd1","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","decimals()"],"raw_result":"Some(6)","result_hash":"c68fe6989b1835302197d0af5be845dfab10ed9f9632205eb4ab5b949b9e1a6a","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","totalSupply()"],"raw_result":"Some(\"47782187158880965\")","result_hash":"8d7a071c1445b8ceffd22bc8426d8e2af437959a8d7e5aa8e1fd6d531c3a454a","slot":null},{"block":null,"method":"eth_call","params":["0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","symbol()"],"raw_result":"Some(\"COINon\")","result_hash":"b497a864914ac6daa740013199f06c88bb67fc6e814b8326e74cbf572873bc5e","slot":null},{"block":null,"method":"eth_call","params":["0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","name()"],"raw_result":"Some(\"Coinbase (Ondo Tokenized)\")","result_hash":"2f6656aa1e674e14882ce26a9c8cbcd2f3a1439ed236401e41afcf921ac3f339","slot":null},{"block":null,"method":"eth_call","params":["0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","totalSupply()"],"raw_result":"Some(\"13401791666408961853271\")","result_hash":"c00fb099ea73dbb31e857a2ff6116c770e3ca46c9ceb7a046d959bebf99f4892","slot":null},{"block":null,"method":"eth_getCode","params":["0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","latest"],"result_hash":"8538a8190a64db88a5e0ec4c95f0129f9eecd6f3a3aacb869262b82d01d123ec","slot":null},{"block":null,"method":"eth_getCode","params":["0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","latest"],"result_hash":"8538a8190a64db88a5e0ec4c95f0129f9eecd6f3a3aacb869262b82d01d123ec","slot":null}],"registry_entry":{"chain":"ethereum","contract":"0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","decimals":null,"issuer":"Ondo","last_checked":"2026-10-19T21:40:22Z","name":"Coinbase (Ondo Tokenized)","official_deployments":[{"address":"0xF042cfa86cf1D598a75Bdb55c3507a1F39f9493b","network":"Ethereum"},{"address":"0xf8589b526FdD65F7F301c605a6e04F0F1b4B3620","network":"BNB Chain"},{"address":"5u6KDiNJXxX4rGMfYT4BApZQC5CuDNrG6MHkwp1ondo","network":"Solana"},{"address":"0x639Bcd00422facAcA534063e3d860e8fcf78B46F","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":"COIN"},"registry_hash":"af3c37a81cb7944cc1629e1bdb3d7e524e4edd4e0a8725e736cdb69f4867e121","signer":"GJWKkiUd3zj1pJGfeE7JitiPiwDJC6XmNFvpJWJuvvpn","slot":null,"subject":"0x6b12D00DBdFC765d57Aba9E6E37560ce2BA3D829","ticker":"COIN","verdict":{"Verified":{"issuer":"Ondo","ticker":"COIN"}},"version":1}

Signature

n9o0hHKBBEZ8q8Fk+uv+BT849c1QNR4sZAvBxm/vDB8TFgTy0VCHr5c/XSYxc5/Nvoi6R/5zDF05/9jhQISOBw==

API call

GET /api/attest/0edba34c397a3c5f575ed9c5b1b151c605d94a1b5bdccec4688dcbdf1101b7ae

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.