Does AAPLx / UDS 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":26274296,"chain":"ethereum","checked_at":"2026-10-26T03:53:21Z","dev":false,"expires_at":"2026-10-27T03:53:21Z","issuer":"Backed xStocks","pool":{"base":{"address":"0x2162FDb116bc95d85b898BdAE77e053eF0C36eAA","balance":"111124018717628986194","decimals":18,"symbol":"UDS"},"chain":"ethereum","dex":"uniswap-v4","pool":"0x0b51427e77cc006882aaea0fc1b102877033a39f573eceda3730c0cb40056c8f","quote":{"address":"0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","balance":"246061411191770995","decimals":18,"symbol":"AAPLx"}},"quote_share_of_supply":3.31866403092573e-6,"reads":[{"block":null,"method":"eth_call","params":["0xbd216513d74c8cf14cf4747e6aaa6420ff64ee9e","poolKeys","0x0b51427e77cc006882aaea0fc1b102877033a39f573eceda37"],"raw_result":"Object {\"currency0\": String(\"0x2162fdb116bc95d85b898bdae77e053ef0c36eaa\"), \"currency1\": String(\"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a\"), \"fee\": String(\"200000\"), \"hooks\": String(\"0x0000000000000000000000000000000000000000\"), \"tickSpacing\": String(\"2000\")}","result_hash":"e0f984fadb5aab6ec22babbde79f37fd58b3f26e4c6d6692fab85788c31e428b","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getSlot0","0x0b51427e77cc006882aaea0fc1b102877033a39f573eceda3730c0cb40056c8f"],"raw_result":"true","result_hash":"18d10c7d2b4b04aaf04254d1ae5d655a5dc0407cbcdd5a8c3986e985370f36ee","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getLiquidity","0x0b51427e77cc006882aaea0fc1b102877033a39f573eceda3730c0cb40056c8f"],"raw_result":"5229085279755969196","result_hash":"925cf1a10611884ebd39ea30a4912287415191f578c726e3483ed051510670d5","slot":null},{"block":null,"method":"eth_call","params":["0x2162FDb116bc95d85b898BdAE77e053eF0C36eAA","symbol()"],"raw_result":"Some(\"UDS\")","result_hash":"2c14e7c075eb8a00642631fde3ab87ede055000cee69e89598dccfade4c11e41","slot":null},{"block":null,"method":"eth_call","params":["0x2162FDb116bc95d85b898BdAE77e053eF0C36eAA","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","symbol()"],"raw_result":"Some(\"AAPLx\")","result_hash":"c700afc7f6ded90a1d2ffbe8bc821567ee617c777989a05562bdcff3f0f4f731","slot":null},{"block":null,"method":"eth_call","params":["0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":26274296,"method":"eth_blockNumber","params":[],"result_hash":"6b9f2eb6a403a18807dde8e2f78c53701ba229dbce201276807fd36f3eb6a8b2","slot":null},{"block":null,"method":"eth_call","params":["0x2162FDb116bc95d85b898BdAE77e053eF0C36eAA","symbol()"],"raw_result":"Some(\"UDS\")","result_hash":"2c14e7c075eb8a00642631fde3ab87ede055000cee69e89598dccfade4c11e41","slot":null},{"block":null,"method":"eth_call","params":["0x2162FDb116bc95d85b898BdAE77e053eF0C36eAA","name()"],"raw_result":"Some(\"Uds My\")","result_hash":"cba9701721a52d21dfbe2b38e11a9a6c9f6386973dbdf6be136ef8464ff28a48","slot":null},{"block":null,"method":"eth_call","params":["0x2162FDb116bc95d85b898BdAE77e053eF0C36eAA","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0x2162FDb116bc95d85b898BdAE77e053eF0C36eAA","totalSupply()"],"raw_result":"Some(\"10000000000000000000000000\")","result_hash":"b1ad9e97341fa8bfcff35922c984d71a77ade48980cbc8ed981d08aa36c9953f","slot":null},{"block":null,"method":"eth_call","params":["0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","symbol()"],"raw_result":"Some(\"AAPLx\")","result_hash":"c700afc7f6ded90a1d2ffbe8bc821567ee617c777989a05562bdcff3f0f4f731","slot":null},{"block":null,"method":"eth_call","params":["0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","name()"],"raw_result":"Some(\"Apple xStock\")","result_hash":"38558e23e8582c8a29fab99f3c180b0d4dfe6162231fc0aee4206b8a94c1926f","slot":null},{"block":null,"method":"eth_call","params":["0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","totalSupply()"],"raw_result":"Some(\"74144718747903202410949\")","result_hash":"81f6a20a09014db1b929586aff07b1b5961037358c71feb59239f0a9da21c628","slot":null},{"block":null,"method":"eth_getCode","params":["0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null},{"block":null,"method":"eth_getCode","params":["0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null}],"registry_entry":{"chain":"ethereum","contract":"0x9d275685dC284C8eB1C79f6ABA7a63Dc75ec890a","decimals":null,"issuer":"Backed xStocks","last_checked":"2026-10-26T03:07:30Z","name":"Apple","official_deployments":[{"address":"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a","network":"Ethereum","wrapper_address":"0x5aa7649fdbda47de64a07ac81d64b682af9c0724","wrapper_address_v2":"0x943bf64d566c32a2bcd41ac92fb63c111cc9de8f"},{"address":"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a","network":"BinanceSmartChain","wrapper_address":"0x5aa7649fdbda47de64a07ac81d64b682af9c0724","wrapper_address_v2":"0x943bf64d566c32a2bcd41ac92fb63c111cc9de8f"},{"address":"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a","network":"Arbitrum","wrapper_address":"0x5aa7649fdbda47de64a07ac81d64b682af9c0724","wrapper_address_v2":"0x943bf64d566c32a2bcd41ac92fb63c111cc9de8f"},{"address":"XsbEhLAtcf6HdfpFZ5xEMdqW8nfAvcsP5bdudRLJzJp","network":"Solana"},{"address":"TZ7nsyCuQq1cusCtex6V4qbzWcb3NbibAM","network":"Tron"},{"address":"EQDsjAwfKo-6FVZv2EYt-1CaZTY_ZL-pfkSId6jeQchNwmdo","network":"Ton"},{"address":"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a","network":"Mantle","wrapper_address":"0x5aa7649fdbda47de64a07ac81d64b682af9c0724","wrapper_address_v2":"0x943bf64d566c32a2bcd41ac92fb63c111cc9de8f"},{"address":"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a","network":"HyperEVM"},{"address":"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a","network":"Ink","wrapper_address_v2":"0x943bf64d566c32a2bcd41ac92fb63c111cc9de8f"},{"address":"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a","network":"XLayer","wrapper_address_v2":"0x943bf64d566c32a2bcd41ac92fb63c111cc9de8f"},{"address":"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a","network":"Optimism","wrapper_address_v2":"0x943bf64d566c32a2bcd41ac92fb63c111cc9de8f"},{"address":"0x9d275685dc284c8eb1c79f6aba7a63dc75ec890a","network":"Monad","wrapper_address_v2":"0x943bf64d566c32a2bcd41ac92fb63c111cc9de8f"}],"source":"xstocks-api","source_url":"https://api.xstocks.fi/api/v2/public/assets","ticker":"AAPL"},"registry_hash":"7ad75971e53a9b74cd62e5856fbcf7d2132f32d176f68774d445939c2b9af77e","signer":"GJWKkiUd3zj1pJGfeE7JitiPiwDJC6XmNFvpJWJuvvpn","slot":null,"subject":"0x0b51427e77cc006882aaea0fc1b102877033a39f573eceda3730c0cb40056c8f","ticker":"AAPL","verdict":{"Verified":{"issuer":"Backed xStocks","ticker":"AAPL"}},"version":1}

Signature

2Fq19kc2/vGhpjNOZ2MCVco9BaZwBWNEXIqO5KIaoc13hv11cASEe2OoXkThmiMGPLwN95j5WnFGCN1DQfpzAg==

API call

GET /api/attest/2cc9cc6ffca1dd8525df5c710f0708d136e9cf082354116cbf62f16e3c6fa84a

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.