Does BSPx / USDT 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":26231263,"chain":"ethereum","checked_at":"2026-10-20T03:59:57Z","dev":false,"expires_at":"2026-10-21T03:59:57Z","issuer":"Backed xStocks","pool":{"base":{"address":"0x3173dc3AF3981c6e98bB63799B9cBeb5526FF752","balance":"3997404094433337966109","decimals":18,"symbol":"USDT"},"chain":"ethereum","dex":"uniswap-v4","pool":"0xbd9f0ea1dbafc918039bb44ce4818ff5e60b1af7c992ef06731b416a84f30e8d","quote":{"address":"0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","balance":"84664096730839821359","decimals":18,"symbol":"BSPx"}},"quote_share_of_supply":0.0002822136557694661,"reads":[{"block":null,"method":"eth_call","params":["0xbd216513d74c8cf14cf4747e6aaa6420ff64ee9e","poolKeys","0xbd9f0ea1dbafc918039bb44ce4818ff5e60b1af7c992ef0673"],"raw_result":"Object {\"currency0\": String(\"0x3173dc3af3981c6e98bb63799b9cbeb5526ff752\"), \"currency1\": String(\"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5\"), \"fee\": String(\"780000\"), \"hooks\": String(\"0x0000000000000000000000000000000000000000\"), \"tickSpacing\": String(\"1\")}","result_hash":"668fabc008d144672c96acdbf1feb55e051deaed3b1bf344b2502f8f18baffab","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getSlot0","0xbd9f0ea1dbafc918039bb44ce4818ff5e60b1af7c992ef06731b416a84f30e8d"],"raw_result":"true","result_hash":"18d10c7d2b4b04aaf04254d1ae5d655a5dc0407cbcdd5a8c3986e985370f36ee","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getLiquidity","0xbd9f0ea1dbafc918039bb44ce4818ff5e60b1af7c992ef06731b416a84f30e8d"],"raw_result":"581753046337841952034","result_hash":"3b4e2ed6bed5b1c062853e301e5ae0ce60818db3c7e82d567c10b51be3bf062d","slot":null},{"block":null,"method":"eth_call","params":["0x3173dc3AF3981c6e98bB63799B9cBeb5526FF752","symbol()"],"raw_result":"Some(\"USDT\")","result_hash":"a851493323e1198c0940c2b2ca5c59e97da9c6f50f63f0c09779709ef2572f84","slot":null},{"block":null,"method":"eth_call","params":["0x3173dc3AF3981c6e98bB63799B9cBeb5526FF752","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","symbol()"],"raw_result":"Some(\"BSPx\")","result_hash":"62cdf440fd3d8f3c5ff631cacc1bc45614c7284e6c4e85c57a869cf138bf144e","slot":null},{"block":null,"method":"eth_call","params":["0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":26231263,"method":"eth_blockNumber","params":[],"result_hash":"8a48baaad16373203d2b870ec79ea5b9c916906a305c00b565add7b40859e8d0","slot":null},{"block":null,"method":"eth_call","params":["0x3173dc3AF3981c6e98bB63799B9cBeb5526FF752","symbol()"],"raw_result":"Some(\"USDT\")","result_hash":"a851493323e1198c0940c2b2ca5c59e97da9c6f50f63f0c09779709ef2572f84","slot":null},{"block":null,"method":"eth_call","params":["0x3173dc3AF3981c6e98bB63799B9cBeb5526FF752","name()"],"raw_result":"Some(\"usdt\")","result_hash":"a45457ba6f160e1f050944262397d040d3c78ed4bdc5316078fd95db2a8b3765","slot":null},{"block":null,"method":"eth_call","params":["0x3173dc3AF3981c6e98bB63799B9cBeb5526FF752","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0x3173dc3AF3981c6e98bB63799B9cBeb5526FF752","totalSupply()"],"raw_result":"Some(\"1000000000000000000000000000\")","result_hash":"9a5063c327faec672db6b50450571675cbfbcc3766ebaf6832c3a9f6636ff4d0","slot":null},{"block":null,"method":"eth_call","params":["0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","symbol()"],"raw_result":"Some(\"BSPx\")","result_hash":"62cdf440fd3d8f3c5ff631cacc1bc45614c7284e6c4e85c57a869cf138bf144e","slot":null},{"block":null,"method":"eth_call","params":["0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","name()"],"raw_result":"Some(\"Bending Spoons xStock\")","result_hash":"79a899aaec3ef0aa3281c2181b06f951428b26190e95ebfc2dd617f572daf40f","slot":null},{"block":null,"method":"eth_call","params":["0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","totalSupply()"],"raw_result":"Some(\"300000000000000000000000\")","result_hash":"c91886ef825bffc6a9ce0434fb1a4026b4eccb0e068e0950fbb5fb86d1e5ef06","slot":null},{"block":null,"method":"eth_getCode","params":["0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null},{"block":null,"method":"eth_getCode","params":["0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null}],"registry_entry":{"chain":"ethereum","contract":"0x7796F4E23a62eF3653829c21032A9E24bEaf4Cf5","decimals":null,"issuer":"Backed xStocks","last_checked":"2026-10-20T03:40:19Z","name":"Bending Spoons","official_deployments":[{"address":"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5","network":"Ethereum","wrapper_address_v2":"0x0dd03af27d401efc721b4f01d906e8df2e385a90"},{"address":"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5","network":"BinanceSmartChain","wrapper_address_v2":"0x0dd03af27d401efc721b4f01d906e8df2e385a90"},{"address":"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5","network":"Arbitrum","wrapper_address_v2":"0x0dd03af27d401efc721b4f01d906e8df2e385a90"},{"address":"XsYMHtwJcWon5GkPHzdDbCCztKtKzEurJnbydxgjsqS","network":"Solana"},{"address":"EQDc3kRBwjDtV_KSm3FbgGNqU9OAPw03DsA13OWnWcThacjd","network":"Ton"},{"address":"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5","network":"Mantle","wrapper_address_v2":"0x0dd03af27d401efc721b4f01d906e8df2e385a90"},{"address":"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5","network":"HyperEVM"},{"address":"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5","network":"Ink","wrapper_address_v2":"0x0dd03af27d401efc721b4f01d906e8df2e385a90"},{"address":"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5","network":"XLayer","wrapper_address_v2":"0x0dd03af27d401efc721b4f01d906e8df2e385a90"},{"address":"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5","network":"Optimism","wrapper_address_v2":"0x0dd03af27d401efc721b4f01d906e8df2e385a90"},{"address":"0x7796f4e23a62ef3653829c21032a9e24beaf4cf5","network":"Monad","wrapper_address_v2":"0x0dd03af27d401efc721b4f01d906e8df2e385a90"}],"source":"xstocks-api","source_url":"https://api.xstocks.fi/api/v2/public/assets","ticker":"BSP"},"registry_hash":"f3939bae933ba4104be438e67c414e84d9eb518cec0448785678b642b9519284","signer":"GJWKkiUd3zj1pJGfeE7JitiPiwDJC6XmNFvpJWJuvvpn","slot":null,"subject":"0xbd9f0ea1dbafc918039bb44ce4818ff5e60b1af7c992ef06731b416a84f30e8d","ticker":"BSP","verdict":{"Verified":{"issuer":"Backed xStocks","ticker":"BSP"}},"version":1}

Signature

STNKy3LGpcUTeLv33uQNu1koCFC74gssFt+8Z+EHB/HZihRYdXOoVmU+YeOA0v8zU/0a3rRNke0zP/Apu3DLDQ==

API call

GET /api/attest/cf446758b23c797133e3477dd96b42ab927fc6ab42090281b5cd71a4ad86c586

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.