Does AMZNx / 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":26276171,"chain":"ethereum","checked_at":"2026-10-26T10:10:12Z","dev":false,"expires_at":"2026-10-27T10:10:12Z","issuer":"Backed xStocks","pool":{"base":{"address":"0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","balance":"17460166037263176","decimals":18,"symbol":"AMZNx"},"chain":"ethereum","dex":"uniswap-v4","pool":"0x31ef8e9b2bca002d1674b7854edf5c3bbf7a6c2a844ae73c8c20ab021496391f","quote":{"address":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","balance":"3176118","decimals":6,"symbol":"USDC"}},"quote_share_of_supply":2.0115398660441447e-7,"reads":[{"block":null,"method":"eth_call","params":["0xbd216513d74c8cf14cf4747e6aaa6420ff64ee9e","poolKeys","0x31ef8e9b2bca002d1674b7854edf5c3bbf7a6c2a844ae73c8c"],"raw_result":"Object {\"currency0\": String(\"0x3557ba345b01efa20a1bddc61f573bfd87195081\"), \"currency1\": String(\"0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48\"), \"fee\": String(\"709000\"), \"hooks\": String(\"0x0000000000000000000000000000000000000000\"), \"tickSpacing\": String(\"14180\")}","result_hash":"655e049bd0cabdab4e40e5bad98549b824e34e0fc850c45b2890c580103dad23","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getSlot0","0x31ef8e9b2bca002d1674b7854edf5c3bbf7a6c2a844ae73c8c20ab021496391f"],"raw_result":"true","result_hash":"18d10c7d2b4b04aaf04254d1ae5d655a5dc0407cbcdd5a8c3986e985370f36ee","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getLiquidity","0x31ef8e9b2bca002d1674b7854edf5c3bbf7a6c2a844ae73c8c20ab021496391f"],"raw_result":"235490053068","result_hash":"9c3c38e6113f8d87da6fc96fdd9fa14902135f9356d1cd8249ba17f1cea00ea2","slot":null},{"block":null,"method":"eth_call","params":["0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","symbol()"],"raw_result":"Some(\"AMZNx\")","result_hash":"3f9571336c2a39f494b3c82a73943c1735ff55d95c82eacaf21b992f1485f9fd","slot":null},{"block":null,"method":"eth_call","params":["0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","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":26276171,"method":"eth_blockNumber","params":[],"result_hash":"8817655e93d7c5ce54381d24751d5998d8299b607ae58db8459ec13fb96b4be1","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(\"47489597858632666\")","result_hash":"77d1d5a7a863e6ed16864fd5b6372e120fd0c6d4c8c0bde428dee38f44cc8d12","slot":null},{"block":null,"method":"eth_call","params":["0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","symbol()"],"raw_result":"Some(\"AMZNx\")","result_hash":"3f9571336c2a39f494b3c82a73943c1735ff55d95c82eacaf21b992f1485f9fd","slot":null},{"block":null,"method":"eth_call","params":["0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","name()"],"raw_result":"Some(\"Amazon.com xStock\")","result_hash":"8f4babbefa287ee9cc8dec91a4001fa2592f133884da76159ad9d9e9b6693bb7","slot":null},{"block":null,"method":"eth_call","params":["0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","totalSupply()"],"raw_result":"Some(\"86800000000000000000000\")","result_hash":"c20dfb0e0456da47f5530f2b46abb142312a5985f3a73539710340dabf75f73e","slot":null},{"block":null,"method":"eth_getCode","params":["0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null},{"block":null,"method":"eth_getCode","params":["0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null}],"registry_entry":{"chain":"ethereum","contract":"0x3557Ba345B01EFa20A1bdDC61F573BFD87195081","decimals":null,"issuer":"Backed xStocks","last_checked":"2026-10-26T10:07:30Z","name":"Amazon.com","official_deployments":[{"address":"0x3557ba345b01efa20a1bddc61f573bfd87195081","network":"Ethereum","wrapper_address":"0xac85d37acbadca37545e21ab0fb991bce8c1187c","wrapper_address_v2":"0x910cabde3eba7fc1ce64fd14bd680b9f60fa0f90"},{"address":"0x3557ba345b01efa20a1bddc61f573bfd87195081","network":"BinanceSmartChain","wrapper_address":"0xac85d37acbadca37545e21ab0fb991bce8c1187c","wrapper_address_v2":"0x910cabde3eba7fc1ce64fd14bd680b9f60fa0f90"},{"address":"0x3557ba345b01efa20a1bddc61f573bfd87195081","network":"Arbitrum","wrapper_address":"0xac85d37acbadca37545e21ab0fb991bce8c1187c","wrapper_address_v2":"0x910cabde3eba7fc1ce64fd14bd680b9f60fa0f90"},{"address":"Xs3eBt7uRfJX8QUs4suhyU8p2M6DoUDrJyWBa8LLZsg","network":"Solana"},{"address":"TKbZf7Ni93pAB6ZHQLR2BxbnukRsB3WNvh","network":"Tron"},{"address":"EQCtD2-7qxHhQoNhxri2JSzH-dlmWqKYCDtlEZqRi3-56gd9","network":"Ton"},{"address":"0x3557ba345b01efa20a1bddc61f573bfd87195081","network":"Mantle","wrapper_address":"0xac85d37acbadca37545e21ab0fb991bce8c1187c","wrapper_address_v2":"0x910cabde3eba7fc1ce64fd14bd680b9f60fa0f90"},{"address":"0x3557ba345b01efa20a1bddc61f573bfd87195081","network":"HyperEVM","wrapper_address_v2":"0x910cabde3eba7fc1ce64fd14bd680b9f60fa0f90"},{"address":"0x3557ba345b01efa20a1bddc61f573bfd87195081","network":"Ink","wrapper_address_v2":"0x910cabde3eba7fc1ce64fd14bd680b9f60fa0f90"},{"address":"0x3557ba345b01efa20a1bddc61f573bfd87195081","network":"XLayer","wrapper_address_v2":"0x910cabde3eba7fc1ce64fd14bd680b9f60fa0f90"},{"address":"0x3557ba345b01efa20a1bddc61f573bfd87195081","network":"Optimism","wrapper_address_v2":"0x910cabde3eba7fc1ce64fd14bd680b9f60fa0f90"},{"address":"0x3557ba345b01efa20a1bddc61f573bfd87195081","network":"Monad","wrapper_address_v2":"0x910cabde3eba7fc1ce64fd14bd680b9f60fa0f90"}],"source":"xstocks-api","source_url":"https://api.xstocks.fi/api/v2/public/assets","ticker":"AMZN"},"registry_hash":"5cba327d28b997e47a2f9585c769494bf288e805a0a5198c6d44c6247cf31a0b","signer":"GJWKkiUd3zj1pJGfeE7JitiPiwDJC6XmNFvpJWJuvvpn","slot":null,"subject":"0x31ef8e9b2bca002d1674b7854edf5c3bbf7a6c2a844ae73c8c20ab021496391f","ticker":"AMZN","verdict":{"Verified":{"issuer":"Backed xStocks","ticker":"AMZN"}},"version":1}

Signature

WydLGvBHJgomTSWtghblA5hmzlLdE/k+ZCxvkKmLhTeyfh2MLPrWRA2MXFyKLAmSJfZWP2WulY/VjeZC8hzxCg==

API call

GET /api/attest/feaad2097524b9b5abc732bb9c52b55351a05369cc94669bfc8262a62e53e3b3

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.