Does MRVLx / 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":26263934,"chain":"ethereum","checked_at":"2026-10-24T17:14:43Z","dev":false,"expires_at":"2026-10-25T17:14:43Z","issuer":"Backed xStocks","pool":{"base":{"address":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","balance":"747281886","decimals":6,"symbol":"USDC"},"chain":"ethereum","dex":"uniswap-v4","pool":"0xcfa3afa1ef6489afd1587465a9830f72be961c8025589988e7f6c80aead830e8","quote":{"address":"0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","balance":"2817721559558428374","decimals":18,"symbol":"MRVLx"}},"quote_share_of_supply":0.00002415848487658586,"reads":[{"block":null,"method":"eth_call","params":["0xbd216513d74c8cf14cf4747e6aaa6420ff64ee9e","poolKeys","0xcfa3afa1ef6489afd1587465a9830f72be961c8025589988e7"],"raw_result":"Object {\"currency0\": String(\"0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48\"), \"currency1\": String(\"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88\"), \"fee\": String(\"20000\"), \"hooks\": String(\"0x0000000000000000000000000000000000000000\"), \"tickSpacing\": String(\"400\")}","result_hash":"c02167c4c53e745628af807c5bb1f299232387f1b9fbf6d8cfa3107284dfb749","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getSlot0","0xcfa3afa1ef6489afd1587465a9830f72be961c8025589988e7f6c80aead830e8"],"raw_result":"true","result_hash":"18d10c7d2b4b04aaf04254d1ae5d655a5dc0407cbcdd5a8c3986e985370f36ee","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getLiquidity","0xcfa3afa1ef6489afd1587465a9830f72be961c8025589988e7f6c80aead830e8"],"raw_result":"45887169053725","result_hash":"4f8002af0f1794907c57608e1082112a6fbb4924e46e117168706f820e3ed495","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":["0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","symbol()"],"raw_result":"Some(\"MRVLx\")","result_hash":"c37ea2d043e5900503fd06a0cb6e6e75e626d8abc0fb5b7a13fe23da34000e05","slot":null},{"block":null,"method":"eth_call","params":["0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":26263934,"method":"eth_blockNumber","params":[],"result_hash":"0830dd910d273fa56c5333db5fcef9958ad3e50aa5650e3f862bbc54aeb6ef44","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(\"47751685700095060\")","result_hash":"88bcc45125c8465390c65582b1e56d9b5aa00e1897961cc3fdce6e896aae2f61","slot":null},{"block":null,"method":"eth_call","params":["0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","symbol()"],"raw_result":"Some(\"MRVLx\")","result_hash":"c37ea2d043e5900503fd06a0cb6e6e75e626d8abc0fb5b7a13fe23da34000e05","slot":null},{"block":null,"method":"eth_call","params":["0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","name()"],"raw_result":"Some(\"Marvell xStock\")","result_hash":"e168ba996c57b4eebace93256058120ffd32456a72a87347defb97f686355c53","slot":null},{"block":null,"method":"eth_call","params":["0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","totalSupply()"],"raw_result":"Some(\"116634862407672468785490\")","result_hash":"2508374bc6e65e0a181a157b100d1183024b2c7b1c71a2c5bd1a79c45ad09045","slot":null},{"block":null,"method":"eth_getCode","params":["0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null},{"block":null,"method":"eth_getCode","params":["0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null}],"registry_entry":{"chain":"ethereum","contract":"0xeAAd46F4146Ded5a47B55AA7F6c48c191dEAEC88","decimals":null,"issuer":"Backed xStocks","last_checked":"2026-10-24T16:48:46Z","name":"Marvell","official_deployments":[{"address":"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88","network":"Ethereum","wrapper_address":"0x0d6fce45796d5c00689c0916b976645a0ff1f0ce","wrapper_address_v2":"0xb4ee60b6b817ca7386422ef1a0f45eaddea13275"},{"address":"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88","network":"BinanceSmartChain","wrapper_address":"0x0d6fce45796d5c00689c0916b976645a0ff1f0ce","wrapper_address_v2":"0xb4ee60b6b817ca7386422ef1a0f45eaddea13275"},{"address":"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88","network":"Arbitrum","wrapper_address":"0x0d6fce45796d5c00689c0916b976645a0ff1f0ce","wrapper_address_v2":"0xb4ee60b6b817ca7386422ef1a0f45eaddea13275"},{"address":"XsuxRGDzbLjnJ72v74b7p9VY6N66uYgTCyfwwRjVCJA","network":"Solana"},{"address":"TB6SgnNZyqz2KnFRw6yQM7AqVSCphfvBXy","network":"Tron"},{"address":"EQDr0UNbQ3fLjH9czsFp-Uq9AG_BLP87yc6abzKfQS727x51","network":"Ton"},{"address":"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88","network":"Mantle","wrapper_address":"0x0d6fce45796d5c00689c0916b976645a0ff1f0ce","wrapper_address_v2":"0xb4ee60b6b817ca7386422ef1a0f45eaddea13275"},{"address":"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88","network":"HyperEVM"},{"address":"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88","network":"Ink","wrapper_address_v2":"0xb4ee60b6b817ca7386422ef1a0f45eaddea13275"},{"address":"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88","network":"XLayer","wrapper_address_v2":"0xb4ee60b6b817ca7386422ef1a0f45eaddea13275"},{"address":"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88","network":"Optimism","wrapper_address_v2":"0xb4ee60b6b817ca7386422ef1a0f45eaddea13275"},{"address":"0xeaad46f4146ded5a47b55aa7f6c48c191deaec88","network":"Monad","wrapper_address_v2":"0xb4ee60b6b817ca7386422ef1a0f45eaddea13275"}],"source":"xstocks-api","source_url":"https://api.xstocks.fi/api/v2/public/assets","ticker":"MRVL"},"registry_hash":"875caaae33462352de557e32fb0c2eaad153831bdcad79185f569e93183515eb","signer":"GJWKkiUd3zj1pJGfeE7JitiPiwDJC6XmNFvpJWJuvvpn","slot":null,"subject":"0xcfa3afa1ef6489afd1587465a9830f72be961c8025589988e7f6c80aead830e8","ticker":"MRVL","verdict":{"Verified":{"issuer":"Backed xStocks","ticker":"MRVL"}},"version":1}

Signature

Sa1R7ZznehgQ6+SFJjxJyivzqBUgn2nZNuzF7z62yiTwcZn9BaMZNDxVBDUqnOk+AMbfJ0hOaHCUI57ck+poDg==

API call

GET /api/attest/6c87e1a7804ffc4ba492739bcd422200b08fecf29362b33835fd4d8a2ba25a75

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.