Does GLWx / 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":26247670,"chain":"ethereum","checked_at":"2026-10-22T10:51:31Z","dev":false,"expires_at":"2026-10-23T10:51:31Z","issuer":"Backed xStocks","pool":{"base":{"address":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","balance":"18174578","decimals":6,"symbol":"USDC"},"chain":"ethereum","dex":"uniswap-v4","pool":"0x2283b61473586aae25ee443d414ecdd57a7fbd3262ae5169c493b7d9a7b78afb","quote":{"address":"0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","balance":"122945503090894571","decimals":18,"symbol":"GLWx"}},"quote_share_of_supply":4.026290915520375e-6,"reads":[{"block":null,"method":"eth_call","params":["0xbd216513d74c8cf14cf4747e6aaa6420ff64ee9e","poolKeys","0x2283b61473586aae25ee443d414ecdd57a7fbd3262ae5169c4"],"raw_result":"Object {\"currency0\": String(\"0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48\"), \"currency1\": String(\"0xdc12f19af085310e952e0a03b173faacddead8c2\"), \"fee\": String(\"910000\"), \"hooks\": String(\"0x0000000000000000000000000000000000000000\"), \"tickSpacing\": String(\"18200\")}","result_hash":"65c91633649e64b53f409eeb5d33b11857198cb871fc1130729deec791bedd40","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getSlot0","0x2283b61473586aae25ee443d414ecdd57a7fbd3262ae5169c493b7d9a7b78afb"],"raw_result":"true","result_hash":"18d10c7d2b4b04aaf04254d1ae5d655a5dc0407cbcdd5a8c3986e985370f36ee","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getLiquidity","0x2283b61473586aae25ee443d414ecdd57a7fbd3262ae5169c493b7d9a7b78afb"],"raw_result":"1494818637367","result_hash":"d6846342945fa30dfb3cf08fd26b14989ff7276c21e16729b0f21741f342cf1c","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":["0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","symbol()"],"raw_result":"Some(\"GLWx\")","result_hash":"c89bcfdecc7c24eb894d6774b4a20938b3092692eeed9ddbdefae40232e636e3","slot":null},{"block":null,"method":"eth_call","params":["0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":26247670,"method":"eth_blockNumber","params":[],"result_hash":"bab61528b462e155868e22bcd11a07dca10e86df199165d56136aef4ffa31c7e","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(\"48102884929622515\")","result_hash":"955d2698b5625805c9842b75f836f9ce6589112761afc3b902f909239ee3b88b","slot":null},{"block":null,"method":"eth_call","params":["0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","symbol()"],"raw_result":"Some(\"GLWx\")","result_hash":"c89bcfdecc7c24eb894d6774b4a20938b3092692eeed9ddbdefae40232e636e3","slot":null},{"block":null,"method":"eth_call","params":["0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","name()"],"raw_result":"Some(\"Corning xStock\")","result_hash":"c119bd9c9954a8f761b13fa22951cf35f41b3d4736363b044b126eef17126657","slot":null},{"block":null,"method":"eth_call","params":["0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","totalSupply()"],"raw_result":"Some(\"30535673072447268106295\")","result_hash":"6c010f6ba84d344c971bba2e8e0fb9c81d27a906cf0a342fa8c33317d55cd3bb","slot":null},{"block":null,"method":"eth_getCode","params":["0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null},{"block":null,"method":"eth_getCode","params":["0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null}],"registry_entry":{"chain":"ethereum","contract":"0xDC12f19AF085310e952e0A03b173fAaCdDeAD8c2","decimals":null,"issuer":"Backed xStocks","last_checked":"2026-10-22T10:11:43Z","name":"Corning","official_deployments":[{"address":"0xdc12f19af085310e952e0a03b173faacddead8c2","network":"Ethereum","wrapper_address_v2":"0x4cecfc4ff06b983af580f164b7adc19785a053e1"},{"address":"0xdc12f19af085310e952e0a03b173faacddead8c2","network":"BinanceSmartChain","wrapper_address_v2":"0x4cecfc4ff06b983af580f164b7adc19785a053e1"},{"address":"0xdc12f19af085310e952e0a03b173faacddead8c2","network":"Arbitrum","wrapper_address_v2":"0x4cecfc4ff06b983af580f164b7adc19785a053e1"},{"address":"Xsg3UgvjxpUgV3WZx9Wt9deLx7qvKYp6ZLY6xMY2Dfq","network":"Solana"},{"address":"EQDb_R6oAj2XJx6J51iCZW0_HMhvaGqAq3Cjr-yMr6FBqEgS","network":"Ton"},{"address":"0xdc12f19af085310e952e0a03b173faacddead8c2","network":"Mantle","wrapper_address_v2":"0x4cecfc4ff06b983af580f164b7adc19785a053e1"},{"address":"0xdc12f19af085310e952e0a03b173faacddead8c2","network":"HyperEVM"},{"address":"0xdc12f19af085310e952e0a03b173faacddead8c2","network":"Ink","wrapper_address_v2":"0x4cecfc4ff06b983af580f164b7adc19785a053e1"},{"address":"0xdc12f19af085310e952e0a03b173faacddead8c2","network":"XLayer","wrapper_address_v2":"0x4cecfc4ff06b983af580f164b7adc19785a053e1"},{"address":"0xdc12f19af085310e952e0a03b173faacddead8c2","network":"Optimism","wrapper_address_v2":"0x4cecfc4ff06b983af580f164b7adc19785a053e1"},{"address":"0xdc12f19af085310e952e0a03b173faacddead8c2","network":"Monad","wrapper_address_v2":"0x4cecfc4ff06b983af580f164b7adc19785a053e1"}],"source":"xstocks-api","source_url":"https://api.xstocks.fi/api/v2/public/assets","ticker":"GLW"},"registry_hash":"b5dff7b8d7f5ed15e9c1f23895249910c0012b90becc15a0b62d06a6a18b1323","signer":"GJWKkiUd3zj1pJGfeE7JitiPiwDJC6XmNFvpJWJuvvpn","slot":null,"subject":"0x2283b61473586aae25ee443d414ecdd57a7fbd3262ae5169c493b7d9a7b78afb","ticker":"GLW","verdict":{"Verified":{"issuer":"Backed xStocks","ticker":"GLW"}},"version":1}

Signature

goq0sJFMW4Wq50CMe0l9MSrYHSVCyxzcAsl/Xt6wa1WtN7/wobSiQXkCJArjUctL3IZfI1JqNVd2SCLNUvRXDg==

API call

GET /api/attest/de23ab0be4857acceda4769f283da0ce9f13b39d647662b0a1e9bb87a507bec8

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.