{"uid":"cap_sMF7JJghIzSKqsNDBGYhS","slug":"eip-712-typed-data-signature-explainer-safety-checker-5428c02c","name":"EIP-712 Typed-Data Signature Explainer & Safety Checker","description":"Explain an EIP-712 typed-data signature before signing it: x402/EIP-3009 payment authorizations, EIP-2612 permits, Permit2 and Seaport orders. Flags unlimited allowances, long validity and non-official tokens, and returns the exact hash to compare with your wallet.","url":"https://api.vextorium.com/revisar-firma-pago?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"required":["datos_firma"],"properties":{"datos_firma":{"type":"object","description":"EIP-712 object as passed to eth_signTypedData_v4: domain, types, primaryType, message"}}},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":["object","null"],"properties":{"red":{"type":["string","null"]},"nota":{"type":["string","null"]},"tipo":{"type":["string","null"]},"alertas":{"type":["array","null"],"items":{}},"resumen":{"type":["object","null"],"properties":{"para":{"type":["string","null"]},"desde":{"type":["string","null"]},"token":{"type":["string","null"]},"accion":{"type":["string","null"]},"importe":{"type":["string","null"]},"valido_desde":{"type":["string","null"]},"valido_hasta":{"type":["string","null"]}}},"veredicto":{"type":["string","null"]},"aplicacion":{"type":["string","null"]},"hash_a_firmar":{"type":["string","null"]},"hash_del_mensaje":{"type":["string","null"]},"contrato_verificador":{"type":["string","null"]},"separador_de_dominio":{"type":["string","null"]}}}}}}},"responseSchema":{"type":"json","example":{"red":"Base","nota":"Compara 'hash_a_firmar' con el que muestre tu wallet: si coinciden, firmas exactamente esto.","tipo":"TransferWithAuthorization","alertas":[],"resumen":{"para":"0x2222222222222222222222222222222222222222","desde":"0x1111111111111111111111111111111111111111","token":"USDC oficial","accion":"Autorizar un pago (EIP-3009, el que usa x402 en redes EVM)","importe":"0.01 USDC","valido_desde":"2026-09-28 22:21 UTC","valido_hasta":"2026-09-28 22:27 UTC"},"veredicto":"ok","aplicacion":"USD Coin","hash_a_firmar":"0x06a81ecc73b8782ba9eb12a8dabd4e939c996fdf315485be12b25b0272724806","hash_del_mensaje":"0xa77c7438121ad832f331edb2dd5a83d0eb089d6d9ebc14b26dc245ea9f447b32","contrato_verificador":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","separador_de_dominio":"0x02fa7265e7c5d81118673727957699e4d68f74cd74b7db77da710fe8a2c7834f"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"registry","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_WkRJsT1Vj6HMBnPItGt-u","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Decodes and audits EIP-712 typed-data signature requests (x402/EIP-3009 payment authorizations, EIP-2612 permits, Permit2, Seaport orders) before signing, flagging risks and returning the exact hash to verify.","exampleAgentPrompt":"Before I sign this wallet request, can you decode and safety-check this EIP-712 payload for me? Here's the typed-data object from MetaMask: {domain: {name: 'USDC', chainId: 1, verifyingContract: '0xa0b8...'}, primaryType: 'TransferWithAuthorization', types: {...}, message: {from: '0xabc...', to: '0xdef...', value: '500000000', validAfter: 0, validBefore: 9999999999, nonce: '0x...'}} — flag any unlimited allowances, suspicious validity windows, or non-official tokens.","exampleUseCases":[{"title":"Safe USDC payment authorization check","prompt":"I'm about to sign a TransferWithAuthorization for USDC on Base — can you decode this eth_signTypedData_v4 payload and tell me exactly who gets paid, how much, for how long it's valid, and whether anything looks risky? Here's the typed-data: {domain: {name:'USD Coin', version:'2', chainId:8453, verifyingContract:'0x833589...'}, primaryType:'TransferWithAuthorization', types:{...}, message:{from:'0xMyWallet', to:'0xMerchant', value:'10000000', validAfter:0, validBefore:1800000000, nonce:'0xabc'}}."},{"title":"EIP-2612 permit unlimited allowance warning","prompt":"My DeFi app is asking me to sign this EIP-2612 permit — can you tell me what it actually allows before I approve it? I need to know the spender, the token, and whether the allowance is unlimited or expiry is suspiciously long. Typed-data: {domain:{name:'DAI',version:'1',chainId:1,verifyingContract:'0x6B175...'}, primaryType:'Permit', types:{...}, message:{owner:'0xMe',spender:'0xUnknown',value:'115792089237316195423570985008687907853...',nonce:0,deadline:9999999999}}."},{"title":"Seaport NFT order signature review","prompt":"OpenSea wants me to sign a Seaport order to sell my NFT — can you decode this EIP-712 payload and confirm what item I'm listing, at what price, and whether any of the fees or conditions look off? Here's the full typed-data object from the Seaport contract on mainnet."}],"resultDescription":"Returns a structured JSON with: a human-readable summary (action, from/to addresses, token, amount, validity window), a verdict (safe/warning/danger), an array of alerts for risks like unlimited allowances or long validity, the application and verifier contract address, the exact hash-to-sign for wallet comparison, domain separator, and message hash.","failureModes":["Malformed or incomplete EIP-712 object returns a validation error","Unrecognized primaryType may result in partial decoding with reduced summary detail","Non-standard token contracts may trigger 'non-official token' alert rather than a hard error","Missing required fields in typed-data (domain, types, primaryType, message) cause a 400-style error","Chain ID not recognized may limit network identification"],"whenToPreferThis":"Use this endpoint when an AI agent or user needs to understand and safety-check an EIP-712 typed-data signature request before signing — especially for x402/EIP-3009 payment authorizations, EIP-2612 permits, Permit2, or Seaport orders. It is the right choice when the goal is risk analysis and human-readable explanation rather than executing a transaction. Prefer it over generic blockchain explorers when you need structured alerts (unlimited allowance, long validity, non-official token) and the exact signing hash for wallet verification.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T00:44:59.547Z","isFirstParty":false,"canonicalSlug":"eip-712-typed-data-signature-explainer-safety-checker-5428c02c"}