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EIP-712 Typed-Data Signature Explainer & Safety Checker
x402
EIP-712 Typed-Data Signature Explainer & Safety Checker is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).
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.
Price / call$0.005
Success—
StatusUnknown
How this service works
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.
Output
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.
Example use cases
Safe USDC payment authorization check
“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'}}.”
EIP-2612 permit unlimited allowance warning
“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}}.”
Seaport NFT order signature review
“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.”
Technical details
Endpoint
POSThttps://api.vextorium.com/revisar-firma-pago?utm_source=zero.xyzWhen to prefer
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.
Side effects
- 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
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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