{"uid":"cap_sU_MxAx4UFQl4J-yTlQ8a","slug":"agentresolver-eip-712-hash-computation-32968905","name":"AgentResolver EIP-712 Hash Computation","description":"Verify an x402 endpoint before paying: live payTo, USDC quote, network, asset, resource binding, TLS and endpoint safety for $0.001 on Base or Solana.","url":"https://agentresolver.vercel.app/api/eip712-hash","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"types":{"type":"object"},"domain":{"type":"object"},"message":{"type":"object"},"primaryType":{"type":"string","maxLength":128,"minLength":1}}},"responseSchema":{"type":"json","example":{}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","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_TmPGMwlbIit5w6gNOff2m","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes an EIP-712 structured data hash from typed domain, message, and primary type inputs for use in x402 payment signing flows","exampleAgentPrompt":"Can you compute the EIP-712 hash for my payment authorization message? The primaryType is 'Payment', the domain includes name 'x402' and chainId 8453, and my message has recipient, amount, and nonce fields.","exampleUseCases":[{"title":"Hash x402 payment authorization before signing","prompt":"I need to hash an EIP-712 structured message for an x402 payment — the primaryType is 'PaymentAuthorization', domain is for Base mainnet chainId 8453, and the message contains the payTo address, USDC amount, and a nonce. Can you compute the digest so I can sign it?"},{"title":"Verify structured data encoding correctness","prompt":"Before I send my signing request, can you compute the EIP-712 hash for this typed data to make sure my encoding is correct? The primaryType is 'Transfer', domain has name 'MyApp' and version '1', and the message has 'to', 'amount', and 'deadline' fields."},{"title":"Prepare digest for smart contract permit flow","prompt":"I'm building a gasless transaction and need the EIP-712 hash for a permit message — primaryType is 'Permit', the domain has the token contract address as verifyingContract on chainId 8453, and the message includes owner, spender, value, nonce, and deadline."}],"resultDescription":"Returns a JSON object containing the computed EIP-712 structured data hash (digest) derived from the provided types, domain, message, and primaryType — ready to be signed by a wallet or used in payment verification flows.","failureModes":["Missing or malformed primaryType returns a validation error","Mismatched types definition and message fields cause hash computation failure","Invalid domain object structure results in encoding error","Empty or null message object returns an error response","Malformed JSON body returns HTTP 400"],"whenToPreferThis":"Use this endpoint when you need to compute a deterministic EIP-712 structured data hash from raw typed data components — especially in x402 payment preflight flows on Base or Solana where you need a signable digest before submitting a payment authorization. Prefer this over local computation when you want a trusted, hosted EIP-712 encoder without implementing the ABI encoding yourself.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-19T06:42:28.044Z","isFirstParty":false}