{"uid":"cap_nJP_SfJfSZIT60thqXegi","slug":"agent402-tools-eip-3009-transfer-authorization-builder-b65a8c7d","name":"agent402.tools EIP-3009 Transfer Authorization Builder","description":"Build the EIP-3009 transferWithAuthorization typed data for a gasless USDC transfer on Base/Polygon/Arbitrum/Optimism/Ethereum/Monad/Celo/Avalanche/Sei - the exact EIP-712 object an agent signs with its OWN key to authorize an x402 payment. We construct it; we never sign or send. Non-custodial.","url":"https://agent402.tools/api/transfer-authorization","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"to":{"type":"string","description":"recipient address"},"from":{"type":"string","description":"payer address (the wallet that will sign)"},"amount":{"type":"number","description":"USDC amount (e.g. 0.01)"},"network":{"type":"string","description":"chain: base | polygon | arbitrum | optimism | ethereum | monad | celo | avalanche | sei | robinhood (default base)"},"validForSeconds":{"type":"number","description":"how long the authorization is valid (default 3600)"}}},"responseSchema":{"type":"json","example":{"network":"base","typedData":{"domain":{"name":"USD Coin","chainId":8453,"version":"2","verifyingContract":"0x833589f…"},"message":{},"primaryType":"TransferWithAuthorization"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_JHBiIQHhyaxAJfNfsEodi","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Constructs the EIP-712 typed data payload for an EIP-3009 transferWithAuthorization gasless USDC transfer, ready for an agent to sign with its own key for x402 payments on EVM chains.","exampleAgentPrompt":"Build the EIP-3009 transferWithAuthorization typed data so I can sign a gasless USDC transfer of 0.05 USDC from my wallet 0xAbC...123 to 0xDeF...456 on Base, valid for 1800 seconds.","exampleUseCases":null,"resultDescription":"Returns a fully constructed EIP-712 typed data object containing the domain separator (contract address, chain ID, USDC token details), the EIP-3009 message struct (from, to, value, validAfter, validBefore, nonce), and all fields required for the agent to call eth_signTypedData_v4 and produce a valid signature for a gasless USDC transfer. The service constructs but never signs.","failureModes":["Invalid Ethereum address format for 'from' or 'to' — returns 400 with address validation error","Unsupported network value — returns 400 listing valid chain options","Amount out of range or non-numeric — returns 400 with schema error","Service unavailable or timeout fetching on-chain nonce — returns 502 or 503","Missing required fields (from, to, amount) — returns 400 with field-level error detail"],"whenToPreferThis":"Use this endpoint when an AI agent needs to autonomously authorize a gasless USDC payment using the x402 protocol on Base, Polygon, Arbitrum, Optimism, or Ethereum — specifically when you need the EIP-712 typed data structure for EIP-3009 transferWithAuthorization. Prefer this over manual construction to avoid encoding errors in domain separators or nonce derivation. Not needed if you are executing a standard on-chain USDC transfer with gas or using a different token.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T06:56:57.131Z","isFirstParty":false}