{"uid":"cap_9wG9d6ZFdtVuWi24eoASN","slug":"erc-721-safe-transfer-calldata-builder-59cfeed7","name":"ERC-721 Safe Transfer Calldata Builder","description":"Build ERC-721 safe transfer calldata","url":"https://evm-canon-base.onrender.com/encode/nft-transfer","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":{"type":"object","required":["args"],"properties":{"args":{"type":"object","description":"arguments keyed by parameter name"},"chain":{"description":"chain name, alias or numeric chainId"},"token":{"type":"string","description":"symbol or contract address"},"value":{"type":"string","description":"native value in wei"},"function":{"type":"string","description":"name or full signature (generic route only)"}}},"type":{"type":"string","const":"http"},"method":{"enum":["POST","PUT","PATCH"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_BLxaF8XkKbXM7Joao2HZY","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Encodes ERC-721 safeTransferFrom calldata for NFT transfers on EVM-compatible chains","exampleAgentPrompt":"Build me the ERC-721 safeTransferFrom calldata to send token ID 42 from 0xAbCd...1234 to 0xDeFa...5678 on the NFT contract at 0x1234...abcd.","exampleUseCases":[{"title":"NFT wallet transfer automation","prompt":"I need to move NFT token ID 7 from my wallet 0xAaAa...1111 to my cold storage at 0xBbBb...2222 — the NFT contract is at 0xCcCc...3333. Can you build the safeTransferFrom calldata for me?"},{"title":"Agent-driven NFT marketplace listing","prompt":"My marketplace bot needs to transfer NFT token ID 999 from seller 0xSell...0001 to buyer 0xBuye...0002 on contract 0xNFTc...0003 — generate the ERC-721 safe transfer calldata so we can broadcast the transaction."},{"title":"Batch NFT migration script","prompt":"I'm migrating NFTs to a new contract and need safeTransferFrom calldata for token ID 512, transferring from 0xOld...aaaa to 0xNew...bbbb on the ERC-721 contract 0xContr...cccc — can you encode that for me?"}],"resultDescription":"Returns hex-encoded ABI calldata for an ERC-721 safeTransferFrom function call, ready to be submitted as the data field of an EVM transaction. Includes the 4-byte function selector and encoded parameters for from address, to address, and token ID.","failureModes":["Invalid or non-checksummed Ethereum address returns a 400 error","Missing required fields (contract, from, to, tokenId) cause validation errors","Malformed token ID (non-integer or negative) causes a 400 error","Service unavailable on Render cold start may cause initial latency or timeout"],"whenToPreferThis":"Choose this endpoint when you need to programmatically generate ERC-721 safeTransferFrom calldata without running a local Ethereum library. Ideal for agents or serverless workflows that need raw transaction data for NFT transfers without a full Web3 stack. Prefer this over manual ABI encoding when working with Base or other EVM chains in lightweight environments.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:51:57.114Z","isFirstParty":false}