{"uid":"cap_KcpTF-o-4RE313sqFBLcN","slug":"ethereum-base-address-classifier-4a99f56f","name":"Ethereum/Base Address Classifier","description":"Address label/classify on Base/Ethereum: contract-vs-EOA + code presence (+ENS). Onchain USDC pay-per-call.","url":"https://build-4c941cab041172e9439ece2f.emblem.build/pub/tasks/x402-onchain/api/address","method":"POST","headers":{},"bodySchema":null,"responseSchema":null,"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_Oqz2MiuIfW7qy1Sl1mTFh","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":"Classifies an Ethereum or Base address as contract vs. EOA, checks for bytecode presence, and resolves ENS names, paid per-call in USDC onchain.","exampleAgentPrompt":"Is the address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Ethereum a smart contract or a regular wallet, and can you resolve its ENS name?","exampleUseCases":[{"title":"Verify counterparty before DeFi interaction","prompt":"Before I interact with 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum, can you tell me whether it's a smart contract or a plain wallet, and whether it has bytecode deployed?"},{"title":"ENS name resolution for a Base address","prompt":"Can you look up the ENS name and classify the address 0x4838B106FCe9647Bdf1E7877BF73cE8B0BAD5f97 on Base — is it a contract or an EOA?"},{"title":"Audit unknown address in a transaction log","prompt":"I found this address in a transaction log — 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D on Ethereum — can you tell me if it's a contract, if there's code there, and whether it has an ENS name?"}],"resultDescription":"Returns a classification of the given address indicating whether it is a smart contract or an externally owned account (EOA), whether bytecode is present at that address, and any resolved ENS name associated with it.","failureModes":["Invalid or malformed Ethereum address returns a validation error","Address not found on the specified chain returns no-code/EOA result","ENS resolution failure if no reverse record is set","Payment failure if USDC onchain payment is not completed via x402","Unsupported chain identifier returns an error","Network or RPC timeout causes request failure"],"whenToPreferThis":"Choose this endpoint when you need a fast, single-call classification of any EVM address (Ethereum or Base) as contract vs. EOA, with bytecode presence detection and optional ENS resolution, paid trustlessly per-call in USDC. Prefer it over manual RPC calls when you want a clean, agent-ready JSON response without managing your own node or provider credentials.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:54:02.020Z","isFirstParty":false}