{"uid":"cap_eI-xu-Tz7Ge_ydUS3tnCp","slug":"base-chain-address-lookup-88774c1b","name":"Base Chain Address Lookup","description":"Base wallet lookup / address balance: ETH balance, transaction count (nonce) and whether the address is a smart contract or an ordinary wallet (EOA), live from Base mainnet in one call. Use it to check a counterparty, deposit address or contract before paying it. Input: address (0x...). For token balances or any other read use chain.rpc.","url":"https://hubvibe-io.com/work/chain/address?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"address":{"type":"string"},"language":{"type":"string","pattern":"^[A-Za-z]{2,3}(-[A-Za-z0-9]{2,8})*$","maxLength":35}}},"responseSchema":{"type":"json","example":{"result":{"address":"0x837C40E2B4e976f43Ffb4451eE281A00fA9477dd","network":"base-mainnet","balance_eth":1.25,"balance_wei":"1250000000000000000","is_contract":false,"code_size_bytes":0,"transaction_count":42},"status":"ok","worker":"chain.address","price_usd":0.05,"provenance":{"steps":[{"ms":640,"ok":true,"step":"address","provider":"base_rpc"}],"attempts":1,"elapsed_ms":660,"providers_used":["base_rpc"]},"receipt_id":"rcpt_9f1c2b3a4d5e6f70","receipt_url":"/work/receipts/rcpt_9f1c2b3a4d5e6f70"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.05","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":"$0.05/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_GkUuTPqLdy3siJlyYo55F","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.05","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns ETH balance, transaction count, and account type (contract vs EOA) for a single Base mainnet address in one call","exampleAgentPrompt":"Can you look up the ETH balance, transaction count, and whether the address 0x742d35Cc6634C0532925a3b844Bc454e4438f44e is a smart contract or a regular wallet on Base mainnet?","exampleUseCases":[{"title":"Wallet due-diligence before a transfer","prompt":"Before I send funds, can you check 0x4838B106FCe9647Bdf1E7877BF73cE8B0BAD5f97 on Base — how much ETH it holds, how many transactions it's done, and whether it's a contract or a real wallet?"},{"title":"Verify a counterparty's on-chain activity","prompt":"I'm about to work with someone who gave me their Base address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 — can you pull their ETH balance and transaction count so I can see if they're an active user?"},{"title":"Detect smart contract addresses in a list","prompt":"Is the address 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD on Base a smart contract or a regular externally owned account? Also grab its ETH balance and tx count."}],"resultDescription":"Returns three aggregated chain-read values for the given Base mainnet address: (1) current ETH balance, (2) total transaction count (nonce), and (3) a flag indicating whether the address is a smart contract or an externally owned account (EOA).","failureModes":["Invalid or malformed address (not 0x-prefixed or wrong length) — likely returns a 400-level error","Address not found or never used on Base — may return zero values for balance and tx count","Base RPC node unavailability or timeout — may return 5xx error","Payment failure or insufficient USDC balance — x402 payment error before the call is processed"],"whenToPreferThis":"Choose this endpoint when you need a quick, consolidated snapshot of a Base mainnet address — especially when you need all three data points (balance, tx count, account type) and want to avoid making three separate RPC calls. Ideal for due-diligence checks, wallet validation, and contract-detection workflows where cost ($0.05/call) is acceptable for the convenience of a single aggregated response.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-27T18:40:08.069Z","isFirstParty":false,"canonicalSlug":"base-chain-address-lookup-88774c1b"}