{"uid":"cap_mLFAE25Q90tp-tl_GDTAm","slug":"base-chain-wallet-balance-lookup-46c3b1be","name":"Base Chain Wallet Balance Lookup","description":"Pay-per-call crypto microdata for trading/onchain AI agents via x402 (USDC on Base): Base gas, token risk, balances, multi-venue prices, Hyperliquid book/funding, kimchi premium. No API keys.","url":"https://kr-x402-mvp.kgy5612.workers.dev/api/chain/balance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["wallet"],"properties":{"wallet":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","examples":["0xe4be4d0bd82d8e68203deff81f79ede0529f2617"],"description":"Wallet"}},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"block":53204016,"chain":"base","nonce":0,"wallet":"0xe4be4d0bd82d8e68203deff81f79ede0529f2617","balance_eth":0,"balance_wei":"0"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_kBojf3QGqnZQ0kwua2xPP","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the current ETH balance (in both ETH and Wei), nonce, and block number for a given wallet address on the Base network, paid via x402 USDC microtransaction.","exampleAgentPrompt":"What's the current ETH balance on Base for wallet 0xe4be4d0bd82d8e68203deff81f79ede0529f2617? I need the balance in both ETH and Wei along with the nonce.","exampleUseCases":[{"title":"Pre-trade liquidity check for DeFi agent","prompt":"Before I execute that swap on Base, check the ETH balance for wallet 0xe4be4d0bd82d8e68203deff81f79ede0529f2617 so I know if there's enough gas to cover the transaction."},{"title":"Portfolio balance snapshot","prompt":"What's the current ETH balance on Base for 0x742d35Cc6634C0532925a3b8D4C9C0F4AC99E9B2? I want to track my onchain holdings."},{"title":"Nonce verification before transaction submission","prompt":"Check the nonce and ETH balance for Base wallet 0xAbCd1234567890AbCd1234567890AbCd12345678 — I need to make sure the nonce is current before I broadcast my next transaction."}],"resultDescription":"Returns a JSON object with the wallet's ETH balance as a decimal float, balance in Wei as a string, current nonce, the Base chain identifier, and the latest block number at time of query.","failureModes":["Invalid wallet address format (not matching 0x + 40 hex chars) returns a validation error","Wallet address not found or zero-balance wallet returns balance_eth: 0 and balance_wei: '0' (valid response, not an error)","x402 payment failure if the agent's USDC balance on Base is insufficient","Network/RPC timeout on Base may return a 5xx error","Malformed query param key returns 400 bad request"],"whenToPreferThis":"Choose this endpoint when your agent needs a lightweight, no-API-key balance lookup for a specific Base wallet address and is already operating in an x402 USDC micropayment context. Ideal for DeFi trading bots, portfolio trackers, or pre-transaction gas checks that need real-time Base chain data without managing API credentials.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:42:11.478Z","isFirstParty":false,"canonicalSlug":"base-chain-wallet-balance-lookup-46c3b1be"}