{"uid":"cap_Ms5LOhgcw8y22PvKOu5p4","slug":"agent-data-tools-base-eth-balance-lookup-c09ff799","name":"Agent Data Tools – Base ETH Balance Lookup","description":"Native ETH balance (eth_getBalance) of any 0x wallet address on Base at the latest block, in wei and in ETH. Use to check whether a wallet can pay gas or a transfer; for ERC-20 tokens use base_token_balance, for all holdings at once use wallet_portfolio. A malformed address is rejected with 400, uncharged.","url":"https://agent-data-tools.revmesh2074.workers.dev/base/balance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","required":["address"],"properties":{"address":{"type":"string","description":"0x wallet or contract address"}}},"responseSchema":{"type":"object","properties":{"block":{"type":"number"},"chain":{"type":"string"},"symbol":{"type":"string"},"address":{"type":"string"},"balance":{"type":"string"},"chainId":{"type":"number"},"balanceWei":{"type":"string"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","displayCostAsset":"USD","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_KloEDk7HPz042V_gDMZGJ","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":"Returns the native ETH balance of any wallet or contract address on the Base blockchain, including the block number, balance in ETH and Wei.","exampleAgentPrompt":"What's the current ETH balance of the wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Base — show me both the human-readable ETH amount and the raw Wei value?","exampleUseCases":[{"title":"Portfolio balance snapshot on Base","prompt":"Can you check how much ETH is sitting in 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Base right now? I need both the ETH amount and the block it was read at."},{"title":"Smart contract ETH reserves check","prompt":"Look up the ETH balance held by the contract at 0xAbC1234567890abcdef1234567890abcdef123456 on Base — I want to know if it has enough reserves."},{"title":"Automated agent treasury monitoring","prompt":"Check the ETH balance of our treasury wallet 0x1234567890abcdef1234567890abcdef12345678 on Base so I can decide whether we need to top it up."}],"resultDescription":"Returns a JSON object containing: the wallet/contract address queried, the chain name ('Base'), the chain ID (8453), the native token symbol ('ETH'), the balance formatted as a human-readable decimal string, the balance in Wei as a string, and the block number at which the balance was read.","failureModes":["Invalid or malformed 0x address returns an error response","Address not found or zero-balance address returns balance of '0'","Network congestion on Base may cause slow or timeout responses","Payment failure via x402 (insufficient USDC) results in no charge and no response","Rate limiting if many rapid calls are made"],"whenToPreferThis":"Choose this endpoint when you need a quick, no-account, pay-per-call native ETH balance check on the Base network specifically. It is ideal for AI agents that need on-chain balance data without setting up API keys or managing subscriptions. Prefer this over RPC node providers when you want micropayment-based access ($0.001/call in USDC) and don't want to manage node infrastructure. Not suitable for ERC-20 token balances or balances on other chains (use sibling endpoints for Ethereum, Arbitrum, Optimism, Polygon).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-28T12:36:33.661Z","isFirstParty":false,"canonicalSlug":"agent-data-tools-base-eth-balance-lookup-c09ff799"}