{"uid":"cap_1-fO3dkBA3CwTC5iqFQ5x","slug":"x402-audit-wallet-balance-eth-erc-20-77dbb373","name":"x402-audit Wallet Balance (ETH/ERC-20)","description":"Pay-per-call on-chain API for AI agents and developers: wallet audits, token safety audits (honeypot detection), live gas prices, token prices, transaction receipts, balances, ENS resolution, block data, ERC-20 allowances, transaction simulation, swap quotes and multicall batches — all computed on-chain via public RPCs (no external market API). Pay per request in USDC on Base via the x402 exact scheme (EIP-3009 transferWithAuthorization). No API key, no signup, no subscription.","url":"https://x402-audit.tatschluizguilherme.workers.dev/balance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":null,"responseSchema":{"type":"json","example":{"token":null,"native":true,"symbol":"ETH","address":"0x8e8d53a67b59E6f2A28e0d6d52012A2b0e3E1886","network":"base","decimals":18,"balanceWei":"194087918645289","blockNumber":24400123,"balanceFormatted":"0.00019408"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"registry","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":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_D28zi5EEenU6Ul2apeC59","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the native ETH or ERC-20 token balance of any wallet address on Base, Optimism, or Ethereum Mainnet, including decimals, formatted value, and current block number — without relying on a block explorer API.","exampleAgentPrompt":"What's the current USDC balance of wallet 0xAbC...123 on Base — give me the formatted amount and the block number it was checked at?","exampleUseCases":[{"title":"Pre-transaction balance check","prompt":"Before I send this swap transaction, can you check how much USDC wallet 0xAbC...123 currently holds on Base so I know there are sufficient funds?"},{"title":"Portfolio audit across networks","prompt":"What's the ETH balance of 0xDef...456 on Ethereum Mainnet right now, including the block number and formatted value?"},{"title":"Token eligibility verification","prompt":"Can you verify whether address 0x789...abc holds at least 100 of token 0xTokenAddr...xyz on Optimism so I can check if they qualify?"}],"resultDescription":"Returns raw balance (in the token's smallest unit), formatted balance (as a human-readable decimal string), token decimals, and the block number at which the balance was read. For native ETH queries no token address is needed; for ERC-20 tokens the contract address is required.","failureModes":["Invalid or malformed wallet address returns an error or zero balance","Unsupported network identifier causes a request failure","Invalid ERC-20 contract address returns an error","RPC/node connectivity issue causes a timeout or 500 error","Querying a non-existent token contract may return zero or revert"],"whenToPreferThis":"Prefer this endpoint when you need a direct on-chain balance read for ETH or any ERC-20 token on Base, Optimism, or Ethereum Mainnet without going through a centralized block explorer like Etherscan. Ideal for pre-flight checks before transactions, balance-based eligibility gates, or portfolio monitoring in an automated agent pipeline. Use it when you need the precise formatted value plus the block number for auditability.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T12:39:30.337Z","isFirstParty":false,"canonicalSlug":"x402-audit-wallet-balance-eth-erc-20-77dbb373"}