{"uid":"cap_XDjLFfigA-AJwVi02kknb","slug":"penny-engine-base-wallet-balance-checker-63bbddff","name":"Penny Engine — Base Wallet Balance Checker","description":"Machine-to-machine result validation via x402. One structured call, deterministic PASS or FAIL and SHA-256 fingerprint, $0.001 USDC on Base.","url":"https://penny-paid-batch-production.up.railway.app/api/base-wallet?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":null,"responseSchema":{"type":"json","example":{"eth":{"balance":"0.000000000000000000","decimals":18},"usdc":{"balance":"0.000000","decimals":6},"address":"0x72ded73b99cffedfc83f5fa74640cdbd1e642ba9","network":"eip155:8453","checkedAt":"example","blockNumber":0}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_yb1yfylEvqoQ-H3Wpy48A","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the ETH and USDC balances, address, network, and block number for a Base-chain wallet, paid via x402 micropayment.","exampleAgentPrompt":"What are the current ETH and USDC balances for the Base wallet at 0x72ded73b99cffedfc83f5fa74640cdbd1e642ba9?","exampleUseCases":[{"title":"Agent pre-flight funds check","prompt":"Before my AI agent submits the next batch of transactions, check whether the Base wallet 0x72ded73b99cffedfc83f5fa74640cdbd1e642ba9 has enough USDC to cover costs."},{"title":"DeFi dashboard balance refresh","prompt":"Refresh the on-chain ETH and USDC balances for our treasury wallet 0x72ded73b99cffedfc83f5fa74640cdbd1e642ba9 on Base and tell me the block number the snapshot was taken at."},{"title":"Post-payment balance verification","prompt":"We just received a payment — can you confirm the updated USDC balance for Base address 0x72ded73b99cffedfc83f5fa74640cdbd1e642ba9 and when it was last checked?"}],"resultDescription":"A JSON object containing the wallet's ETH balance (18 decimal precision), USDC balance (6 decimal precision), the queried address, the network identifier (eip155:8453 for Base), the block number at query time, and a checkedAt timestamp.","failureModes":["Invalid or malformed wallet address returns an error or empty balances","Network unavailability on Base RPC causes lookup failure","Micropayment (x402) not fulfilled results in 402 Payment Required response","Rate limiting if too many requests are sent in quick succession"],"whenToPreferThis":"Choose this endpoint when you need a fast, on-chain balance snapshot for an Ethereum-compatible wallet on the Base L2 network, especially in agent pipelines where micropayment-gated access (x402) is already supported and cost-per-call must stay near zero ($0.001 USDC). Prefer this over manual RPC calls when you want a structured, ready-to-parse JSON response rather than raw hex values.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-23T18:30:22.952Z","isFirstParty":false,"canonicalSlug":"penny-engine-base-wallet-balance-checker-63bbddff"}