{"uid":"cap_EnnimhuKyZlIuORgr82Sl","slug":"polyform-crypto-balance-lookup-a23ce903","name":"Polyform Crypto Balance Lookup","description":"Pay-per-call data endpoints for AI agents. USDC on Base via x402. No account, no API key — one micropayment per call.","url":"https://api.polyform.org/v1/crypto/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","properties":{}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"eth":0.5,"usdc":1200.5,"chain":"base","address":"0x…"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_k9Fzv8IYukM5EHrtN-3HK","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the ETH and USDC token balances for a given wallet address on the Base chain","exampleAgentPrompt":"What are the current ETH and USDC balances for the Base wallet 0xAbCd1234...? Pay with USDC on Base via x402 at $0.003 per call.","exampleUseCases":[{"title":"Agent treasury monitoring","prompt":"Check the ETH and USDC balances on my agent's Base wallet 0x1a2b3c4d... so I can see if it has enough funds to keep paying for API calls."},{"title":"DeFi portfolio snapshot","prompt":"Pull the current ETH and USDC balances for this Base address 0xDeAdBeEf... — I want to know my on-chain holdings before deciding whether to rebalance."},{"title":"Payment verification before transfer","prompt":"Before I send funds, can you check the USDC and ETH balance on Base for wallet 0x9f8e7d6c... to confirm it has enough to cover the transaction?"}],"resultDescription":"A JSON object containing the ETH balance (float), USDC balance (float), the chain identifier ('base'), and the queried wallet address. For example: {\"eth\": 0.5, \"usdc\": 1200.5, \"chain\": \"base\", \"address\": \"0x…\"}.","failureModes":["Invalid or malformed wallet address returns an error response","Address with no activity on Base may return zero balances rather than an error","Network issues or Base RPC downtime may cause timeout or 5xx errors","Insufficient x402 USDC payment results in 402 Payment Required response","Unsupported chain or non-Base addresses may return unexpected results"],"whenToPreferThis":"Choose this endpoint when you need a quick, no-account, pay-per-call lookup of ETH and USDC balances specifically on the Base network. It is ideal for AI agents using the x402 micropayment protocol that need to avoid API key management. Prefer this over general-purpose blockchain APIs when low overhead and per-call pricing are priorities.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T00:45:23.849Z","isFirstParty":false,"canonicalSlug":"polyform-crypto-balance-lookup-a23ce903"}