{"uid":"cap_Nwx-e-qdlAug5C6_4oy4z","slug":"first-dollar-on-chain-balance-api-a610dbbc","name":"First Dollar On-Chain Balance API","description":"Live Base chain reads sold per call over x402 (exact, USDC on Base, $0.02/call).","url":"https://firstdollar-api.onrender.com/balance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$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":["address"],"properties":{"token":{"type":"string","description":"Optional ERC-20 contract address to include"},"address":{"type":"string","description":"Wallet address to read (0x…)"}}}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_FeUo8JqEW4UXWpbeNK2TU","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the on-chain token balance of a given wallet address on the Base blockchain, paid per call via x402.","exampleAgentPrompt":"What's the current on-chain balance for wallet 0xAbC123...def456 on Base — and also check how much USDC it holds using the USDC contract 0xd9aAEc86B65D86f6A7B5B1b0c42FFA531710b6CA?","exampleUseCases":[{"title":"DeFi portfolio balance check","prompt":"Can you pull the live on-chain balance for my wallet 0x1234567890abcdef1234567890abcdef12345678 on Base, and also check my USDC balance using contract 0xd9aAEc86B65D86f6A7B5B1b0c42FFA531710b6CA?"},{"title":"Payment eligibility verification","prompt":"Before I process this payout, check if wallet 0xAbCdEf0987654321AbCdEf0987654321AbCdEf09 has any balance on Base — I need to know if it's funded."},{"title":"Token airdrop recipient audit","prompt":"For each wallet address I give you, look up their current token balance on Base using contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 — start with 0xDEAD000000000000000042069420694206942069."}],"resultDescription":"Returns the on-chain balance of the specified wallet address on Base, either in the native token or for a specified ERC-20 contract if provided. The response reflects the live state of the blockchain at the time of the call.","failureModes":["Invalid or malformed wallet address (0x... format required) returns an error","Missing required 'address' query parameter returns a 400-level error","Unrecognized ERC-20 contract address may return zero or an error","Network issues with Base chain RPC may cause timeouts or stale data","Payment failure via x402 prevents the call from executing"],"whenToPreferThis":"Use this endpoint when you need a live, real-time balance read from the Base blockchain for a specific wallet, especially when paying per-call is acceptable (e.g. spot checks, agent workflows). Prefer this over indexer APIs when you need the most current chain state rather than indexed/historical data, and when Base is specifically the target network.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T12:33:12.221Z","isFirstParty":false,"canonicalSlug":"first-dollar-on-chain-balance-api-a610dbbc"}