{"uid":"cap_h3DbNMUEMm6YSgj2gWwOm","slug":"phantom-api-base-token-balances-efeaf958","name":"Phantom API — Base Token Balances","description":"Lightning-fast access to blockchain data, smart contract insights, and Web3 infrastructure across 57+ networks. Pay-per-call via x402.","url":"https://phantom-api-omega.vercel.app/api/base/token/balances","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"owner":{"type":"string"},"contractAddresses":{"type":"array","items":{"type":"string"}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/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_4guNNQMMYGMetrlAqqJb_","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 ERC-20 token balances on the Base network for a given wallet address, optionally filtered by specific contract addresses","exampleAgentPrompt":"What ERC-20 token balances does wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 hold on Base? Check specifically for USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) and DAI (0x50c5725949A6F0c72E6C4a641F24049A917DB0Cb).","exampleUseCases":[{"title":"DeFi portfolio snapshot on Base","prompt":"Can you pull all the token balances for my Base wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 and tell me what ERC-20 tokens I'm holding?"},{"title":"Verify user holds required token","prompt":"Check if wallet 0x1234567890abcdef1234567890abcdef12345678 holds any USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base — I need to confirm they meet the token-gating requirement."},{"title":"Monitor whale wallet token positions","prompt":"Look up the current ERC-20 token balances on Base for wallet 0xabc123def456abc123def456abc123def456abc1, specifically for these three contracts: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, 0x4200000000000000000000000000000000000006, and 0x50c5725949A6F0c72E6C4a641F24049A917DB0Cb."}],"resultDescription":"A list of token balances for the specified owner wallet on the Base network, including token amounts for each ERC-20 contract address provided (or all held tokens if no contracts are specified).","failureModes":["Invalid or malformed wallet address returns an error or empty result","Unknown or invalid contract address returns zero balance or an error","Network unavailability or RPC outage causes a timeout or 5xx error","Payment failure via x402 returns a 402 Payment Required response","Empty contractAddresses array may return all tokens or require at least one entry depending on implementation"],"whenToPreferThis":"Use this endpoint when you need fast, pay-per-call ERC-20 token balance lookups specifically on the Base network without setting up your own RPC node or indexer. Ideal for agents that need lightweight, on-demand balance checks for one or more token contracts for a given wallet, especially when cost-per-query matters more than a subscription model.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T00:35:14.419Z","isFirstParty":false}