{"uid":"cap_wQLDQ7ArnLDi_24bH-rh-","slug":"ontario-protocol-base-wallet-balance-reader-59833556","name":"Ontario Protocol Base Wallet Balance Reader","description":"What does this Base wallet hold? ETH, USDC and about 25 widely held Base tokens, plus up to 20 ERC-20 contracts you name, with symbol, decimals, raw and formatted amounts and the block number read, live from Base RPC. Required: address. $0.002 USDC on Base. Failed read, no charge. No account, no API key. Base mainnet only; no prices or USD values; tokens outside the list and your extras are not discovered. By Ontario Protocol.","url":"https://ontarioprotocol.com/api/x402/base/balances?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","required":["input","output"],"properties":{"input":{"type":"object","required":["queryParams"],"properties":{"queryParams":{"type":"object","required":["address"],"properties":{"tokens":{"type":"string","description":"Optional comma-separated ERC-20 contract addresses to read as well, max 20."},"address":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"Base wallet or contract address to read."}},"additionalProperties":false}}},"output":{"type":"object","required":["example"],"properties":{"example":{"type":"object","additionalProperties":true}}}}},"responseSchema":{"example":{"block":53049908,"native":{"raw":"14098622686720","symbol":"ETH","decimals":18,"formatted":"0.00001409862268672"},"schema":"ontario.base_balances.v1","source":"Base RPC","tokens":[{"raw":"10402131","source":"default_list","symbol":"USDC","address":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","decimals":6,"formatted":"10.402131"}],"address":"0xa2d72aBF2C5e939fdDCA4156B74dE482e03CA3ec","network":"eip155:8453","read_at":"2026-10-25T00:46:04Z","coverage":{"requested":0,"default_list_size":25,"default_list_unread":0},"coverage_note":"Default-list tokens appear only with a nonzero balance; requested tokens always appear. Tokens outside the list and the request are not discovered. No prices or USD values.","block_timestamp":"2026-10-25T00:46:03Z"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_3HTFAF4xpBaGD5WKi2_JM","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns ETH and ERC-20 token balances for any Base mainnet wallet address, including a default list of ~25 widely held tokens plus up to 20 custom contract addresses.","exampleAgentPrompt":"What are the current ETH and USDC balances for Base wallet 0xa2d72aBF2C5e939fdDCA4156B74dE482e03CA3ec? Also check for token at contract 0x50c5725949A6F0c72E6C4a641F24049A917DB0Cb.","exampleUseCases":[{"title":"DeFi portfolio snapshot for a Base wallet","prompt":"Pull all the token balances for my Base wallet 0xa2d72aBF2C5e939fdDCA4156B74dE482e03CA3ec — I want to see ETH, USDC, and any other widely held tokens it's holding right now."},{"title":"Custom ERC-20 balance check before a swap","prompt":"Before I do a swap, check the balance of token contract 0x4ed4E862860beD51a9570b96d89aF5E1B0Efefed in my Base wallet 0x1234567890abcdef1234567890abcdef12345678."},{"title":"Agent verifying funding before executing on-chain action","prompt":"Check whether wallet 0xAbcdef1234567890AbCdEf1234567890aBcDeF12 has at least some USDC on Base before I proceed — show me the current USDC and ETH balances."}],"resultDescription":"Returns a JSON object with the block number and timestamp of the read, the wallet's native ETH balance (raw and formatted), and an array of ERC-20 token balances (symbol, address, decimals, raw amount, formatted amount, and source). Coverage metadata explains how many default-list and requested tokens were read. No prices or USD values are included.","failureModes":["Invalid or malformed wallet address returns an error without charging","Tokens outside the default list and not in the 'tokens' parameter are silently omitted (not discovered)","More than 20 custom token addresses in the 'tokens' parameter may be rejected","Base RPC read failure returns an error with no charge","Non-Base (non-eip155:8453) addresses are not supported and will not return cross-chain data"],"whenToPreferThis":"Use this endpoint when you need live, on-chain token balances for a Base mainnet wallet without setting up an API key or account. It is especially useful for agents that need quick portfolio snapshots, pre-action funding checks, or balance reads for specific custom ERC-20 contracts. Prefer this over generic blockchain explorers when you need formatted and raw amounts together with block-level provenance at low cost ($0.002 USDC) and no authentication overhead.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T22:15:32.205Z","isFirstParty":false,"canonicalSlug":"ontario-protocol-base-wallet-balance-reader-59833556"}