{"uid":"cap_eJaD36jmI334aexbPcHg8","slug":"base-erc-20-token-allowance-lookup-0cae0a61","name":"Base ERC-20 Token Allowance Lookup","description":"Read public static documentation as text or Markdown with code, tables, headings and links for $0.002 USDC on Base via x402. Inspect real cached examples and an unsigned quote, then buy with a capped Node CLI. No account or API key. No JavaScript rendering, authenticated or paywalled access. Other paid utilities remain available.","url":"https://agent-data-tools.revmesh2074.workers.dev/base-allowance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$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":["token","owner","spender"],"properties":{"owner":{"type":"string","description":"Wallet address that holds the token (0x...)"},"token":{"type":"string","description":"ERC-20 token contract address on Base (0x...)"},"spender":{"type":"string","description":"Address allowed to spend, usually a router or protocol contract (0x...)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"chain":"base","owner":"0x4200000000000000000000000000000000000006","token":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","symbol":"USDC","spender":"0x000000000022D473030F116dDEE9F6B43aC78BA3","approved":false,"decimals":6,"allowance":"0","unlimited":false,"allowanceFormatted":"0"}},"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_dI8muqQ1V_miv6nx7TEiS","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 the current ERC-20 token allowance (approved spending limit) that a spender address has been granted by an owner wallet on Base mainnet.","exampleAgentPrompt":"Check how much USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) my wallet 0x4200000000000000000000000000000000000006 has approved the Uniswap Permit2 contract (0x000000000022D473030F116dDEE9F6B43aC78BA3) to spend on Base.","exampleUseCases":[{"title":"Pre-swap approval check for DeFi bot","prompt":"Before I execute this Uniswap swap, check if my wallet 0xAbCd...1234 has already approved the Uniswap Permit2 router 0x000000000022D473030F116dDEE9F6B43aC78BA3 to spend USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base — and tell me how much."},{"title":"Audit unlimited token approvals","prompt":"I want to know if my wallet 0xAbCd...1234 has granted an unlimited allowance to the Aave lending pool contract 0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2 for WETH (0x4200000000000000000000000000000000000006) on Base."},{"title":"DeFi security review for risky approvals","prompt":"Check what allowance the suspicious contract at 0xDead...Beef has to spend my USDC from wallet 0x1234...5678 on Base — I want to know if it's unlimited or any specific amount."}],"resultDescription":"Returns a JSON object with the chain name ('base'), owner address, token contract address, token symbol, spender address, whether any approval exists (approved boolean), raw allowance in base units, formatted allowance as a human-readable string, token decimals, and a flag indicating whether the approval is unlimited (unlimited boolean).","failureModes":["Invalid or malformed wallet/contract address returns an error","Token address is not a valid ERC-20 contract on Base — may return empty or error response","Spender address with no approval returns allowance '0' and approved: false (not an error)","Network or RPC timeout causes a failed lookup","Payment failure (insufficient USDC balance or allowance for x402 fee) prevents the request"],"whenToPreferThis":"Use this endpoint when an AI agent needs to check ERC-20 token spending permissions on Base mainnet without running its own blockchain node or holding an API key. It is ideal for pre-transaction validation in DeFi workflows (confirming a router can spend tokens before swapping), security audits of wallet approvals, or any agent pipeline that needs real-time on-chain allowance data for a fraction of a cent per call via x402 USDC micropayment.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-14T12:30:06.282Z","isFirstParty":false,"canonicalSlug":"base-erc-20-token-allowance-lookup-0cae0a61"}