{"uid":"cap_o4LaL0t9E6pPsXCnOj6xt","slug":"erc-20-token-allowance-lookup-9beefb28","name":"ERC-20 Token Allowance Lookup","description":"Read the current ERC-20 allowance for an owner, spender, and token from a supported EVM network without signing or broadcasting.","url":"https://ai-data-marketplace-1042299154756.us-central1.run.app/api/v1/erc20_allowance","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":{"chain":{"type":"string","description":"base, ethereum, or arbitrum; defaults to base."},"owner":{"type":"string","description":"Wallet that granted the allowance."},"token":{"type":"string","description":"ERC-20 token contract address."},"spender":{"type":"string","description":"Address authorized to spend."}},"additionalProperties":true}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["success","symbol","allowance_raw","allowance_formatted","approval_present"],"properties":{"symbol":{"type":"string"},"success":{"type":"boolean"},"allowance_raw":{"type":"string"},"approval_present":{"type":"boolean"},"allowance_formatted":{"type":"string"}},"additionalProperties":true}}}}},"responseSchema":{"type":"json","example":{"symbol":"USDC","success":true,"allowance_raw":"0","approval_present":false,"allowance_formatted":"0.0"}},"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_TcDjOg4YF8J1G3O4gMyQC","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":"Looks up the current ERC-20 token spending allowance granted by an owner wallet to a spender address on Base, Ethereum, or Arbitrum.","exampleAgentPrompt":"Check how much USDC the Uniswap v3 router (0xE592427A0AEce92De3Edee1F18E0157C05861564) is allowed to spend from wallet 0xAbCd...1234 on Base — I want to know the exact allowance and whether any approval is present.","exampleUseCases":[{"title":"Audit DeFi Protocol Token Approvals","prompt":"Can you check if Aave's lending pool contract 0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2 has any USDC approval from my wallet 0x1234...abcd on Ethereum? I want to know the exact amount it's allowed to spend."},{"title":"Detect Unlimited Token Approvals","prompt":"Look up the USDT allowance that Uniswap's swap router 0xE592427A0AEce92De3Edee1F18E0157C05861564 has from wallet 0xDeAd...BeeF on Arbitrum — I'm trying to figure out if there's an unlimited approval I should revoke."},{"title":"Pre-transaction Allowance Check","prompt":"Before I proceed, can you verify whether the 1inch aggregator at 0x1111111254EEB25477B68fb85Ed929f73A960582 already has enough WETH allowance from wallet 0xBaAd...Face on Base to cover a 2 WETH swap?"}],"resultDescription":"Returns a JSON object with the token symbol, a boolean indicating whether any approval exists (approval_present), the raw allowance as a string integer (allowance_raw), and the human-readable formatted allowance (allowance_formatted), along with a success flag.","failureModes":["Invalid token contract address returns an error or empty result","Unsupported chain identifier causes a bad request response","Owner or spender address formatted incorrectly returns a failure","Network timeout or RPC node unavailability may cause transient errors","Token contract that does not implement ERC-20 allowance method may return an error"],"whenToPreferThis":"Use this endpoint when you need a lightweight, pay-per-call lookup of ERC-20 token allowances across Base, Ethereum, or Arbitrum without setting up your own blockchain RPC infrastructure. Ideal for security audits, pre-transaction checks, and DeFi workflow automation where you need to verify approvals granted to a specific spender.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T12:40:36.879Z","isFirstParty":false}