{"uid":"cap_Duw5FlO8Zg3lMrykOLmQq","slug":"erc20-allowance-checker-deb186d3","name":"ERC20 Allowance Checker","description":"60 paid endpoints with no metering, no API key and no account. Each endpoint has one flat price per call, whatever the size of the request: LLM completions with automatic failover across several large models, read-only EVM tooling over Base, Ethereum, Polygon, Arbitrum and Optimism, and pure crypto utilities that touch no network.","url":"https://flat-rate-llm.kikoribera03.workers.dev/v1/evm/erc20-allowance","method":"POST","headers":{},"bodySchema":{"type":"object","required":["owner","token","spender"],"properties":{"chain":{"type":"string","description":"base | ethereum | polygon | arbitrum | optimism."},"owner":{"type":"string","description":"Address that owns the tokens."},"token":{"type":"string","description":"ERC20 contract address."},"spender":{"type":"string","description":"Address allowed to spend them."}}},"responseSchema":{"type":"object","properties":{"raw":{"type":"string"},"amount":{"type":"number"},"decimals":{"type":"number"},"unlimited":{"type":"boolean"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_uD5L4MpqYPr5CUCNKS66n","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns how many tokens a spender is approved to transfer on an ERC20 owner's behalf, including whether the approval is effectively unlimited.","exampleAgentPrompt":"Check the ERC20 allowance on Base — how many USDC tokens is the Uniswap router (0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD) approved to spend from my wallet (0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045), and is the approval unlimited?","exampleUseCases":[{"title":"Audit forgotten infinite approvals","prompt":"Check if I ever gave unlimited approval to the Aave lending pool (0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2) to spend my WETH (0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2) — my wallet is 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Ethereum mainnet."},{"title":"Pre-approve transfer check","prompt":"Before I call approve, can you tell me the current allowance the 1inch router (0x1111111254EEB25477B68fb85Ed929f73A960582) has to spend my USDC (0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48) from address 0xAbCd1234...5678 on Ethereum?"},{"title":"DeFi security monitoring","prompt":"I want to know if any unlimited approvals are set for the SushiSwap router (0xd9e1cE17f2641f24aE83637ab66a2cca9C378B9F) on my Polygon wallet 0x1234abcd...ef56 for the MATIC token at 0x7D1AfA7B718fb893dB30A3aBc0Cfc608AaCfeBB0."}],"resultDescription":"Returns an object with: raw (raw big-integer allowance as a string), amount (human-readable decimal amount adjusted for token decimals), decimals (the token's decimal precision), and unlimited (boolean flag indicating whether the approval is effectively infinite, i.e. max uint256).","failureModes":["Invalid or non-checksummed Ethereum address returns an error","Unsupported chain name returns a validation error","Non-ERC20 contract address (e.g. EOA or non-standard contract) may return zero or error","Network congestion or RPC errors may cause timeouts","Token contract with no allowance function returns an error"],"whenToPreferThis":"Use this endpoint when you need a quick, read-only ERC20 allowance lookup without setting up your own RPC connection or Web3 library. It is ideal for agents performing DeFi safety checks, pre-flight approval validation before a swap or transfer, or auditing wallets for forgotten infinite approvals. Prefer this over raw eth_call endpoints when you want decimals-adjusted human-readable output and the unlimited flag already computed.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T18:57:37.406Z","isFirstParty":false}