{"uid":"cap_iKoSAQYyOdAbYhzIO-dwM","slug":"eth-mainnet-erc-20-allowance-00590ab7","name":"ETH Mainnet ERC-20 Allowance","description":"Ethereum mainnet ERC-20 allowance. Takes query parameters token (ERC-20 contract, 0x + 40 hex), owner (0x + 40 hex) and spender (0x + 40 hex). Returns the raw allowance read from the contract.","url":"https://ari001.tailb4ac3a.ts.net/v1/ventures/x402_eth_reads_v1/eth_mainnet_erc20_allowance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","properties":{"owner":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"0x + 40 hex"},"token":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"ERC-20 contract, 0x + 40 hex"},"spender":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"0x + 40 hex"}}}},"additionalProperties":false}}},"responseSchema":null,"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_8rQpcnMaU12DDOhWNZAwB","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":"Reads the on-chain ERC-20 token allowance on Ethereum mainnet for a given token, owner, and spender address triple.","exampleAgentPrompt":"What's the current ERC-20 allowance for USDC (0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48) from my wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 to the Uniswap v3 router at 0xE592427A0AEce92De3Edee1F18E0157C05861564 on Ethereum mainnet?","exampleUseCases":[{"title":"Pre-swap approval audit","prompt":"Before I try to swap on Uniswap, check whether the router at 0xE592427A0AEce92De3Edee1F18E0157C05861564 is already approved to spend my USDC (0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48) from 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Ethereum mainnet."},{"title":"Token approval security review","prompt":"I want to audit my Ethereum wallet 0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B — what's the current DAI (0x6B175474E89094C44Da98b954EedeAC495271d0F) allowance granted to the Maker DSProxy contract at 0x82a998C9dE88b6F49c25fb56C3b7e67a8F77d6e?"},{"title":"DeFi protocol risk monitoring","prompt":"Check the WETH allowance on Ethereum mainnet — how many tokens from owner 0x47ac0Fb4F2D84898e4D9E7b4DaB3C24507a6D503 has the Aave lending pool at 0x7d2768dE32b0b80b7a3454c06BdAc94A69DDc7A9 been approved to spend for token 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2?"}],"resultDescription":"Returns the raw uint256 allowance value representing the maximum number of token units the spender is permitted to transfer on behalf of the owner, as currently recorded in the ERC-20 contract's storage on Ethereum mainnet.","failureModes":["Invalid or malformed Ethereum address (not 0x + 40 hex) returns a 400 validation error","Token address is not a deployed ERC-20 contract — call may revert or return zero","Network connectivity issues with the Ethereum node result in a 5xx error","Rate limiting or payment failure at $0.002 per call may cause request rejection","Allowance may be stale if read during a pending state-change transaction"],"whenToPreferThis":"Use this endpoint when you need the ERC-20 allowance specifically on Ethereum mainnet (not Base, Gnosis, or other chains). A sibling endpoint covers Base. Prefer this over generic RPC calls when you want a clean REST interface without manually encoding eth_call ABI data. Ideal for pre-transaction approval checks, wallet audits, and DeFi risk monitoring on mainnet.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T12:30:02.832Z","isFirstParty":false,"canonicalSlug":"eth-mainnet-erc-20-allowance-00590ab7"}