{"uid":"cap_4oLWw9Nz_ERljGyXMT6yE","slug":"arbitrum-one-erc-20-allowance-checker-9c4db0b1","name":"Arbitrum One ERC-20 Allowance Checker","description":"ERC-20 allowance on Arbitrum One: how much a spender may transfer from an owner, whether the approval is effectively unlimited, the owner's balance, and the amount the spender could move right now.","url":"https://onchaincheck.dev/arbitrum/allowance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["token","owner","spender"],"properties":{"owner":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"Address that granted the approval"},"token":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"ERC-20 contract on Arbitrum One"},"spender":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"Address allowed to spend"}},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"raw":"6","chain":"arbitrum","owner":"0xFD03AbCAdaF3F930fA4E37Eb2f6ea3A44a41b7F0","token":"0xaf88d065e77c8cC2239327C5EDb3A432268e5831","symbol":"USDC","spender":"0xe35e9842fceaCA96570B734083f4a58e8F7C5f2A","allowance":"0.000006","unlimited":false,"ownerBalance":"83629.179457","spendableNow":"0.000006"}},"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_E4cSlteTJaDPY1-NufwWE","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 the ERC-20 allowance a spender has on an owner's tokens on Arbitrum One, including whether it's unlimited, the owner's balance, and the actual spendable amount right now.","exampleAgentPrompt":"Check the ERC-20 allowance for USDC token at 0xaf88d065e77c8cC2239327C5EDb3A432268e5831 on Arbitrum One — owner is 0xFD03AbCAdaF3F930fA4E37Eb2f6ea3A44a41b7F0 and the spender is 0xe35e9842fceaCA96570B734083f4a58e8F7C5f2A — is the approval unlimited, and how much can the spender actually move right now?","exampleUseCases":[{"title":"Audit DeFi protocol approval before swap","prompt":"Before I do this Uniswap swap on Arbitrum, check how much USDC at 0xaf88d065e77c8cC2239327C5EDb3A432268e5831 my wallet 0xFD03AbCAdaF3F930fA4E37Eb2f6ea3A44a41b7F0 has approved for the router 0xe35e9842fceaCA96570B734083f4a58e8F7C5f2A — and tell me if it's an unlimited approval or capped."},{"title":"Verify spendable amount for automated trading bot","prompt":"My trading bot at 0xe35e9842fceaCA96570B734083f4a58e8F7C5f2A needs to move tokens from 0xFD03AbCAdaF3F930fA4E37Eb2f6ea3A44a41b7F0 — check the current allowance for ERC-20 token 0xaf88d065e77c8cC2239327C5EDb3A432268e5831 on Arbitrum One and tell me exactly how much it can spend right now."},{"title":"Security check for suspicious wallet approval","prompt":"I think I may have approved a suspicious contract on Arbitrum — can you look up whether 0xe35e9842fceaCA96570B734083f4a58e8F7C5f2A has any allowance to spend my USDC at 0xaf88d065e77c8cC2239327C5EDb3A432268e5831 from wallet 0xFD03AbCAdaF3F930fA4E37Eb2f6ea3A44a41b7F0, and whether it's unlimited?"}],"resultDescription":"Returns a JSON object with the raw and formatted allowance amount, the token symbol, whether the approval is effectively unlimited, the owner's current token balance, and the actual amount the spender can move right now — all scoped to Arbitrum One.","failureModes":["Invalid Ethereum address format for token, owner, or spender returns a validation error","Token address is not a valid ERC-20 contract on Arbitrum One — returns error or zero values","No approval exists between owner and spender — returns allowance of 0","Network or RPC issues on Arbitrum One may cause timeouts or stale data","Missing required query parameters (token, owner, spender) returns a 400 error"],"whenToPreferThis":"Use this endpoint when you need real-time ERC-20 allowance data specifically on Arbitrum One, including whether the approval is unlimited and how much the spender can actually move given the owner's current balance. Prefer this over generic blockchain RPC calls when you want a clean, structured response without writing contract ABI calls. Best suited for DeFi agents auditing approvals, security monitors checking for dangerous unlimited allowances, or automated trading systems verifying they have sufficient spend authorization before executing a transaction.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T12:44:06.920Z","isFirstParty":false,"canonicalSlug":"arbitrum-one-erc-20-allowance-checker-9c4db0b1"}