{"uid":"cap_letvxq6F0MsCkZj1TEE80","slug":"base-transfer-risk-check-5af5c505","name":"Base Transfer Risk Check","description":"Check a Base ERC-20 for a honeypot-style transfer cost before a swap or send. Input: one token address. Output: allow, warn, or block. Block: not a contract or not an ERC-20. Warn: bytecode contains taxFee, liquidityFee, sellFee, buyFee, transferFee, isBlacklisted, or maxTxAmount. USDC warns because it contains isBlacklisted(address). A selector does not prove the fee, blacklist, or cap runs on every transfer, and this check does not simulate one.","url":"https://base-token-check.fly.dev/v1/transfer-check?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","required":["address"],"properties":{"address":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$","description":"ERC-20 contract address on Base to check for a transfer fee, blacklist, or max transfer size."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_-IJBDNW9oAfJYUHhHDx-L","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Analyzes a Base ERC-20 token contract's bytecode for honeypot-style transfer cost indicators (fees, blacklists, transfer caps) and returns allow, warn, or block.","exampleAgentPrompt":"Before I swap into this Base token, can you check if the contract at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 has any transfer fees, blacklist functions, or transfer size caps that could cost me money or block me?","exampleUseCases":[{"title":"Pre-swap honeypot check","prompt":"I'm about to buy this Base token at 0xd9aAEc86B65D86f6A7B5B1b0c42FFA531710b6CA — can you check if it has any taxFee, sellFee, or blacklist bytecode that might trap my funds when I try to sell?"},{"title":"DeFi bot transfer safety gate","prompt":"My trading bot wants to execute a swap on Base into token 0x4200000000000000000000000000000000000006 — first check whether the contract has any transfer fees or maxTxAmount restrictions that would break the trade."},{"title":"Token screening before airdrop send","prompt":"I need to send some tokens from this Base ERC-20 contract 0x50c5725949A6F0c72E6C4a641F24049A917DB0Cb to a bunch of wallets — can you check if it has a transferFee or isBlacklisted function that might block recipients?"}],"resultDescription":"Returns a verdict of 'allow', 'warn', or 'block'. Block means the address is not a contract or not a valid ERC-20. Warn means the bytecode contains known fee, blacklist, or transfer-cap selectors (taxFee, liquidityFee, sellFee, buyFee, transferFee, isBlacklisted, or maxTxAmount). Allow means none of those selectors were found. Note: a warn verdict does not prove fees run on every transfer — only that the selector exists in bytecode.","failureModes":["Address is not a valid ERC-20 contract → block verdict returned","Address fails 0x + 40 hex character validation → request rejected with schema error","Contract bytecode cannot be fetched (network issue or unverified contract) → error or block","USDC and other legitimate tokens with isBlacklisted may receive warn verdict (false positive)","Selector presence does not confirm fee execution on every transfer — may produce false positives"],"whenToPreferThis":"Use this endpoint specifically when you need a fast, bytecode-level signal about transfer-cost risk for a Base ERC-20 before executing a swap, send, or approval — especially when you want to catch honeypot-style taxes or blacklist traps. Prefer this over general token safety checks when the concern is specifically about transfer costs rather than broader token legitimacy. Note it does not simulate an actual transfer, so it complements but does not replace on-chain simulation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-18T00:35:37.629Z","isFirstParty":false,"canonicalSlug":"base-transfer-risk-check-5af5c505"}