{"uid":"cap_sunLanG2x5q3lUTSoAoM1","slug":"chainanalyzer-address-poisoning-similarity-check-91fb39f3","name":"ChainAnalyzer Address Poisoning Similarity Check","description":"Is this destination a lookalike of an address the sender already trusts? Applies the address-poisoning similarity rule (leading and trailing characters that wallet UIs abbreviate to) between one destination and a caller-supplied list of known-good addresses. Pure string comparison when `known` is given, so it answers in milliseconds and never runs a scan.","url":"https://chain-analyzer.com/api/v1/x402/address/:address/poisoning-check?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"properties":{"input":{"properties":{"queryParams":{"type":"object","properties":{"chain":{"type":"string"},"known":{"type":"string"},"address":{"type":"string"}}}}},"output":{"properties":{"example":{}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.05","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":"$0.05/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_p6KYizbPfnUIWIRqBo9_e","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.05","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Detects whether a destination blockchain address is a lookalike (address-poisoning attack) of any address in a caller-supplied list of trusted addresses, by comparing leading and trailing characters.","exampleAgentPrompt":"Before I send funds, check if 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 is a poisoned lookalike of any of my trusted addresses — 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 and 0xdAC17F958D2ee523a2206206994597C13D831ec7 — on Ethereum.","exampleUseCases":[{"title":"Pre-transfer address spoofing check","prompt":"I'm about to send USDC on Ethereum — can you verify that 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 isn't a poisoned lookalike of any address in my trusted list: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, 0xdAC17F958D2ee523a2206206994597C13D831ec7?"},{"title":"Wallet UI address substitution detection","prompt":"Someone just pasted a new address into my payment flow — check if 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 is trying to impersonate any of my whitelisted addresses on Ethereum: 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96040, 0xAbcdef1234567890AbcDef1234567890aBcDeF12."},{"title":"DeFi protocol outbound address validation","prompt":"Before my smart contract releases funds to 0x742d35Cc6634C0532925a3b844Bc454e4438f44e on Polygon, run a poisoning similarity check against our treasury's known addresses: 0x742d35Cc6634C0532925a3b8A4Bc454e4438f44e and 0x1234567890abcdef1234567890abcdef12345678."}],"resultDescription":"Returns whether the destination address matches the leading and trailing characters of any address in the known-good list, indicating a potential address-poisoning attack. Responses are delivered in milliseconds as a pure string comparison with no external scan required.","failureModes":["Missing or malformed destination address returns an error response","Empty or unparseable 'known' list may result in no comparison being performed","Unsupported chain identifier may cause a validation error","Very long 'known' lists may exceed query parameter size limits","Network timeout or service unavailability returns a non-200 error"],"whenToPreferThis":"Choose this endpoint when you need an instant, zero-latency check of whether a destination address visually mimics a trusted address — especially before executing a blockchain transfer. It is ideal for pre-flight address validation in wallets, DeFi protocols, or payment agents where speed is critical and no external blockchain scan is needed. Prefer it over full AML screening when the threat model is specifically address-poisoning/substitution attacks rather than sanctions or illicit fund flows.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-13T12:32:31.529Z","isFirstParty":false,"canonicalSlug":"chainanalyzer-address-poisoning-similarity-check-91fb39f3"}