{"uid":"cap_kNGgdlHbRtNvm2PEhloyV","slug":"fastapi-online-blockchain-address-info-lookup-a28126fd","name":"fastapi.online — Blockchain Address Info Lookup","description":"Chat, embeddings, OCR, speech-to-text, image editing, image understanding (captioning/Q&A), text-to-speech, translation, writing tools, classification tools, developer tools, local utilities, format/checksum validators, encoding & crypto utilities, date/time calculators, geo/coordinate math, math & finance calculators, novelty tools, and business/social writing generators — 179 endpoints in all, across multiple specialized self-hosted models. Pay per call with crypto — no signup — or get an API key.","url":"https://api.fastapi.online/address-info?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"chain":{"enum":["ethereum","base","polygon","arbitrum","optimism"],"type":"string"},"address":{"type":"string"}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_l70XhfOFgj3ojzjqgOTdm","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Looks up metadata and information about a blockchain address on a specified EVM-compatible chain","exampleAgentPrompt":"Can you look up info for the address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Ethereum?","exampleUseCases":[{"title":"Wallet due diligence before transfer","prompt":"Before I send funds, can you pull up the address info for 0xAbCd1234...5678 on Base so I can verify it looks legitimate?"},{"title":"DeFi protocol contract inspection","prompt":"Look up address 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D on Ethereum — I want to see what info is available about it on-chain."},{"title":"Cross-chain address comparison","prompt":"Can you fetch address info for 0x1234567890abcdef1234567890abcdef12345678 on both Polygon and Arbitrum so I can compare what's there?"}],"resultDescription":"Returns metadata and on-chain information about the queried blockchain address on the specified EVM-compatible chain, which may include contract status, transaction history indicators, labels, or other available address attributes.","failureModes":["Invalid address format returns an error","Unsupported chain value (outside the allowed enum) returns validation error","Address not found or no data available on the specified chain","Network or RPC connectivity issues for the target chain","Payment failure or insufficient USDC balance"],"whenToPreferThis":"Choose this endpoint when you need quick, pay-per-call blockchain address lookups across major EVM chains (Ethereum, Base, Polygon, Arbitrum, Optimism) without signup. Ideal for agents that need on-demand address enrichment with no API key commitment and micro-payment pricing via crypto.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T00:33:39.998Z","isFirstParty":false,"canonicalSlug":"fastapi-online-blockchain-address-info-lookup-a28126fd"}