{"uid":"cap_aVB7UKJjYCZLrr_aO2qsA","slug":"farcaster-profile-lookup-by-ethereum-address-365ab73c","name":"Farcaster Profile Lookup by Ethereum Address","description":"Reverse-lookup an Ethereum address to its Farcaster account (via verified address). Returns FID, username, display name, bio, follower/following counts, and Warpcast URL, or found=false if the address has not verified on Farcaster. Use to label wallet activity with the owner's Farcaster identity when ENS is missing.","url":"https://agent402.tools/api/farcaster-by-address","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"address":{"type":"string","description":"Ethereum address (0x-prefixed 40-hex)."}}},"responseSchema":{"type":"json","example":{"bio":"Working on Farcaster.","fid":3,"found":true,"pfpUrl":"https://...","source":"neynar","address":"0xd7029bdea1c17493893aafe29aad69ef892b8ff2","username":"dwr","venueUrl":"https://warpcast.com/dwr","displayName":"Dan Romero","followerCount":500000,"followingCount":1000}},"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_AiUquSfpCSCtFscojZ7GL","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":"Reverse-lookups an Ethereum address to its associated Farcaster account profile via verified address linkage","exampleAgentPrompt":"Can you tell me who this Ethereum address belongs to on Farcaster — 0x742d35Cc6634C0532925a3b8D4C9C6B9a2b4F1e8? I want their username, bio, and follower count.","exampleUseCases":null,"resultDescription":"Returns a JSON object with found=true and profile fields (FID, username, display name, bio, follower count, following count, Warpcast URL) if the address has a verified Farcaster account, or found=false if no Farcaster account is linked to that address.","failureModes":["Address not verified on Farcaster returns found=false rather than an error","Malformed or non-0x-prefixed address may return a validation error","Address verified on Farcaster under a deactivated account may return incomplete profile data","Network timeout if Farcaster hub is temporarily unavailable"],"whenToPreferThis":"Use this endpoint when you have an Ethereum wallet address and need to identify the corresponding Farcaster social identity — for example, to label on-chain actors with their social profiles, enrich NFT holder lists, or attribute blockchain transactions to social accounts. Prefer this over forward-lookup (username→address) when the address is your starting point.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T06:59:08.532Z","isFirstParty":false}