{"uid":"cap_PziUoRFoAZ716bg9VgDNZ","slug":"blockscout-arbitrum-message-claim-data-lookup-627b9fe3","name":"Blockscout Arbitrum Message Claim Data Lookup","description":"Explore crypto activities with Blockscout's multichain search. Find transactions, addresses, tokens, and dapps across top blockchain networks — your go-to explorer for cross-chain blockchain data","url":"https://api.blockscout.com/%7Bchain_id%7D/api/v2/arbitrum/messages/claim/%7Bmessage_id%7D","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"},"pathParams":{"type":"object","properties":{"chain_id":{"type":"string"},"message_id":{"type":"integer"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"calldata":"string","outbox_address_hash":"string"}},"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_VGdepjC-yDdSaPwjpkd-O","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":"Retrieves the calldata and outbox address hash needed to claim a specific Arbitrum cross-chain message by message ID and chain","exampleAgentPrompt":"Pull the claim calldata and outbox address for Arbitrum message ID 42 on chain 42161 using Blockscout — I need it to execute the withdrawal on L1.","exampleUseCases":[{"title":"Claiming an Arbitrum L2-to-L1 withdrawal","prompt":"I withdrew ETH from Arbitrum to Ethereum mainnet and I need the calldata to claim message ID 1087 on chain 42161 — can you fetch that from Blockscout?"},{"title":"Automating cross-chain bridge monitoring","prompt":"For our bridge bot, fetch the outbox address and calldata for Arbitrum message ID 305 on chain 42161 so we can automatically submit the claim transaction."},{"title":"Debugging a failed Arbitrum message claim","prompt":"Our Arbitrum withdrawal for message ID 88 on chain 42161 isn't going through — can you pull the raw calldata and outbox address from Blockscout so we can inspect what's wrong?"}],"resultDescription":"Returns a JSON object containing the raw calldata string needed to execute the claim transaction and the outbox_address_hash (the Arbitrum outbox contract address) associated with the specified message ID on the given chain.","failureModes":["Invalid or unknown message_id returns an empty or error response","Invalid chain_id results in a 404 or unsupported chain error","Message not yet claimable (still in challenge period) may return incomplete data","Malformed path parameters return a 400 or validation error","Network timeout if the Blockscout node is temporarily unavailable"],"whenToPreferThis":"Choose this endpoint when you need the exact calldata and outbox address to claim a specific Arbitrum cross-chain message on L1. It is purpose-built for Arbitrum L2-to-L1 message finalization, unlike generic block explorers. Use it over manual RPC calls when you need structured, pre-formatted claim data without constructing raw contract calls yourself.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-12T00:54:21.062Z","isFirstParty":false}