{"uid":"cap_q3y-kELUSzC_MDJ7iBeI9","slug":"northline-chainkit-address-profile-c4713d08","name":"Northline ChainKit Address Profile","description":"x402 pay-per-call onchain API (Base + Arc).","url":"https://northline-chainkit.northline-c86.workers.dev/v1/address/profile?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["address"],"properties":{"chain":{"enum":["base","arc"],"type":"string","default":"base"},"address":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"kind":"contract","chain":"base","flags":["upgradeable_proxy"],"proxy":{"eip1967Implementation":"0x2ce6311ddae708829bc0784c967b7d77d19fd779"},"token":{"symbol":"USDC","decimals":6}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_n5HiZSYt9Dxwn_lvOej9g","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns onchain profile information for an Ethereum address on Base or Arc, including whether it is a contract, token type, proxy status, and ERC metadata.","exampleAgentPrompt":"Can you look up the onchain profile for the address 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Base — I want to know if it's a contract, whether it's an upgradeable proxy, and what token it represents?","exampleUseCases":[{"title":"Identify unknown contract before interaction","prompt":"Before I interact with 0x2ce6311ddae708829bc0784c967b7d77d19fd779 on Base, can you tell me what kind of address it is and whether it's an upgradeable proxy?"},{"title":"Verify token contract metadata","prompt":"I need to confirm that this address 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Base is a real ERC20 token — what's its symbol and decimals?"},{"title":"Audit proxy implementation on Arc","prompt":"Can you pull the onchain profile for 0xd9aAEc86B65D86f6A7B5B1b0c42FFA531710b6CA on Arc and tell me what the current proxy implementation address is?"}],"resultDescription":"A JSON object containing the address kind (e.g. 'contract' or 'eoa'), the chain it was queried on, an array of flags such as 'upgradeable_proxy', proxy details including the EIP-1967 implementation address, and token metadata such as symbol and decimals if the address is a token contract.","failureModes":["Invalid address format (must match ^0x[0-9a-fA-F]{40}$) returns a validation error","Address not found or not deployed on the specified chain returns empty or null profile","Unsupported chain value (anything other than 'base' or 'arc') returns a parameter error","Payment failure via x402 protocol results in 402 response before query is executed","Network or RPC timeout for the underlying chain returns a 503 or timeout error"],"whenToPreferThis":"Use this endpoint when you need a quick, pay-per-call onchain lookup of an Ethereum-compatible address specifically on Base or Arc — especially when you want contract classification, proxy detection (EIP-1967), and token metadata in a single call without running your own node or indexer. Prefer this over generic block explorers when you need structured JSON output suitable for agent pipelines.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T00:36:26.970Z","isFirstParty":false,"canonicalSlug":"northline-chainkit-address-profile-c4713d08"}