{"uid":"cap_g5pTg3_3NAJMfK3jeriq_","slug":"joe-evm-rpc-chain-id-lookup-8ec0528f","name":"Joe EVM RPC – Chain ID Lookup","description":"Live Base and Ethereum RPC for AI agents: block tip, balances, transactions, and ENS. $0.001 USDC per call on Base.","url":"https://joe-evm-rpc.marnick-yezo.workers.dev/api/chain/chain-id","method":"GET","headers":{},"bodySchema":{"type":"object","$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"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"pathParams":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","properties":{"network":{"enum":["base","ethereum"],"type":"string","default":"base","description":"EVM network. Default base."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"data":{"result":"0x2105"},"meta":{"rpc":"https://mainnet.base.org","network":"base","endpoint":"/api/chain/chain-id","cost_usdc":"0.001","request_id":"00000000abcdef01"}}},"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_EetIEYdbokyJrNIXPSsVC","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":"Returns the EVM chain ID for a specified network (Base or Ethereum) via a pay-per-call RPC endpoint.","exampleAgentPrompt":"What is the chain ID for the Base network right now — can you check via a live RPC call and give me the hex result?","exampleUseCases":[{"title":"Verify chain ID before transaction signing","prompt":"Before I sign this transaction, can you look up the live chain ID for Base mainnet so I can confirm I'm on the right network?"},{"title":"Check Ethereum chain ID for contract deployment","prompt":"What chain ID should I use when deploying my smart contract to Ethereum mainnet? Fetch it live from the RPC so I have the latest value."},{"title":"Validate network in multi-chain agent workflow","prompt":"My agent needs to confirm whether it's operating on Base or Ethereum — can you fetch the chain ID for Base and tell me what hex value comes back?"}],"resultDescription":"Returns a JSON object with a `data.result` field containing the chain ID as a hex string (e.g. '0x2105' for Base), plus metadata including the RPC URL used, network name, endpoint path, cost in USDC, and a unique request ID.","failureModes":["Invalid network parameter (not 'base' or 'ethereum') returns an error response","Payment failure or insufficient USDC balance blocks the request under x402 protocol","Network timeout from upstream RPC (mainnet.base.org or Ethereum node) causes delayed or failed response","Malformed path parameter returns 4xx error"],"whenToPreferThis":"Choose this endpoint when an AI agent needs a live, pay-per-call EVM chain ID lookup without managing its own RPC credentials. Ideal for agents operating on Base or Ethereum that need to programmatically verify the chain ID before signing transactions, deploying contracts, or switching networks. The x402 micropayment model ($0.001 USDC) makes it suitable for high-frequency automated queries with no subscription overhead.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T18:35:43.605Z","isFirstParty":false}