{"uid":"cap_jQsepwV8hgo4KJUfRg-PD","slug":"riley-craig-x402-agent-store-chain-id-lookup-4555ccd4","name":"Riley Craig x402 Agent Store – Chain ID Lookup","description":"The EIP-155 chain ID for any supported network via eth_chainId — the read multi-chain agents make to confirm which chain an RPC is on before signing. Across Base, Ethereum, Optimism, Arbitrum, Polygon, Gnosis. Free public RPC; undercuts onesource (Ethereum-only) at $0.001 on 6 chains.","url":"https://store.agentexchange.work/chain/chain-id","method":"GET","headers":{},"bodySchema":{"type":"object","$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"],"type":"string"},"queryParams":{"type":"object","properties":{"chain":{"type":"string","description":"base|ethereum|optimism|arbitrum|polygon|gnosis (default base)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"chain_id":{"type":"number"}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","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_4uOHCFSmw5Y7c0HbKbQ-I","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 numeric chain ID for a specified EVM-compatible blockchain network (e.g. Base, Ethereum, Polygon)","exampleAgentPrompt":"What is the chain ID for the Base network?","exampleUseCases":null,"resultDescription":"A JSON object containing the canonical chain name string and its numeric chain ID — for example {\"chain\":\"base\",\"chain_id\":8453}. Paid via x402 micropayment of $0.001 USDC on Base, no API key required.","failureModes":["Unsupported chain name returns an error or empty response","Invalid chain parameter value (not one of the six supported enums) may return 400 or default to Base","Payment failure via x402 protocol returns 402 Payment Required"],"whenToPreferThis":"Use this endpoint when an AI agent needs to programmatically resolve a human-readable blockchain network name (base, ethereum, optimism, arbitrum, polygon, gnosis) to its canonical numeric chain ID without requiring API keys or signup — ideal for autonomous agents paying per call via x402/USDC micropayments.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:47:13.447Z","isFirstParty":false}