{"uid":"cap_jCtmgxPOhvzdNQN1-mU93","slug":"chain-health-check-b0403e4f","name":"Chain Health Check","description":"60 paid endpoints with no metering, no API key and no account. Each endpoint has one flat price per call, whatever the size of the request: LLM completions with automatic failover across several large models, read-only EVM tooling over Base, Ethereum, Polygon, Arbitrum and Optimism, and pure crypto utilities that touch no network.","url":"https://flat-rate-llm.kikoribera03.workers.dev/v1/evm/chains","method":"POST","headers":{},"bodySchema":null,"responseSchema":{"type":"json","example":{"chains":[{"ok":true,"chain":"eip155:8453","ageSeconds":2,"blockNumber":51047956}]}},"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_6xFWlShxZO95OU7EcH8cj","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 live health status for every supported EVM chain, including chain ID, latest block number, and data staleness in seconds.","exampleAgentPrompt":"Give me a live health check across all supported EVM chains — I want to see which ones are responding, their current block numbers, and how stale the chain head is, so I can pick a chain that's actually live before sending my transaction.","exampleUseCases":[{"title":"Pick a healthy chain before bridging","prompt":"Before I initiate a bridge transfer, check which EVM chains are currently healthy and have fresh block data — I don't want to route to a chain that's lagging."},{"title":"Alert on stale chain heads","prompt":"Monitor all supported EVM chains and flag any chain whose block head is more than 30 seconds stale so I can alert my team."},{"title":"Dashboard for multi-chain status","prompt":"Pull the current block height and staleness for every supported chain so I can populate my infrastructure status dashboard."}],"resultDescription":"A JSON array of chain health objects, each containing a boolean `ok` field, the chain identifier in CAIP-2 format (e.g. eip155:8453), the latest block number, and `ageSeconds` indicating how many seconds old the chain head is.","failureModes":["Upstream RPC node unavailable: chain entry may show ok:false or be omitted","Rate-limit or payment failure (x402): 402 response requiring payment","Network timeout from Cloudflare Worker to RPC: stale or missing chain data","No chains currently supported: empty chains array returned"],"whenToPreferThis":"Use this endpoint when you need a single call that covers all supported EVM chains simultaneously, rather than querying each chain individually. It is especially useful before submitting transactions or routing logic where you need to confirm a chain is live and up-to-date. Prefer it over per-chain block-height endpoints when chain selection or fallback logic is required.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T18:52:10.083Z","isFirstParty":false}