{"uid":"cap_CWx71N-J6Or6NXv6pXvVR","slug":"agent-rest-stop-block-lag-acd92393","name":"Agent Rest Stop – Block Lag","description":"How many blocks behind the cached head.","url":"https://agent-gas-station.agent-gas-station.workers.dev/v1/BlockLag?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"chain":{"type":"string"},"client_block":{"type":"string"}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_y91_ON36H9nK3aXGiyfab","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns how many blocks behind the cached head a given chain's client block is.","exampleAgentPrompt":"How many blocks behind is my Ethereum client at block 20500000 right now?","exampleUseCases":[{"title":"Ethereum node sync health check","prompt":"Can you check how many blocks behind my Ethereum node is? My client is currently at block 20500000."},{"title":"Base chain lag monitoring for agent","prompt":"My agent is running on Base and its cached block is 14200000 — how far behind is that from the current head?"},{"title":"Polygon sync delay before transaction submission","prompt":"Before I submit this transaction, can you tell me how many blocks behind the Polygon chain my client block 55000000 is?"}],"resultDescription":"A numeric value indicating how many blocks the provided client block lags behind the cached chain head for the specified blockchain network.","failureModes":["Invalid or unsupported chain identifier returns an error","Malformed or non-numeric client_block string causes a parsing error","Payment not attached or insufficient USDC results in 402 Payment Required","Network or worker timeout if upstream chain data is unavailable"],"whenToPreferThis":"Use this endpoint when an agent or service needs to quickly determine whether its cached or local block reference is stale relative to the current chain head — especially before making time-sensitive on-chain decisions or transactions. Prefer it over full node RPC calls when you only need a lightweight block lag number rather than full block data.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:40:19.139Z","isFirstParty":false,"canonicalSlug":"agent-rest-stop-block-lag-acd92393"}