{"uid":"cap_cb_Cszi1g2aZ2z_g_VL5G","slug":"keyronne-chain-block-header-lookup-21311cb2","name":"Keyronne Chain Block Header Lookup","description":"Fetch a block header by number, hash, or \"latest\" on Ethereum, Base, Arbitrum, Optimism, Polygon, or BNB Chain: timestamp, miner, gas used/limit, base fee, transaction count, size. Public JSON-RPC, no API keys. POST a JSON body like: {\"chain\":\"base\",\"block\":\"latest\"}","url":"https://keyronne.com/api/chain-block","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"block":{"description":"Block number, \"latest\" (default), or a 0x block hash."},"chain":{"enum":["ethereum","base","arbitrum","optimism","polygon","bsc"],"type":"string"}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_-G77MV6PQguNnl0xOVqap","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Fetch block header details (timestamp, miner, gas used/limit, base fee, tx count, size) by block number, hash, or 'latest' on major EVM chains","exampleAgentPrompt":"Can you grab the block header for the latest block on Base — I need the timestamp, miner, gas used, base fee, and transaction count?","exampleUseCases":null,"resultDescription":"Returns a JSON object with block header fields including timestamp, miner address, gas used, gas limit, base fee per gas, transaction count, block size, and block hash for the requested block on the specified chain.","failureModes":["Block number not found on the specified chain — returns error indicating invalid block","Invalid or malformed block hash — returns parsing or not-found error","Unsupported chain value outside the allowed enum — returns validation error","Downstream RPC node unavailable or rate-limited — returns 5xx or timeout","Malformed JSON body — returns 400 bad request"],"whenToPreferThis":"Use this endpoint when you need block-level metadata (timestamp, miner, gas metrics, base fee, tx count) on a specific EVM chain without needing full transaction data. Prefer this over a transaction lookup endpoint when you want chain-wide block info rather than a specific tx, and over a gas price endpoint when you need historical block data rather than current fee suggestions.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T00:37:23.173Z","isFirstParty":false}