{"uid":"cap_ceZ_lOiGXCLdoQ1W5yHLI","slug":"seneschal-ethereum-base-fee-live-query-2ebf62de","name":"Seneschal Ethereum Base Fee Live Query","description":"Single-fact: what does Ethereum mainnet gas cost RIGHT NOW? Returns the latest block’s base fee + blob base fee AND the consensus-computed next-block projection (not a guess — the protocol’s own EIP-1559/4844 arithmetic), straight from eth_feeHistory. Fields: {block, base_fee_gwei, blob_base_fee_gwei, gas_used_ratio, next_base_fee_gwei, next_blob_base_fee_gwei}. Bulk per-block history: /v1/premium/fee-history.csv ($0.05, up to 1024 blocks/call).","url":"https://api.seneschal.space/v1/q/base-fee","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"properties":{"type":"string"}}},"responseSchema":{"type":"json","example":{"block":23012001,"as_of_ms":1765532000000,"next_block":23012002,"base_fee_wei":"747213960","base_fee_gwei":0.74721396,"gas_used_ratio":0.4993,"blob_base_fee_wei":"1","blob_base_fee_gwei":1e-9,"next_base_fee_gwei":0.747189,"blob_gas_used_ratio":0.25,"next_blob_base_fee_gwei":1e-9}},"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_dSPRQ2GIS9duVhqa_iWCP","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 current Ethereum mainnet base fee and blob base fee for the latest block, plus the protocol-computed next-block fee projections using EIP-1559/EIP-4844 arithmetic.","exampleAgentPrompt":"What's the current Ethereum mainnet base fee and blob base fee right now, and what does the protocol predict the next block's base fee will be?","exampleUseCases":null,"resultDescription":"Returns a JSON object with the latest Ethereum block number, current base fee in gwei and wei, blob base fee in gwei and wei, gas used ratio, blob gas used ratio, timestamp in milliseconds, and the protocol-computed next-block projections for both base fee and blob base fee.","failureModes":["Upstream Ethereum node unavailability may return 5xx errors","Payment not included or invalid x402 token returns 402 Payment Required","Rate limiting if too many requests are made in a short window","Stale data if the underlying node is behind the chain tip"],"whenToPreferThis":"Use this endpoint when you need a real-time, single-fact snapshot of Ethereum mainnet gas costs with protocol-accurate next-block projections derived from EIP-1559/4844 arithmetic — not a third-party estimate. Prefer this over Etherscan or other gas oracles when you want both base fee and blob base fee together in one call, or when you need the canonical protocol-level next-block fee prediction rather than a heuristic.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T00:42:34.362Z","isFirstParty":false}