{"uid":"cap_cFQKuk8-qrnX3KNMAkPMT","slug":"crosschain-gas-priority-fee-oracle-20fa8913","name":"Crosschain Gas & Priority Fee Oracle","description":"Current base fee and priority-fee percentiles (10th, 50th, 99th) for Ethereum, Base or Arbitrum from public RPC nodes, with the next block's base fee projected from the last block's fullness (EIP-1559 rule). Solana is not included here. Forecasts are a one-block projection, not a congestion model.","url":"https://api.fadeandco.workers.dev/api/agent-intel/crosschain-gas-priority-fee?utm_source=zero.xyz","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","required":[],"properties":{"chain":{"type":"string","description":"ethereum, base or arbitrum (default ethereum)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"chain":"base","source":"https://base-rpc.publicnode.com","checkedAt":"2026-10-23T09:35:18.792Z","baseFeeGwei":0.005,"nextBaseFeeGwei":0.004516,"priorityFeeGwei":{"p10":0.00001,"p50":0.001,"p99":0.1467},"lastBlockGasUsedRatio":0.112419,"averagePriorityFeeGweiLast5Blocks":{"p10":0.000353,"p50":0.001,"p99":0.07469}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Pdkn1gn0i-CoOATswDai4","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns current base fee, next-block projected base fee (EIP-1559), and priority-fee percentiles (p10/p50/p99) for Ethereum, Base, or Arbitrum from live public RPC nodes.","exampleAgentPrompt":"What are the current base fee and priority fee percentiles on Base right now — including the projected next-block base fee?","exampleUseCases":[{"title":"Optimize DeFi transaction timing","prompt":"Before I submit this Uniswap swap on Ethereum, can you check the current base fee and priority fee percentiles so I know if gas is cheap enough to go ahead?"},{"title":"Arbitrum vs Base gas comparison","prompt":"Fetch the current gas fees on both Arbitrum and Base so I can decide which chain is cheaper to transact on right now."},{"title":"Automate gas-aware transaction gating","prompt":"Check the current p50 priority fee on Ethereum — if it's above 2 gwei, hold off on submitting the transaction and alert me instead."}],"resultDescription":"A JSON object containing the chain name, source RPC URL, timestamp (checkedAt), current baseFeeGwei, projected nextBaseFeeGwei (one-block EIP-1559 projection from last block's gas used ratio), priorityFeeGwei percentiles (p10, p50, p99) from the latest block, lastBlockGasUsedRatio, and averagePriorityFeeGweiLast5Blocks (p10, p50, p99).","failureModes":["Unsupported chain value returns error (only ethereum, base, arbitrum accepted; Solana not supported)","Public RPC node unavailability or rate limiting may cause a timeout or stale data","nextBaseFeeGwei is a single-block projection only, not a multi-block congestion forecast — may not reflect sudden demand spikes","No authentication errors since it is public RPC-based, but x402 payment failure blocks access"],"whenToPreferThis":"Choose this endpoint when you need real-time EIP-1559 gas data (base fee + tip percentiles) for Ethereum, Base, or Arbitrum and want a single unified interface rather than querying multiple RPC nodes directly. Prefer this over generic gas APIs when you need the next-block base fee projection and multi-block averaged priority fee percentiles together in one call. Not suitable for Solana, multi-block congestion forecasting, or historical gas time-series.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T00:34:07.369Z","isFirstParty":false,"canonicalSlug":"crosschain-gas-priority-fee-oracle-20fa8913"}