{"uid":"cap_-TJZD1aTSu1A-7alFPabE","slug":"base-gas-oracle-eip-1559-fee-estimator-b05d273f","name":"Base Gas Oracle (EIP-1559 Fee Estimator)","description":"Base gas oracle for agents sending Base txs: EIP-1559 slow / standard / fast tiers (maxFeePerGas + maxPriorityFeePerGas in gwei and wei hex, from eth_feeHistory 20 blocks p10/p50/p90), base fee, congestion 0-1, recommended_tier, ready-to-sign tx_fields, and est. cost in ETH + USD for your gas_limit (default 21000; use 65000 for an ERC-20 transfer). Cheapest paid call ($0.001).","url":"https://kr-x402-mvp.kgy5612.workers.dev/crypto/base-gas?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$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","properties":{"gas_limit":{"type":"integer","maximum":30000000,"minimum":21000,"examples":[21000,150000],"description":"Gas units to price (default 21000)"}},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"block":37000000,"chain":"base","tiers":{"fast":{"est_cost_usd":0.0007,"max_fee_gwei":0.025,"max_priority_fee_gwei":0.01},"slow":{"est_cost_usd":0.0005,"max_fee_gwei":0.006,"max_priority_fee_gwei":0.001},"standard":{"est_cost_usd":0.0005,"max_fee_gwei":0.011,"max_priority_fee_gwei":0.001}},"sources":["https://mainnet.base.org"],"chain_id":8453,"tx_fields":{"gas":"0x5208","type":"0x2","maxFeePerGas":"0xa7d8c0","maxPriorityFeePerGas":"0xf4240"},"congestion":0.42,"updated_at":"2026-10-29T13:30:00Z","base_fee_gwei":0.005,"gas_price_gwei":0.006,"recommended_tier":"standard","gas_price_wei_hex":"0x5b8d80","est_transfer_cost_eth":1.26e-7,"max_priority_fee_gwei":0.001,"max_priority_fee_wei_hex":"0xf4240"}},"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_nzYX3wPJEApWziQHwhejQ","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 real-time EIP-1559 gas fee tiers (slow/standard/fast), base fee, network congestion score, and estimated transaction cost in ETH and USD for the Base L2 blockchain.","exampleAgentPrompt":"Check the current Base gas fees and tell me which tier is recommended right now — I need the maxFeePerGas, maxPriorityFeePerGas, and the estimated USD cost for an ERC-20 transfer (65000 gas units).","exampleUseCases":[{"title":"Pre-flight gas check for token transfer","prompt":"Before I send this ERC-20 token on Base, what's the current gas price? Use 65000 gas units and tell me the estimated cost in USD and which fee tier you recommend."},{"title":"Congestion-aware onchain agent routing","prompt":"Is the Base network congested right now? Give me the congestion score and current slow/standard/fast gas tiers so I can decide whether to wait or send immediately."},{"title":"ETH cost estimation for a simple transfer","prompt":"How much ETH will a basic ETH transfer cost me on Base at the current gas price? Use the default 21000 gas limit and show me the fast tier cost."}],"resultDescription":"A JSON object containing: the current block number, all three EIP-1559 fee tiers (slow/standard/fast) each with maxFeePerGas and maxPriorityFeePerGas in both gwei and wei hex, base_fee_gwei, gas_price_gwei, network congestion score (0–1), the recommended_tier string, ready-to-sign tx_fields (type, gas, maxFeePerGas, maxPriorityFeePerGas in hex), estimated transfer cost in ETH and USD for the requested gas_limit, and a timestamp.","failureModes":["Base RPC unavailable: upstream eth_feeHistory call fails, returns 5xx error","Payment failure: x402 USDC payment not provided or insufficient, returns 402 Payment Required","Invalid gas_limit: value outside 21000–30000000 range returns 400 validation error","Stale data: if Base RPC is slow, updated_at may lag by several blocks","Network congestion spike: fast-tier fee estimates may be outdated within seconds during high volatility"],"whenToPreferThis":"Choose this endpoint when your agent needs real-time, structured EIP-1559 gas fee data specifically for the Base L2 network, including ready-to-sign tx_fields and USD cost estimates. It is ideal for onchain trading bots, DeFi automation agents, or any workflow that must decide whether to submit a transaction now or wait. At $0.001 per call it is extremely cheap for programmatic gas checking. Prefer this over generic Ethereum gas oracles when targeting Base, and over RPC-direct calls when you want pre-computed tiered recommendations with congestion context.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:40:48.326Z","isFirstParty":false,"canonicalSlug":"base-gas-oracle-eip-1559-fee-estimator-b05d273f"}