{"uid":"cap_Dk65wATXY0tSuZlCcgXxN","slug":"halowerk-kettenwerk-gas-fee-estimator-f75c6400","name":"HALOWERK kettenwerk Gas Fee Estimator","description":"Reads the fee history of the last 20 blocks on Ethereum, Base, Arbitrum, Optimism, Polygon or BNB Smart Chain and returns what a transaction costs right now. Priority fees come from the 10th, 50th and 90th percentile of the tips actually paid in those blocks — the percentile used is named, not hidden. On rollups the L1 data fee is quoted separately from the L2 execution fee, because it is often the larger part and an estimate that merges them is simply wrong; the L1 part is computed from the cha","url":"https://kette.halowerk.com/gas?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"chain":{"enum":["ethereum","base","arbitrum","optimism","polygon","bsc"],"type":"string","description":"Chain to read fees from."},"speed":{"enum":["langsam","normal","schnell","alle"],"type":"string","default":"alle","description":"Which speed level to highlight. All three are always returned."},"tx_type":{"enum":["native_transfer","erc20_transfer","erc20_approve","swap","nft_mint","contract_deploy"],"type":"string","default":"erc20_transfer","description":"Transaction profile used for the total cost estimate. Its assumed gas limit and byte size are stated in the answer."}}},"responseSchema":null,"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_H6O-g5L6nJpdejYAftiqq","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 gas fee estimates (slow/normal/fast) for a specified EVM chain, with L1 and L2 fees quoted separately for rollups, based on the last 20 blocks of fee history.","exampleAgentPrompt":"What does a swap transaction cost right now on Base — break out the L1 data fee and L2 execution fee separately, and show me all three speed levels.","exampleUseCases":[{"title":"Pre-trade gas check for DeFi swap","prompt":"Before I submit this swap on Arbitrum, can you check what the current gas fees look like? I want to see the fast, normal, and slow options for a swap transaction, including the L1 and L2 fee breakdown."},{"title":"ERC-20 transfer cost on Polygon","prompt":"How much would an ERC-20 transfer cost on Polygon right now? Show me what the normal speed option would run me in total gas fees."},{"title":"NFT mint cost estimate on Ethereum","prompt":"I'm about to mint an NFT on Ethereum — what's the current gas fee for that kind of transaction? Show me the 10th, 50th, and 90th percentile priority fees so I can decide what to bid."}],"resultDescription":"Returns the current base fee, priority fees at 10th/50th/90th percentile (labeled slow/normal/fast), and total estimated transaction cost for the specified transaction type. For rollups (Base, Arbitrum, Optimism), the L1 data fee and L2 execution fee are quoted separately. The assumed gas limit and byte size for the chosen transaction profile are included in the response.","failureModes":["Unsupported chain value returns validation error","RPC unavailability for a given chain may cause stale or missing data","Highly volatile fee environments may cause estimates to shift before transaction submission","Invalid tx_type or speed enum values return a schema error"],"whenToPreferThis":"Use this endpoint when you need accurate, percentile-labeled gas fee estimates across major EVM chains, especially when working with rollups where the L1 data component must be understood separately. It is superior to single-block fee snapshots and to estimates that merge L1+L2 costs opaquely. Ideal before submitting any transaction where cost matters — swaps, mints, deploys, transfers.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-13T06:44:06.724Z","isFirstParty":false,"canonicalSlug":"halowerk-kettenwerk-gas-fee-estimator-f75c6400"}