{"uid":"cap_LsU7JUebNRLAIT9mP-MFF","slug":"delx-evm-eip-1559-fee-check-0c194944","name":"Delx EVM EIP-1559 Fee Check","description":"EVM Eip1559 Fee Check: EVM Eip1559 Fee Check checks dynamic-fee caps and calculates the worst-case transaction fee from bounded caller-supplied values without an external provider. Call EVM Eip1559 Fee Check before signing, submitting, replacing, or accepting an EVM/Base transaction assembled from caller-owned data. Returns normalized transaction evidence, calculated budget or shape findings, and a fail-closed preflight status for EVM Eip1559 Fee Check as versioned deterministic JSON. Price: $0…","url":"https://api.delx.ai/api/v1/x402/evm-eip1559-fee-check","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"gas_limit":{"type":"integer","description":"Gas Limit supplied to EVM Eip1559 Fee Check; used only for this bounded calculation and processed in memory without retention."},"max_fee_per_gas_wei":{"type":"string","maxLength":8192,"description":"Max Fee Per Gas Wei supplied to EVM Eip1559 Fee Check; used only for this bounded calculation and processed in memory without retention."},"max_priority_fee_per_gas_wei":{"type":"string","maxLength":8192,"description":"Max Priority Fee Per Gas Wei supplied to EVM Eip1559 Fee Check; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"fee_ceiling_wei":"42000000000000","fee_caps_ordered":true,"priority_fee_ceiling_wei":"2100000000000"},"schema":"delx/util-evm-eip1559-fee-check/v1","status":"pass","evidence":{"retained":false,"input_sha256":"09e6859a0243cf6df6f99d660a7735e0bfb2893802645cebf1d03fa659f21a65","external_calls":0},"operation":"evm_preflight:evm_eip1559_fee_check"}},"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_c1k1-B82U0LPiWwbqj6bL","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":"Validates EIP-1559 transaction fee parameters (gas limit, max fee per gas, max priority fee per gas) and computes ceiling values for EVM preflight checks.","exampleAgentPrompt":"Before I submit this Ethereum transaction, check if my EIP-1559 fee parameters are valid: gas limit is 21000, max fee per gas is 2000000000000 wei, and max priority fee per gas is 100000000000 wei — tell me the fee ceiling and whether the caps are properly ordered.","exampleUseCases":[{"title":"Preflight EVM transaction fee validation","prompt":"I'm about to send an EVM transaction with a gas limit of 21000, max fee per gas of 2000000000000 wei, and max priority fee of 100000000000 wei — can you verify these fee parameters are valid and give me the fee ceiling before I broadcast it?"},{"title":"DeFi agent gas safety check","prompt":"My DeFi agent is about to submit a smart contract interaction with gas limit 150000, max fee per gas 50000000000 wei, and max priority fee 1500000000 wei. Run a preflight fee check to confirm the caps are ordered correctly and compute the fee ceiling in wei."},{"title":"Detect misconfigured transaction fees","prompt":"I think my transaction builder might have the max fee and max priority fee in the wrong order — can you check: gas limit 80000, max fee per gas 3000000000 wei, max priority fee 5000000000 wei? I need to know if the fee caps are valid before submitting."}],"resultDescription":"Returns a JSON object with: fee_ceiling_wei (maximum possible transaction fee in wei), priority_fee_ceiling_wei (maximum priority fee in wei), fee_caps_ordered (boolean indicating whether max_fee >= max_priority_fee), and an overall status ('pass' or 'fail'). Also includes evidence metadata confirming no external calls were made and inputs were not retained.","failureModes":["Invalid or non-numeric wei string values may cause parsing errors","Gas limit of zero or negative may produce invalid calculations","Missing required fields returns a validation error","Malformed JSON request body returns a 400-level error","max_priority_fee_per_gas_wei exceeding max_fee_per_gas_wei results in fee_caps_ordered=false (not a hard error, but a failed check)"],"whenToPreferThis":"Use this endpoint when you need a fast, cheap, privacy-preserving preflight validation of EIP-1559 fee parameters before submitting an EVM transaction. Prefer this over on-chain or RPC-based fee checks when you want deterministic, in-memory computation with no external blockchain calls and a guaranteed evidence trail. Ideal for AI agents building or reviewing EVM transactions programmatically.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T18:42:54.452Z","isFirstParty":false}