{"uid":"cap_thGHEqhb7AUTN8oAFMxMz","slug":"seneschal-cheapest-flashloan-query-65c9a75a","name":"Seneschal Cheapest Flashloan Query","description":"Single-fact: cheapest flash-loan provider for `asset` on `chain` (default ethereum). Returns {provider, fee_bps, address}.","url":"https://api.seneschal.space/v1/q/cheapest-flashloan","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":["asset"],"properties":{"asset":{"type":"string","description":"Asset symbol, e.g. WETH, USDC."},"chain":{"type":"string","description":"Chain name (default ethereum)."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"asset":{"type":"string"},"chain":{"type":"string"},"found":{"type":"boolean"},"address":{"type":"string"},"fee_bps":{"type":"number"},"provider":{"type":"string"}}}}}}},"responseSchema":{"type":"json","example":{"asset":"WETH","chain":"ethereum","found":true,"address":"0xBBBBBbbBBb9cC5e90e3b3Af64bdAF62C37EEFFCb","fee_bps":0,"provider":"morpho-blue"}},"example":{"request":{"asset":"ETH"},"response":{"asset":"ETH","chain":"ethereum","found":true,"address":"0xBA12222222228d8Ba445958a75a0704d566BF2C8","fee_bps":0,"provider":"balancer-v2"}},"exampleRequest":{"asset":"ETH"},"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","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_iWsZJFbzhH2rKLoVSytN2","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 cheapest available flash loan offer across DeFi protocols on Ethereum mainnet","exampleAgentPrompt":"What's the cheapest flash loan available on Ethereum mainnet right now — I need to know which protocol to use and what the fee is before I execute an arbitrage trade.","exampleUseCases":[{"title":"Cheapest flash loan for liquidation","prompt":"Before I trigger this undercollateralized position liquidation on mainnet, find me the cheapest flash loan available right now — I need the protocol, fee rate, and whether there's enough liquidity to cover the full liquidation amount."},{"title":"Compare flash loan rates across protocols","prompt":"I'm about to run an MEV strategy and need to know which protocol — Aave, dYdX, Uniswap, or anything else — is offering the lowest fee flash loan on Ethereum mainnet at this moment, and how much liquidity is on offer."},{"title":"Optimal flash loan source for arbitrage","prompt":"I've spotted a cross-DEX arbitrage opportunity on Ethereum and need to borrow 500k USDC uncollateralized — tell me which protocol has the cheapest flash loan for that asset right now so I can route the trade optimally."}],"resultDescription":"Returns data about the cheapest flash loan currently available, including the protocol offering it, the fee rate, and available liquidity for the requested asset parameters.","failureModes":["No flash loan liquidity available for requested asset — empty result set","Malformed properties parameter returns 400 bad request","Rate limit exceeded returns 402 payment required (x402 USDC on Base)","Ethereum node connectivity issues may cause stale or unavailable data","Insufficient x402 USDC balance returns payment error"],"whenToPreferThis":"Use this endpoint when you need to programmatically find the lowest-cost flash loan on Ethereum mainnet before executing an MEV, arbitrage, or liquidation strategy. Particularly useful when integrated with Seneschal's block builder service, as the data is sourced from mainnet block-building telemetry.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T00:31:54.683Z","isFirstParty":false}