{"uid":"cap_b1oVCzM1eo-2rMUtx8J3i","slug":"api-carbon-cashmere-de-843fdcc5","name":"Bitcoin Smart Fee Curve API","description":"Bitcoin smart-fee curve for 1/3/6/12/24/144-block confirmation targets + trend classification (rising/stable/falling/surging) from 2h moving average.","url":"https://api.carbon-cashmere.de/v1/btc-derivatives/fee-curve","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"properties":{"type":"string"}}},"responseSchema":{"type":"json","example":{"trend":"stable","sat_vb":{"1block":4.2,"3block":3.1,"6block":2.8,"12block":2.5,"24block":2.1,"144block":1.4},"pressure":"low","min_relay_fee_sat_vb":1}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_0GqaCgX1q9oOz6gLHun0X","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns Bitcoin smart-fee estimates across 1/3/6/12/24/144-block confirmation targets with trend classification derived from a 2-hour moving average, sourced from an own-node estimatesmartfee call.","exampleAgentPrompt":"What are the current Bitcoin fee rates for 1, 6, and 24-block confirmation targets, and is the fee market trending rising, stable, or falling right now?","exampleUseCases":null,"resultDescription":"A fee curve object containing sat/vByte fee estimates for each of the 1, 3, 6, 12, 24, and 144-block confirmation targets, a trend classification label (rising/stable/falling/surging) derived from a 2-hour moving average, and min relay fee context — all sourced live from an own Bitcoin node's estimatesmartfee RPC.","failureModes":["Node connectivity issue — own Bitcoin node temporarily unavailable, returns 503","Fee estimation unavailable — mempool insufficient data for certain block targets, partial curve returned","Rate limiting — exceeded call quota, returns 429","Invalid endpoint path — returns 404"],"whenToPreferThis":"Use this endpoint when an AI agent needs real-time Bitcoin fee data across multiple confirmation horizons in a single call, especially for fee-aware transaction timing or execution planning. Prefer this over generic mempool explorers when you also need trend classification (rising/stable/falling/surging) to decide whether to transact now or wait. Ideal for automated agents that must optimize BTC transaction costs dynamically.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T06:49:04.997Z","isFirstParty":false}