{"uid":"cap_nzGqPbT1mE0THWLONhve7","slug":"satoshi-api-bitcoin-next-block-fee-intelligence-d2e8437e","name":"Satoshi API - Bitcoin Next Block Fee Intelligence","description":"Know when to send Bitcoin and when to wait. Satoshi API gives apps and AI agents live fee recommendations, mempool context, and cost estimates. Free, open source.","url":"https://bitcoinsapi.com/api/v1/mining/nextblock","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"properties":{"type":"string"}}},"responseSchema":{"type":"json","schema":{"type":"object","required":["height","tx_count","median_fee_rate"],"properties":{"top_5":{"type":"array"},"height":{"type":"integer"},"tx_count":{"type":"integer"},"max_fee_rate":{"type":"number"},"min_fee_rate":{"type":"number"},"total_fees_btc":{"type":"number"},"median_fee_rate":{"type":"number"}}},"example":{"top_5":[{"txid":"example-txid","fee_rate":122}],"height":840000,"tx_count":2800,"max_fee_rate":122,"min_fee_rate":5.1,"total_fees_btc":0.36,"median_fee_rate":14.2},"mimeType":"application/json"},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"registry","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_VK6VCHUsotcrslrk73x7D","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns live fee rates, transaction count, and cost data for the next Bitcoin block to help apps and AI agents decide when to send Bitcoin transactions.","exampleAgentPrompt":"What are the current Bitcoin fee rates for the next block — specifically the median, min, and max sat/vbyte — so I can decide whether to send my transaction now or wait?","exampleUseCases":[{"title":"Optimal Bitcoin send timing","prompt":"I need to send some Bitcoin to a friend. Check the current next-block fee rates and tell me whether fees are low right now or if I should wait — and what median fee rate I should use."},{"title":"Automated wallet fee estimation","prompt":"Before broadcasting this Bitcoin transaction, pull the latest next-block fee data so I can set the right fee rate and make sure it confirms quickly without overpaying."},{"title":"Bitcoin network congestion dashboard","prompt":"Give me a live snapshot of the next Bitcoin block — how many transactions are queued, what the fee range looks like from min to max, and what the top 5 highest-fee transactions are paying."}],"resultDescription":"A JSON object containing the projected next block's height, transaction count, median/min/max fee rates in sat/vbyte, total fees in BTC, and an array of the top 5 transactions by fee rate with their txid and fee rate.","failureModes":["Network or node connectivity issues returning 5xx errors","Mempool data temporarily unavailable during node sync","Stale or delayed fee data if the Bitcoin node is behind tip","Invalid or malformed request body returning 400 errors","Rate limiting or payment failures if x402 payment not included"],"whenToPreferThis":"Use this endpoint when you need real-time Bitcoin mempool fee intelligence specifically for next-block inclusion decisions. Prefer this over generic blockchain explorers when you need structured fee data (median, min, max, top transactions) in a single call optimized for programmatic use by apps or AI agents. Ideal for wallets, payment automation, and any agent that needs to decide whether to send Bitcoin now or defer.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T06:30:35.256Z","isFirstParty":false}