# mempool.space API > mempool.space returns Bitcoin fee estimates, address balances, and recent transactions as a workflow and API. mempool.space, also called Mempool, returns Bitcoin fee recommendations, estimated costs, and the Bitcoin price; it needs no input. Get bitcoin address returns address balances and recent transactions; it needs a Bitcoin address and optionally a transaction count. - Page: https://fous.com/workflows/mempool-space - Handle: `@mempool-space` - Category: [Blockchain](https://fous.com/workflows/category/blockchain) - Source website: https://mempool.space - Last verified: Sep 29, 2026 - Fous is not affiliated with mempool.space. ## Methods ### Get bitcoin address Operation `get_bitcoin_address`, version 1. 1 credit per call. See a Bitcoin address’s confirmed and pending balances, lifetime received and sent amounts, and up to 50 recent transactions. USD balance uses the latest reported Bitcoin price; received and sent totals include pending transactions. **Input** | Field | Type | Required | Example | Description | |---|---|---|---|---| | `address` | string | yes | `"1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa"` | Bitcoin address starting with 1, 3 or bc1, for example 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa. | | `max_transactions` | integer | no | `10` | Maximum recent transactions to return, for example 10. Defaults to 10; maximum 50. | **Input schema** ```json { "type": "object", "required": [ "address" ], "properties": { "address": { "type": "string", "description": "Bitcoin address starting with 1, 3 or bc1, for example 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa.", "examples": [ "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa", "3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy", "1BYym9pkkPXM7He9QtdJQ93eGXTu462mdJ" ] }, "max_transactions": { "type": "integer", "default": 10, "maximum": 50, "minimum": 1, "description": "Maximum recent transactions to return, for example 10. Defaults to 10; maximum 50.", "x-fous-developer": true, "examples": [ 10, 50 ] } }, "additionalProperties": false, "examples": [ { "address": "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa", "max_transactions": 10 }, { "address": "3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy", "max_transactions": 50 }, { "address": "1BYym9pkkPXM7He9QtdJQ93eGXTu462mdJ" } ] } ``` **Output** | Field | Type | Example | Description | |---|---|---|---| | `address` | string | `"1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa"` | | | `total_sent_btc` | number | `0` | | | `transaction_count` | integer | `66619` | | | `total_received_btc` | number | `57.47644956` | | | `recent_transactions` | array | | | | `recent_transactions[].link` | string | `"https://mempool.space/tx/c99e446ab2d43e999de5708e62a8384f187f8015cc6d188af2a23e8d313b39a4"` | Transaction page on mempool.space. | | `recent_transactions[].fee_btc` | number | `2e-7` | Whole transaction network fee in BTC, not necessarily paid by this address. | | `recent_transactions[].confirmed` | string | `"no"` | Whether this transaction is confirmed. | | `recent_transactions[].date_time` | string or null | | Confirmation date and time in UTC, or null when unconfirmed. | | `recent_transactions[].block_height` | integer or null | | Block height, or null when unconfirmed. | | `recent_transactions[].net_change_btc` | number | `0.00003672` | Change in this address’s balance in BTC, negative for a net send. | | `recent_transactions[].transaction_id` | string | `"c99e446ab2d43e999de5708e62a8384f187f8015cc6d188af2a23e8d313b39a4"` | Transaction ID. | | `confirmed_balance_btc` | number | `57.47633581` | | | `confirmed_balance_usd` | number | `4779042.37` | | | `unconfirmed_balance_btc` | number | `0.00011375` | | **Example input** ```json { "address": "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa", "max_transactions": 10 } ``` **Example output** ```json { "address": "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa", "total_sent_btc": 0, "transaction_count": 66619, "total_received_btc": 57.47644956, "recent_transactions": [ { "link": "https://mempool.space/tx/c99e446ab2d43e999de5708e62a8384f187f8015cc6d188af2a23e8d313b39a4", "fee_btc": 2e-7, "confirmed": "no", "date_time": null, "block_height": null, "net_change_btc": 0.00003672, "transaction_id": "c99e446ab2d43e999de5708e62a8384f187f8015cc6d188af2a23e8d313b39a4" }, { "link": "https://mempool.space/tx/4fe8b2b6fec09c158e1bd622e236a629510c87d4f77a9778f416a850aab041db", "fee_btc": 4.3e-7, "confirmed": "no", "date_time": null, "block_height": null, "net_change_btc": 0.00000546, "transaction_id": "4fe8b2b6fec09c158e1bd622e236a629510c87d4f77a9778f416a850aab041db" }, { "link": "https://mempool.space/tx/5b38b8e6c131189d1366d8b73241a6034ccd637edd4d5ad1c7195dfb92d9e847", "fee_btc": 5.5e-7, "confirmed": "no", "date_time": null, "block_height": null, "net_change_btc": 0.00000546, "transaction_id": "5b38b8e6c131189d1366d8b73241a6034ccd637edd4d5ad1c7195dfb92d9e847" } ], "confirmed_balance_btc": 57.47633581, "confirmed_balance_usd": 4779042.37, "unconfirmed_balance_btc": 0.00011375 } ``` ### Get bitcoin fees Operation `get_bitcoin_fees`, version 1. 1 credit per call. Get current Bitcoin fee-rate recommendations, estimated USD costs for a 140-vbyte transaction, and the Bitcoin price in USD. Confirmation times are estimates, not guarantees. **Input** No input. **Output** | Field | Type | Example | Description | |---|---|---|---| | `reading_time` | string | `"2026-09-29T04:48:00Z"` | Time these readings were fetched, in UTC. | | `currency_code` | string | `"USD"` | Currency of estimated costs and Bitcoin price (USD). | | `economy_cost_usd` | number | `0.1164184` | Estimated USD fee for a 140-vbyte transaction at the economy rate. | | `minimum_cost_usd` | number | `0.1164184` | Estimated USD fee for a 140-vbyte transaction at the minimum rate. | | `bitcoin_price_usd` | number | `83156` | Price of one bitcoin in US dollars. | | `one_hour_cost_usd` | number | `0.1164184` | Estimated USD fee for a 140-vbyte transaction at the about 1 hour rate. | | `next_block_cost_usd` | number | `0.4656736` | Estimated USD fee for a 140-vbyte transaction at the next block (fastest) rate. | | `thirty_minutes_cost_usd` | number | `0.4656736` | Estimated USD fee for a 140-vbyte transaction at the about 30 minutes rate. | | `economy_fee_sat_per_vbyte` | number | `1` | Economy recommended transaction fee rate in satoshis per virtual byte. | | `minimum_fee_sat_per_vbyte` | number | `1` | Minimum recommended transaction fee rate in satoshis per virtual byte. | | `one_hour_fee_sat_per_vbyte` | number | `1` | About 1 hour recommended transaction fee rate in satoshis per virtual byte. | | `next_block_fee_sat_per_vbyte` | number | `4` | Next block (fastest) recommended transaction fee rate in satoshis per virtual byte. | | `thirty_minutes_fee_sat_per_vbyte` | number | `4` | About 30 minutes recommended transaction fee rate in satoshis per virtual byte. | **Example input** ```json {} ``` **Example output** ```json { "reading_time": "2026-09-29T04:48:00Z", "currency_code": "USD", "economy_cost_usd": 0.1164184, "minimum_cost_usd": 0.1164184, "bitcoin_price_usd": 83156, "one_hour_cost_usd": 0.1164184, "next_block_cost_usd": 0.4656736, "thirty_minutes_cost_usd": 0.4656736, "economy_fee_sat_per_vbyte": 1, "minimum_fee_sat_per_vbyte": 1, "one_hour_fee_sat_per_vbyte": 1, "next_block_fee_sat_per_vbyte": 4, "thirty_minutes_fee_sat_per_vbyte": 4 } ``` ## Quick start Call the API with a Fous API key (`FOUS_API_KEY`). To create one, turn on Developer mode in Fous Studio, then open Keys & connections → API keys (https://app.fous.com/keys). ```bash # First set your key: export FOUS_API_KEY='YOUR_FOUS_API_KEY' : "${FOUS_API_KEY:?Set FOUS_API_KEY before running this example}" curl 'https://api.fous.com/v1/query' \ --fail-with-body --silent --show-error --max-time 120 \ -H "Authorization: Bearer $FOUS_API_KEY" \ -H 'Content-Type: application/json' \ --data-raw '{ "api": "@mempool-space", "visibility": "public", "operation": "get_bitcoin_address", "version": 1, "input": { "address": "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa", "max_transactions": 10 }, "response": { "format": "json" } }' ``` ```python # Save as fous.py and run with python3 fous.py. No packages needed. # First set your key: export FOUS_API_KEY='YOUR_FOUS_API_KEY' import json import os import urllib.error import urllib.request api_key = os.environ.get("FOUS_API_KEY") if not api_key: raise RuntimeError("Set FOUS_API_KEY before running this example") body = json.loads("{\n \"api\": \"@mempool-space\",\n \"visibility\": \"public\",\n \"operation\": \"get_bitcoin_address\",\n \"version\": 1,\n \"input\": {\n \"address\": \"1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa\",\n \"max_transactions\": 10\n },\n \"response\": {\n \"format\": \"json\"\n }\n}") request = urllib.request.Request( "https://api.fous.com/v1/query", data=json.dumps(body).encode("utf-8"), headers={ "Authorization": f"Bearer {api_key}", "Content-Type": "application/json", }, method="POST", ) try: with urllib.request.urlopen(request, timeout=120) as response: result = json.load(response) except urllib.error.HTTPError as error: raise RuntimeError(f"HTTP {error.code}: {error.read().decode('utf-8', errors='replace')}") from error if result.get("success") is False: raise RuntimeError(result.get("error", {}).get("message", "Request failed")) print(json.dumps(result["data"]["output"], indent=2)) ``` ```typescript // Save as fous.mts and run with npx tsx fous.mts. // First set your key: export FOUS_API_KEY='YOUR_FOUS_API_KEY' const apiKey = process.env.FOUS_API_KEY; if (!apiKey) throw new Error("Set FOUS_API_KEY before running this example"); const response = await fetch("https://api.fous.com/v1/query", { method: "POST", headers: { "Authorization": `Bearer ${apiKey}`, "Content-Type": "application/json", }, signal: AbortSignal.timeout(120_000), body: JSON.stringify({ "api": "@mempool-space", "visibility": "public", "operation": "get_bitcoin_address", "version": 1, "input": { "address": "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa", "max_transactions": 10 }, "response": { "format": "json" } }), }); type ApiResult = { success: boolean; data?: { output: unknown }; error?: { message: string } }; const result: ApiResult = await response.json(); if (!response.ok || result.success === false) { throw new Error(result.error?.message ?? `HTTP ${response.status}`); } if (!result.data) throw new Error("Missing API response data"); console.log(result.data.output); ``` Or describe the data in plain language: send `{"api":"@mempool-space","prompt":"Describe the data you need, with every detail"}` to the same URL. Fous fills in the input, runs the method that fits and returns only the fields you asked for; `data.route.calls[].request` is the exact call it made. Routing is free; the run costs the same. ## Use cases - Compare estimated Bitcoin transaction costs across confirmation speeds. - Track confirmed and pending balances for a Bitcoin address. - Review recent transactions and balance changes for an address. - Monitor lifetime Bitcoin received and sent by an address. ## FAQ ### Is Fous affiliated with mempool.space? No. Fous is not affiliated with mempool.space. This workflow reads the public mempool.space website and returns its data. ### How much does it cost? Each run costs 1 credit. With pay-as-you-go, a credit costs 1¢; monthly plans cost less per credit. ### Do I need a mempool.space account? No. You only need a Fous account. ### How current is the data? Fous gets the data from mempool.space when you run it; repeating the same request within a day may return the saved result. Fous checks this workflow automatically; it last passed a check on Sep 29, 2026. ### What are the recommended Bitcoin fee rates? Get bitcoin fees returns recommended fee rates for economy, minimum, about one hour, about 30 minutes, and the next block. ### What is the balance of a Bitcoin address? Get bitcoin address returns confirmed and unconfirmed balances, including the confirmed balance in USD. ### Which transactions were recently made by an address? Get bitcoin address returns up to 50 recent transactions, including confirmation status and the address’s net balance change. ## Related - [Etherscan API](https://fous.com/workflows/etherscan.md): Etherscan shows current gas prices, estimated costs, wallet balances, displayed token holdings and newest confirmed transactions, plus transaction status and details; pending fees are unconfirmed. - [Coinbase API](https://fous.com/workflows/coinbase.md): Coinbase provides public cryptocurrency prices and market overviews, including changing spot, buy, and sell quotes and 24-hour statistics; unavailable page facts may be missing. - [Binance API](https://fous.com/workflows/binance.md): Binance provides latest prices and rolling 24-hour statistics for active spot pairs, historical spot candles for a selected date range or newest first (up to 1,000), and current aggregated bid and ask levels. - [CoinMarketCap API](https://fous.com/workflows/coinmarketcap.md): CoinMarketCap returns prices, rankings and current Fear and Greed readings; gainers and losers include up to 30 top-100 coins above $50,000 in 24-hour volume. - [Kraken API](https://fous.com/workflows/kraken.md): Live cryptocurrency market prices and trading statistics from Kraken. - [CoinGecko API](https://fous.com/workflows/coingecko.md): CoinGecko returns cryptocurrency prices and histories, sector rankings and details, and trending coins; non-USD historical values cover 365 days, histories 7–365 days, and today’s prices may change. - [US Census Bureau API](https://fous.com/workflows/us-census-bureau.md): US Census Bureau returns statistics from varying Census years, population estimates through July 1, and address geographies using Census vintages that may differ from representation. - [Best Buy API](https://fous.com/workflows/best-buy.md): Best Buy returns US electronics and appliance listings, prices, deals, specifications, images, reviews, and nearby store pickup and shipping details; prices and availability can change by location and before checkout. - [All Blockchain workflows](https://fous.com/workflows/category/blockchain)