Mempool Space
Recommended fee tiers in sat/vB, as mempool.space's own estimator sees them.
5 endpoints1.1k calls5/5 passing
Fees
GET
/v1/finance:mempool-space/feespassing · 0.4s1m cache
Parameters
No parameters. Call it as is.
Example response
{"project":"finance:mempool-space", "data": {"unit":"sat/vB","dataset":"fees","hourFee":1,"provider":"mempool-space","economyFee":1,"fastestFee":1,"minimumFee":1,"halfHourFee":1 },"timestamp":"2026-08-21T02:24:38Z"}
Errors
- 401Missing or invalid x-api-key
- 404Not found or private
- 429Rate limit or monthly quota reached
Blocks
The last 15 blocks, decorated with mempool.space's own per-block analysis.
GET
/v1/finance:mempool-space/blockspassing · 0.7s2m cache
Parameters
| Name | Type | In | Description |
|---|---|---|---|
| height | number | query | Start height. Returns that block and the 14 below it. Omit for the chain tip. |
Example response
{"project":"finance:mempool-space", "data": {"count":15, "items": [ {"bits":386020669,"date":"2026-08-20T16:13:55.000Z","hash":"000000000000000000012494c7465e63c75e19b5ea6fac791a9e17deb9b9821b","size":1692049,"time":1787242435,"nonce":4184907309,"stale":false,"avgFee":494,"height":963330,"poolId":44,"reward":314443642,"weight":3994084,"txCount":3932,"version":637640704, "feeRange": [ 0, 0, 1 ],"poolName":"AntPool","poolSlug":"antpool","avgTxSize":430.19,"matchRate":91.02,"medianFee":1,"totalFees":1943642,"avgFeeRate":1,"difficulty":127479855693691.4,"medianTime":1787240341,"merkleRoot":"3a862f73950ada239a23900a5af2c1b096897c212c7c9c42af055837f65b1fce","similarity":null,"totalInputs":8803,"virtualSize":998521,"expectedFees":1983549,"totalOutputs":8787,"utxoSetChange":-16,"expectedWeight":3991925,"segwitTotalTxs":3127,"totalOutputAmt":916989493513,"coinbaseAddress":"37jKPSmbEGwgfacCr2nayn1wTaqMAbA94Z","segwitTotalSize":1554524,"previousBlockHash":"000000000000000000010b9a7c4cd90b904ae75d8a58b7583d24f8546bc3094d","segwitTotalWeight":3444092 }, {"bits":386020669,"date":"2026-08-20T16:10:10.000Z","hash":"000000000000000000010b9a7c4cd90b904ae75d8a58b7583d24f8546bc3094d","size":1687761,"time":1787242210,"nonce":497520903,"stale":false,"avgFee":960,"height":963329,"poolId":115,"reward":315138459,"weight":3994731,"txCount":2747,"version":537919488, "feeRange": [ 0, 0, 1 ],"poolName":"MARA Pool","poolSlug":"marapool","avgTxSize":614.29,"matchRate":97.92,"medianFee":2,"totalFees":2638459,"avgFeeRate":2,"difficulty":127479855693691.4,"medianTime":1787240064,"merkleRoot":"3b8f723ecb4bc3f5f47e8bab0964479c726633d78bf0db82bf9583ffa1cf197b","similarity":null,"totalInputs":9417,"virtualSize":998682.75,"expectedFees":2860693,"totalOutputs":6595,"utxoSetChange":-2822,"expectedWeight":3991950,"segwitTotalTxs":2474,"totalOutputAmt":880748033230,"coinbaseAddress":"32i1m6gNcSHwiPX9nfTNXVjme9j5DU8y5g","segwitTotalSize":1521952,"previousBlockHash":"000000000000000000007f37c59f2281d657b83257db8788a26572c5e7369b29","segwitTotalWeight":3331603 }, {"bits":386020669,"date":"2026-08-20T16:05:37.000Z","hash":"000000000000000000007f37c59f2281d657b83257db8788a26572c5e7369b29","size":1548015,"time":1787241937,"nonce":3099071765,"stale":false,"avgFee":906,"height":963328,"poolId":73,"reward":315854966,"weight":3993615,"txCount":3703,"version":699105280, "feeRange": [ 0, 1, 2 ],"poolName":"ViaBTC","poolSlug":"viabtc","avgTxSize":417.92,"matchRate":97.2,"medianFee":3,"totalFees":3354966,"avgFeeRate":3,"difficulty":127479855693691.4,"medianTime":1787239225,"merkleRoot":"36fbc55f29dad244a6578994f499d3ce0b39b7990fdcfb5bc61b3056468c243c","similarity":null,"totalInputs":7719,"virtualSize":998403.75,"expectedFees":3406355,"totalOutputs":8437,"utxoSetChange":718,"expectedWeight":3991908,"segwitTotalTxs":3301,"totalOutputAmt":1463544994069,"coinbaseAddress":"1PuJjnF476W3zXfVYmJfGnouzFDAXakkL4","segwitTotalSize":1358046,"previousBlockHash":"00000000000000000001ae083ea48f0a77511d01b73c4b27e8e7b77bd4363223","segwitTotalWeight":3233847 } ],"height":963330,"dataset":"blocks","provider":"mempool-space" },"timestamp":"2026-08-21T02:24:38Z"}
Errors
- 401Missing or invalid x-api-key
- 404Not found or private
- 429Rate limit or monthly quota reached
Mempool
Pending transactions and the fee-rate histogram behind them.
GET
/v1/finance:mempool-space/mempoolpassing · 0.9s1m cache
Parameters
No parameters. Call it as is.
Example response
{"project":"finance:mempool-space", "data": {"count":226, "items": [ {"vsize":93728,"feeRate":5.0099845 }, {"vsize":51246,"feeRate":2.8633094 }, {"vsize":54421,"feeRate":2 }, {"vsize":62099,"feeRate":1.005336 }, {"vsize":50137,"feeRate":0.70642203 }, {"vsize":50840,"feeRate":0.5343321 }, {"vsize":52056,"feeRate":0.5043951 }, {"vsize":52014,"feeRate":0.500987 } ],"vsize":43778589,"dataset":"mempool","txCount":84482,"provider":"mempool-space","totalFee":8637374 },"timestamp":"2026-08-21T02:24:38Z"}
Errors
- 401Missing or invalid x-api-key
- 404Not found or private
- 429Rate limit or monthly quota reached
Difficulty Adjustment
Retarget progress and the difficulty change mempool.space projects from it.
GET
/v1/finance:mempool-space/difficulty-adjustmentslow · 2.2s2m cache
Parameters
No parameters. Call it as is.
Example response
{"project":"finance:mempool-space", "data": {"dataset":"difficulty-adjustment","provider":"mempool-space","timeOffset":0,"previousDate":"2026-08-08T19:35:55.000Z","previousTime":1786217755,"expectedBlocks":1768.8733333333332,"timeAvgSeconds":609,"progressPercent":86.5079365079365,"remainingBlocks":272,"difficultyChange":-1.3496349842272548,"previousRetarget":0.9889358055576736,"remainingSeconds":165528,"nextRetargetHeight":963648,"estimatedRetargetDate":"2026-08-23T00:23:26.504Z","estimatedRetargetTime":1787444607,"adjustedTimeAvgSeconds":609 },"timestamp":"2026-08-21T02:24:38Z"}
Errors
- 401Missing or invalid x-api-key
- 404Not found or private
- 429Rate limit or monthly quota reached
Fee Projection
The blocks mempool.space projects from the current mempool, by fee band.
GET
/v1/finance:mempool-space/fee-projectionpassing · 0.8s1m cache
Parameters
No parameters. Call it as is.
Example response
{"project":"finance:mempool-space", "data": {"unit":"sat/vB","count":8, "items": [ {"txCount":5458, "feeRange": [ 0.5004868549172347, 0.5029596412556053, 0.5058749663646964, 0.5320310255673657, 0.5946145333825157, 1.019225839528326, 30.54054054054054 ],"blockSize":1605900,"medianFee":0.5322800718132853,"totalFees":1153306,"blockIndex":0,"blockVsize":997950 }, {"txCount":3215, "feeRange": [ 0.41651705565529623, 0.41759319816873774, 0.41759319816873774, 0.43198191835004945, 0.452189949285385, 0.4853376378800108, 0.5008757456530016 ],"blockSize":2082583,"medianFee":0.4320060088865006,"totalFees":444893,"blockIndex":1,"blockVsize":997999 }, {"txCount":7165, "feeRange": [ 0.3838383838383838, 0.41651705565529623, 0.41651705565529623, 0.41651705565529623, 0.41651705565529623, 0.41656104773975494, 0.41756594724220625 ],"blockSize":1583481,"medianFee":0.4165170556552962,"totalFees":415722,"blockIndex":2,"blockVsize":997993.5 }, {"txCount":6938, "feeRange": [ 0.3832752613240418, 0.38640236792537447, 0.3962703962703963, 0.4022266115999282, 0.41651705565529623, 0.41651705565529623, 0.41651705565529623 ],"blockSize":1590664,"medianFee":0.4096576576576578,"totalFees":403880,"blockIndex":3,"blockVsize":997987 }, {"txCount":419, "feeRange": [ 0.3487544483985765, 0.3700719424460432, 0.3700719424460432, 0.3700719424460432, 0.3817427385892116, 0.3861945316001793, 0.38626378552855734 ],"blockSize":1037107,"medianFee":0.3749687560752076,"totalFees":374388,"blockIndex":4,"blockVsize":997973.5 }, {"txCount":60, "feeRange": [ 0.21212121212121213, 0.3314805457301668, 0.34197333333333335, 0.34197333333333335, 0.3493603881782091, 0.37402867234573034, 0.37490628384194596 ],"blockSize":1048847,"medianFee":0.37402867234573034,"totalFees":372841,"blockIndex":5,"blockVsize":997991.75 }, {"txCount":252, "feeRange": [ 0.2949852507374631, 0.2966292134831461, 0.2980618124672603, 0.3000475963826749, 0.30205949656750575, 0.3143631436314363, 0.350679931712486 ],"blockSize":2999333,"medianFee":0.30007109045827335,"totalFees":313519,"blockIndex":6,"blockVsize":997893.5 }, {"txCount":60988, "feeRange": [ 0.09973274888411843, 0.10364055970076447, 0.10500230998134744, 0.12021287065004276, 0.12021287065004277, 0.13023565659089015, 0.13023565659089018, 0.13023565659089018 ],"blockSize":112784000,"medianFee":0.13023565659089015,"totalFees":5163610,"blockIndex":7,"blockVsize":36822692.75 } ],"dataset":"fee-projection","provider":"mempool-space" },"timestamp":"2026-08-21T02:24:38Z"}
Errors
- 401Missing or invalid x-api-key
- 404Not found or private
- 429Rate limit or monthly quota reached
Try it
Live request with your key
const data = await client.run( "finance:mempool-space", "fees", {});
Mempool Space
Recommended fee tiers in sat/vB, as mempool.space's own estimator sees them.
5 endpoints1.1k calls5/5 passing
GET
/v1/…mempool-space/feespassing · 0.4s1m cache
Try it
Parameters
No parameters. Call it as is.
Example response
{"project":"finance:mempool-space", "data": {"unit":"sat/vB","dataset":"fees","hourFee":1,"provider":"mempool-space","economyFee":1,"fastestFee":1,"minimumFee":1,"halfHourFee":1 },"timestamp":"2026-08-21T02:24:38Z"}
Errors
- 401Missing or invalid x-api-key
- 404Not found or private
- 429Rate limit or monthly quota reached
Code
const data = await client.run( "finance:mempool-space", "fees", {});