npm package: @owstack/btc-explorer-api
Description: A Bitcoin blockchain REST and web socket API service for Btc.
Latest version: 0.0.6

Btc Explorer API
======

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A Bitcoin blockchain REST and web socket API service for [Btc Node](https://github.com/owstack/btc-node).

This is a backend-only service. If you're looking for the web frontend application, take a look at https://github.com/owstack/ows-explorer.

## Getting Started

```bashl
npm install -g btc-node@latest
btc-node create mynode
cd mynode
btc-node install btc-explorer-api
btc-node start
```

The API endpoints will be available by default at: `http://localhost:3001/btc-explorer-api/`

## Prerequisites

- [Btc Node](https://github.com/owstack/btc-node)

**Note:** You can use an existing Bitcoin data directory, however `txindex`, `addressindex`, `timestampindex` and `spentindex` needs to be set to true in `bitcoin.conf`, as well as a few other additional fields.

## Query Rate Limit

To protect the server, explorer-api has a built it query rate limiter. It can be configurable in `btc-node.json` with:
``` json
  "servicesConfig": {
    "explorer-api": {
      "rateLimiterOptions": {
        "whitelist": ["::ffff:127.0.0.1"]
      }
    }
  }
```
With all the configuration options available: https://github.com/owstack/btc-explorer-api/blob/master/lib/ratelimiter.js#L10-17

Or disabled entirely with:
``` json
  "servicesConfig": {
    "explorer-api": {
      "disableRateLimiter": true
    }
  }
  ```

## API HTTP Endpoints

### Block
```
  /explorer-api/block/[:hash]
  /explorer-api/block/00000000a967199a2fad0877433c93df785a8d8ce062e5f9b451cd1397bdbf62
```

### Block Index
Get block hash by height
```
  /explorer-api/block-index/[:height]
  /explorer-api/block-index/0
```
This would return:
```
{
  "blockHash":"000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"
}
```
which is the hash of the Genesis block (0 height)


### Raw Block
```
  /explorer-api/rawblock/[:blockHash]
  /explorer-api/rawblock/[:blockHeight]
```

This would return:
```
{
  "rawblock":"blockhexstring..."
}
```

### Block Summaries

Get block summaries by date:
```
  /explorer-api/blocks?limit=3&blockDate=2016-04-22
```

Example response:
```
{
  "blocks": [
    {
      "height": 408495,
      "size": 989237,
      "hash": "00000000000000000108a1f4d4db839702d72f16561b1154600a26c453ecb378",
      "time": 1461360083,
      "txlength": 1695,
      "poolInfo": {
        "poolName": "BTCC Pool",
        "url": "https://pool.btcc.com/"
      }
    }
  ],
  "length": 1,
  "pagination": {
    "next": "2016-04-23",
    "prev": "2016-04-21",
    "currentTs": 1461369599,
    "current": "2016-04-22",
    "isToday": true,
    "more": true,
    "moreTs": 1461369600
  }
}
```

### Transaction
```
  /explorer-api/tx/[:txid]
  /explorer-api/tx/525de308971eabd941b139f46c7198b5af9479325c2395db7f2fb5ae8562556c
  /explorer-api/rawtx/[:rawid]
  /explorer-api/rawtx/525de308971eabd941b139f46c7198b5af9479325c2395db7f2fb5ae8562556c
```

### Address
```
  /explorer-api/addr/[:addr][?noTxList=1][&from=&to=]
  /explorer-api/addr/mmvP3mTe53qxHdPqXEvdu8WdC7GfQ2vmx5?noTxList=1
  /explorer-api/addr/mmvP3mTe53qxHdPqXEvdu8WdC7GfQ2vmx5?from=1000&to=2000
```

### Address Properties
```
  /explorer-api/addr/[:addr]/balance
  /explorer-api/addr/[:addr]/totalReceived
  /explorer-api/addr/[:addr]/totalSent
  /explorer-api/addr/[:addr]/unconfirmedBalance
```
The response contains the value in Satoshis.

### Unspent Outputs
```
  /explorer-api/addr/[:addr]/utxo
```
Sample return:
```
[
  {
    "address":"mo9ncXisMeAoXwqcV5EWuyncbmCcQN4rVs",
    "txid":"d5f8a96faccf79d4c087fa217627bb1120e83f8ea1a7d84b1de4277ead9bbac1",
    "vout":0,
    "scriptPubKey":"76a91453c0307d6851aa0ce7825ba883c6bd9ad242b48688ac",
    "amount":0.000006,
    "satoshis":600,
    "confirmations":0,
    "ts":1461349425
  },
  {
    "address": "mo9ncXisMeAoXwqcV5EWuyncbmCcQN4rVs",
    "txid": "bc9df3b92120feaee4edc80963d8ed59d6a78ea0defef3ec3cb374f2015bfc6e",
    "vout": 1,
    "scriptPubKey": "76a91453c0307d6851aa0ce7825ba883c6bd9ad242b48688ac",
    "amount": 0.12345678,
    "satoshis: 12345678,
    "confirmations": 1,
    "height": 300001
  }
]
```

### Unspent Outputs for Multiple Addresses
GET method:
```
  /explorer-api/addrs/[:addrs]/utxo
  /explorer-api/addrs/2NF2baYuJAkCKo5onjUKEPdARQkZ6SYyKd5,2NAre8sX2povnjy4aeiHKeEh97Qhn97tB1f/utxo
```

POST method:
```
  /explorer-api/addrs/utxo
```

POST params:
```
addrs: 2NF2baYuJAkCKo5onjUKEPdARQkZ6SYyKd5,2NAre8sX2povnjy4aeiHKeEh97Qhn97tB1f
```

### Transactions by Block
```
  /explorer-api/txs/?block=HASH
  /explorer-api/txs/?block=00000000fa6cf7367e50ad14eb0ca4737131f256fc4c5841fd3c3f140140e6b6
```
### Transactions by Address
```
  /explorer-api/txs/?address=ADDR
  /explorer-api/txs/?address=mmhmMNfBiZZ37g1tgg2t8DDbNoEdqKVxAL
```

### Transactions for Multiple Addresses
GET method:
```
  /explorer-api/addrs/[:addrs]/txs[?from=&to=]
  /explorer-api/addrs/2NF2baYuJAkCKo5onjUKEPdARQkZ6SYyKd5,2NAre8sX2povnjy4aeiHKeEh97Qhn97tB1f/txs?from=0&to=20
```

POST method:
```
  /explorer-api/addrs/txs
```

POST params:
```
addrs: 2NF2baYuJAkCKo5onjUKEPdARQkZ6SYyKd5,2NAre8sX2povnjy4aeiHKeEh97Qhn97tB1f
from (optional): 0
to (optional): 20
noAsm (optional): 1 (will omit script asm from results)
noScriptSig (optional): 1 (will omit the scriptSig from all inputs)
noSpent (option): 1 (will omit spent information per output)
```

Sample output:
```
{ totalItems: 100,
  from: 0,
  to: 20,
  items:
    [ { txid: '3e81723d069b12983b2ef694c9782d32fca26cc978de744acbc32c3d3496e915',
       version: 1,
       locktime: 0,
       vin: [Object],
       vout: [Object],
       blockhash: '00000000011a135e5277f5493c52c66829792392632b8b65429cf07ad3c47a6c',
       confirmations: 109367,
       time: 1393659685,
       blocktime: 1393659685,
       valueOut: 0.3453,
       size: 225,
       firstSeenTs: undefined,
       valueIn: 0.3454,
       fees: 0.0001 },
      { ... },
      { ... },
      ...
      { ... }
    ]
 }
```

Note: if pagination params are not specified, the result is an array of transactions.

### Transaction Broadcasting
POST method:
```
  /explorer-api/tx/send
```
POST params:
```
  rawtx: "signed transaction as hex string"

  eg

  rawtx: 01000000017b1eabe0209b1fe794124575ef807057c77ada2138ae4fa8d6c4de0398a14f3f00000000494830450221008949f0cb400094ad2b5eb399d59d01c14d73d8fe6e96df1a7150deb388ab8935022079656090d7f6bac4c9a94e0aad311a4268e082a725f8aeae0573fb12ff866a5f01ffffffff01f0ca052a010000001976a914cbc20a7664f2f69e5355aa427045bc15e7c6c77288ac00000000

```
POST response:
```
  {
      txid: [:txid]
  }

  eg

  {
      txid: "c7736a0a0046d5a8cc61c8c3c2821d4d7517f5de2bc66a966011aaa79965ffba"
  }
```

### Historic Blockchain Data Sync Status
```
  /explorer-api/sync
```

### Live Network P2P Data Sync Status
```
  /explorer-api/peer
```

### Status of the Bitcoin Network
```
  /explorer-api/status?q=xxx
```

Where "xxx" can be:

 * getInfo
 * getDifficulty
 * getBestBlockHash
 * getLastBlockHash


### Utility Methods
```
  /explorer-api/utils/estimatefee[?nbBlocks=2]
```


## Web Socket API
The web socket API is served using [socket.io](http://socket.io).

The following are the events published by explorer:

`tx`: new transaction received from network. This event is published in the 'inv' room. Data will be a app/models/Transaction object.
Sample output:
```
{
  "txid":"00c1b1acb310b87085c7deaaeba478cef5dc9519fab87a4d943ecbb39bd5b053",
  "processed":false
  ...
}
```


`block`: new block received from network. This event is published in the `inv` room. Data will be a app/models/Block object.
Sample output:
```
{
  "hash":"000000004a3d187c430cd6a5e988aca3b19e1f1d1727a50dead6c8ac26899b96",
  "time":1389789343,
  ...
}
```

`<bitcoinAddress>`: new transaction concerning <bitcoinAddress> received from network. This event is published in the `<bitcoinAddress>` room.

`status`: every 1% increment on the sync task, this event will be triggered. This event is published in the `sync` room.

Sample output:
```
{
  blocksToSync: 164141,
  syncedBlocks: 475,
  upToExisting: true,
  scanningBackward: true,
  isEndGenesis: true,
  end: "000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943",
  isStartGenesis: false,
  start: "000000009f929800556a8f3cfdbe57c187f2f679e351b12f7011bfc276c41b6d"
}
```

### Example Usage

The following html page connects to the socket.io explorer API and listens for new transactions.

html
```
<html>
<body>
  <script src="http://<explorer-server>:<port>/socket.io/socket.io.js"></script>
  <script>
    eventToListenTo = 'tx'
    room = 'inv'

    var socket = io("http://<explorer-server>:<port>/");
    socket.on('connect', function() {
      // Join the room.
      socket.emit('subscribe', room);
    })
    socket.on(eventToListenTo, function(data) {
      console.log("New transaction received: " + data.txid)
    })
  </script>
</body>
</html>
```

## License
(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.