bwt-daemon v1.0.0

bwt-daemon

A nodejs library for programmatically managing the Bitcoin Wallet Tracker Electrum RPC and HTTP API servers using the libbwt FFI interface.

⚠️ WARNING: This is an alpha preview, released to gather developers' feedback. It is not ready for general use.

Install

$ npm install bwt-daemon

This will download the libbwt library for your platform. The currently supported platforms are Linux, Mac, Windows and ARMv7/8.

The hash of the downloaded library is verified against the SHA256SUMS file that ships with the npm package.

The library comes with the electrum and http servers by default. If you're only interested in the Electrum server, you can install with BWT_VARIANT=electrum_only npm install bwt-daemon. This reduces the download size by ~1.6MB.

Note: bwt-daemon uses ffi-napi, which requires a recent nodejs version. If you're running into errors during installation or segmentation faults, try updating to a newer version.

Use

Below is a minimally viable configuration. If bitcoind is running locally on the default port, at the default datadir location and with cookie auth enabled (the default), this should Just Work™ \o/

import BwtDaemon from 'bwt-daemon'

const bwtd = await BwtDaemon({
  xpubs: [ 'xpub66...' ],
  electrum: true,
})

console.log('bwt electrum server ready on', bwtd.electrum_addr)

With some more advanced options:

const bwtd = await BwtDaemon({
  // Network and Bitcoin Core RPC settings
  network: 'regtest',
  bitcoind_dir: '/home/satoshi/.bitcoin',
  bitcoind_url: 'http://127.0.0.1:9008/',
  bitcoind_wallet: 'bwt',

  // Descriptors and xpubs to track
  descriptors: [ 'wpkh(tpub61.../0/*)' ],
  xpubs: [ 'tpub66...' ],

  // Rescan since timestamp. Accepts unix timestamps, date strings, Date objects, or 'now' to look for new transactions only
  rescan_since: '2020-01-01',

  // Enable HTTP and Electrum servers
  http: true,
  electrum: true,

  // Bind on port 0 to use any available port (the default)
  electrum_addr: '127.0.0.1:0',
  http_addr: '127.0.0.1:0',

  // Set the gap limit of watched unused addresses
  gap_limit: 100,

  // Progress notifications for history scanning (a full rescan from genesis can take 20-30 minutes)
  progress: (type, progress, detail) => console.log('bwt %s progress %f%%', type, progress*100, detail),
})

// Get the assigned address/port for the Electrum/HTTP servers
console.log('bwt electrum server ready on', bwtd.electrum_addr)
console.log('bwt http server ready on', bwtd.http_url)

// Shutdown
bwtd.shutdown()

See example.js for an even more complete example, including connecting to the HTTP API.

The full list of options is available in the FFI documentation. The nodejs wrapper also provides the following additional convenience options:

• electrum - setting to true is an alias for electrum_addr=127.0.0.1:0
• http - setting to true is an alias for http_addr=127.0.0.1:0

License

MIT