Books

const ws = require('ws')
const w = new ws('wss://api-pub.bitfinex.com/ws/2')

w.on('message', (msg) => console.log(msg))

let msg = JSON.stringify({ 
  event: 'subscribe', 
  channel: 'book', 
  symbol: 'tBTCUSD' 
})

w.on('open', () => w.send(msg))

wscat -c wss://api-pub.bitfinex.com/ws/2
{ "event": "subscribe", "channel": "book", "symbol": "tBTCUSD" }

ws = websocket.WebSocketApp('wss://api-pub.bitfinex.com/ws/2')

ws.on_open = lambda self: self.send('{ "event": "subscribe", "channel": "book", "symbol": "tBTCUSD"}')

ws.on_message = lambda self, evt:  print (evt)

// request
{
	event: 'subscribe',
	channel: 'book',
	symbol: SYMBOL,
	prec: PRECISION,
	freq: FREQUENCY,
	len: LENGTH,
	subId: SUBID
}

{"event":"subscribe","channel":"book","symbol":"tBTCUSD","prec":"P0","freq":"F0","len":"25","subId": 123}

// response
{
	event: 'subscribed',
	channel: 'book',
	chanId: CHANNEL_ID,
	symbol: SYMBOL,
	prec: PRECISION,
	freq: FREQUENCY,
	len: LENGTH,
	subId: SUBID,
	pair: PAIR 
}

{"event":"subscribed","channel":"book","chanId":10092,"symbol":"tETHUSD","prec":"P0","freq":"F0","len":"25","subId":123,"pair":"ETHUSD"}

// on trading pairs (ex. tBTCUSD)

[
  17082, //CHANNEL_ID
  [
    [
      7254.7, //PRICE
      3, //COUNT
      3.3 //AMOUNT
    ], //BOOK_ENTRY
    ...
  ] //BOOK_ENTRIES
]
  
// on funding currencies (ex. fUSD)

[
  431549, //CHANNEL_ID
  [
    [
      0.00023112, //RATE
      30, //PERIOD
      1, //COUNT
      -15190.7005375 //AMOUNT
    ], //BOOK_ENTRY
    ...
  ] //BOOK_ENTRIES
]

// on trading pairs (ex. tBTCUSD)

[
  17082, //CHANNEL_ID
  [
    7254.5, //PRICE
    0, //COUNT
    1 //AMOUNT
  ] //BOOK_ENTRY
]
  
// on funding currencies (ex. fUSD)

[
  348748, //CHANNEL_ID
  [
    0.00023157, //RATE
    2, //PERIOD
    1, //COUNT
    66.35007188 //AMOUNT
  ] //BOOK_ENTRY
]

//Bulk updates can be enabled using a conf event flag of 536870912

// on trading pairs (ex. tBTCUSD)

[
  17082, //CHANNEL_ID
  [
    [
      7254.5, //PRICE
      0, //COUNT
      1 //AMOUNT
    ], //BOOK_ENTRY
  	...
  ] //BOOK_ENTRIES
]
  
// on funding currencies (ex. fUSD)

[
  348748, //CHANNEL_ID
  [
    [
      0.00023157, //RATE
      2, //PERIOD
      1, //COUNT
      66.35007188 //AMOUNT
    ], //BOOK_ENTRY
    ...
  ]//BOOK_ENTRIES
]