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: 'trades', 
  symbol: 'tBTCUSD' 
})

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

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

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

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

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

// request
{ 
  event: "subscribe", 
  channel: "trades", 
  symbol: SYMBOL 
}

// response Trading
{
  event: "subscribed",
  channel: "trades",
  chanId: CHANNEL_ID,
  symbol: "tBTCUSD"
  pair: "BTCUSD"
}

{"event":"subscribed","channel":"trades","chanId":19111,"symbol":"tBTCUSD","pair":"BTCUSD"}

// response Funding
{
  event: "subscribed",
  channel: "trades",
  chanId: CHANNEL_ID,
  symbol: "fUSD",
  currency: "USD"
}

{"event":"subscribed","channel":"trades","chanId":339521,"symbol":"fUSD","currency":"USD"}

// on trading pairs (ex. tBTCUSD)

[
  17470, //CHANNEL_ID
  [
    [
      401597393, //ID
      1574694475039, //MTS
      0.005, //AMOUNT
      7244.9 //PRICE
    ], //TRADE
    ...
  ] //SNAPSHOT
]  

// on funding currencies (ex. fUSD)
 
[
  339521, //CHANNEL_ID
  [
    [
      133323072, //ID
      1574694245478, //MTS
      -258.7458086, //AMOUNT
      0.0002587, //RATE
      2 //PERIOD
    ], //TRADE
    ...
  ]
]

// on trading pairs (ex. tBTCUSD)

[
  17470, //CHANNEL_ID
  "te", //MSG_TYPE
  [
    401597395, //ID
    1574694478808, //MTS
    0.005, //AMOUNT
    7245.3 //PRICE
  ] //TRADE
]

// on funding currencies (ex. fUSD)

[
  337371, //CHANNEL_ID
  "fte", //MSG_TYPE
  [
    133323543, //ID
    1574694605000, //MTS
    -59.84, //AMOUNT
    0.00023647, //RATE
    2 //PERIOD
  ] //TRADE
]

Request fields

Fields	Type	Description
SYMBOL	String	Trading pair or funding currency

Trade snapshot data

Index	Field	Type	Description
[0]	CHANNEL_ID	Int	Identification number assigned to the channel for the duration of this connection.
[1]	SNAPSHOT	Array	Array with an array of recent trades (Indices [0...n] will be trades)
[0...n]	TRADE	Array	Trade array or funding trade array

Trade update data

Index	Field	Type	Description
[0]	CHANNEL_ID	Int	Identification number assigned to the channel for the duration of this connection.
[1]	MSG_TYPE	String	"te" (trade executed), "tu" (trade updated), "fte" (funding trade executed), "ftu" (funding trade updated
[2]	TRADE	Trade	Trade array or funding trade array

Trade arrays

Index	Field	Type	Description
[0]	ID	Int	Trade ID
[1]	MTS	Int	Millisecond time stamp
[2]	AMOUNT	Float	Amount bought (positive) or sold (negative).
[3]	PRICE	Float	Price at which the trade was executed

Funding trade arrays

Index	Field	Type	Description
[0]	ID	Int	Trade ID
[1]	MTS	Int	Millisecond time stamp
[2]	AMOUNT	Float	Amount of funding provided (positive) or taken (negative).
[3]	RATE	Float	Funding rate of the trade
[4]	PERIOD	Int	Funding offer period in days

📘
Amount
The order that causes the trade (the taker) determines if it is a buy or a sell (for trades) or if funding is provided or taken (for funding)