$3

This is a reference adapter for receiving realtime data from the BitMEX API.

#### Usage

> The following is runnable in example.js.

To get started, create a new client:

``js
const BitMEXClient = require('bitmex-realtime-api');
// See 'options' reference below
const client = new BitMEXClient({testnet: true});
`

Then subscribe to a symbol and table, and pass a callback.

`js
client.addStream('XBTUSD', 'instrument', function (data, symbol, tableName) {
// Do something with the table data...
});
`

#### API Reference

##### new BitMEXClient(object options)

Options:

`js
{
testnet: false, // set true to connect to the testnet site (testnet.bitmex.com)
// Set API Key ID and Secret to subscribe to private streams.
// See Available Private Streams below.
apiKeyID: '',
apiKeySecret: '',
maxTableLen: 10000 // the maximum number of table elements to keep in memory (FIFO queue)
}
`

##### client.addStream(string symbol, [string tableName], function callback)

Subscribe to a data stream. Pass a symbol to subscribe to all public data for an instrument.

Pass tableName to receive data for a specific table.

`js
client.addStream('XBTUSD', 'quote', function (data, symbol, tableName) {
if (!data.length) return;
const quote = data[data.length - 1]; // the last data element is the newest quote
// Do something with the quote (.bidPrice, .bidSize, .askPrice, .askSize)
});
`

##### client.on(string eventName, function callback)

The client also doubles as a basic EventEmitter. The following events are fired:

`
"initialize" // Socket initialized, client.streams available
"error"
"open"
"close"
`
Example:
`js
client.on('initialize', () => {
console.log(client.streams); // Log .public, .private and .all stream names
});
`

Note: Don't forget to attach an error handler! If one is not attached, errors will be thrown
and crash your client.

##### client.getData([string symbol], [string tableName])

Use this function to access data directly. Pass either a symbol, or tableName, or both.
Data returned by this method is safe to modify as it is cloned from the internal stores.

If speed is a concern, all data is accessible directly inside the client via the client._data property.
Do not modify this data, or you will corrupt further updates!

##### client.getSymbol(string symbol)

Same as above, but returns all tables for a given symbol.

##### client.getTable(string tableName)

Same as above, but returns all symbols for a given table.

`js
client.addStream('XBTUSD', 'trade', () => {});
setTimeout(() => {
console.log('XBTUSD trades during the last few seconds:', client.getTable('trade').XBTUSD);
}, 5000);
`

#### Available Public Streams

The streams below echo the models described in the API Explorer.

`
"chat", // Trollbox
"instrument", // Instrument updates including turnover and bid/ask
"liquidation", // Liquidations
"orderBookL2_25", // Top 25 levels of level 2 order book
"orderBook10", // Last 10 bids and asks (price and size)
"quote", // Top level of the book
"trade" // Trades
... // See https://www.bitmex.com/app/wsAPI#Subscriptions for more streams
`

#### Available Private Streams

The following streams require authentication via an API key.

`
"execution", // Individual order placements and executions, settlements, commissions
"margin", // Your account's margin details
"order", // Order creations, cancellations, and updates
"position" // Your positions, per instrument
... // See https://www.bitmex.com/app/wsAPI#Subscriptions for more streams
`

$3

For much more information on what this module is doing, run it with the DEBUG environment variable. For example:

`bash


Display all debug messages

DEBUG=* node example.js

Display all high-level debug messages

DEBUG=BitMEX:* node example.js
`

$3

https://www.bitmex.com/app/wsAPI#Heartbeats

you can implement a more thorough solution, but hope this helps along
`
setInterval(() => {
client.socket.send("ping")
}, 30 * 1000); // sends ping every 30 s
``