Bitmex-simple-rest

npm install bitmex-simple-rest

API wrapper for the Bitmex REST API. Please refer to their documentation for all calls explained. Check out sample.js for some example calls.

This is a low level wrapper with zero dependencies focussed on:

• Speed
  • Uses keep-alive
  • Disables Nagle's algorithm
  • No complex code
  • No third party libraries
  • allows you to pre compile your message (see below under low latency usage)
• Userland control
  • Passes on response headers such as information on your rate limit quota
  • Allows you to specity timeout & expiration date per call

Used by my low latency market maker that's running in production. I don't think you can go much faster in nodejs without rewriting Node.js' core http library (if you think you can, feel free to open an issue or propose a PR).

Usage

// your api key & secret
const key = 'x';
const secret = 'y';

const BitmexRest = require('bitmex-simple-rest');
const bm = new BitmexRest({
  key,
  secret,

  // these are optional
  timeout: 90 * 1000, // ms - when this lib should timeout the call
  expiration: 60 * 1000, // ms - after how many ms bitmex should refuse this call
  userAgent: 'bearwhale' // string - custom ua
});

const { data, headers } = await bm.request({
  path: '/user/margin',
  method: 'GET',
  data: { currency: 'XBt' }
});

Low latency usage

Sending an API request to Bitmex requires hashing the payload with your API key. In nodejs, this process can easily take 0.15 millisecond (on the non compute optimized AWS boxes I tested this on - because yes, you should run on AWS-EU-1 if you want to trade fast on Bitmex). You can test the speed of creating API requests yourself on your system by running benchmark.js, preferably with real keys and and a request similar to what your system might send.

This library allows you to prepare an API request draft before hand (doing all the heavy work). The microsecond you realize you actually want to send it you simply send the draft you created previously:

// create the draft before hand
const draft = bm.createDraft({
  path: '/user/margin',
  method: 'GET',
  data: { currency: 'XBt' }
});

// later when you actually want to send
const { data, headers } = await bm.requestDraft(draft);

Note that this only works in scenarios where you can estimate what will happen or which scenarios might happen: You can create drafts for all of them and only end up sending one later.

TODO

• Figure out if we can reliably skip the end event of the packetstream (see requestDraft comment).
• String compare for common errors (overload), skipping JSON.parse.

Final

If this library is helping you trade better on Bitmex feel free to use my ref link. You'll get a 10% fee discount for the first 6 months, lowering your market fees (on the perpetual swap) from 0.075% to a mere 0.0675%!