Gemini WebSocket Demo

HTML

<link rel="stylesheet" href="https://netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css">
<h3>Gemini WebSocket Demo</h3>

<h5><a href="https://docs.gemini.com/rest-api/#streaming-market-data" target="_blank">API Documentation</a></h5>

<div id="status">Not connected.</div>
<br />
<ul id="messages">
</ul>

CSS

/*

This is a very simple demo of Gemini's WebSocket streaming market data.  

It is intended for demonstration purposes only.

*/

JavaScript

var socket = new WebSocket('wss://api.gemini.com/v1/marketdata/btcusd');

function addMessage(message) {
  $("#messages").prepend("<li class=\"message\"><b>" + new Date() + "</b><br /><pre>" + message + "</pre></li>");
  $("#messages").find("li:gt(10)").remove();
}

$("#status").text("Connecting to Gemini API...");

socket.onerror = function(error) {
  console.log('WebSocket Error: ' + error);
};

socket.onopen = function(event) {
  $("#status").text("Connected to Gemini API.");
};

socket.onmessage = function(event) {
  var message = JSON.stringify(JSON.parse(event.data), undefined, 2);
  addMessage(message);
};

socket.onclose = function(event) {
  addMessage('Disconnected.');
};