(quick and dirty) Gemini bitcoin exchange order-book listrequires node, run with node gemini.js

gemini.js

var https = require('https');

var options = {
  hostname: 'api.gemini.com',
  port: 443,
  method: 'GET',
  path: '/v1/book/btcusd'
};

var rLimit = 10; // number of results
var refresh = 5; // in seconds

var reqCallback = function(response) {
  var str = '';
  response.on('data', function (chunk) {
    str += chunk;
  });

  response.on('end', function () {
    var data = JSON.parse(str);
    // clear the console
    console.log('\033[2J');

    console.log(new Date());
    console.log();
    console.log("ASKS (%d/%d):", rLimit, data.asks.length);
    for(var i=0; i<data.asks.length; i++) {
      console.log("\t%s\t%s", data.asks[i].price, data.asks[i].amount);
      if(i+1==rLimit) {
        break;
      }
    }

    console.log("BIDS (%d/%d):", rLimit, data.bids.length);
    for(var i=0; i<data.bids.length; i++) {
      console.log("\t%s\t%s", data.bids[i].price, data.bids[i].amount);
      if(i+1==rLimit) {
        break;
      }
    }
  });
}

function doReq() {
  var req = https.request(options, reqCallback);
  req.on('error', function() {
    console.log('error in request');
  });
  req.end();
}

setInterval(doReq, refresh * 1000);