Only add the Keen IO JS SDK to the page if it's not already there; otherwise configure a new client instance

keen_client_noconflict.js

// useful if you are injecting code into 3rd party websites that may already have Keen
// this code will use the Keen SDK on the page if found, or initialize it's own otherwise.

// this approach will work in the average case, but could break if the 3rd party website
// is modifying or configuring the Keen library in an unexpected way

// a more durable approach would be to use an iFrame containing only the SDK and pass it messages

var context = this;
var myKeenClient = null;
var projectId = "xxx";
var writeKey = "yyy";

function addKeenEvent(collection, properties) {
  
  if (myKeenClient !== null) {
    myKeenClient.uploadEvent(collection, properties);
    
  } else {
    if (typeof context.Keen === 'object') {
      // put this logic inside the onChartsReady callback; 
      // The Keen.Client object isn't available until the full library is present
      context.Keen.onChartsReady(function() {
        myKeenClient = new context.Keen.Client({ projectId: projectId, writeKey: writeKey });
        myKeenClient.uploadEvent(collection, properties);
      });
    } else {
      context.Keen = {configure:function(e){this._cf=e},addEvent:function(e,t,n,i){this._eq=this._eq||[],this._eq.push([e,t,n,i])},setGlobalProperties:function(e){this._gp=e},onChartsReady:function(e){this._ocrq=this._ocrq||[],this._ocrq.push(e)}};(function(){var e=document.createElement("script");e.type="text/javascript",e.async=!0,e.src=("https:"==document.location.protocol?"https://":"http://")+"dc8na2hxrj29i.cloudfront.net/code/keen-2.1.0-min.js";var t=document.getElementsByTagName("script")[0];t.parentNode.insertBefore(e,t)})();
      context.Keen.onChartsReady(function() {
        myKeenClient = new context.Keen.Client({ projectId: projectId, writeKey: writeKey });
        myKeenClient.uploadEvent(collection, properties);
      });
    }
  }
}

addKeenEvent("foo", { "bar" : "baz "});