Measuring Experiments

Using Autocapture

Sidecar comes loaded with an event collection tool that will autocapture various web activities, allowing you to create both simple and complex Metrics within Statsig console without writing a line of code.

Autocapture tracks the following events and properties automatically:

Captured across all events

Property	description	example value (strings)
value	Url of the current page	https://www.example.com/utm=FALL_2024
tagName	Tag name of the target element	button

auto_capture::click

Property	description	example value (strings)
metadata.content	innerText value of the clicked element	Add to Cart
metadata.page_url	Current URL with path and parameters	https://www.example.com/?utm=FALL_2024
metadata.href	Link to url if tag is <a>	https://www.target-url.com/
metadata.[dataset keys]	Data set values expanded	metadata.attributionKey=demoLink

auto_capture::page_view

Property	description	example value (strings)
metadata.queryParams	A json representation of query string params	{\"utm\":\"FALL_2024\"}
metadata.referrer	URL of the prior page	https://www.google.com
metadata.title	Title of the current webpage from <title>	Homepage
metadata.screen_width	Width of the current screen in pixels	3440
metadata.screen_height	Height of the current screen in pixels	1440
metadata.viewport_width	Width of the browser window in pixels	960
metadata.viewport_height	Height of the browser window in pixels	600

auto_capture::page_view_end

Property	description	example value (strings)
value	Current URL with path and parameters	https://www.FULL-URL.com/?utm=FALL_2024
metadata.pageViewLength	total number of milliseconds spent on the page	61370
metadata.scrollDepth	percentage of page scrolled (integer 0-100)	47

auto_capture::form_submit

Property	description	example value (strings)
value	Fixed string	"form"
metadata.action	action attribute on the form element	/submit.php
metadata.formId	id attribute on the form element	user-info
metadata.formName	name attribute on the form element	user-info
metadata.method	Http method on the form element	POST

auto_capture::performance

Property	description	example value (strings)
metadata.dom_interactive_time_ms	Time until DOM is qualified as interactive as implemented by browser performanceTiming API	1807.90
metadata.first_contentful_paint_time_ms	First contentful paint metric as implemented by browser performanceTiming API	1523.90
metadata.load_time_ms	Total load time as implemented by browser performanceTiming API	2766.90
metadata.page_url	Current URL with path and parameters	https://www.FULL-URL.com/?utm=FALL_2024
metadata.transfer_bytes	Total number of bytes transferred in document body as implemented by browser performanceTiming API	48360

Disabling All Logging

To disable all logging to statsig (both autocapture events and logging who has seen your experiments) append the following query string parameter to the Sidecar script URL: &autostart=0. This may be useful if you're dealing with GDPR compliance, and you can later re-enable events with client.updateRuntimeOptions({disableLogging: false})

Auto Capturing Data Attributes

Data attribute tags will automatically be added to the event metadata object. Note that this is available for click events only for now!

The metadata will be in the format of data-(camelCasedAttributeName). For example:

<button data-button-attribute="important button attribute">Add to Cart</button>
<a href="/checkout" data-a-tag-attribute="important a tag attribute">Checkout</a>

Metadata on the events tab will be

{
  "content": "Add to Cart",
  "data-buttonAttribute": "important button attribute",
  "page_url": "http://localhost:4200/",
  "sessionID": "7ccb4e03-3599-443e-8d41-4b89f7168728",
  "tagName": "button"
}

{
  "content": "Checkout",
  "data-aTagAttribute": "important a tag attribute",
  "href": "/checkout",
  "page_url": "http://localhost:4200/",
  "sessionID": "7ccb4e03-3599-443e-8d41-4b89f7168728",
  "tagName": "a"
}

Using the tracking API

You can track events manually for actions that are not autocaptured by the feature described above. To track events back to Statsig, you can call StatsigSidecar.logEvent which takes the same arguments as the Statsig JS SDK as documented here. This method can be called prior to completion of the init routine.

// example order event
StatsigSidecar.logEvent('Order', null, {
  total: 54.66,
  units: 3,
  unitAvgCost: 18.22
});

Post-Experiment Callback for outbound integrations

You can bind a callback that gets invoked after Sidecar has run experiments (also gets called when there are no experiments), allowing you to run code that processes the experiment assignments as needed.

This method should be defined anywhere prior to the Sidecar client script.

window.postExperimentCallback = function(statsigClient, experimentIds) {
  /** 
   * add your own callback routine here
   * ie; annotating 3rd party analytics tools with assignment info
      
    var evarValue = [];
    experimentIds.forEach(function(expId) {
      var inExp = statsigClient.getExperiment(expId, { disableExposureLog: true }).groupName;
      if(inExp) {
        evarValue.push(expId + ':' + inExp);
      }
    });
    evarValue = evarValue.join(',');
   */
}