Sources Overview

What is a source?

In Segment, you create a source (or more than one!) for each website or app you want to track. While it’s not required that you have a single Source for each server, site or app, we highly recommend creating a Source for each unique source of data.

You can create new sources using the button in the workspace view. Each source you create has a write key, which is used to send data to that source. For example, to load analytics.js, the Segment JavaScript library on your page, the snippet on the Quickstart Guide includes:

analytics.identify('user_123', {
  email: '',
  name: 'Jane Kim'

Website libraries

Analytics.js, our Javascript library, is the most powerful way to track customer data from your website. If you’re just starting out, we recommend it over server-side libraries as the simplest installation for any website.


Our Mobile SDKs are the best way to simplify your iOS, Android, and Xamarin app tracking. We recommend them over server-side sources as the default installation for any mobile app.

Pilot Libraries

Pilot releases of the Analytics-Swift and Analytics-Kotlin libraries are available. This library is governed by Segment’s First-Access and Beta terms, and should not be used in production scenarios.


Our server-side sources let you send analytics data directly from your servers. We only recommend tracking from your servers when device-mode tracking (tracking on the client) won’t work. Check out our guide on server-side tracking if you’re not sure whether it makes sense for your use case.

Cloud-mode tracking

Server-side data management is when tag sends data to the Segment servers, which then pass that data to the destination system.

Cloud Apps

Cloud app sources empower you to pull together data from all of your different third-party tools into a Segment warehouse or to your other enabled integrated tools. There are two types of Cloud Apps: Object and Event sources.

Object Cloud Sources

These Cloud App Sources can export data from its third party tool and import it directly into your Segment warehouse. Make sure you have a Segment warehouse enabled before you enable any of the following sources:

Event Cloud Sources

These Cloud App Sources can not only export data into your Segment warehouse, but they can also federate the exported data into your other enabled Segment integrations:

To dig into some examples of how to pull this data together, check out our sample queries in the Segment Community.


If we don’t have a library for your environment yet, you can always send your data directly to our HTTP Tracking API. All of Segment’s other sources and platforms use the HTTP API to work their magic behind the scenes.


Our Pixel Tracking API lets you track events from environments where you can’t execute code, like tracking email opens.

Event name Description
Email Delivered Message has been successfully delivered to the receiving server
Email Opened Recipient has opened the HTML message. You need to enable Open Tracking for getting this type of event
Email Link Clicked Recipient clicked on a link within the message. You need to enable Click Tracking for getting this type of event
Email Bounced Receiving server could not or would not accept message
Email Marked as Spam Recipient marked message as spam
Unsubscribe Recipient clicked on message’s subscription management link

Source request

We’d love to know what other sources of data you’d like to analyze. Contact the Support Team to log a request.

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This page was last modified: 17 May 2021

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