Analytics Kotlin Firebase Plugin

Firebase is Google’s platform for mobile apps. The Segment Firebase destination requires that you bundle the Firebase SDK with your project. The Segment-wrapped destination code then runs on the user’s device, and sends its tracking calls to the Firebase API endpoints, and a copy to Segment for archiving.

Firebase’s destination plugin code is open source and available on GitHub. You can view it here.

Adding the dependency

To install the Segment-Firebase integration, simply add this line to your gradle file:

implementation '<latest_version>'

Or the following for Kotlin DSL


Using the Plugin in your App

Open the file where you setup and configure the Analytics-Kotlin library. Add this plugin to the list of imports.


Just under your Analytics-Kotlin library setup, call analytics.add(plugin = ...) to add an instance of the plugin to the Analytics timeline.

    analytics = Analytics("<YOUR WRITE KEY>", applicationContext) {
        this.flushAt = 3
        this.trackApplicationLifecycleEvents = true
    analytics.add(plugin = FirebaseDestination(applicationContext))

Your events will now begin to flow to Firebase in device mode.


When you call identify Segment will map to the corresponding Firebase Analytics calls:

  • If there is a userId on your identify call, Segment triggers setUserId using the Firebase SDK
  • If there are traits included, Segment will set user properties for each trait you include on the identify call

You can use these traits to create audiences and views to analyze your users’ behavior.

Note: Google prohibits sending PII to Firebase unless “robust notice” is given to your app users. For iOS apps, some Analytics features, such as audiences and campaign attribution, and some user properties, such as Age and Interests, require the AdSupport framework to be enabled.

Learn more about Firebase’s reporting dashboard here.

Firebase has strict requirements for User Property names; they must:

  • Begin with a letter (not a number or symbol, including an underscore)
  • Contain only alphanumeric characters and underscores
  • Be no longer than 40 characters

User Property values must be fewer than 100 characters.

You are limited to 25 unique user properties per Firebase Console.

Firebase automatically collects these user properties.


When you call track Segment will log the event with Firebase. Firebase automatically tracks the events listed here and it will still do so when bundling with Segment.

Firebase has a limit of 500 distinctly named events so it pays off to be intentional in what you track.

When you call track, Segment maps from the Segment spec to those that match Firebase’s spec. For anything that does not match, Segment will pass the event to Firebase as a custom event. Custom parameters cannot be seen directly in the Firebase Analytics dashboard but they can be used as filters in Audiences.

Like with user properties, Segment will perform the following transformations on both your event names and event parameters. Unlike user properties, you do not need to pre-define event parameters in your Firebase dashboard.

  • Trims leading and trailing whitespace from property names
  • Replaces spaces with underscores
  • Trims property names to 40 characters (Android only)

Event parameter values must be fewer than 100 characters.

Event Mappings

Segment adheres to Firebase’s semantic event specification and maps the following Segment spec-matching events (left) to the corresponding Firebase events (right):

Segment Event Firebase Event
Products Searched search
Product List Viewed view_item_list
Product Viewed view_item
Product Clicked select_content
Product Shared share
Product Added add_to_cart
Product Added To Wishlist add_to_wishlist
Checkout Started begin_checkout
Promotion Viewed present_offer
Payment Info Entered add_payment_info
Order Completed purchase
Order Refunded purchase_refund

Property Mappings

Segment maps the followed Segment spec-matching properties (left) to the corresponding Firebase event parameters (right):

Segment Property Firebase Property Accepted Value(s)
category item_category (String) “kitchen supplies”
product_id item_id (String) “p1234”
name item_name (String) “Le Creuset pot”
price price (double) 1.0
quantity quantity (long) 1
query search_term (String) “Le Creuset”
shipping shipping (double) 2.0
tax tax (double) 0.5
total value (double) 3.99 or (long) 3.99
revenue value (double) 3.99 or (long) 3.99
order_id transaction_id (String) “o555636”
currency currency (String) “USD”

Passing Revenue and Currency

Ecommerce events containing “revenue” or “total” must also include the appropriate ISO 4217 “currency” string for revenue data to populate to the Firebase dashboard. If a “currency” value is not included, Segment default to “USD”.

analytics.track("Order Completed", buildJsonObject {
    put("orderId", "order-123")
    put("revenue", 23.00)
    put("currency", "USD")


Segment doesn’t map screen events to Firebase - that’s because Firebase’s SDK collects screen information out of the box for you.

For iOS, you can configure recordScreenViews which will automatically track screen views, or pass in a screen manually using a screen call. You should be able to disable the Automatic Screen reporting by adding the plist flag FirebaseScreenReportingEnabled to Info.plist and set its value to NO (Boolean).

Google Analytics for Firebase iOS does NOT support the case of manual-only screen reporting. Firebase only supports automatic + manual screen reporting or no screen reporting at all.

Conversion Tracking and Adwords Conversions

Firebase is Google’s recommended method for reporting conversions to Adwords. To use Firebase, track the conversion events as you normally would with Segment and Segment will send them through to Firebase.


Firebase has great logging. If you are having any issues, you can enable debug mode as outlined here.

This page was last modified: 21 Apr 2023

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