Ampli for Android-Kotlin SDK

The Ampli Wrapper is a generated, strongly typed API for tracking Analytics events based on your Tracking Plan in Amplitude Data. The tracking library exposes a function for every event in your team's tracking plan. The function's arguments correspond to the event's properties.

Ampli provides autocompletion for events and properties defined in Data and enforces your event schemas in code to prevent bad instrumentation.

Quick start

1. (Prerequisite) Create a Tracking Plan in Amplitude Data

   Plan your events and properties in Amplitude Data.

2. Install the Amplitude SDK

   kotlin

   Copy

   implementation 'com.amplitude:analytics-android:1.+'
   

3. Install the Ampli CLI

   bash

   Copy

   npm install -g @amplitude/ampli
   

4. Pull the Ampli Wrapper into your project

   bash

   Copy

   ampli pull [--path ./app/src/main/java/com/amplitude/ampli]
   

5. Initialize the Ampli Wrapper

   kotlin

   API keyCopy

   import com.amplitude.ampli.*
   
   ampli.load(appContext, LoadOptions(
     client = LoadClientOptions(apiKey = AMPLITUDE_API_KEY)
   ))
   

6. Identify users and set user properties

   kotlin

   Copy

   ampli.identify(userId, Identify(
       userProp = "A trait associated with this user"
   ))
   

7. Track events with strongly typed methods and classes

   kotlin

   Copy

   ampli.songPlayed(songId = "song-1")
   ampli.track(SongFavorited(songId = "song-2"))
   

8. Flush events before application exit

   kotlin

   Copy

   ampli.flush();
   

9. Verify implementation status with CLI

   bash

   Copy

   ampli status [--update]
   

Install the Amplitude SDK

If you haven't already, install the core Amplitude SDK dependencies.

implementation 'com.amplitude:analytics-android:1.+'

Install the Ampli CLI

You can install the Ampli CLI from Homebrew or npm.

brew tap amplitude/ampli
brew install ampli

Pull the Ampli Wrapper into your project

Run the Ampli CLI pull command to log in to Amplitude Data and download the strongly typed Ampli Wrapper for your tracking plan. Run Ampli CLI commands from the project root directory.

ampli pull

API

Ampli generates a thin facade over the Amplitude SDK that provides convenience methods. The Ampli Wrapper also grants access to every method of the underlying Amplitude SDK through ampli.client. For more details, refer to Wrapping the Amplitude SDK.

Load

Initialize Ampli in your code. The load() method accepts configuration option arguments:

import com.amplitude.ampli.*

ampli.load(appContext, LoadOptions(
 client = LoadClientOptions(apiKey = AMPLITUDE_API_KEY)
))

Identify

Call identify() to identify a user in your app and associate all future events with their identity, or to set their properties.

Just as Ampli creates types for events and their properties, it creates types for user properties.

The identify() function accepts an optional userId, optional user properties, and optional options.

For example your tracking plan contains a user property called userProp. The property's type is a string.

ampli.identify(userId, Identify(
 userProp = "A trait associated with this user"
))

The options argument lets you pass Amplitude fields for this call, such as deviceId.

val eventOptions = EventOptions();
eventOptions.deviceId = "device-id";

ampli.identify(
 userId,
 Identify(
 userProp = "A trait associated with this user",
 ),
 eventOptions
)

Group identify

Call groupIdentify() to identify a group in your app and set or update group properties.

Just as Ampli creates types for events and their properties, Ampli creates types for group properties.

The groupIdentify() function accepts a string group_type, a string group_name, a Group event instance, and an optional EventOptions.

For example, your tracking plan contains a group test group:android-java-ampli with a property called requiredBoolean of type boolean.

ampli.groupIdentify("test group", "android-kotlin-ampli", Group(requiredBoolean = true))

Group

Call setGroup() to associate a user with their group (for example, their department or company). The setGroup() function accepts a required groupType, and groupName and an optional EventOptions.

ampli.client?.setGroup("groupType", "groupName")

Amplitude supports assigning users to groups and performing queries, such as Count by Distinct, on those groups. If at least one member of the group performs the specific event, the count includes the group.

For example, you want to group users by organization using an orgId. Joe is in orgId 10, and Sue is in orgId 15. Sue and Joe both perform a certain event. You can query their organizations in the Event Segmentation Chart.

When you set groups, define a groupType and groupName. In the previous example, orgId is the groupType and 10 and 15 are the values for groupName. Another example of a groupType is sport with groupName values like tennis and baseball.

Setting a group also sets groupType:groupName as a user property and overwrites any existing groupName value for that user's groupType. groupType is a string. groupName can be a string or an array of strings to show that a user belongs to multiple groups. For example, if Joe is in orgId 10 and 20, then groupName is [10, 20].

Your code might look like this:

ampli.client?.setGroup("orgId", arrayOf("10", "20"))

Track

To track an event, call the event's corresponding function. Every event in your tracking plan has its own function in the Ampli Wrapper. The call uses this structure:

ampli.eventName(...eventNameProperties)

The options argument lets you pass Amplitude fields, like deviceID.

For example, in the following code snippets, your tracking plan contains an event called songPlayed. The event has two required properties: songId and songFavorited. The property type for songId is string, and songFavorited is a boolean.

ampli.songPlayed(
 songId = "songId", // String,
 songFavorited = true, // Boolean
)

Ampli also generates a class for each event.

val myEventObject = SongPlayed(
 songId = "songId", // String,
 songFavorited = true, // Boolean
);

Send event objects using the generic track method.

val options = EventOptions()
options.userId = "user_id"

ampli.track(SongPlayed(
 songId = "songId", // String
 songFavorited = true, // Boolean
 ), options);

Flush

The Ampli Wrapper queues events and sends them on an interval based on the configuration.

Call flush() to send any pending events immediately.

The flush() method returns a promise you can use to ensure Ampli sends all pending events before continuing. Call flush() before the application exits to avoid losing queued events.

Ampli flushes events in the buffer automatically when the queue reaches flushQueueSize or the timer reaches flushInterval.

ampli.flush()

Plugin

Plugins let you extend Amplitude behavior. For example, you can modify event properties (enrichment type) or send to third-party APIs (destination type).

First, define your plugin. The following code shows a Destination Plugin example.

class SegmentDestinationPlugin(appContext: Context, segmentApiKey: String) : DestinationPlugin() {
 var analytics: Analytics? = null;
 val context: Context = appContext;
 init {
 analytics = Analytics.Builder(appContext, segmentApiKey).build()
 }

 override fun track(event: BaseEvent): BaseEvent {
 val eventProperties = Properties();
 event.eventProperties?.forEach { entry -> entry.value?.let {
 eventProperties.put(entry.key,
 it)
 } }

 analytics?.track(event.eventType, eventProperties);
 return event
 }
}

Add your plugin after you initialize Ampli.

ampli.client?.add(
 YourDestinationPlugin(this, DESTINATION_API_KEY)
 )

Ampli CLI

Pull

The pull command downloads the Ampli Wrapper code to your project. Run the pull command from the project root.

ampli pull

Log in to your workspace when prompted and select a source.

➜ ampli pull
Ampli project is not initialized. No existing `ampli.json` configuration found.
? Create a new Ampli project here? Yes
? Organization: Amplitude
? Workspace: My Workspace
? Source: My Source

Learn more about ampli pull.

Status

Verify that events exist in your code with the status command:

ampli status [--update]

The output displays status and indicates which events are missing.

➜ ampli status
✘ Verifying event tracking implementation in source code
 ✔ Song Played (1 location)
 ✘ Song Stopped Called when a user stops playing a song.
Events Tracked: 1 missed, 2 total

Learn more about ampli status.