SDK Installation

Add dependencies

• Go to the pubspec.yaml file and add Amplitude SDK as a dependency.

dependencies:
  amplitude_flutter: ^3.7.0

• Run flutter pub get in the terminal to install the SDK.

iOS Installation

• Add platform :ios, '10.0' to your Podfile.
• If you want to enable Bitcode, please follow the Flutter's documentation.

Usage & Examples

Initialization

Initialization is necessary before any instrumentation is done. The API key for your Amplitude project is required.

import 'package:amplitude_flutter/amplitude.dart';
import 'package:amplitude_flutter/identify.dart';

class YourClass {
  Future<void> exampleForAmplitude() async {
    // Create the instance
    final Amplitude analytics = Amplitude.getInstance(instanceName: "project");

    // Initialize SDK
    analytics.init(widget.apiKey);
    
    // Log an event
    analytics.logEvent('MyApp startup', eventProperties: {
      'friend_num': 10,
      'is_heavy_user': true
    });
  }
}

EU Data Residency

Starting from version 3.6.0, you can configure the server zone after initializing the client for sending data to Amplitude's EU servers. SDK will switch and send data based on the server zone if it is set. The server zone config supports dynamic configuration as well.

For previous versions, you need to configure the serverURL property after initializing the client.

Warning: For EU data residency, project need to be set up inside Amplitude EU and SDK initialized with api key from Amplitude EU first. This method won't work without proper set up first.

// For versions starting from 3.6.0
// No need to call setServerUrl for sending data to Amplitude's EU servers
Amplitude.getInstance().setServerZone("EU");

// For earlier versions
Amplitude.getInstance().setServerUrl("https://api.eu.amplitude.com")

Sending Events

Basic Events

Events represent how users interact with your application. For example, “button clicked” may be an action you want to track.

Amplitude.getInstance().logEvent('BUTTON_CLICKED');

Events with Properties

Events can also contain properties. They provide context about the event taken. For example, “hover time” may be a relevant event property to “button click”

Amplitude.getInstance().logEvent('BUTTON_CLICKED', {"Hover Time": "100ms"});

Flush Events

Events are typically stored in a buffer and flushed periodically. This behavior is configurable. You can also flush events manually

Amplitude.getInstance().uploadEvents();

User Properties

User properties help you understand your users at the time they performed some action within your app such as their device details, their preferences, or language. Amplitude-Flutter's identify manage this feature. You need to import the identify before using it.

import 'package:amplitude_flutter/identify.dart';

🚧

IMPORTANT NOTE

Please be sure to not track any user data that may be against your privacy terms.

Setting a User Property

set

set sets the value of a user property. You can also chain together multiple identify calls.

final Identify identify = Identify()
                          ..set('gender','female')
                          ..set('age',20);
Amplitude.getInstance().identify(identify);

setOnce

setOnce sets the value of a user property only once. Subsequent calls using setOnce will be ignored.

final Identify identify1 = Identify();
identify1.setOnce('sign_up_date', '2015-08-24');
Amplitude.getInstance().identify(identify1);
final Identify identify2 = Identify();
identify2.setOnce('sign_up_date', '2015-08-24');
Amplitude.getInstance().identify(identify2);// is ignored

add

add increments a user property by some numerical value. If the user property does not have a value set yet, it will be initialized to 0 before being incremented.

final Identify identify = Identify().add('karma', 0.123);
Amplitude.getInstance().identify(identify);

Setting multiple user properties

You can use setUserProperties as a shorthand to set multiple user properties at once. This method is simply a wrapper around Identify.set and identify.

Map<String, dynamic> userProps = {
  'KEY': 'VALUE',
  'OTHER_KEY': 'OTHER_VALUE'
};
Amplitude.getInstance().setUserProperties(userProperties);

Arrays in user properties

Arrays can be used as user properties. You can directly set arrays or use append to generate an array.

const colors = ["rose", "gold"];
const numbers = [4, 5];
final Identify identify = Identify()
                          ..set("colors", colors)
                          ..append("ab-tests", "campaign_a")
                          ..prepend("existing_list", numbers);
Amplitude.getInstance().identify(identify);

preappend/append

• prepend will prepend a value or values to a user property.
• append will append a value or values to a user property array.
  If the user property does not have a value set yet, it will be initialized to an empty list before the new values are added. If the user property has an existing value and it is not a list, it will be converted into a list with the new value added.

const array = ["some_string", 56];
final Identify identify = Identify()
                          ..append("ab-tests", "new-user-test")
                          ..preappend("some_list", array)
Amplitude.getInstance().identify(identify);

Removing User Properties

Clearing All User Properties

clearUserProperties will wipe all of the current user's user properties.

❗️

The result is irreversible!

Amplitude will not be able to sync the user's user property values before the wipe to any future events that the user triggers as they will have been reset.

Amplitude.getInstance().clearUserProperties();

remove

remove will remove a value or values to a user property, if it does exist in the user property. Remove means remove the existing value(s) from the given list. If the item does not exist in the user property, there will be no operation.

const array = ["some_string", 56];
final Identify identify = Identify()
                          ..remove("ab-tests", "new-user-test")
                          ..remove("some_list",array);
Amplitude.getInstance().identify(identify);

unset

unset unsets and removes a user property.

final Identify identify = Identify()
                          ..unset("ab-tests", "new-user-test")
                          ..unset("some_list",array);
Amplitude.getInstance().identify(identify)

Track Revenue

Amplitude can track revenue generated by a user. Revenue is tracked through distinct revenue objects, which have special fields that are used in Amplitude's Event Segmentation and Revenue LTV charts. This allows Amplitude to automatically display data relevant to revenue in the platform.

String productId = "product001";
int quantity = 2;
double price = 20;
double amount = 35;
Amplitude.getInstance().logRevenue(productId, quantity, price);
Amplitude.getInstance().logRevenueAmount(amount);

📘

Price can be negative, which may be useful for tracking revenue lost (such as refunds or costs)

🚧

Amplitude currently does not support currency conversion. All revenue data should be normalized to a currency of choice before being sent to Amplitude.

Group User Properties

groupIdentify used for updating properties of particular groups

final Identify identify = Identify()
                          ..set("gender", "female")
                          ..set("age", 20);
Amplitude.getInstance().groupIdentify("groupType", "groupValue", identify);

User Sessions

A session is a period of time that a user has the app in the foreground. Events that are logged within the same session will have the same session_id. Sessions are handled automatically so you do not have to manually call an API like startSession() or endSession().
Amplitude groups events together by session. A session represents a single period of user activity, with a start and end time. Different SDKs will track sessions differently, depending on the requirements of the platform.
You are able to determine whether to automatically log start and end session events corresponding to the start and end of a user's session.

//Enable automatically log start and end session events 
Ampiltidue.getInstance().trackingSessionEvents(true);
//Disable automatically log start and end session events 
Amplitidue.getInstance().trackingSessionEvents(false);

Set Custom User ID

If your app has its own login system that you want to track users with, you can call setUserId at any time.

Amplitude.instance().setUserId("test_user_id");

Advanced topic

COPPA Control

COPPA (Children's Online Privacy Protection Act) restrictions on IDFA, IDFV, city, IP address and location tracking can be enabled or disabled all at once. Remember that apps asking for information from children under 13 years of age must comply with COPPA.

//Enable COPPA Control
Amplitude.getInstance().enableCoppaControl();
//Disable COPPA Control
Amplitude.getInstance().disableCoppaControl();

Advertising Id

Advertiser ID (also referred to as IDFA) is a unique identifier provided by the iOS and Google Play stores. As it is unique to every person and not just their devices, it is useful for mobile attribution. Mobile attribution is the attribution of an installation of a mobile app to its original source (e.g. ad campaign, app store search). Mobile apps need permission to ask for IDFA, and apps targeted to children cannot track at all. Consider IDFV, device id, or an email login system as alternatives when IDFA is not available.
Please check the iOS Advertising Id or the Android Advertising Id info based on your needs.

Opt Out of Tracking

Users may wish to opt out of tracking entirely, which means no events and no records of their browsing history. setOptOut provides a way to fulfill certain users’ requests for privacy.

//Disables instrumentation
Amplitude.getInstance().setOptOut(true);
//Enables instrumentation
Amplitude.getInstance().setOptOut(false);

Dynamic Configuration

Flutter SDK allows users to configure their apps to use dynamic configuration. This feature will find the best server url automatically based on app users' geo location.

• If you have your own proxy server and use setServerUrl API, please leave this OFF.
• If you have users in China Mainland, we suggest you turn this on.
• By default, this feature is OFF. So you need to explicitly set it to ON to use it.
• By default, this feature returns server url for Amplitude's US servers, if you need to send data to Amplitude's EU servers, please use setServerZone to set it to EU zone.

Amplitude.getInstance().setUseDynamicConfig(true);

Flutter Web Support

Flutter web support delivers the same experiences on the web as on mobile. Amplitude-Flutter starts to support flutter web from v3.8.0.

The following APIs are not supported in flutter web

• enableCoppaControl
• disableCoppaControl
• trackingSessionEvents
• useAppSetIdForDeviceId

Usage

Please append the following Amplitude-JavaScript snippet into web/index.html in your Flutter project. Noticed that Amplitude-JavaScript version should be v8.12.0 and higher.

<script type="text/javascript" defer>
   (function(e,t){var n=e.amplitude||{_q:[],_iq:{}};var r=t.createElement("script")
    ;r.type="text/javascript"
    ;r.integrity="sha384-UcvEbHmT0LE2ZB30Y3FmY3Nfw6puAKXz/LpCFuoywywYikMOr/519Uu1yNq2nL9w"
    ;r.crossOrigin="anonymous";r.async=true
    ;r.src="https://cdn.amplitude.com/libs/amplitude-8.12.0-min.gz.js"
    ;r.onload=function(){if(!e.amplitude.runQueuedFunctions){
    console.log("[Amplitude] Error: could not load SDK")}}
    ;var s=t.getElementsByTagName("script")[0];s.parentNode.insertBefore(r,s)
    ;function i(e,t){e.prototype[t]=function(){
    this._q.push([t].concat(Array.prototype.slice.call(arguments,0)));return this}}
    var o=function(){this._q=[];return this}
    ;var a=["add","append","clearAll","prepend","set","setOnce","unset","preInsert","postInsert","remove"]
    ;for(var c=0;c<a.length;c++){i(o,a[c])}n.Identify=o;var u=function(){this._q=[]
    ;return this}
    ;var l=["setProductId","setQuantity","setPrice","setRevenueType","setEventProperties"]
    ;for(var p=0;p<l.length;p++){i(u,l[p])}n.Revenue=u
    ;var d=["init","logEvent","logRevenue","setUserId","setUserProperties","setOptOut","setVersionName","setDomain","setDeviceId","enableTracking","setGlobalUserProperties","identify","clearUserProperties","setGroup","logRevenueV2","regenerateDeviceId","groupIdentify","onInit","logEventWithTimestamp","logEventWithGroups","setSessionId","resetSessionId","getDeviceId","getUserId","setMinTimeBetweenSessionsMillis","setEventUploadThreshold","setUseDynamicConfig","setServerZone","setServerUrl","sendEvents","setLibrary","setTransport"]
    ;function v(e){function t(t){e[t]=function(){
    e._q.push([t].concat(Array.prototype.slice.call(arguments,0)))}}
    for(var n=0;n<d.length;n++){t(d[n])}}v(n);n.getInstance=function(e){
    e=(!e||e.length===0?"$default_instance":e).toLowerCase()
    ;if(!Object.prototype.hasOwnProperty.call(n._iq,e)){n._iq[e]={_q:[]};v(n._iq[e])
    }return n._iq[e]};e.amplitude=n})(window,document);
</script>

Troubleshooting

• Errors on turning on Bitcode in iOS?
  Please follow the Flutter's documentation

Need Help?

If you have any problems or issues over our SDK, feel free to create a github issue or submit a request on Amplitude Help.