---
title: Flutter SDK quickstart
slug: feature-experimentation/docs/flutter-sdk-quickstart
docTags: 
createdAt: 2026-08-05T20:39:58.000Z
---

## Part 1: Create a sample app

### 1. Access or create your account

You need an Optimizely account to follow this guide. If you do not have an account, you can [register for a free account](https://www.optimizely.com/free-feature-flagging/). If you already have an account, navigate to your Feature Experimentation project.

### 2. Get your SDK key

To find your SDK key in an Optimizely project:

1. Go to **Settings** > **Primary Environment**.
2. Copy and save the **SDK Key** for your primary environment.

:::hint{type="warning"}
**Important**
Each environment has its own SDK key. Ensure you copy the correct key.
:::

![copy your SDK key from your primary environment](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/DdC_xbzmgH15uOw2__O0v-20260723-144350.png "sdk_key.png")

### 3. Copy the sample code

To work with the Flutter SDK:

1. Install the Flutter plugin in [Android Studio](https://docs.flutter.dev/development/tools/android-studio).
2. In Android Studio, create a new Flutter project (**File** -> **New** -> **New Flutter Project...**) called `optimizely_flutter_quickstart`.
3. Select **Java** for Android language. Select **Swift** for iOS language.
4. Toggle **Android** and **iOS** for Platform.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/BD8fVnh_itydAm3hlq0K0-20260723-150042.png)

5. Click **Finish**.
6. To install the Optimizely Feature Experimentation Flutter SDK. Open the **pubspec.yaml** file and add:

```groovy
dependencies:
  optimizely_flutter_sdk: ^1.0.1
```

The full source code is available on [GitHub](https://github.com/optimizely/flutter-sdk).

7. Copy the following code sample into the *main.dart* file (located in the lib directory) for your app. Replace `<Your_SDK_Key>` with the SDK key you found in a previous step.

```dart
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:optimizely_flutter_sdk/optimizely_flutter_sdk.dart';
import 'dart:async';

// NOTE: You need to change this SDK key to your project's SDK Key
const String sdkKey = "Your_SDK_Key";
const String logTag = "OPTIMIZELY_QUICK_START";

void main() {
  runApp(const MyApp());
  var productSorter = ProductSorter();
  productSorter.initializeQuickStart();
}

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String uiResponse = 'Unknown';

  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Quick start example app'),
        ),
        body: Center(
          child: Text(uiResponse),
        ),
      ),
    );
  }
}

class ProductSorter {
  String _datafileHost = "https://cdn.optimizely.com";
  String _datafileSuffixAndroid = "/datafiles/%s.json";
  String _datafileSuffixIOS = "/datafiles/%@.json";

  Future<void> initializeQuickStart() async {
    // Setting up custom datafile URL format
    Map<ClientPlatform, DatafileHostOptions> datafileHostOptions = {};

    datafileHostOptions[ClientPlatform.android] =
        DatafileHostOptions(_datafileHost, _datafileSuffixAndroid);

    datafileHostOptions[ClientPlatform.iOS] =
        DatafileHostOptions(_datafileHost, _datafileSuffixIOS);

    // Initializing OptimizelyClient
    var flutterSDK = OptimizelyFlutterSdk(
        sdkKey, datafileHostOptions: datafileHostOptions);
    var response = await flutterSDK.initializeClient();
    if (response.success) {
      flutterSDK.addConfigUpdateNotificationListener((msg) {
        runQuickStart(flutterSDK);
      });
      await runQuickStart(flutterSDK);
    }
  }

  Future<void> runQuickStart(OptimizelyFlutterSdk flutterSDK) async {
    /* --------------------------------
     * to get rapid demo results, generate random users. Each user always sees the same variation unless you reconfigure the flag rule.
     * --------------------------------
     */
    // simulate 50 users
    var rangeMax = 9999;
    var rangeMin = 1000;
    var range = Random();
    var hasOnFlags = false;

    for (int i = 0; i < 10; i++) {
      var userId = "${range.nextInt(rangeMax - rangeMin) + rangeMin}";
      /* --------------------------------
       Create hardcoded user & bucket user into a flag variation
       --------------------------------
      */
      var user = await flutterSDK.createUserContext(userId: userId);
      // "product_sort" corresponds to a flag key in your Optimizely project
      var decisionResponse = await user!.decide("product_sort");
      var decision = decisionResponse.decision;
      // did decision fail with a critical error?
      if (decision?.variationKey == null) {
        print("\n\n$logTag decision error: ${decisionResponse.reason}");
      }
      // get a dynamic configuration variable
      // "sort_method" corresponds to a variable key in your Optimizely project
      String sortMethod = decision?.variables["sort_method"] as String;

      if (decision!.enabled) {
        // Keep count how many users had the flag enabled
        hasOnFlags = true;
      }
      /* --------------------------------
         Mock what the user sees with print statements (in production, use flag variables to implement feature configuration)
         --------------------------------
      */
      var userIdResponse = await user.getUserId();
      // always returns false until you enable a flag rule in your Optimizely project
      print("\n\n$logTag Flag ${(decision.enabled
          ? "on"
          : "off")}. User number ${userIdResponse.userId} saw flag variation: ${decision
          .variationKey} and got products sorted by: ${sortMethod} config variable as part of flag rule: ${decision
          .ruleKey}");
    }
    if (!hasOnFlags) {
      print(
          "\n\n$logTag Flag was off for everyone. Some reasons could include:" +
              "\n1. Your sample size of users was too small. Rerun, or increase the iterations in the FOR loop" +
              "\n2. By default you have 2 keys for 2 project environments (dev/prod). Verify in Settings>Environments that you used the right key for the environment where your flag is toggled to ON." +
              "\nCheck your key at  https://app.optimizely.com/v2/projects/YOUR_PROJECT_ID/settings/implementation");
    }
  }
}
```

:::hint{type="info"}
**Note**
Do not run your app yet. You still need to configure the flag and flag delivery rule in the Optimizely app.
:::

## Part 2: Run your app

After completing [Part 1](docId\:uN6JBMKPgk3zSUmelFQhA), your sample app still does nothing. You need to create a flag and a flag rule in the Optimizely app to enable your sample application.

### 1. Create the feature flag

A [flag](docId\:CFAu9P5PdLLMB8GsFn_fo) lets you control the users that are exposed to new code in your application. For this quickstart, imagine that you are rolling out a redesigned sorting feature for displaying products.

Create a flag in your Feature Experimentation project named **product\_sort** and give it a variable named **sort\_method**:

1. Select **Create New Flag...** from the **Flags** tab.
2. Enter *product\_sort* in the **Name** field.
3. Keep the auto-created **Key**, *product\_sort*, and click **Create Flag**. The **Key** corresponds to the flag key in your sample app.

Next, create a variable in your flag:

1. In your new flag, `product_sort`, under **Flag Setup**, go to **Variables** and click **Add Variable** (**+**).
2. Select **String** in the **Add Variable** drop-down.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/0aRY8G1jYzUmu4oqc8y_s_1e50b1f-add-variable-string.png)

3. Enter *sort\_method* for the **Variable Key**, which corresponds to the variable key in your sample app.
4. Enter *alphabetical* for the **Default Value**, which represents your old sorting method. The new sorting method is what you are rolling out.
5. Click **Save**.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/1eR-WLI6mm4tqi3B1pI9l_0ce58bf-flutter-string-variable.png)

Next, create a variation in your flag:

1. Under **Flag Setup** go to **Variations** and select the **On** variation. A variation is a wrapper for a collection of variable values.
2. For the **sort\_method** variable value, enter *popular\_first*, which represents your new sorting method.
3. Click **Save**.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/atqDYiTL1_7Aj6prVa8t1_18e334a-on-variation-popular-first.png)

### 2. Create the flag delivery rule

Your sample app *still* does nothing because you need to create and enable a [flag rule](docId\:CFAu9P5PdLLMB8GsFn_fo).

Make a [targeted delivery rule](docId\:R0KSPrSRYev0Q6jXL27QK) for the **On** variation for the **product\_sort** flag. A targeted delivery lets you gradually release a feature flag to users but with the flexibility to roll it back if you encounter bugs.

1. Ensure you are in your primary environment (because you are using the primary environment SDK key from [Part 1](docId\:uN6JBMKPgk3zSUmelFQhA)).

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/RtAsh_IifAIFq35w6NSsR_0a5d0f9-image.png)

2. Click **Add Rule** and select **Targeted Delivery**.
3. Enter *Targeted Delivery* for the **Name** field.
4. Keep the default **Key** and **Audiences**.
5. Set the **Traffic Allocation** slider to 50%. This delivers the **product\_sort** flag to 50% of everyone who triggers the flag in this environment. You can roll out or roll back the **product\_sort** flag to a percentage of traffic whenever you want.
6. From the **Deliver** drop-down list, select the **On** variation.
7. Click **Save**.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/Amt-ksRr-q3urU8UtQsIk_0878a69-image.png)

### 3. Run your sample app

To run your sample application:

1. Click **Run** on your targeted delivery rule:

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/XmGdpCrD9PUacZfMisVdO_de01aa0-image.png)

2. Click **Ok** on the **Ready to Run Status** page. This lets you know that your ruleset has not been set to run, yet.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/_aDAwcuNhUJG50GImI1Aa_7b4d47d-image.png)

3. Click **Run** on your ruleset (flag):

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/1ViozqHULL_HdyUYN8wck_326a7bb-turn-flag-on.png)

\{ /\*-\*/ }

3. In Android Studio, start an emulator. Click **Run** to execute the sample app code you created earlier. Your output displays similar to the following:

```javascript
Flag on. User number 6998 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: targeted_delivery

Flag on. User number 1177 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: targeted_delivery

Flag on. User number 9714 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: targeted_delivery

Flag on. User number 4140 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: targeted_delivery

Flag on. User number 4994 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: targeted_delivery

Flag off. User number 8700 saw flag variation: off and got products sorted by: alphabetical config variable as part of flag rule: default-rollout-208-19963693913

Flag off. User number 9912 saw flag variation: off and got products sorted by: alphabetical config variable as part of flag rule: default-rollout-208-19963693913

Flag on. User number 6560 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: targeted_delivery

Flag on. User number 9252 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: targeted_delivery

Flag on. User number 6582 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: targeted_delivery
```

:::hint{type="info"}
**Note**
You will not get exactly 50% of your user traffic in the "on" variation, because you are working with such a small number of users. Also, users who get an "off" flag will not make it into the 50% traffic you set, so they fall through to the default "off" rule (*default-rollout* in the preceding print statements).
:::

### 4. How it works

So far, you:

- Created a flag, flag variable, and a flag variation (wrapper for your variables) in the Optimizely app.
- Implemented a flag in your app with the Decide method from the Flutter SDK.

What is going on in your sample app?

### How it works: decide to show a user a flag

The Flutter SDK’s [Decide](docId\:Wth3ZIcrotIP7aPeFcJ36) method determines whether to show or hide the feature flag for a specific user.

:::hint{type="info"}
**Note**
You can reuse this method for different flag rules, for example for delivering more traffic or running an experiment to show different sorting methods to just a portion of users.
:::

After you learn which sorting method works best to increase sales, roll out the product sort flag to all traffic with the method set to the optimum value.

In your sample app:

```dart
var user = await optimizelyClient.createUserContext(userId: userId);
// "product_sort" corresponds to the flag key you create in the Optimizely app
var decideResponse = await user!.decide("product_sort"); 
```

:::hint{type="info"}
**Note**
Optionally include attributes when you create your user (not shown in your sample app), so you can target specific audiences. For example:

```dart
var attributes = <String, dynamic>{};
attributes["logged_in"] = true;
var user = await optimizelyClient.createUserContext(userId: "user123", attributes: attributes);
```
:::

### How it works: configure flag variations

You can dynamically configure a flag variation using flag variables. In your sample app:

```dart
// always returns false until you enable a flag rule in the Optimizely app
if (decideResponse.decision!.enabled) {
  // "sort_method" corresponds to variable key you define in Optimizely app
  var sortMethod = decideResponse.decision!.variables["sort_method"] as String;
  print("sort_method: $sortMethod");
}
```

For your **product\_sort** flag, you can configure variations with different **sort\_method** values, sorting by popular products, relevant products, promoted products and so on.  Set different values for the sort method at any time in the Optimizely app.

## Part 3: Run an A/B test

[Part 2](docId\:uN6JBMKPgk3zSUmelFQhA) of this tutorial guided you through a targeted delivery because it is the most straightforward flag rule. However, you often want to [A/B test](docId\:raDQAUQpQJywODzUkXKhZ) how users react to feature flag variations *before* you roll out a flag delivery.

- [Targeted delivery rule](docId\:R0KSPrSRYev0Q6jXL27QK) – You can roll out your flag to a percentage of your general user base (or to specific audiences), or roll back if you encounter bugs.
- [A/B test rule](docId\:raDQAUQpQJywODzUkXKhZ) – Experiment by A/B testing a flag before you invest in delivering, so you know what to build. Track how users behave in flag variations, then interpret your experiment results using the Optimizely Stats Engine.

For Part 3, you will run an A/B test on the **On** variation of your **product\_sort** flag.

### 1. Add event tracking

You need to add a [Track Event method](docId:7z1ZuPEvPJJkghG28HRv9) to your sample app, so you can mock up user events and then see [metrics](docId:06YPvA1xY9tK6261dIE66).

1. Delete your old sample code, and paste in the following code.
2. **Replace your SDK key**. See [Get your SDK Key](docId\:uN6JBMKPgk3zSUmelFQhA).
3. Do not run your app yet because you still need to configure the A/B test in the Optimizely application.

```dart
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:optimizely_flutter_sdk/optimizely_flutter_sdk.dart';
import 'dart:async';
import 'package:optimizely_flutter_sdk/src/user_context/optimizely_user_context.dart';

// NOTE: You need to change this SDK key to your project's SDK Key
const String sdkKey = "Your_SDK_Key";
const String logTag = "OPTIMIZELY_QUICK_START";

void main() {
  runApp(const MyApp());
  var productSorter = ProductSorter();
  productSorter.initializeQuickStart();
}

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String uiResponse = 'Unknown';

  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Quick start example app'),
        ),
        body: Center(
          child: Text(uiResponse),
        ),
      ),
    );
  }
}

class ProductSorter {
  String _datafileHost = "https://cdn.optimizely.com";
  String _datafileSuffixAndroid = "/datafiles/%s.json";
  String _datafileSuffixIOS = "/datafiles/%@.json";

  Future<void> initializeQuickStart() async {
    // Setting up custom datafile URL format
    Map<ClientPlatform, DatafileHostOptions> datafileHostOptions = {};

    datafileHostOptions[ClientPlatform.android] =
        DatafileHostOptions(_datafileHost, _datafileSuffixAndroid);

    datafileHostOptions[ClientPlatform.iOS] =
        DatafileHostOptions(_datafileHost, _datafileSuffixIOS);

    // Initializing OptimizelyClient
    var flutterSDK = OptimizelyFlutterSdk(
        sdkKey, datafileHostOptions: datafileHostOptions);
    var response = await flutterSDK.initializeClient();
    if (response.success) {
      flutterSDK.addConfigUpdateNotificationListener((msg) {
        runQuickStart(flutterSDK);
      });
      await runQuickStart(flutterSDK);
    }
  }

  Future<void> runQuickStart(OptimizelyFlutterSdk flutterSDK) async {
    /* --------------------------------
     * to get rapid demo results, generate random users. Each user always sees the same variation unless you reconfigure the flag rule.
     * --------------------------------
     */

    /* --------------------------------
       OPTIONAL: Add a notification listener so you can integrate with third-party analytics platforms
       --------------------------------
    */
    // var notificationId = await flutterSDK.addDecisionNotificationListener((decisionNotification) {
    //   if (decisionNotification.type == "flag") {
    //
    //     var serializedInfo = decisionNotification.decisionInfo.toString();
    //     print("$logTag Feature flag access related information: ${serializedInfo}");
    //     // Send data to analytics provider here
    //   }
    // });


    // simulate 50 users
    var rangeMax = 9999;
    var rangeMin = 1000;
    var range = Random();
    var hasOnFlags = false;

    for (int i = 0; i < 10; i++) {
      var userId = "${range.nextInt(rangeMax - rangeMin) + rangeMin}";
      /* --------------------------------
       Create hardcoded user & bucket user into a flag variation
       --------------------------------
      */
      var user = await flutterSDK.createUserContext(userId: userId);
      // "product_sort" corresponds to a flag key in your Optimizely project
      var decisionResponse = await user!.decide("product_sort");
      var decision = decisionResponse.decision;
      // did decision fail with a critical error?
      if (decision?.variationKey == null) {
        print("\n\n$logTag decision error: ${decisionResponse.reason}");
      }
      // get a dynamic configuration variable
      // "sort_method" corresponds to a variable key in your Optimizely project
      String sortMethod = decision?.variables["sort_method"] as String;

      if (decision!.enabled) {
        // Keep count how many users had the flag enabled
        hasOnFlags = true;
      }
      /* --------------------------------
         Mock what the user sees with print statements (in production, use flag variables to implement feature configuration)
         --------------------------------
      */
      // always returns false until you enable a flag rule in your Optimizely project
      var userIdResponse = await user.getUserId();
      print("\n\n$logTag Flag ${(decision.enabled
          ? "on"
          : "off")}. User number ${userIdResponse.userId} saw flag variation: ${decision
          .variationKey} and got products sorted by: ${sortMethod} config variable as part of flag rule: ${decision
          .ruleKey}");
      await mockPurchase(user);
    }
    if (!hasOnFlags) {
      print(
          "\n\n$logTag Flag was off for everyone. Some reasons could include:\n1. Your sample size of users was too small. Rerun, or increase the iterations in the FOR loop\n2. By default you have 2 keys for 2 project environments (dev/prod). Verify in Settings>Environments that you used the right key for the environment where your flag is toggled to ON.\nCheck your key at  https://app.optimizely.com/v2/projects/YOUR_PROJECT_ID/settings/implementation");
    }
  }

  // mock tracking a user event so you can see some experiment reports
  Future<void> mockPurchase(OptimizelyUserContext user) async {
    print("\n\n$logTag Pretend that user made a purchase? y/n ");
    Random rnd = new Random();
    int yesOrNo = rnd.nextInt(2);
    // Assigning random yes and no
    String answer = yesOrNo == 1? "y" : "n";
    print("\n\n$logTag $answer");
    var userIdResponse = await user.getUserId();
    if (answer == "y") {
      // track a user event you defined in the Optimizely app
      await user.trackEvent("purchase");
      print("\n\n$logTag Optimizely recorded a purchase in experiment results for user ${userIdResponse.userId}");
    } else {
      print("\n\n$logTag Optimizely didn't record a purchase in experiment results  for user ${userIdResponse.userId}");
    }
  }
}
```

### 2. Delete other rules in free accounts

If you have a free Optimizely account, you must delete the Targeted Delivery you created in [Part 2](docId\:uN6JBMKPgk3zSUmelFQhA) before you save your A/B test:

1. Select the **Flag** that contains the Targeted Delivery you created in Part 2 from the Flags tab.
2. Select the primary environment and the Targeted Delivery rule you created in Part 2.
3. Click **More Options** > **Delete**:

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/7Bzb69sbZSZFHT9NTQ4ED_9c4d711-image.png)

4. Click **Save**

### 3. Create the A/B test

To create an A/B Test rule in your Feature Experimentation project, in the flag you created in [Part 2](docId\:uN6JBMKPgk3zSUmelFQhA):

1. click **Add Rule** and select **A/B Test**.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/t8JzgOKwAp-ye_AsdtgIa_3a71c79-a-b-test-rule.png)

2. Enter *Experiment* for the **Name** field.
3. Keep the default **Key** and **Audiences**
4. Keep the **Traffic Allocation** slider set to 100%.

### 4. Add an event

In an experiment, you track users' relevant actions to measure how they react to your flag variations. To define the actions you want to track, called [events](docId\:SViQcZpYCosJLYzXIiAhP):

1. Click on the **Metrics** field.
2. Click **Create new event**.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/ABtmFjVvhSrqNwPs7CHLn_b3754e5-create-new-event.png)

3. Enter *purchase* for the **Event Name**, and the **Event Key** is automatically filled.
4. (Optional) Enter a **Description**. You want to know whether the new sorting flag helps customers figure out what to buy, so track whether the user makes a purchase after they were shown the products in a new order.
5. Click **Create Event**.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/wK_5hBVXnjMReYlY1nqKs_c45b593-flutter-create-event.png)

6. In the **Add Metric** modal, leave the defaults, measure **increase** in **unique conversions**.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/EorXUtND6roo_kPfTgshg_e111a6b-add-metric-flutter.png)

7. Click **Add Metric**.
8. Leave the default **Off** variation as a control. Select the **On** variation you configured in [Part 2](docId\:uN6JBMKPgk3zSUmelFQhA):

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/CNv7VonmAHhMtwD0xieeR_92c5706-on-variation.png)

:::hint{type="info"}
**Note**
You are not limited to two variations; you can also create A/B tests with multiple variations.
:::

9. Click **Save** to create your A/B Test rule.
10. Click **Run** on the A/B test rule.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/fDdLaCLlJP_hoKLjtNI54_9ae34f5-image.png)

### 5. Run the A/B test

Ensure your ruleset's (flag's) status is **Running**, and the rule's status is **Running** so your experiment can run:

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/PlkFsMB2R-JpWpSpqy3Hj_cce40a5-image.png)

Click **Run** in Android Studio and answer the command-line prompts. Your output should display similar to the following:

```powershell
Flag on. User number 1496 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: experiment_1
Pretend that user made a purchase? y/n
n
Optimizely didn't record a purchase in experiment results for user 1496


Flag off. User number 1194 saw flag variation: off and got products sorted by: alphabetical config variable as part of flag rule: experiment_1
Pretend that user made a purchase? y/n
y
Optimizely recorded a purchase in experiment results for user 1194


Flag off. User number 5815 saw flag variation: off and got products sorted by: alphabetical config variable as part of flag rule: experiment_1
Pretend that user made a purchase? y/n
y
Optimizely recorded a purchase in experiment results for user 5815


Flag on. User number 1248 saw flag variation: on and got products sorted by: popular_first config variable as part of flag rule: experiment_1
Pretend that user made a purchase? y/n
y
Optimizely recorded a purchase in experiment results for user 1248


Flag off. User number 9580 saw flag variation: off and got products sorted by: alphabetical config variable as part of flag rule: experiment_1
Pretend that user made a purchase? y/n
n
Optimizely didn't record a purchase in experiment results for user 9580


Done with your mocked A/B test.
Check out your report at  https://app.optimizely.com/v2/projects/<your-project-id>/reports
Be sure to select the environment that corresponds to your SDK key
```

### 6. View your A/B test results

Go to the [Reports](docId:_K6n7h_MZ8b0xn6yWPrrq) tab and select your experiment to see your results.

![](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/zYDryKUjWrJUJBHZvBANP_730c491-experiment-results-page.png)

Your results should look similar:

![results](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/Zzei7R-AXYnccmJzVr1Fd-20260723-144350.png "experiment overview.png")

:::hint{type="info"}
- **Note**
  You might not see the exact user traffic percentages you configured for your flag variations until you have a larger number of users.
- You might not see your user traffic immediately. Refresh the browser to refresh traffic.
- Your experiment results will not tell you a winning variation until you have a larger number of users (on the order of 100,000 or more).
:::

### 7. How it works

For an A/B test, you need a way to tell Optimizely when users make purchases in your app and map this event in your app code to the specific event you created in Optimizely. The SDK has a method for that! Use the [Track Event](docId\:taYyvX3Qk-LN3jd7nOY55) method and pass in the key for the event you created (`purchase`).  In your sample app:

```dart
// Track how users behave when they see a flag variation
// for example, after your app processed a purchase, let Optimizely know what happened:
user.trackEvent("purchase"); 
```

:::hint{type="info"}
**Note**
Optionally add tags to your event to enrich it (not shown in your sample app). You can also use [reserve tag keys](docId:_e6OMtVKWG51DUFShdlUN) like **revenue** to track quantitative results.
:::

Event tracking is currently supported only for experiment rules, not delivery rules. Tracking for deliveries will be supported in a future release.

Either way, you should include event tracking when you implement a flag because it can help you integrate with a third-party analytics platform. It also gives you flexibility when you create A/B tests.

## Conclusion

Congratulations! You configured and launched your first Feature Experimentation experiment. While this example focused on optimizing sales, Optimizely’s experimentation platform can support an open-ended set of experimentation use cases.

See the complete [Flutter SDK documentation](docId\:RjcdDlKorm2rsRDRgsb2z) to learn more ways to optimize your software using experimentation.