### Get Experiment Manager Service (PHP)

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Access the ExperimentManager service to work with experiments server-side. Handles user enrollment and experiment coordination.

```php
use MediaWiki\MediaWikiServices;

// Get the ExperimentManager service
$experimentManager = MediaWikiServices::getInstance()
    ->getService('TestKitchen.ExperimentManager');

// Initialize with request data (typically done in hooks)
$experimentManager->setRequest($request);

// Update enrollment based on logged-in user
$experimentManager->updateUser($user);

// Update enrollment using identifier directly
$experimentManager->updateIdentifier('mw-user', (string)$centralId);
```

--------------------------------

### Get Experiment and Check Assignment (PHP)

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Retrieve an experiment and work with it server-side. Similar API to the JavaScript SDK for checking group assignments.

```php
use MediaWiki\MediaWikiServices;

$experimentManager = MediaWikiServices::getInstance()
    ->getService('TestKitchen.ExperimentManager');

// Get experiment by name
$experiment = $experimentManager->getExperiment('my-awesome-experiment');

// Check assigned group
$group = $experiment->getAssignedGroup(); // Returns string or null

// Check if user is in specific group(s)
if ($experiment->isAssignedGroup('treatment')) {
    // Show treatment variant
}

// Check multiple groups
if ($experiment->isAssignedGroup('treatment-a', 'treatment-b')) {
    // User is in one of the treatment groups
}
```

--------------------------------

### Retrieve All User Assignments

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Get a map of all current experiment assignments. This is primarily intended for internal use cases like error logging.

```javascript
const assignments = mw.testKitchen.getAssignments();
// Returns: { 'experiment-1': 'treatment', 'experiment-2': 'control' }

// Check if user has any assignments
if (Object.keys(assignments).length > 0) {
    console.log('User is enrolled in experiments:', assignments);
}
```

--------------------------------

### Get Instrument for Analytics

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Retrieves an instrument for analytics data collection. Use this to track non-experiment analytics with configurable sampling rates.

```javascript
const instrument = mw.testKitchen.getInstrument('my-analytics-instrument');

// Check if the instrument is in sample
if (instrument.isInSample()) {
    // Send analytics event
    instrument.send('page_load', {
        load_time_ms: performance.now()
    });
}

// Send event (no-op if out of sample)
instrument.send('feature_used', {
    feature_name: 'dark_mode_toggle'
});

// Send event immediately using sendBeacon (for page unload scenarios)
instrument.sendImmediately('page_exit', {
    time_on_page_ms: getTimeOnPage()
});
```

--------------------------------

### Configure Extension in LocalSettings.php

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Define global configuration variables for experiment features, API endpoints, and event intake services.

```php
// Enable experiment features
$wgTestKitchenEnableExperiments = true;

// Enable fetching configs from Test Kitchen UI (not for production)
$wgTestKitchenEnableConfigsFetching = false;

// Base URL for Test Kitchen UI API
$wgTestKitchenInstrumentConfiguratorBaseUrl = 'https://testkitchen.example.org';

// Event intake service name (must be a key in $wgEventServices)
$wgTestKitchenEventIntakeServiceName = 'eventgate-analytics';

// Event intake URLs for different experiment types
$wgTestKitchenExperimentEventIntakeServiceUrl = 'https://eventgate.example.org/v1/events';
$wgTestKitchenLoggedInExperimentEventIntakeServiceUrl = 'https://eventgate.example.org/v1/events';
$wgTestKitchenInstrumentEventIntakeServiceUrl = 'https://eventgate.example.org/v1/events';

// Stream names for Test Kitchen experiments
$wgTestKitchenExperimentStreamNames = [
    'product_metrics.web_base'
];

// Experiments to preserve in auth query params
$wgTestKitchenAuthPreserveQueryParamsExperiments = [];

// Exposure log reset epoch (seconds) for global invalidation
$wgTestKitchenExposureResetEpoch = 0;
```

--------------------------------

### Extension Configuration

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Configuration settings for TestKitchen in LocalSettings.php.

```APIDOC
## LocalSettings.php Configuration

### Description
Global configuration variables for enabling experiments and setting event intake service URLs.

### Configuration Variables
- **$wgTestKitchenEnableExperiments** (bool) - Enable experiment features.
- **$wgTestKitchenEventIntakeServiceName** (string) - The service name for event intake.
- **$wgTestKitchenExperimentStreamNames** (array) - List of stream names for experiments.
```

--------------------------------

### Configure Custom Stream and Schema

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Override default stream and schema settings for experiment events using fluent method chaining.

```php
$experiment = $experimentManager->getExperiment('my-awesome-experiment');

// Set custom stream (updates contextual attributes automatically)
$experiment->setStream('my_custom_stream');

// Set custom schema
$experiment->setSchema('/my/custom/schema/1.0.0');

// Chain methods and send
$experiment
    ->setStream('my_custom_stream')
    ->setSchema('/my/custom/schema/1.0.0')
    ->send('custom_action', ['data' => 'value']);
```

--------------------------------

### Retrieve Experiments by Prefix

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Fetch multiple experiments matching a specific naming prefix. Useful for managing sequential or related experiments.

```javascript
// User is enrolled in:
// - my-awesome-experiment-1
// - my-awesome-experiment-2
// - my-other-awesome-experiment

// Get all experiments starting with 'my-awesome-experiment-'
const experiments = mw.testKitchen.getExperimentsByPrefix('my-awesome-experiment-');
// Returns array with my-awesome-experiment-1 and my-awesome-experiment-2

experiments.forEach((exp) => {
    exp.send('interaction', { action_source: 'weekly_survey' });
});
```

--------------------------------

### Retrieve and Check Experiment Assignments

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Use getExperiment to access an experiment object. Check group assignments using isAssignedGroup or retrieve the group name directly with getAssignedGroup.

```javascript
// Get an experiment and check the assigned group
const experiment = mw.testKitchen.getExperiment('my-awesome-experiment');

// Check if user is in a specific group
if (experiment.isAssignedGroup('treatment')) {
    // Show treatment variant
    showNewFeature();
}

// Check multiple groups at once
if (experiment.isAssignedGroup('treatment-a', 'treatment-b')) {
    // User is in one of the treatment groups
}

// Get the assigned group name directly
const group = experiment.getAssignedGroup(); // Returns 'control', 'treatment', etc. or null
```

--------------------------------

### JavaScript SDK Experiment Methods

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Methods for retrieving experiments, checking group assignments, and managing experiment overrides.

```APIDOC
## mw.testKitchen.getExperiment(name)

### Description
Retrieves an experiment object by name to check group assignments and send events.

### Parameters
- **name** (string) - Required - The name of the experiment.

## mw.testKitchen.getExperimentsByPrefix(prefix)

### Description
Retrieves all experiments that match a given prefix.

### Parameters
- **prefix** (string) - Required - The prefix string to match experiment names.

## mw.testKitchen.overrideExperimentGroup(name, group)

### Description
Manually overrides the assigned group for an experiment for testing and QA purposes.

### Parameters
- **name** (string) - Required - The experiment name.
- **group** (string) - Required - The group name to assign.
```

--------------------------------

### Stub Experiments for Unit Testing (QUnit)

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Stub experiments for unit testing to test experiment-dependent code without actual experiment enrollment. Requires QUnit.

```javascript
// In QUnit tests
QUnit.test('my feature with experiment', function(assert) {
    // Create fake experiments helper
    const tk = mw.testKitchen.useFakeExperiments();

    // Stub an experiment with specific group assignment
    const experiment = tk.stubExperiment('my-awesome-experiment', 'treatment');

    // Run code under test that calls mw.testKitchen.getExperiment()
    myFeature.initialize();

    // Assert events were sent
    assert.strictEqual(experiment.eventCount, 1);
    assert.strictEqual(experiment.events[0].action, 'feature_init');
    assert.deepEqual(experiment.events[0].interactionData, { source: 'auto' });

    // Check global event count across all stubbed experiments
    assert.strictEqual(tk.globalEventCount, 1);

    // Restore original getExperiment
    tk.restore();
});
```

--------------------------------

### Define Experiment Interface

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

The ExperimentInterface contract for managing experiment states and event dispatching.

```php
namespace MediaWiki\Extension\TestKitchen\Sdk;

interface ExperimentInterface {
    /**
     * Gets the assigned group for the current user
     * @return string|null
     */
    public function getAssignedGroup(): ?string;

    /**
     * Checks if assigned to one of the given groups
     * @param string ...$groups
     * @return bool
     */
    public function isAssignedGroup(string ...$groups): bool;

    /**
     * Sends an interaction event
     * @param string $action
     * @param array $interactionData
     * @param array $contextualAttributes
     */
    public function send(
        string $action,
        array $interactionData = [],
        array $contextualAttributes = []
    ): void;

    /**
     * Sends an exposure event with deduplication
     */
    public function sendExposure(): void;
}
```

--------------------------------

### Stub Instruments for Unit Testing (QUnit)

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Stub instruments for unit testing to test instrument-dependent code without actual sampling. Requires QUnit.

```javascript
// In QUnit tests
QUnit.test('my analytics with instrument', function(assert) {
    // Create fake instruments helper
    const tk = mw.testKitchen.useFakeInstruments();

    // Stub an instrument
    const instrument = tk.stubInstrument('my-analytics-instrument');

    // Run code under test
    myAnalytics.trackPageLoad();

    // Assert events were sent
    assert.strictEqual(instrument.eventCount, 1);
    assert.strictEqual(instrument.events[0].action, 'page_load');

    // Stubbed instruments always return true for isInSample()
    assert.true(instrument.isInSample());

    // Restore original getInstrument
    tk.restore();
});
```

--------------------------------

### ExperimentManager Service

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Methods for interacting with experiments, sending events, and configuring event streams or schemas.

```APIDOC
## PHP ExperimentManager Service

### Description
Access the ExperimentManager service to retrieve experiments and send analytics events associated with them.

### Method
PHP Service Call

### Parameters
- **experimentName** (string) - Required - The identifier of the experiment.
- **action** (string) - Required - The action name for the event.
- **interactionData** (array) - Optional - Key-value pairs of interaction data.
- **contextualAttributes** (array) - Optional - List of contextual attributes to include.

### Request Example
$experiment->send('form_submit', ['action_source' => 'special_page']);

### Response
- **void** - This method does not return a value.
```

--------------------------------

### Send Experiment Events in PHP

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Use the ExperimentManager service to send various types of analytics events, including simple actions, interaction data, and exposure events.

```php
$experimentManager = MediaWikiServices::getInstance()
    ->getService('TestKitchen.ExperimentManager');

$experiment = $experimentManager->getExperiment('my-awesome-experiment');

// Send simple action event
$experiment->send('api_request');

// Send event with interaction data
$experiment->send('form_submit', [
    'action_source' => 'special_page',
    'action_context' => 'settings'
]);

// Send event with additional contextual attributes
$experiment->send('page_save',
    ['revision_id' => $revId],
    ['performer_is_logged_in', 'performer_edit_count_bucket']
);

// Send exposure event with automatic deduplication
$experiment->sendExposure();
```

--------------------------------

### JavaScript SDK Event Tracking

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Methods for sending analytics events and logging experiment exposure.

```APIDOC
## experiment.send(action, data, attributes)

### Description
Sends analytics events associated with an experiment, including metadata.

### Parameters
- **action** (string) - Required - The event action name.
- **data** (object) - Optional - Interaction data.
- **attributes** (array) - Optional - Additional contextual attributes.

## experiment.sendExposure()

### Description
Logs an experiment exposure event with automatic deduplication to prevent duplicate events across page views and sessions.
```

--------------------------------

### Log Experiment Exposure

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Log exposure events using sendExposure. This method includes built-in deduplication to prevent redundant logging across page views.

```javascript
const experiment = mw.testKitchen.getExperiment('my-awesome-experiment');

// Send exposure event when user is exposed to the experiment
// Automatically deduplicated - safe to call multiple times
experiment.sendExposure();

// Typical usage: call when the experimental feature is rendered
if (experiment.isAssignedGroup('treatment')) {
    experiment.sendExposure();
    renderTreatmentUI();
}
```

--------------------------------

### InstrumentManager Service

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Methods for managing analytics instruments and sending custom metrics.

```APIDOC
## PHP InstrumentManager Service

### Description
Access the InstrumentManager service to perform server-side analytics instrumentation.

### Method
PHP Service Call

### Parameters
- **instrumentName** (string) - Required - The name of the analytics instrument.
- **action** (string) - Required - The action name for the event.
- **data** (array) - Optional - Data payload for the event.

### Request Example
$instrument->send('api_call', ['response_time_ms' => 100]);

### Response
- **void** - This method does not return a value.
```

--------------------------------

### Manage Experiment Group Overrides

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Manually set or clear experiment group assignments for testing purposes. Overridden experiments log to the console instead of sending events.

```javascript
// Override experiment assignment to 'treatment' group and reload page
mw.testKitchen.overrideExperimentGroup('my-awesome-experiment', 'treatment');

// Clear override for a specific experiment
mw.testKitchen.clearExperimentOverride('my-awesome-experiment');

// Clear all experiment overrides
mw.testKitchen.clearExperimentOverrides();
```

--------------------------------

### Access Instrument Manager Service

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Retrieve the InstrumentManager service to send analytics events with custom schemas and interaction data.

```php
use MediaWiki\MediaWikiServices;

// Get the InstrumentManager service
$instrumentManager = MediaWikiServices::getInstance()
    ->getService('TestKitchen.InstrumentManager');

// Get instrument by name
$instrument = $instrumentManager->getInstrument('my-analytics-instrument');

// Send analytics event
$instrument->send('api_call', [
    'endpoint' => '/api/query',
    'response_time_ms' => $responseTime
]);

// Set custom schema
$instrument->setSchema('/analytics/custom/schema/1.0.0')
    ->send('custom_metric', ['value' => 42]);
```

--------------------------------

### Send Experiment Analytics Events

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Send events associated with an experiment using the send method. Metadata is automatically included in the event payload.

```javascript
const experiment = mw.testKitchen.getExperiment('my-awesome-experiment');

// Send a simple action event
experiment.send('button_click');

// Send event with interaction data
experiment.send('form_submit', {
    action_source: 'signup_form',
    action_context: 'homepage'
});

// Send event with additional contextual attributes
experiment.send('page_view',
    { action_source: 'navigation' },
    ['performer_is_logged_in', 'performer_is_bot']
);

// Listen to UI events and track them
const dialog = require('my.awesome.dialog');
['open', 'default-action', 'primary-action'].forEach((event) => {
    dialog.on(event, () => experiment.send(event));
});
```

--------------------------------

### Set Custom Schema for Events

Source: https://context7.com/wikimedia/mediawiki-extensions-testkitchen/llms.txt

Override the default schema ID for experiment or instrument events to send events with custom schemas.

```javascript
const experiment = mw.testKitchen.getExperiment('my-awesome-experiment');

// Set custom schema for this experiment's events
experiment
    .setSchema('/my/custom/schema/1.0.0')
    .send('custom_action');

const instrument = mw.testKitchen.getInstrument('my-instrument');

// Set custom schema for instrument events
instrument
    .setSchema('/analytics/custom/instrument/1.0.0')
    .send('custom_metric', { value: 42 });
```

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