---
title: Example usage of the Swift SDK
slug: feature-experimentation/docs/example-usage-swift
docTags: 
createdAt: 2026-08-05T20:39:52.000Z
---

After installing the Swift SDK, import the Optimizely library, get your project's datafile, and create a client. Use the client to evaluate flag rules like A/B tests and flag deliveries.

This example walks through the following three key steps:

1. Evaluate a flag with the key `product_sort` using the `decide` method. This also sends a decision event to Optimizely to record that the user was exposed to the experiment.
2. Run code based on the flag result. The SDK evaluates your flag rules and determines which variation the user is in. You can either:
   - Check the flag's enabled state and read a configuration variable (`sort_method`) to determine which experience the user gets.
   - Check the flag variation directly and run the corresponding control or treatment code.
3. Track a conversion event called `purchased` to measure the experiment's impact. The `trackEvent` method ties the purchase back to the A/B test and sends it to Optimizely so it displays on your [Experiment Results page](docId:_K6n7h_MZ8b0xn6yWPrrq).

```swift
// initialize an Optimizely client
optimizely = OptimizelyClient(sdkKey: "<Your_SDK_Key>")

// create a user and decide a flag rule (such as an A/B test) for them
let user = optimizely.createUserContext(userId: "user123", attributes: ["logged_in":true])
let decision = user.decide(key: "product_sort")

// did the decision fail with a critical error?
guard let variationKey = decision.variationKey else {
  print("decide error: \(decision.reasons)")
	return
}

// execute code based on flag enabled state
let enabled = decision.enabled

if (enabled) {
  // get flag variable values
  let sortMethod: String? = decision.variables.getValue(jsonPath: "sort_method")
  // or:
  let sortMethodFromMap: String? = decision.variables.toMap()["sort_method"] as? String
  
}

// or execute code based on flag variation:
if (variationKey == "control") {
	// Execute code for control variation 
} else if (variationKey == "treatment") {
  // Execute code for treatment variation
}

// Track a user event
try? user.trackEvent(eventKey: "purchased")
```