iOS/tvOS/macOS Client SDK
Getting Started
The following will outline how to get up and running with Statsig for iOS/tvOS/macOS.Create an Account
To work with the SDK, you will need a Statsig account. If you don't yet have an account, go ahead and sign up for a free account now.
You could skip this for now, but you will need an SDK key and some gates/experiments to use with the SDK in just a minute.
Installation
To use the SDK in your project, you must add Statsig as a dependency.
- Swift Package Manager
- Cocoapods
In your Xcode, select File > Swift Packages > Add Package Dependency and enter the URL https://github.com/statsig-io/ios-sdk.git.
You can also include it directly in your project's Package.swift. Find out the latest release version on our GitHub page.
//...
dependencies: [
// see the latest version on https://github.com/statsig-io/ios-sdk/releases
.package(url: "https://github.com/statsig-io/ios-sdk.git", .upToNextMinor("X.Y.Z")),
],
//...
targets: [
.target(
name: "YOUR_TARGET",
dependencies: ["Statsig"]
)
],
//...
If you are using CocoaPods, our pod name is 'Statsig', and you can include the following line to your Podfile:
use_frameworks!
target 'TargetName' do
//...
pod 'Statsig', '~> X.Y.Z'
end
Find the latest versions by searching cocoapods.org or on Github.
Initialize the SDK
After installation, you will need to initialize the SDK using a Client SDK key from the "API Keys" tab on the Statsig console.
These Client SDK Keys are intended to be embedded in client side applications. If need be, you can invalidate or create new SDK Keys for other applications/SDK integrations.
info
Do NOT embed your Server Secret Key in client side applications
In addition to the SDK key, you should also pass in a StatsigUser for feature gate targeting and experimentation grouping purposes.
The 3rd parameter is optional and allows you to pass in a StatsigOptions to customize the SDK.
- Swift
- Objective-C
Statsig.start(
sdkKey: "my_client_sdk_key",
user: StatsigUser(userID: "my_user_id"),
options: StatsigOptions(environment: StatsigEnvironment(tier: .Staging)))
{ errorMessage in
// Statsig has finished fetching the latest feature gate and experiment values for your user.
// If you need the most recent values, you can get them now.
// You can also check errorMessage for any debugging information.
}
StatsigUser *user = [[StatsigUser alloc] initWithUserID:@"my_user_id"];
[Statsig startWithSDKKey:@"my_client_sdk_key", user:user, completion:^(NSString * errorMessage) {
// Statsig has finished fetching the latest feature gate and experiment values for your user.
// If you need the most recent values, you can get them now.
// You can also check errorMessage for any debugging information.
}];
The completion block is called after the network request to fetch the latest feature gate and experiment values for your user. If you try to get any value before the completion block is called, you could get either the cached value from the previous session, or the default value. If you need the latest value, please wait for the completion block to be called first.
Working with the SDK
Checking a Gate
Now that your SDK is initialized, let's fetch a Feature Gate. Feature Gates can be used to create logic branches in code that can be rolled out to different users from the Statsig Console. Gates are always CLOSED or OFF (think return false;
) by default.
- Swift
- Objective-C
if Statsig.checkGate("new_homepage_design") {
// Gate is on, show new home page
} else {
// Gate is off, show old home page
}
if ([Statsig checkGateForName:@"new_homepage_design"]) {
// Gate is on, show new home page
} else {
// Gate is off, show old home page
}
Reading a Dynamic Config
Feature Gates can be very useful for simple on/off switches, with optional but advanced user targeting. However, if you want to be able send a different set of values (strings, numbers, and etc.) to your clients based on specific user attributes, e.g. country, Dynamic Configs can help you with that. The API is very similar to Feature Gates, but you get an entire json object you can configure on the server and you can fetch typed parameters from it. For example:
- Swift
- Objective-C
let config = Statsig.getConfig("awesome_product_details")
// The 2nd parameter is the default value to be used in case the given parameter name does not exist on
// the Dynamic Config object. This can happen when there is a typo, or when the user is offline and the
// value has not been cached on the client.
let itemName = config.getValue(forKey: "product_name", defaultValue: "Awesome Product v1")
let price = config.getValue(forKey: "price", defaultValue: 10.0)
let shouldDiscount = config.getValue(forKey: "discount", defaultValue: false)
DynamicConfig *config = [Statsig getConfigForName:@"awesome_product_details"];
// The 2nd parameter is the default value to be used in case the given parameter name does not exist on
// the Dynamic Config object. This can happen when there is a typo, or when the user is offline and the
// value has not been cached on the client.
NSString *itemName = [config.getStringForKey:@"product_name" defaultValue:@"Awesome Product v1"];
double price = [config getDoubleForKey:@"price" defaultValue:10.0];
BOOL shouldDiscount = [config getBoolForKey:@"discount" defaultValue:false];
Getting an Layer/Experiment
Then we have Layers/Experiments, which you can use to run A/B/n experiments. We offer two APIs, but we recommend the use of layers to enable quicker iterations with parameter reuse.
- Swift
- Objective-C
// Values via getLayer
let layer = Statsig.getLayer("user_promo_experiments")
let promoTitle = layer.getValue(forKey: "title", defaultValue: "Welcome to Statsig!")
let discount = layer.getValue(forKey: "discount", defaultValue: 0.1)
// or, via getExperiment
let titleExperiment = Statsig.getExperiment("new_user_promo_title")
let priceExperiment = Statsig.getExperiment("new_user_promo_price")
let promoTitle = titleExperiment.getValue(forKey: "title", defaultValue: "Welcome to Statsig")
let discount = priceExperiment.getValue(forKey: "discount", defaultValue: 0.1)
...
let price = msrp * (1 - discount);
DynamicConfig *expConfig = [Statsig getExperimentForName:@"new_user_promo"];
NSString *promoTitle = [expConfig.getStringForKey:@"title" defaultValue:@"Welcome to Statsig! Use discount code WELCOME10OFF for 10% off your first purchase!"];
double discount = [expConfig getDoubleForKey:@"discount" defaultValue:0.1];
double price = msrp * (1 - discount);
Logging an Event
Now that you have a Feature Gate or an Experiment set up, you may want to track some custom events and see how your new features or different experiment groups affect these events. This is super easy with Statsig - simply call the Log Event API for the event, and you can additionally provide some value and/or an object of metadata to be logged together with the event:
- Swift
- Objective-C
Statsig.logEvent(withName: "purchase", value: 2.99, metadata: ["item_name": "remove_ads"])
[Statsig logEvent:@"purchase" doubleValue:2.99 metadata:@{@"item_name" : @"remove_ads"}];
Statsig User
You should provide a StatsigUser object whenever possible when initializing the SDK, passing as much information as possible in order to take advantage of advanced gate and config conditions (like country or OS/browser level checks). Most of the time, the userID
field is needed in order to provide a consistent experience for a given user (see logged-out experiments to understand how to correctly run experiments for logged-out users). If the user is logged out at the SDK init time, you can leave the userID
out for now, and we will use a stable device ID that we create and store in the local storage for targeting purposes.
Besides userID
, we also have email
, ip
, userAgent
, country
, locale
and appVersion
as top-level fields on StatsigUser. In addition, you can pass any key-value pairs in an object/dictionary to the custom
field and be able to create targeting based on them.
Once the user logs in or has an update/changed, make sure to call updateUser
with the updated userID
and/or any other updated user attributes:
- Swift
- Objective-C
let newUser = StatsigUser(userID: "new_user_id", email: "newUser@gmail.com", country: "US")
Statsig.updateUser(newUser) { errorMessage in
// Statsig has finished fetching the latest feature gate and experiment values for your updated user.
// If you need the most recent values, you can get them now.
}
StatsigUser *newUser = [[StatsigUser alloc] initWithUserID:@"new_user_id" email:@"newUser@gmail.com" ip:nil country:@"US" custom:custom:@{@"is_new_user": @YES}];
[Statsig updateUserWithNewUser:user completion:^(NSString * errorMessage) {
// Statsig has finished fetching the latest feature gate and experiment values for your updated user.
// If you need the most recent values, you can get them now.
}];
Private Attributes
Have sensitive user PII data that should not be logged? No problem, we have a solution for it! On the StatsigUser object we also have a field called privateAttributes
, which is a simple object/dictionary that you can use to set private user attributes. Any attribute set in privateAttributes
will only be used for evaluation/targeting, and removed from any logs before they are sent to Statsig server.
For example, if you have feature gates that should only pass for users with emails ending in "@statsig.com", but do not want to log your users' email addresses to Statsig, you can simply add the key-value pair { email: "my_user@statsig.com" }
to privateAttributes
on the user and that's it!
Statsig Options
Statsig.start()
takes an optional parameter options
in addition to sdkKey
and user
that you can provide to customize the Statsig client. Here are the current options and we are always adding more to the list:
- initTimeout: double, default 3.0
- used to decide how long the Statsig client waits for the initial network request to respond before calling the completion block. The Statsig client will return either cached values (if any) or default values if checkGate/getConfig/getExperiment is called before the initial network request completes.
- If you always want to wait for the latest values fetched from Statsig server, you should set this to 0 so we do not timeout the network request.
- disableCurrentVCLogging: boolean, default false
- by default, any custom event your application logs with
Statsig.logEvent()
includes the current root View Controller. This is so we can generate user journey funnels for your users. You can set this parameter to true to disable this behavior.
- by default, any custom event your application logs with
- environment: StatsigEnvironment, default nil
- StatsigEnvironment is a class for you to set environment variables that apply to all of your users in the same session and will be used for targeting purposes.
- e.g. passing in a value of
StatsigEnvironment(tier: .Staging)
will allow your users to pass any condition that pass for the staging environment tier, and fail any condition that only passes for other environment tiers.
- enableAutoValueUpdate: boolean, default false
- by default, feature values for a user is fetched once during
Statsig.start
and don't change throughout the session. Setting this value to true will turn on the feature for Statsig to periodically fetch updated values for the current user.
- by default, feature values for a user is fetched once during
- overrideStableID: string?, default null
- overrides the stableID in the SDK that is set for the user.
- disableCurrentVCLogging: bool, default false
- By default we log the name of the ViewController the user is currently in with events you log to Statsig. Set this to true to disable the behavior.
Shutting Statsig Down
In order to save users' data and battery usage, as well as prevent logged events from being dropped, we keep event logs in client cache and flush periodically. Because of this, some events may not have been sent when your app shuts down.
To make sure all logged events are properly flushed or saved locally, you should tell Statsig to shutdown when your app is closing:
- Swift
- Objective-C
Statsig.shutdown()
[Statsig shutdown];
Local Overrides
If you want to locally override gates/configs/experiments/layers, there are a set of override APIs as follows.
- Swift
- Objective-C
// Overrides the given gate to the specified value
Statsig.overrideGate("a_gate_name", value: true)
// Overrides the given config (dynamic config or experiment) to the provided value
Statsig.overrideConfig("a_config_or_experiment_name", value: ["key": "value"])
// Overrides the given layer to the provided value
Statsig.overrideLayer("a_layer_name", value: ["key": "value"])
// Removes any overrides associated with the provided gate/config/experiment/layer name
Statsig.removeOverride("a_gate_name")
Statsig.removeOverride("a_config_or_experiment_name")
Statsig.removeOverride("a_layer_name")
// Removes all overrides
Statsig.removeAllOverrides()
// Returns a StatsigOverrides object, contain all the current overrides
let currentOverrides = Statsig.getAllOverrides()
// Overrides the given gate to the specified value
[Statsig overrideGate:@"a_gate_name" value:true];
// Overrides the given config (dynamic config or experiment) to the provided value
[Statsig overrideConfig:@"a_config_or_experiment_name" value:@{@"key": @"value"}];
// Overrides the given layer to the provided value
[Statsig overrideLayer:@"a_layer_name" value:@{@"key": @"value"}];
// Removes any overrides associated with the provided gate/config/experiment/layer name
[Statsig removeOverride:@"a_gate_name"];
[Statsig removeOverride:@"a_config_or_experiment_name"];
[Statsig removeOverride:@"a_layer_name"];
// Removes all overrides
[Statsig removeAllOverrides];
// Returns a StatsigOverrides object, contain all the current overrides
StatsigOverrides *currentOverrides = [Statsig getAllOverrides];
note
- These only apply locally on the device where they are being tested - they do not update definitions in the Statsig console or elsewhere.
- These will be persisted to local storage on the device, so overrides will persist across sessions. If you want to clear out the overrides, you can remove them all with
removeAllOverrides
or remove a specific override withremoveOverride
- The local override API is not designed to be a full mock. They are only a convenient way to override the value of the gate/config/etc.
Manual Exposures v1.16.0+
warning
Manually logging exposures can be tricky and may lead to an imbalance in exposure events. For example, only triggering exposures for users in the Test group of an experiment will imbalance the experiment, making it useless.
- Check Gate
- Get Config
- Get Experiment
- Get Layer
To check a gate without an exposure being logged, call the following.
// Swift
let result = Statsig.checkGateWithExposureLoggingDisabled("a_gate_name")
// Objective C
bool result = [Statsig checkGateWithExposureLoggingDisabled:@"a_gate_name"];
Later, if you would like to expose this gate, you can call the following.
// Swift
Statsig.manuallyLogGateExposure("a_gate_name")
// Objective C
[Statsig manuallyLogGateExposure:@"a_gate_name"];
To get a dynamic config without an exposure being logged, call the following.
// Swift
let config = Statsig.getConfigWithExposureLoggingDisabled("a_config_name")
// Objective C
DynamicConfig *config = [Statsig getConfigWithExposureLoggingDisabled:@"a_config_name"];
Later, if you would like to expose the dynamic config, you can call the following.
// Swift
Statsig.manuallyLogConfigExposure("a_config_name")
// Objective C
[Statsig manuallyLogConfigExposure:@"a_config_name"];
To get an experiment without an exposure being logged, call the following.
// Swift
Statsig.getExperimentWithExposureLoggingDisabled("an_experiment_name")
// Objective C
DynamicConfig *experiment = [Statsig getExperimentWithExposureLoggingDisabled:@"an_experiment_name"];
Later, if you would like to expose the experiment, you can call the following.
// Swift
Statsig.manuallyLogExperimentExposure("an_experiment_name")
// Objective C
[Statsig manuallyLogExperimentExposure:@"an_experiment_name"];
To get a layer parameter without an exposure being logged, call the following.
// Swift
let layer = Statsig.getLayerWithExposureLoggingDisabled("a_layer_name")
let result = layer.getValue(forKey: "a_parameter_name", defaultValue: "fallback")
// Objective C
Layer *layer = [Statsig getLayerWithExposureLoggingDisabled:@"a_layer_name"];
NSString *result = [layer getStringForKey:@"a_parameter_name" defaultValue:@"fallback"];
Later, if you would like to expose the layer parameter, you can call the following.
// Swift
Statsig.manuallyLogLayerParameterExposure("a_layer_name", "a_parameter_name")
// Objective C
[Statsig manuallyLogLayerParameterExposure:@"a_layer_name" parameterName:@"a_parameter_name"];
Stable ID
Each client SDK has the notion of StableID, and identifier that is generated the first time the SDK is initialized and is stored locally for all future sessions. Unless storage is wiped (or app deleted), the StableID will not change. This allows us to run device level experiments and experiments when other user identifiable information is unavailable (Logged out users).
You can get the StableID for the current device with:
Statsig.getStableID();
If you have your own form of StableID and would prefer to use it instead of the Statsig generated ID, you can override it through StatsigOptions:
let opts = StatsigOptions(overrideStableID: "my_stable_id")
Statsig.start(sdkKey: "client-xyx", options: opts)
StatsigListening v1.14.0+
In version v1.14.0+, you can now listen for changes in Statsig values.This can be useful if you have one location that calls Statsig.start or Statsig.updateUser and you would like these changes to flow to separate locations.To use this API, simply have the class you wish to respond to these changes implement the StatsigListening
protocol and add it as a listener.
The StatsigListening protocol has two methods that can be implemented:
onInitialized
- Will be called when the initialize request is returned in Statsig.start().
An error string may be passed to this function if something went wrong with the network request.
onUserUpdated
- Will be called when the network request for Statsig.updateUser is returned.
An error string may be passed to this function if something went wrong with the network request.
You may also check the new Statsig.isInitialized()
to verify if Statsig has already completed initialization.
The following is an example of how this could be done in a ViewController
class MyViewController: UIViewController, StatsigListening {
override func viewDidLoad() {
super.viewDidLoad()
if Statsig.isInitialized() {
render()
} else {
Statsig.addListener(self)
renderLoading()
}
}
private func render() {
var showNewUI = Statsig.checkGate("new_ui_enabled", false)
if showNewUI {
// Render the new
} else {
// Render the old
}
}
private func renderLoading() { /* Some Loading UI */ }
private func renderError(error: String) { /* Some Error UI */ }
// StatsigListening Implementation
func onInitialized(_ error: String?) {
if (error) {
renderError(error)
}
render()
}
func onUserUpdated(_ error: String?) { /* Optional rerender when User changed */ }
}
FAQ
How do I run experiments for logged out users?
See the guide on device level experiments
Does the SDK support tvOS?
v1.13.1+
of the statsig ios SDK will supports tvOS