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Go Server SDK for Statsig

Statsig server SDK for Go applications. This SDK is open source and hosted on github.

The Basics

Get started in a few quick steps.

  1. Create a free account on
  2. Install the SDK
  3. Initialize the SDK
  4. Fetch Feature Gates, Dynamic Configs, or Experiments
  5. Log a custom event

Step 1 - Create a free account on

You could skip this for now, but you will need an SDK Key and some Feature Gates or Dynamic Configs to use with the SDK in just a minute.

Step 2 - Install the SDK

In your go.mod, add a dependency on the most recent version of the SDK:

require ( v1.1.1

Or with the go get CLI:

go get

See the Releases tab in GitHub for the latest versions.

Step 3 - Initialize the SDK

After installation, you will need to initialize the SDK using a Server Secret Key from the statsig console.


Do NOT embed your Server Secret Key in client side applications, or expose it in any external facing documents. However, if you accidentally exposed it, you can create a new one in Statsig console.

There is also an optional parameter options that allows you to pass in a StatsigOptions to customize the SDK.

import (
statsig ""


// Or, if you want to initialize with certain options
statsig.InitializeWithOptions("server-secret-key", &Options{Environment: Environment{Tier: "staging"}})

initialize will perform a network request. After initialize completes, virtually all SDK operations will be synchronous1--the SDK will fetch updates from Statsig in the background, independently of your API calls.

Step 4 - Fetch Feature Gates, Dynamic Configs, or Experiments

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.

From this point on, all APIs will require you to specify the user (see Statsig user) associated with the request. For example, check a gate for a certain user like this:

user := statsig.User{UserID: "some_user_id"}
feature := statsig.CheckGate(user, "use_new_feature")
if feature {
// Gate is on, enable new feature
} else {
// Gate is off

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:

config := statsig.GetConfig(user, "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.
itemName := config.GetString("product_name", "Awesome Product v1");
double price = config.GetNumber("price", 10.0);
bool shouldDiscount = config.GetBool("discount", false);

// Or just get the whole json object backing this config if you prefer
json := config.Value

Then we have Experiments, which you can use to run A/B/n experiments and use advanced features like layers (coming soon) to avoid collision and enable quicker iterations with parameter reuse.

expConfig := statsig.GetExperiment(user, "new_user_promo");

promoTitle := expConfig.GetString("title", "Welcome to Statsig! Use discount code WELCOME10OFF for 10% off your first purchase!");
discount := expConfig.GetNumber("discount", 0.1);


price := msrp * (1 - discount);

Step 5 - Log a custom 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 and specify the user and event name to log; you additionally provide some value and/or an object of metadata to be logged together with the event:

User: user,
EventName: "add_to_cart",
Value: "SKU_12345",
Metadata: map[string]string{"price": "9.99","item_name": "diet_coke_48_pack"},

Statsig User

When calling APIs that require a user, you should pass as much information as possible in order to take advantage of advanced gate and config conditions (like country or OS/browser level checks), and correctly measure impact of your experiments on your metrics/events. The userID field is required because it's needed to provide a consistent experience for a given user (click here to understand further why it's important to always provide a userID).

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.

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 "", but do not want to log your users' email addresses to Statsig, you can simply add the key-value pair { email: "" } to privateAttributes on the user and that's it!

Statsig Options

You can specify optional parameters with options when initializing using InitializeWithOptions()

type Options struct {
API string `json:"api"`
Environment Environment `json:"environment"`
LocalMode bool `json:"localMode"`
ConfigSyncInterval time.Duration
IDListSyncInterval time.Duration
  • Environment: default nil
    • An object you can use to set environment variables that apply to all of your users in the same session and will be used for targeting purposes.
    • The most common usage is to set the environment tier (string), and have feature gates pass/fail for specific environments. The accepted values are "production", "staging" and "development".
  • Environment: default nil
    • An object you can use to set environment variables that apply to all of your users in the same session and will be used for targeting purposes.
    • The most common usage is to set the environment tier (string), and have feature gates pass/fail for specific environments. The accepted values are "production", "staging" and "development".
  • LocalMode: default false
    • Disables all network requests from the SDK, so it will only return default values. Useful in tests/non production environments.
  • ConfigSyncInterval: default 10 seconds
    • The interval to poll for gate/experiment/config changes.
  • IDListSyncInterval: default 1 minute
    • The interval to poll for ID list changes.

Shutting down Statsig

Because we batch and periodically flush events, some events may not have been sent when your app/server shuts down. To make sure all logged events are properly flushed, you should tell Statsig to shutdown when your app/server is closing:




// User specific attributes for evaluating Feature Gates, Experiments, and DyanmicConfigs
// NOTE: UserID is **required** - see
// PrivateAttributes are only used for user targeting/grouping in feature gates, dynamic configs,
// experiments and etc; they are omitted in logs.
type User struct {
UserID string `json:"userID"`
Email string `json:"email"`
IpAddress string `json:"ip"`
UserAgent string `json:"userAgent"`
Country string `json:"country"`
Locale string `json:"locale"`
AppVersion string `json:"appVersion"`
Custom map[string]interface{} `json:"custom"`
PrivateAttributes map[string]interface{} `json:"privateAttributes"`
StatsigEnvironment map[string]string `json:"statsigEnvironment"`
CustomIDs map[string]string `json:"customIDs"`


How do I run experiments for logged out users?

You can run experiments for arbitrary unit IDs (sessionID, groupID, etc), rather than at the userID level, if you choose. These custom unit IDs must be predefined in your Statsig project, and then selected in the Experiment creation flow. For more information, see our guide on experimenting on custom ID types

How can I mock Statsig in tests

We recommend using the override apis in v1.3.0+, in combination with the LocalMode option in StatsigOptions to force gate/config values in test environments and remove network access to statsig servers.

func OverrideGate(gate string, val bool)

func OverrideConfig(config string, val map[string]interface{})

For example:

c := NewClientWithOptions(secret, &Options{LocalMode: true})

user := User{
UserID: "123",
gateDefault := c.CheckGate(user, "any_gate")
// "any_gate" is false by default

c.OverrideGate("any_gate", true)
// "any_gate" is now true

See also