Initialization

The Eppo Java SDK is easy to initialize while offering robust customization options, making it adaptable to various use cases.

Initialize the SDK

To complete basic initialization, you only need to provide an SDK key. Create an SDK key if you don't already have one.

EppoClient.builder(sdkKey)
  .buildAndInit();

sdkKeystring

Your SDK key. Create an SDK key if you don't already have one.

Use the SDK instance

After initialization, you can access the client instance using EppoClient.getInstance(). The client is a singleton that should be used throughout your application's lifecycle.

EppoClient eppoClient = EppoClient.getInstance();

Advanced Configuration

Basic initialization is great for most use cases, but the SDK provides options that you can use during initialization to customize the behavior of the SDK.

Loggers

assignmentLoggerAssignmentLoggerDefault: null

An implementation of AssignmentLogger; sends assignment event data to your data warehouse

banditLoggerBanditLoggerDefault: null

An implementation of BanditLogger; sends bandit selection event data to your data warehouse

Initialization Options

gracefulModebooleanDefault: true

When on (which is the default), flag evaluation errors will be caught, and the default value returned. When off, the errors will be rethrown.

forceReinitializebooleanDefault: false

If true, a new client will be initialized and a new fetch for configuration will be performed even if the SDK has already been initialized. If false (which is the default), all subsequent initializations will be ignored and the previously initialized client will continue to be used.

pollingIntervalMslongDefault: 30000

How often, in milliseconds, the client should check for updated configurations. The default is 30,000 (poll every 30 seconds).

apiBaseUrlStringDefault: Eppo CDN

Where the SDK should fetch configurations. The default is the Eppo-backed Fastly Content Delivery Network (CDN).

Example Configuration

Here's an example of using multiple configuration options:

EppoClient.builder(sdkKey)
  .gracefulMode(true)
  .pollingIntervalMs(60000) // Poll every minute
  .assignmentLogger(assignmentLogData -> {
    // Log assignments for experiments
    System.out.println(assignmentLogData);
  })
  .banditLogger(banditLogData -> {
    // Log bandit actions
    System.out.println(banditLogData);
  })
  .buildAndInit();

Additional Methods

The SDK provides several utility methods that can be useful:

// Toggle graceful mode on/off after initialization
eppoClient.setIsGracefulFailureMode(false);

// Stop polling for configuration updates
eppoClient.stopPolling();