Initialization

The Eppo .NET SDK is easy to initialize while offering robust customization options, making it adaptable to various use cases such as custom caching requirements and ultra-low-latency initialization.

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.

var eppoClientConfig = new EppoClientConfig("<SDK_KEY>", null);
var eppoClient = EppoClient.Init(eppoClientConfig);

Use the SDK instance

After initialization, you can use the SDK instance to assign a variation to a subject using the Get*Assignment methods.

// Get the current user from your application context
var user = GetCurrentUser();

// Make an assignment
var variation = eppoClient.GetStringAssignment(
    "my-feature",
    user.Id,
    user.Attributes,
    "default"
);

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.

Initialization Options

How the SDK fetches, serves, and caches experiment configurations is configurable via the EppoClientConfig class:

PollingIntervalInMillisintDefault: 30000

The interval in milliseconds between polling attempts to fetch updated configurations from the Eppo API.

PollingJitterlongDefault: 5000

The maximum amount of time in milliseconds to add to the polling interval.

AssignmentLoggerIAssignmentLoggerDefault: null

A callback that sends each assignment to your data warehouse. Required for experiment analysis.

BaseUrlstringDefault: https://fscdn.eppo.cloud/api

The base URL for the Eppo API. You typically won't need to change this unless you're using a custom endpoint.

Example Configuration

Here's an example of initializing the SDK with custom configuration:

var config = new EppoClientConfig("<SDK_KEY>", new MyAssignmentLogger())
{
    PollingIntervalInMillis = 5000,  // Poll every 5 seconds
    BaseUrl = "https://my-custom-endpoint.com/api",
    HttpClient = new HttpClient 
    { 
        Timeout = TimeSpan.FromSeconds(10) 
    }
};

var eppoClient = EppoClient.Init(config);

Configuration Caching

The SDK caches configurations in memory to ensure fast assignment evaluations. The cache is automatically updated based on the polling interval.

// Example showing how to initialize with a shorter polling interval for more frequent updates
var config = new EppoClientConfig("<SDK_KEY>", myLogger)
{
    PollingIntervalInMillis = 5000  // Update cache every 5 seconds
};

Error Handling

Wrap your initialization in a try/catch block to handle errors gracefully.

try 
{
    var eppoClient = EppoClient.Init(config);
}
catch (EppoInitializationException ex)
{
    // Handle initialization failure
    Logger.Error("Failed to initialize Eppo SDK", ex);
}

Best Practices

1. Initialize Once: Create a single instance of the SDK at application startup and reuse it throughout your application.

2. Handle Errors: Always implement error handling around initialization to ensure your application degrades gracefully.

3. Configure Timeouts: Set appropriate timeout values for your use case to prevent hanging operations.

4. Monitor Memory: Be mindful of memory usage when setting polling intervals, as configurations are cached in memory.