Feature Flags

The ADK uses feature flags to safely roll out experimental components, manage breaking changes, and offer developers the ability to opt-in or opt-out of specific internal behaviors dynamically.

Enabling Features

Feature flags are evaluated dynamically via the AdkFeatures utility class. The most robust way to enable a feature is by setting the associated environment variable prior to application startup.

Flags generally follow the naming convention ADK_ENABLE_FEATURENAME.

using GoogleAdk.Core.Features;

// Enable via Environment Variables before AdkEnv is loaded
Environment.SetEnvironmentVariable("ADK_ENABLE_LIVEBIDISTREAMING", "1");
Environment.SetEnvironmentVariable("ADK_ENABLE_OUTPUTSCHEMA_WITH_TOOLS", "True");

AdkEnv.Load();

Temporary Overrides

If you need to test a feature flag temporarily without polluting the global environment (for instance, during unit tests), you can utilize the TemporaryOverride block.

using GoogleAdk.Core.Features;

using (AdkFeatures.TemporaryOverride(FeatureName.OutputSchemaWithTools, true))
{
    // The feature is dynamically active here
    Assert.True(AdkFeatures.IsFeatureEnabled(FeatureName.OutputSchemaWithTools));

    // Execute logic heavily dependent on Output Schema configurations
}

// Upon exiting the using block, the feature flag automatically reverts.
Assert.False(AdkFeatures.IsFeatureEnabled(FeatureName.OutputSchemaWithTools));