Evaluating Flags

`GetFlag(key, context)`

Returns the data for a specific flag, or null if the flag does not exist.


var flag = client.GetFlag("new-checkout", new FlagEvaluationContext
{
    UserId = "user-42",
});
// FlagData? or null

The UserId in the context is used to evaluate rollout flags consistently: the same user always gets the same result. When the context or UserId is empty, a per-instance anonymous ID is used.

Safe check


if (flag?.Enabled == true)
{
    // Flag is enabled for this user
}

`GetFlags(context)`

Returns all flags for the environment as a read-only list.


var flags = client.GetFlags(new FlagEvaluationContext { UserId = "user-42" });
 
foreach (var flag in flags)
{
    Console.WriteLine($"{flag.Key}: {flag.Enabled}");
}

Examples by flag type

Boolean flag


var maintenance = client.GetFlag("maintenance-mode", context);
 
if (maintenance?.Enabled == true)
{
    return MaintenancePage();
}

Rollout flag


var newDashboard = client.GetFlag("new-dashboard", context);
 
// flag.Enabled is true or false based on userId and percentage
if (newDashboard?.Enabled == true)
{
    return NewDashboard();
}
 
// To see the configured percentage:
if (newDashboard?.Type == "rollout")
{
    Console.WriteLine($"{newDashboard.Percent}% of users will see this feature");
}

Before `InitAsync()`

If you call GetFlag() before InitAsync(), the flag will return null (the local cache is still empty).


var client = new CanaryGateClient("cg_key");
// Do not do this:
client.GetFlag("feature"); // null
 
// Do this instead:
await client.InitAsync();
client.GetFlag("feature"); // FlagData? or null

Flags that do not exist

If the flag does not exist in the environment, GetFlag() returns null. Always use the null-safe pattern to avoid breaking the application flow:


// If 'new-feature' does not exist in the environment, enabled will be false
var flag = client.GetFlag("new-feature");
var enabled = flag?.Enabled ?? false;

GetFlag(key, context)