Named meter registration

Use named registration when you want multiple logical meter sources in the same application and resolve them explicitly with keyed services.

Register a named meter

using Microsoft.Extensions.DependencyInjection;

var services = new ServiceCollection();

services.AddNamedMeter("orders");

This registers:

• keyed System.Diagnostics.Metrics.Meter with the name orders
• keyed IMeter<T> that resolves to that same named Meter

Register an instrumentation scope version

Pass version to identify the instrumentation scope version:

services.AddNamedMeter("orders", version: "1.2.3");

The keyed meter exposes Version == "1.2.3". The existing overload without a version remains supported and keeps a null version.

Resolve the named meter in consumers

using Cratis.Metrics;
using Microsoft.Extensions.DependencyInjection;

public class OrderService([FromKeyedServices("orders")] IMeter<OrderService> meter)
{
}

IMeter<T> remains available as a non-keyed service as well, where the underlying meter name defaults to typeof(T).FullName. These per-type meters are not subscribed by default. Explicitly subscribe that name in your telemetry provider (for example, with AddMeter in OpenTelemetry), or use a named meter that your provider subscribes to.

Registration boundaries

The name is both the diagnostics source name and the dependency-injection key. Use the same string when registering, resolving, and configuring your telemetry provider. A null, empty, or whitespace-only name is rejected. Different names create separate singleton sources; typed consumers resolved with the same key share the underlying meter even when their generic type arguments differ.

Registration uses TryAddKeyedSingleton. Registering the same name again does not replace its existing services, so choose the version on the first registration rather than trying to update it with a later call. Registration alone does not configure an exporter or subscribe a telemetry provider.

See also

• Overview — typed metrics APIs and usage
• Roslyn — generate instrumentation methods
• Named activity sources — configure the other diagnostics signal