arbiter-opentelemetry

name	arbiter-opentelemetry
description	Use when wiring OpenTelemetry tracing/metrics for Arbiter — adding the mediator ActivitySource and Meter (MediatorTelemetry.SourceName / MediatorTelemetry.MeterName), calling Arbiter.OpenTelemetry.Server.AddOpenTelemetry on a HostApplicationBuilder, or exposing log queries via Arbiter.OpenTelemetry.Monitor.AddLogQuery.

Arbiter OpenTelemetry

Three packages, layered:

Package	Purpose
Arbiter.OpenTelemetry	Shared models + the MediatorTelemetry ActivitySource/Meter names
Arbiter.OpenTelemetry.Server	One-call AddOpenTelemetry extension for ASP.NET Core hosts, pre-wires the mediator source
Arbiter.OpenTelemetry.Monitor	AddLogQuery — exposes telemetry log queries via the CQRS pipeline

Manual wiring (any host)

dotnet add package Arbiter.Mediation
dotnet add package OpenTelemetry.Extensions.Hosting

using Arbiter.Mediation;
using OpenTelemetry.Metrics;
using OpenTelemetry.Trace;

services.AddOpenTelemetry()
    .WithTracing(t => t
        .AddSource(MediatorTelemetry.SourceName)
        .AddAspNetCoreInstrumentation()
        .AddOtlpExporter())
    .WithMetrics(m => m
        .AddMeter(MediatorTelemetry.MeterName)
        .AddAspNetCoreInstrumentation()
        .AddOtlpExporter());

MediatorTelemetry.SourceName and MediatorTelemetry.MeterName are the only names you need — every Arbiter mediator activity/metric is emitted on them.

One-call wiring (ASP.NET Core)

dotnet add package Arbiter.OpenTelemetry.Server

using Arbiter.OpenTelemetry.Server;

var builder = WebApplication.CreateBuilder(args);

builder.AddOpenTelemetry(
    configureOptions:   opts    => opts.ServiceName = "MyService",
    configureMetrics:   metrics => metrics.AddRuntimeInstrumentation(),
    configureTracing:   tracing => tracing.AddHttpClientInstrumentation(),
    configureOpenTelemetry: ot  => ot.UseAzureMonitor() // optional
);

The extension auto-adds the mediator source/meter, ASP.NET Core instrumentation, and an exporter (OTLP by default; honor OTEL_* env vars).

Log query API

dotnet add package Arbiter.OpenTelemetry.Monitor

using Arbiter.OpenTelemetry.Monitor;

services.AddCommandQuery();
services.AddLogQuery();      // registers handlers for the log-query requests

Then send the log queries through IMediator / IDispatcher just like any other Arbiter query — useful for surfacing observability data inside an admin UI.

Notes

• Don't add MediatorTelemetry.SourceName twice — the server extension already wires it.
• If you only need metrics or only traces, pass null to the unused configurator delegate.

Reference

• Source: https://github.com/loresoft/Arbiter/tree/main/src/Arbiter.OpenTelemetry
• Server extension: https://github.com/loresoft/Arbiter/blob/main/src/Arbiter.OpenTelemetry.Server/HostApplicationBuilderExtensions.cs