.NET

Integration

Instrument your .NET applications to send traces, logs, and metrics to Kopai.

Installation

dotnet add package OpenTelemetry.Extensions.Hosting
dotnet add package OpenTelemetry.Instrumentation.AspNetCore
dotnet add package OpenTelemetry.Exporter.OpenTelemetryProtocol

Basic Setup

Add OpenTelemetry to your ASP.NET Core application:

using OpenTelemetry.Exporter;
using OpenTelemetry.Logs;
using OpenTelemetry.Metrics;
using OpenTelemetry.Resources;
using OpenTelemetry.Trace;

var builder = WebApplication.CreateBuilder(args);

var endpoint = Environment.GetEnvironmentVariable("OTEL_EXPORTER_OTLP_ENDPOINT")
    ?? "http://localhost:4318";
var serviceName = Environment.GetEnvironmentVariable("OTEL_SERVICE_NAME")
    ?? "my-service";

// Setup Traces and Metrics
builder.Services.AddOpenTelemetry()
    .ConfigureResource(r => r.AddService(serviceName))
    .WithTracing(tracing => tracing
        .AddAspNetCoreInstrumentation()
        .AddOtlpExporter(opts =>
        {
            opts.Endpoint = new Uri($"{endpoint}/v1/traces");
            opts.Protocol = OtlpExportProtocol.HttpProtobuf;
        }))
    .WithMetrics(metrics => metrics
        .AddAspNetCoreInstrumentation()
        .AddOtlpExporter(opts =>
        {
            opts.Endpoint = new Uri($"{endpoint}/v1/metrics");
            opts.Protocol = OtlpExportProtocol.HttpProtobuf;
        }));

// Setup Logs
builder.Logging.AddOpenTelemetry(logging =>
{
    logging.SetResourceBuilder(ResourceBuilder.CreateDefault().AddService(serviceName));
    logging.AddOtlpExporter(opts =>
    {
        opts.Endpoint = new Uri($"{endpoint}/v1/logs");
        opts.Protocol = OtlpExportProtocol.HttpProtobuf;
    });
});

Important: Use OtlpExportProtocol.HttpProtobuf and append the signal path (/v1/traces, /v1/logs, /v1/metrics) to the endpoint.

Running Your Application

Set the required environment variables and run:

export OTEL_EXPORTER_OTLP_ENDPOINT="https://otlp.kopai.app"
export OTEL_SERVICE_NAME="my-service"
dotnet run

Variable	Description
OTEL_EXPORTER_OTLP_ENDPOINT	Kopai OTLP endpoint
OTEL_SERVICE_NAME	Name shown in Kopai UI

Sending Headers

For authentication, add headers to the exporter:

opts.Headers = "Authorization=Bearer YOUR_TOKEN";

Working Example

For a complete working example:

.NET Example