Configuration

One registration

AddBitBelemetryServices follows the Options pattern and is idempotent: call it in every project that hosts Blazor, and every configure callback passed across calls runs, in order, on the same BelemetryOptions. A shared method called from both the server and the client project keeps the two in step, and each project adds what is its own on top. Every line below sets an option to something other than its default, or spells a default out where it is a decision worth reading in code.

using Bit.Belemetry;
using Microsoft.Extensions.Logging;

builder.Services.AddBitBelemetryServices(options =>
{
    // The resource: who is sending. service.name is what every backend groups by.
    options.ServiceName = "MyShop";
    options.ServiceNamespace = "contoso";
    options.Environment = builder.Environment.EnvironmentName;
    options.ResourceAttributes["deployment.region"] = "westeurope";

    // What may be collected at all. A feature is sent only when it is here AND the user granted it.
    options.Features = BelemetryFeatures.All & ~BelemetryFeatures.Interactions;

    // Consent: opt-in, so nothing is sent before the user decides - except error reports,
    // which this app covers by legitimate interest.
    options.Consent.Default = BelemetryFeatures.Errors;
    options.Consent.Persist = true;
    options.Consent.HonorGlobalPrivacyControl = true;

    // Privacy rules, applied on both sides before anything is queued.
    options.Privacy.RedactQueryParameters.Add("voucher");
    options.Privacy.BlockedAttributes.Add("user_agent.original");

    // The browser script.
    options.Browser.Transport = BelemetryBrowserTransport.Auto;      // Relay in Hybrid, Direct elsewhere
    options.Browser.ResourceTiming = true;
    options.Browser.PropagateTraceContextTo.Add(@"^https://api\.contoso\.com/");
    options.Browser.IgnoreUrls.Add("/health");
    options.Browser.SessionSampleRatio = 0.5;

    // The .NET collectors.
    options.Logs.MinimumLevel = LogLevel.Information;
    options.Traces.Sources.Add("MyShop*");
    options.Traces.SamplingRatio = 0.25;
    options.Metrics.Meters.Add("MyShop*");
    options.Metrics.ExportInterval = TimeSpan.FromSeconds(30);

    // Delivery.
    options.Batch.FlushInterval = TimeSpan.FromSeconds(5);
    options.Persistence.MaxAge = TimeSpan.FromHours(24);

    // The server's own telemetry (ASP.NET Core hosts only), governed by Server.Features.
    options.Server.CollectDotnetTelemetry = true;

    // Exporters: any number, combined.
    options.AddOtlpExporter("http://otel-collector:4318", otlp =>
    {
        otlp.Protocol = BelemetryOtlpProtocol.HttpProtobuf;
        otlp.BrowserEndpoint = new Uri("https://otel.contoso.com");  // public, CORS-enabled
        otlp.Compression = BelemetryCompression.Gzip;
    });

    options.AddAzureMonitorExporter(builder.Configuration["ApplicationInsights:ConnectionString"]!, azure =>
    {
        azure.Signals = BelemetrySignals.Traces | BelemetrySignals.Logs;
    });

    if (builder.Environment.IsDevelopment())
    {
        options.AddConsoleExporter();
        options.Debug = true;
        options.Browser.Debug = true;
    }
});

From appsettings

Every option can come from configuration instead. Bind the section the way a trimmed or AOT app binds any options: the configuration binder's source generator (EnableConfigurationBindingGenerator in the app's project) handles BelemetryOptions without reflection, and Belemetry takes no dependency on the binder. What only code can add - custom exporters, processors, a token provider - goes on top.

// Program.cs - the binder's source generator (EnableConfigurationBindingGenerator) makes this trim- and AOT-safe.
builder.Services.AddBitBelemetryServices(options =>
{
    builder.Configuration.GetSection("Belemetry").Bind(options);
    options.AddExporter(new MyExporter());   // what only code can add: custom exporters, processors, token providers
});

Two binder rules worth knowing: a bound list adds to the option's defaults (Privacy.RedactQueryParameters keeps its built-in names and gains yours), and a bound array replaces nothing either, which is why Metrics.HistogramBoundaries is empty by default and means the OpenTelemetry defaults until you set it. Enums and flags bind by name ("Features": "Errors, Logs, Traces"), TimeSpans by hh:mm:ss.

Per-category log levels

Logs.MinimumLevel is the floor: nothing below it is collected, whatever a category says. Above it, per-category levels use the standard logging configuration, under the Belemetry provider alias, so they can differ from what the console logger shows.

{
  "Logging": {
    "Belemetry": {
      "LogLevel": {
        "Default": "Information",
        "Microsoft.AspNetCore": "Warning",
        "MyShop.Polling": "Warning"
      }
    }
  }
}

Environment variables

Outside the browser, with options.UseEnvironmentVariables (on by default), the standard variables fill in what the code leaves unset - this is how the .NET Aspire AppHost and most container platforms wire telemetry in. Explicit options always win.

BelemetryOptions

BelemetryConsentOptions

options.Consent - see Consent and GDPR.

BelemetryPrivacyOptions

options.Privacy - see Privacy.

BelemetryBrowserOptions

options.Browser - see Browser instrumentation and Transport.

BelemetryLoggingOptions

options.Logs - see .NET instrumentation.

BelemetryTracingOptions

options.Traces.

BelemetryMetricsOptions

options.Metrics.

BelemetryBatchOptions

options.Batch - the .NET pipeline. The browser script batches with options.Browser.FlushInterval, MaxBatchSize and MaxQueueSize.

BelemetryPersistenceOptions

options.Persistence - see Offline persistence.

BelemetryServerOptions

options.Server - see Server pipeline.

BelemetryOtlpExporterOptions

Configured by options.AddOtlpExporter(...) - see OTLP.

BelemetryAzureMonitorExporterOptions

Configured by options.AddAzureMonitorExporter(...) - see Azure Monitor.

BelemetryConsoleExporterOptions

Configured by options.AddConsoleExporter(...) - see Console, in-memory and custom.

BelemetryFeatures

BelemetryHostKind

BelemetryBrowserTransport

BelemetryOtlpProtocol

BelemetryCompression

BelemetrySignals

BelemetryMetricTemporality