.NET MAUI SDK observability reference

This LaunchDarkly observability plugin is available for early accessThis LaunchDarkly observability plugin is currently available in Early Access, and APIs are subject to change until a 1.x version is released.

This topic documents how to get started with the LaunchDarkly observability and session replay SDK for .NET MAUI. The .NET MAUI SDK supports observability for error monitoring and logging, and session replay for capturing UI snapshots. It provides cross-platform support for both Android and iOS through .NET MAUI’s native platform bindings.

SDK quick linksLaunchDarkly SDKs are open source. In addition to this reference guide, we provide source, API reference documentation, and a sample application:

Resource	Location
GitHub repository	LaunchDarkly.SessionReplay
Published package	NuGet

Prerequisites and dependencies

This SDK requires:

.NET 9 or .NET 10 with the MAUI workload installed
Android API level 23 or higher (Android 6.0, Marshmallow)
iOS 15 or higher

Get started

Follow these steps to get started:

Install the SDK
Initialize the SDK
Enable HTTP request tracing
Configure observability options
Configure session replay
Configure session replay privacy options
Use custom masking
Explore supported features
Review observability data in LaunchDarkly

Install the SDK

Add the LaunchDarkly.SessionReplay NuGet package to your MAUI project:

dotnet add package LaunchDarkly.SessionReplay

<PackageReference Include="LaunchDarkly.SessionReplay" Version="0.*" />

After installing, run dotnet clean before building. This is especially important for iOS targets, as stale build artifacts can cause issues. If you encounter dependency resolution problems, run dotnet restore first:

dotnet restore
dotnet clean
dotnet build

Visual Studio with Android SDK on WindowsVisual Studio on Windows can have issues installing the SDK due to the Android SDK being in a system-protected directory. If you encounter build errors related to Android SDK access, you may need to move the Android SDK to a user-writable location.For detailed instructions, read the Android SDK relocation guide for Windows.

Then, import the SDK namespaces in your code:

using LaunchDarkly.SessionReplay;
using LaunchDarkly.Sdk.Client;
using LaunchDarkly.Sdk.Client.Integrations;
using LaunchDarkly.Observability;

Initialize the SDK

Initialize the SDK by registering the ObservabilityPlugin on the LaunchDarkly client configuration. Call this during your app’s startup, typically in MauiProgram.cs. The ObservabilityPlugin handles both observability and session replay. Register it using the PluginConfigurationBuilder to integrate it directly with the LaunchDarkly client lifecycle. To turn on session replay, pass a SessionReplayOptions object as the plugin’s second argument. To learn more, read Configure session replay.

.NET MAUI observability SDK credentialsThe .NET MAUI observability SDK uses a mobile key. Keys are specific to each project and environment. They are available on the SDK keys page under Settings. To learn more about key types, read Keys.Mobile keys are not secret and you can expose them in your client-side code without risk. However, never embed a server-side SDK key into a client-side application.

Here’s how to initialize the SDK:

using LaunchDarkly.Observability;
using LaunchDarkly.Sdk;
using LaunchDarkly.Sdk.Client;
using LaunchDarkly.Sdk.Client.Integrations;

public static class MauiProgram
{
  public static MauiApp CreateMauiApp()
  {
      var builder = MauiApp.CreateBuilder();

      // ... other configuration ...

      var mobileKey = "example-mobile-key";

      var ldConfig = Configuration.Builder(mobileKey, ConfigurationBuilder.AutoEnvAttributes.Enabled)
          .Plugins(new PluginConfigurationBuilder()
              .Add(new ObservabilityPlugin(new ObservabilityOptions(
                  isEnabled: true,
                  serviceName: "my-maui-app"
              )))
          ).Build();

      var context = Context.New("example-user-key");
      var client = LdClient.Init(ldConfig, context, TimeSpan.FromSeconds(10));

      return builder.Build();
  }
}

Enable HTTP request tracing

The SDK automatically creates spans for outgoing HTTP requests made through HttpClient. For these spans to be recorded, set HttpActivityPropagationSupport to true in your app’s project file. Here is an example:

<PropertyGroup>
<HttpActivityPropagationSupport>true</HttpActivityPropagationSupport>
</PropertyGroup>

The .NET Android SDK sets HttpActivityPropagationSupport to false by default in every build configuration, and the .NET iOS SDK sets it to false in Release builds. While it is false, the trimmer removes the System.Net.Http diagnostics that the observability SDK listens to. As a result, the SDK records no HTTP spans, even if you enable NetworkRequests instrumentation. The SDK cannot turn this setting on at runtime.

Configure observability options

You can customize the observability behavior by passing an ObservabilityOptions object to the ObservabilityPlugin constructor. Here is an example:

var ldConfig = Configuration.Builder(mobileKey, ConfigurationBuilder.AutoEnvAttributes.Enabled)
  .Plugins(new PluginConfigurationBuilder()
      .Add(new ObservabilityPlugin(new ObservabilityOptions(
          isEnabled: true,
          serviceName: "my-maui-app",
          serviceVersion: "2.4.0",
          customHeaders: new Dictionary<string, string> { { "X-Proxy-Token", "example-token" } },
          logsApiLevel: ObservabilityLogLevel.Warn
      )))
  ).Build();

The available ObservabilityOptions configuration options are:

IsEnabled: Whether the SDK records observability telemetry. Defaults to true.
ServiceName: The service name for the application. Defaults to "observability-maui".
ServiceVersion: The version of the service. If you do not set it, the SDK reports your app’s version, from AppInfo.Current.VersionString.
OtlpEndpoint: The endpoint URL for the OpenTelemetry Protocol (OTLP) exporter. Defaults to the LaunchDarkly endpoint. Override it to send data through a proxy.
BackendUrl: The backend URL for the observability service. Defaults to the LaunchDarkly backend.
ContextFriendlyName: An optional friendly name for the user context, displayed in the LaunchDarkly UI.
Attributes: Additional resource attributes to attach to every exported signal, such as deployment.environment.
CustomHeaders: Additional HTTP headers to add to OTLP exports, for example, for a proxy or for authentication.
LogsApiLevel: The minimum severity of logs to export. Uses the ObservabilityLogLevel enum, whose values match the OpenTelemetry severity numbers, from Trace to Fatal4. Set it to ObservabilityLogLevel.None to turn off log export. Defaults to ObservabilityLogLevel.Info.
Instrumentation: An InstrumentationOptions object with two settings, NetworkRequests and LaunchTimes, that turn automatic instrumentation of HttpClient requests and app launch times on or off. Both default to true.

Default service version changed in version 0.13.0In SDK versions earlier than 0.13.0, ServiceVersion defaults to "0.1.0". Starting in version 0.13.0, apps that do not set ServiceVersion report their own app version instead. The ObservabilityOptions.DefaultServiceVersion constant is obsolete.

After the SDK initializes, LDObserve.NativeVersion returns the version of the underlying native observability SDK. Include it when you contact LaunchDarkly Support. For more information on plugin options, read Configuration for client-side observability.

Configure session replay

The .NET MAUI SDK supports session replay, which captures snapshots of your app’s UI at regular intervals. This lets you visually review user sessions in LaunchDarkly to better understand user behavior and diagnose issues. To turn on session replay, pass a SessionReplayOptions object as the second argument to the ObservabilityPlugin constructor. Here’s how to configure session replay:

var ldConfig = Configuration.Builder(mobileKey, ConfigurationBuilder.AutoEnvAttributes.Enabled)
  .Plugins(new PluginConfigurationBuilder()
      .Add(new ObservabilityPlugin(
          new ObservabilityOptions(
              isEnabled: true,
              serviceName: "my-maui-app"
          ),
          new SessionReplayOptions(
              isEnabled: true,
              sampleRate: 0.25,
              privacy: new SessionReplayOptions.PrivacyOptions(
                  maskTextInputs: true,
                  maskWebViews: false,
                  maskLabels: false
              )
          )
      ))
  ).Build();

The available SessionReplayOptions configuration options are:

IsEnabled: Enables or disables session replay. Defaults to true.
ServiceName: The service name for session replay telemetry. Defaults to "sessionreplay-dotnet".
Privacy: Controls how UI elements are masked in the replay. To learn more, read Configure session replay privacy options.
SampleRate: The probability, from 0.0 to 1.0, that the SDK records a session. For example, 0.25 records about a quarter of sessions. Defaults to 1.0.
FrameRate: The target capture rate, in frames per second. Defaults to 1.0.
Scale: The capture resolution. 1.0 is 1x (160 dots per inch), 2.0 is 2x, and so on. Higher values capture more detail but produce larger frames. Defaults to 1.0.
ImageQuality: The JPEG quality of exported frames, from 0.0 (smallest) to 1.0 (best). Defaults to 0.3.

Configure session replay privacy options

The PrivacyOptions class controls how UI elements are masked during session replay. By default, text inputs are masked to protect user privacy. Here’s how to configure privacy settings:

var replay = new SessionReplayOptions(
  isEnabled: true,
  privacy: new SessionReplayOptions.PrivacyOptions(
      maskTextInputs: true,
      maskWebViews: false,
      maskLabels: false,
      maskImages: false,
      minimumAlpha: 0.02
  )
);

The available privacy options are:

MaskTextInputs: When true, masks all text input fields. Defaults to true.
MaskWebViews: When true, masks the contents of web views. Web views are rendered as blank rectangles in session replays. Defaults to false.
MaskLabels: When true, masks all text labels. Defaults to false.
MaskImages: When true, masks all images. Defaults to false.
MinimumAlpha: Minimum alpha value for view visibility in recordings. Views with alpha below this threshold are not captured. Defaults to 0.02.

Common privacy configurations

For maximum privacy (recommended for production):

var privacy = new SessionReplayOptions.PrivacyOptions(
  maskTextInputs: true,
  maskWebViews: true,
  maskLabels: true,
  maskImages: true
);

For debugging or development, you can turn masking off:

var privacy = new SessionReplayOptions.PrivacyOptions(
  maskTextInputs: false,
  maskWebViews: false,
  maskLabels: false,
  maskImages: false
);

For selective masking, you can mask inputs but show regular text and images:

var privacy = new SessionReplayOptions.PrivacyOptions(
  maskTextInputs: true,
  maskWebViews: true,
  maskLabels: false,
  maskImages: false
);

For more information on session replay configuration, read Configuration for session replay.

Use custom masking

In addition to the privacy profile settings, you can explicitly mask or unmask individual MAUI views using the LDMask() and LDUnmask() extension methods. This gives you fine-grained control over which UI elements are captured in session replay recordings. Here is an example:

using LaunchDarkly.SessionReplay;

// Mask a sensitive field in session replay
var passwordEntry = new Entry { Placeholder = "Password", IsPassword = true };
passwordEntry.LDMask();

// Unmask a field that would otherwise be masked by privacy settings
var publicInfoLabel = new Label { Text = "Public information" };
publicInfoLabel.LDUnmask();

Handler must be attachedThe LDMask() and LDUnmask() methods work by accessing the underlying native platform view. The MAUI view’s handler must be attached before calling these methods. Call them after the view has been added to the visual tree, such as in a page’s Appearing event or in OnHandlerChanged. Before the handler is attached, these methods have no effect.

The .LDMask() and .LDUnmask() extension methods work on any MAUI View, and they apply to the underlying native view on both Android and iOS.

Explore supported features

The .NET MAUI observability SDK supports the following features. After the SDK is initialized, you can access these from within your application:

Using .NET System.Diagnostics

As with other LaunchDarkly observability SDK plugins, the .NET MAUI observability plugin supports OpenTelemetry operations using the following span methods.

Method	Description	Return value
`LDObserve.StartActiveSpan(name)`	Uses the current active span as its parent.	`TelemetrySpan`
`LDObserve.StartActiveSpan(name, parentContext)`	Uses the provided `SpanContext` as its parent.	`TelemetrySpan`
`LDObserve.StartActiveSpan(name, kind, parentContext)`	Uses the provided `SpanContext` with a custom kind as its parent.	`TelemetrySpan`
`LDObserve.StartRootSpan(name)`	Creates a new trace.	`TelemetrySpan`
`LDObserve.GetTracer()`	Returns an OpenTelemetry tracer.	`Tracer`

If your .NET application already uses Microsoft’s System.Diagnostics API, LaunchDarkly’s observability plugin provides the following methods help you continue using your existing trace code.

Method	Description	Return value
`LDObserve.StartActivity(name)`	Uses the current activity as its parent.	`Activity?`
`LDObserve.StartRootActivity(name)`	Creates a new trace.	`Activity?`
`LDObserve.GetActivitySource()`	Returns an `ActivitySource` to create and start `Activity` objects.	`ActivitySource`

Here’s an example of using the LaunchDarkly observability plugin with the System.Diagnostics API:

using System.Diagnostics;

using var activity = LDObserve.StartActivity("api_request");
activity?.SetTag("endpoint", "/api/users");
activity?.SetTag("method", "GET");
activity?.AddEvent(new ActivityEvent("cache.miss"));

// Create a root activity (no parent), equivalent to StartRootSpan in OpenTelemetry
using var root = LDObserve.StartRootActivity("independent-operation");
root?.SetTag("sequence", "1");

// Or, get the ActivitySource directly for full control
var source = LDObserve.GetActivitySource();
using var custom = source.StartActivity("custom", ActivityKind.Client);

Distributed tracing

To implement distributed tracing, all spans generated across different function calls and services for the same user request must share the same context. This section shows techniques for nesting spans and propagating span contexts across services when using the .NET MAUI observability SDK.

Creating a root span

Creating a root span creates a new trace regardless of any current span context that might exist. Use StartRootSpan to create your initial trace and span context.

using var span = LDObserve.StartRootSpan("app-cold-start");
span.SetAttribute("launch_type", "cold");
span.SetAttribute("device_model", DeviceInfo.Model);
span.AddEvent("splash_rendered");

// ... initialization work ...

span.AddEvent("home_screen_ready");

Nesting spans

Use StartActiveSpan to create new spans using the parent span context. This pattern enables you to trace multi-step operations in the same application. The following example nests all newly-created spans under LoadProducts. The DeserializeJson span is further nested under FetchFromApi.

private async Task LoadProductsAsync()
{
  using var loadSpan = LDObserve.StartActiveSpan("LoadProducts");

  List<Product> products;
  using (var fetchSpan = LDObserve.StartActiveSpan("FetchFromApi"))
  {
      var response = await _httpClient.GetAsync("https://api.example.com/products");
      fetchSpan.SetAttribute("http.status_code", (int)response.StatusCode);
      var json = await response.Content.ReadAsStringAsync();

      using var parseSpan = LDObserve.StartActiveSpan("DeserializeJson");
      products = JsonSerializer.Deserialize<List<Product>>(json)!;
      parseSpan.SetAttribute("product_count", products.Count);
  }

  using (var renderSpan = LDObserve.StartActiveSpan("RenderUI"))
  {
      Products.Clear();
      foreach (var p in products)
          Products.Add(p);
  }
}

Propagating span context across threads

When work runs on a detached thread, for example, using Task.Run, the span context is lost. Use span.Context to capture the context and pass it to other threads.

private async void OnUploadClicked(object? sender, EventArgs e)
{
  var span = LDObserve.StartActiveSpan("UploadReport");
  span.SetAttribute("report.type", "daily");
  var capturedContext = span.Context;
  span.End();

  await Task.Run(() =>
  {
      // Activity.Current is null here -- pass capturedContext explicitly
      LDObserve.RecordLog(
          "Upload processing on background thread",
          Severity.Info,
          new Dictionary<string, object?> { { "thread", Environment.CurrentManagedThreadId } },
          spanContext: capturedContext);

      // ... heavy processing ...

      LDObserve.RecordLog(
          "Upload complete",
          Severity.Info,
          spanContext: capturedContext);
  });
}

Using spans with HttpClient

When calling a remote service you must preserve the current span context when creating new spans, or capture details of the service call in the current span. When InstrumentationOptions.NetworkRequests is enabled, every HttpClient request generates a System.Net.Http span automatically. This is the default behavior, but it requires the HttpActivityPropagationSupport project setting. To learn more, read Enable HTTP request tracing. If a custom span is active at call time, the HTTP span becomes its child. The following example automatically generates a new span for the HTTP GET call and nests it under the active SyncOrders span. You do not need to create a span for the HTTP call itself:

private async Task SyncOrdersAsync()
{
  using var span = LDObserve.StartActiveSpan("SyncOrders");
  span.SetAttribute("sync.direction", "pull");

  // The HTTP span for this GET is auto-created as a child of "SyncOrders"
  var response = await _httpClient.GetAsync("https://api.example.com/orders?since=yesterday");
  span.SetAttribute("http.status_code", (int)response.StatusCode);

  var orders = await response.Content.ReadFromJsonAsync<List<Order>>();
  span.SetAttribute("order_count", orders?.Count ?? 0);
}

As an alternative, you can wrap an HTTP call in a span to capture timing, status codes, and errors in a single trace unit.

private async Task<UserProfile?> FetchUserProfileAsync(string userId)
{
  using var span = LDObserve.StartActiveSpan("FetchUserProfile");
  span.SetAttribute("user.id", userId);
  span.SetAttribute("http.method", "GET");

  try
  {
      var url = $"https://api.example.com/users/{userId}";
      span.SetAttribute("http.url", url);

      var response = await _httpClient.GetAsync(url);
      span.SetAttribute("http.status_code", (int)response.StatusCode);

      if (!response.IsSuccessStatusCode)
      {
          span.SetStatus(Status.Error);
          span.SetAttribute("error.type", $"HTTP {response.StatusCode}");
          return null;
      }

      var profile = await response.Content.ReadFromJsonAsync<UserProfile>();
      span.SetStatus(Status.Ok);
      return profile;
  }
  catch (Exception ex)
  {
      span.RecordException(ex);
      span.SetStatus(Status.Error);
      throw;
  }
}

Additional distributed tracing techniques

Your application may also need to perform other, more advanced distributed tracing activities such as:

Correlating log entries within a span
Correlating log entries or across different threads
Recording span exceptions
Using the Activity API in place of OpenTelemetry methods

To learn more about these techniques, read the .NET MAUI Distributed Tracing Guide.

Review observability data in LaunchDarkly

After you initialize the SDK, your application automatically starts sending observability data back to LaunchDarkly, including errors, logs, and session replay recordings. You can review this information in the LaunchDarkly user interface. To learn how, read Observability.

​Prerequisites and dependencies

​Get started

​Install the SDK

​Initialize the SDK

​Enable HTTP request tracing

​Configure observability options

​Configure session replay

​Configure session replay privacy options

​Common privacy configurations

​Use custom masking

​Explore supported features

​Using .NET System.Diagnostics

​Distributed tracing

​Creating a root span

​Nesting spans

​Propagating span context across threads

​Using spans with HttpClient

​Additional distributed tracing techniques

​Review observability data in LaunchDarkly

Prerequisites and dependencies

Get started

Install the SDK

Initialize the SDK

Enable HTTP request tracing

Configure observability options

Configure session replay

Configure session replay privacy options

Common privacy configurations

Use custom masking

Explore supported features

Using .NET System.Diagnostics

Distributed tracing

Creating a root span

Nesting spans

Propagating span context across threads

Using spans with HttpClient

Additional distributed tracing techniques

Review observability data in LaunchDarkly