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.NET Aspire Seq component

  • Article

In this article, you learn how to use the .NET Aspire Seq component to add OpenTelemetry Protocol (OTLP) exporters that send logs and traces to a Seq Server. The component supports persistent logs and traces across application restarts via configuration.

Get started

To get started with the .NET Aspire Seq component, install the Aspire.Seq NuGet package.

dotnet add package Aspire.Seq

For more information, see dotnet add package or Manage package dependencies in .NET applications.

Example usage

In the Program.cs file of your projects, call the AddSeqEndpoint extension method to register OpenTelemetry Protocol exporters to send logs and traces to Seq and the .NET Aspire Dashboard. The method takes a connection name parameter.

builder.AddSeqEndpoint("seq");

App host usage

To model the Seq resource in the app host, install the Aspire.Hosting.Seq NuGet package.

dotnet add package Aspire.Hosting.Seq

In your app host project, register a Seq database and consume the connection using the following methods:

var seq = builder.AddSeq("seq");

var myService = builder.AddProject<Projects.MyService>()
                       .WithReference(seq);

Configuration

The .NET Aspire Seq component provides options to configure the connection to Seq.

Use configuration providers

The .NET Aspire Seq component supports Microsoft.Extensions.Configuration. It loads the SeqSettings from configuration by using the Aspire:Seq key. Example appsettings.json that configures some of the options:

{
  "Aspire": {
    "Seq": {
      "DisableHealthChecks": true,
      "ServerUrl": "http://localhost:5341"
    }
  }
}

Use inline delegates

You can pass the Action<SeqSettings> configureSettings delegate to set up some or all the options inline, for example to disable health checks from code:

builder.AddSeqEndpoint("seq", static settings => 
{
    settings.DisableHealthChecks  = true;
    settings.ServerUrl = "http://localhost:5341"
});

AppHost extensions

In your AppHost project, install the Aspire.Hosting.Seq library with NuGet:

dotnet add package Aspire.Hosting.Seq

Then, in the Program.cs file of the .AppHost project, register a Seq server and propagate its configuration using the following methods (note that you must accept the Seq End User Licence Agreement for Seq to start):

var seq = builder.AddSeq("seq");

var myService = builder.AddProject<Projects.MyService>()
                       .WithReference(seq);

In the Program.cs file of the MyService project, configure logging and tracing to Seq using the following code:

builder.AddSeqEndpoint("seq");

Persistent logs and traces

Register Seq with a data directory in your AppHost project to retain Seq's data and configuration across application restarts.

var seq = builder.AddSeq("seq", seqDataDirectory: "./seqdata");

The directory specified must already exist.

Seq in the .NET Aspire manifest

Seq isn't part of the .NET Aspire deployment manifest. It's recommended you set up a secure production Seq server outside of .NET Aspire.

Health checks

By default, .NET Aspire components enable health checks for all services. For more information, see .NET Aspire components overview.

The .NET Aspire Seq component handles the following:

  • Integrates with the /health HTTP endpoint, which specifies all registered health checks must pass for app to be considered ready to accept traffic.

Observability and telemetry

.NET Aspire components automatically set up Logging, Tracing, and Metrics configurations, which are sometimes known as the pillars of observability. For more information about component observability and telemetry, see .NET Aspire components overview. Depending on the backing service, some components may only support some of these features. For example, some components support logging and tracing, but not metrics. Telemetry features can also be disabled using the techniques presented in the Configuration section.

Logging

The .NET Aspire Seq component uses the following log categories:

  • Seq

See also