.NET Aspire

What is Aspire?

.NET Aspire is an opinionated, cloud-ready stack for building observable, production-ready, distributed applications. It provides:

• Orchestration - Coordinate multi-service apps with AppHost
• Components - Pre-configured NuGet packages for common services (Redis, PostgreSQL, RabbitMQ, etc.)
• Tooling - Dashboard for logs, traces, metrics; CLI for management
• Service Defaults - Shared configuration for health checks, telemetry, resilience

AppHost (Orchestrator)

// MyApp.AppHost/Program.cs
var builder = DistributedApplication.CreateBuilder(args);

// Infrastructure resources
var postgres = builder.AddPostgres("postgres").WithDataVolume().WithPgAdmin();
var redis = builder.AddRedis("redis").WithRedisInsight();
var rabbitmq = builder.AddRabbitMQ("messaging").WithManagementPlugin();

// Databases
var appDb = postgres.AddDatabase("appdb");

// Projects (services)
var api = builder.AddProject<Projects.Api>("api")
    .WithReference(appDb)
    .WithReference(redis)
    .WithReference(rabbitmq)
    .WithExternalHttpEndpoints();

var web = builder.AddProject<Projects.Web>("web")
    .WithReference(api)
    .WithReference(redis)
    .WithExternalHttpEndpoints();

var worker = builder.AddProject<Projects.Worker>("worker")
    .WithReference(rabbitmq)
    .WithReference(appDb);

builder.Build().Run();

Service Defaults

// ServiceDefaults/Extensions.cs (shared project)
public static IHostApplicationBuilder AddServiceDefaults(this IHostApplicationBuilder builder)
{
    builder.ConfigureOpenTelemetry();
    builder.AddDefaultHealthChecks();
    builder.Services.AddServiceDiscovery();

    builder.Services.ConfigureHttpClientDefaults(http =>
    {
        http.AddStandardResilienceHandler();
        http.AddServiceDiscovery();
    });

    return builder;
}

Component Integrations

Component	NuGet Package	AddXxx Method
PostgreSQL (EF)	Aspire.Npgsql.EntityFrameworkCore.PostgreSQL	AddNpgsqlDbContext<T>()
SQL Server (EF)	Aspire.Microsoft.EntityFrameworkCore.SqlServer	AddSqlServerDbContext<T>()
Redis Cache	Aspire.StackExchange.Redis.DistributedCaching	AddRedisDistributedCache()
Redis Output Cache	Aspire.StackExchange.Redis.OutputCaching	AddRedisOutputCache()
RabbitMQ	Aspire.RabbitMQ.Client	AddRabbitMQClient()
Azure Service Bus	Aspire.Azure.Messaging.ServiceBus	AddAzureServiceBusClient()
Azure Blob Storage	Aspire.Azure.Storage.Blobs	AddAzureBlobClient()
Cosmos DB	Aspire.Microsoft.Azure.Cosmos	AddAzureCosmosClient()

Dashboard

The Aspire dashboard provides:

• Structured logs from all services
• Distributed traces across service boundaries
• Metrics (request rates, latencies, error rates)
• Resource status and health checks

Access at: https://localhost:18888 (default)

Deployment

# Deploy to Azure Container Apps
azd init
azd provision  # Creates Azure resources
azd deploy     # Deploys all services

# Or use Aspire CLI
aspire publish --publisher azure

Key Patterns

• Every service project calls builder.AddServiceDefaults()
• Use WithReference() to establish service dependencies
• Use WithExternalHttpEndpoints() for publicly accessible services
• Service discovery uses https+http://service-name URIs
• All telemetry is automatically correlated across services