With .NET Aspire, you can orchestrate a full AI chat system — backend, model, data store, and frontend — from one place.
This sample shows how Aspire can manage a large language model (LLM), a Postgres conversation database, a Redis message broker, and a React-based chat UI, all within a single orchestration file.

Folder layout

11_AIChat/
├─ AppHost/ # Aspire orchestration
├─ ChatApi/ # .NET 9 backend API (SignalR + EF)
├─ chatui/ # React + Vite frontend
├─ ServiceDefaults/ # shared settings (logging, health, OTEL)
└─ README.md

Overview

This example demonstrates:

• AI model orchestration with local Ollama or hosted OpenAI
• Postgres database for conversation history
• Redis for live chat streaming and cancellation coordination
• Chat API using ASP.NET Core + SignalR
• React/Vite frontend for real-time conversations
• Full Docker Compose publishing via Aspire

The AppHost (orchestration)

AppHost/Program.cs

var builder = DistributedApplication.CreateBuilder(args);

// Publish this as a Docker Compose application
builder.AddDockerComposeEnvironment("env")
       .WithDashboard(db => db.WithHostPort(8085))
       .ConfigureComposeFile(file =>
       {
           file.Name = "aspire-ai-chat";
       });

// The AI model definition
var model = builder.AddAIModel("llm");

if (OperatingSystem.IsMacOS())
{
    model.AsOpenAI("gpt-4o-mini");
}
else
{
    model.RunAsOllama("phi4", c =>
    {
        c.WithGPUSupport();
        c.WithLifetime(ContainerLifetime.Persistent);
    })
    .PublishAsOpenAI("gpt-4o-mini");
}

// Postgres for conversation history
var pgPassword = builder.AddParameter("pg-password", secret: true);

var db = builder.AddPostgres("pg", password: pgPassword)
                .WithDataVolume(builder.ExecutionContext.IsPublishMode ? "pgvolume" : null)
                .WithPgAdmin()
                .AddDatabase("conversations");

// Redis for message streams + coordination
var cache = builder.AddRedis("cache").WithRedisInsight();

// Chat API service
var chatapi = builder.AddProject<Projects.ChatApi>("chatapi")
                     .WithReference(model).WaitFor(model)
                     .WithReference(db).WaitFor(db)
                     .WithReference(cache).WaitFor(cache);

// Frontend served via Vite
builder.AddNpmApp("chatui", "../chatui")
       .WithNpmPackageInstallation()
       .WithHttpEndpoint(env: "PORT")
       .WithReverseProxy(chatapi.GetEndpoint("http"))
       .WithExternalHttpEndpoints()
       .WithOtlpExporter()
       .WithEnvironment("BROWSER", "none");

builder.Build().Run();

Continue reading “Building an AI Chat app with .NET Aspire, Ollama/OpenAI, Postgres, and Redis” →