diff --git a/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.AppHost/Fitnet.Contracts.AppHost.csproj b/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.AppHost/Fitnet.Contracts.AppHost.csproj
new file mode 100644
index 00000000..dfeb5025
--- /dev/null
+++ b/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.AppHost/Fitnet.Contracts.AppHost.csproj
@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Sdk Name="Aspire.AppHost.Sdk" Version="13.0.0" />
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Aspire.Hosting.AppHost" />
+    <PackageReference Include="Aspire.Hosting.PostgreSQL" />
+    <PackageReference Include="Aspire.Hosting.RabbitMQ" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Fitnet.Contracts\Fitnet.Contracts.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.AppHost/Program.cs b/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.AppHost/Program.cs
new file mode 100644
index 00000000..1248f767
--- /dev/null
+++ b/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.AppHost/Program.cs
@@ -0,0 +1,21 @@
+using Projects;
+
+var builder = DistributedApplication.CreateBuilder(args);
+
+var postgres = builder.AddPostgres("postgres")
+    .WithImage("postgres", "14.3")
+    .WithPgAdmin();
+
+var fitnetDatabase = postgres.AddDatabase("fitnetsdb", "fitnet");
+
+var rabbitmq = builder.AddRabbitMQ("rabbitmq")
+    .WithManagementPlugin();
+
+builder.AddProject<Fitnet_Contracts>("fitnet-contracts-microservice")
+    .WithEnvironment("ASPNETCORE_ENVIRONMENT", "Development")
+    .WithReference(fitnetDatabase, "Database__ConnectionString")
+    .WithReference(rabbitmq, "EventBus__ConnectionString")
+    .WaitFor(postgres)
+    .WaitFor(rabbitmq);
+
+await builder.Build().RunAsync();
diff --git a/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.AppHost/appsettings.json b/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.AppHost/appsettings.json
new file mode 100644
index 00000000..c06aa74a
--- /dev/null
+++ b/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.AppHost/appsettings.json
@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning",
+      "Aspire.Hosting.DistributedApplication": "Information"
+    }
+  }
+}
diff --git a/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.slnx b/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.slnx
index 5d06360a..ef063611 100644
--- a/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.slnx
+++ b/Chapter-4-applying-tactical-domain-driven-design/Fitnet.Contracts/Src/Fitnet.Contracts.slnx
@@ -6,6 +6,7 @@
   </Folder>
   <Project Path="Fitnet.Contracts.Api/Fitnet.Contracts.Api.csproj" />
   <Project Path="Fitnet.Contracts.Application/Fitnet.Contracts.Application.csproj" />
+  <Project Path="Fitnet.Contracts.AppHost/Fitnet.Contracts.AppHost.csproj" />
   <Project Path="Fitnet.Contracts.Core/Fitnet.Contracts.Core.csproj" />
   <Project Path="Fitnet.Contracts.Infrastructure/Fitnet.Contracts.Infrastructure.csproj" />
   <Project Path="Fitnet.Contracts.IntegrationEvents/Fitnet.Contracts.IntegrationEvents.csproj" />