diff --git a/Backend.Tests/Backend.Tests.csproj b/Backend.Tests/Backend.Tests.csproj
new file mode 100644
index 0000000..4a1d69a
--- /dev/null
+++ b/Backend.Tests/Backend.Tests.csproj
@@ -0,0 +1,28 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.*" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+    <PackageReference Include="xunit" Version="2.5.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Backend\Backend.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/Backend/Backend.csproj b/Backend/Backend.csproj
new file mode 100644
index 0000000..7b58c45
--- /dev/null
+++ b/Backend/Backend.csproj
@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.29" />
+    <PackageReference Include="Microsoft.ML.OnnxRuntime" Version="1.19.*" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.6.2" />
+  </ItemGroup>
+
+</Project>
diff --git a/Backend/Backend.http b/Backend/Backend.http
new file mode 100644
index 0000000..95be889
--- /dev/null
+++ b/Backend/Backend.http
@@ -0,0 +1,6 @@
+@Backend_HostAddress = http://localhost:5281
+
+GET {{Backend_HostAddress}}/weatherforecast/
+Accept: application/json
+
+###
diff --git a/Backend/Program.cs b/Backend/Program.cs
new file mode 100644
index 0000000..f0282f0
--- /dev/null
+++ b/Backend/Program.cs
@@ -0,0 +1,5 @@
+// Placeholder. Rewritten in Task 6.
+var builder = WebApplication.CreateBuilder(args);
+var app = builder.Build();
+app.MapGet("/", () => "GameCli Backend placeholder");
+app.Run();
diff --git a/Backend/Properties/launchSettings.json b/Backend/Properties/launchSettings.json
new file mode 100644
index 0000000..61f1f13
--- /dev/null
+++ b/Backend/Properties/launchSettings.json
@@ -0,0 +1,31 @@
+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:7830",
+      "sslPort": 0
+    }
+  },
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "applicationUrl": "http://localhost:5281",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}
diff --git a/Backend/appsettings.json b/Backend/appsettings.json
new file mode 100644
index 0000000..8522165
--- /dev/null
+++ b/Backend/appsettings.json
@@ -0,0 +1,13 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*",
+  "Lander": {
+    "CliPath": "publish/GameCli/GameCli",
+    "ModelPath": "models/ppo_lander.onnx"
+  }
+}
diff --git a/GameCli.sln b/GameCli.sln
index e08854a..bace6b6 100644
--- a/GameCli.sln
+++ b/GameCli.sln
@@ -7,6 +7,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "GameCli", "GameCli\GameCli.
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "GameCli.Tests", "GameCli.Tests\GameCli.Tests.csproj", "{C0C7008D-E7BE-47E2-8CBB-2630AF817CC7}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Backend", "Backend\Backend.csproj", "{69BB68BF-2864-497E-993C-CB9D67A21041}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Backend.Tests", "Backend.Tests\Backend.Tests.csproj", "{BA5C4CD7-66EC-4512-8155-D81E48A6A568}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -41,6 +45,30 @@ Global
 		{C0C7008D-E7BE-47E2-8CBB-2630AF817CC7}.Release|x64.Build.0 = Release|Any CPU
 		{C0C7008D-E7BE-47E2-8CBB-2630AF817CC7}.Release|x86.ActiveCfg = Release|Any CPU
 		{C0C7008D-E7BE-47E2-8CBB-2630AF817CC7}.Release|x86.Build.0 = Release|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Debug|x64.Build.0 = Debug|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Debug|x86.Build.0 = Debug|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Release|Any CPU.Build.0 = Release|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Release|x64.ActiveCfg = Release|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Release|x64.Build.0 = Release|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Release|x86.ActiveCfg = Release|Any CPU
+		{69BB68BF-2864-497E-993C-CB9D67A21041}.Release|x86.Build.0 = Release|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Debug|x64.Build.0 = Debug|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Debug|x86.Build.0 = Debug|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Release|Any CPU.Build.0 = Release|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Release|x64.ActiveCfg = Release|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Release|x64.Build.0 = Release|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Release|x86.ActiveCfg = Release|Any CPU
+		{BA5C4CD7-66EC-4512-8155-D81E48A6A568}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE