diff --git a/TeamsISO.sln b/TeamsISO.sln
index 9ff9eea..4917a30 100644
--- a/TeamsISO.sln
+++ b/TeamsISO.sln
@@ -7,6 +7,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{46E05E34-8A8
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine", "src\TeamsISO.Engine\TeamsISO.Engine.csproj", "{F0D24EAE-9225-4DC4-B3D2-6966077287A0}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine.NdiInterop", "src\TeamsISO.Engine.NdiInterop\TeamsISO.Engine.NdiInterop.csproj", "{E737E54B-73DE-4F74-909C-1F0F5CF82AC6}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -20,8 +22,13 @@ Global
 		{F0D24EAE-9225-4DC4-B3D2-6966077287A0}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{F0D24EAE-9225-4DC4-B3D2-6966077287A0}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{F0D24EAE-9225-4DC4-B3D2-6966077287A0}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E737E54B-73DE-4F74-909C-1F0F5CF82AC6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E737E54B-73DE-4F74-909C-1F0F5CF82AC6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E737E54B-73DE-4F74-909C-1F0F5CF82AC6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E737E54B-73DE-4F74-909C-1F0F5CF82AC6}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{F0D24EAE-9225-4DC4-B3D2-6966077287A0} = {46E05E34-8A87-4986-87D3-FE0DE4E05F44}
+		{E737E54B-73DE-4F74-909C-1F0F5CF82AC6} = {46E05E34-8A87-4986-87D3-FE0DE4E05F44}
 	EndGlobalSection
 EndGlobal
diff --git a/src/TeamsISO.Engine.NdiInterop/Placeholder.cs b/src/TeamsISO.Engine.NdiInterop/Placeholder.cs
new file mode 100644
index 0000000..08eb145
--- /dev/null
+++ b/src/TeamsISO.Engine.NdiInterop/Placeholder.cs
@@ -0,0 +1,9 @@
+namespace TeamsISO.Engine.NdiInterop;
+
+/// <summary>
+/// Phase A placeholder. The production P/Invoke implementations of <c>INdiInterop</c>
+/// will live in this assembly, added in Phase B.
+/// </summary>
+internal static class Placeholder
+{
+}
diff --git a/src/TeamsISO.Engine.NdiInterop/TeamsISO.Engine.NdiInterop.csproj b/src/TeamsISO.Engine.NdiInterop/TeamsISO.Engine.NdiInterop.csproj
new file mode 100644
index 0000000..b7908a0
--- /dev/null
+++ b/src/TeamsISO.Engine.NdiInterop/TeamsISO.Engine.NdiInterop.csproj
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <ItemGroup>
+    <ProjectReference Include="..\TeamsISO.Engine\TeamsISO.Engine.csproj" />
+  </ItemGroup>
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>