diff --git a/src/TeamsISO.Engine/Domain/Enums.cs b/src/TeamsISO.Engine/Domain/Enums.cs
new file mode 100644
index 0000000..e18418b
--- /dev/null
+++ b/src/TeamsISO.Engine/Domain/Enums.cs
@@ -0,0 +1,51 @@
+namespace TeamsISO.Engine.Domain;
+
+public enum NdiSourceKind
+{
+    Participant,
+    ActiveSpeaker,
+    Audio,
+    ScreenShare
+}
+
+public enum IsoState
+{
+    Idle,
+    Receiving,
+    Sending,
+    NoSignal,
+    Error
+}
+
+public enum AspectMode
+{
+    Pillarbox,
+    Letterbox,
+    Stretch
+}
+
+public enum AudioMode
+{
+    Auto,
+    Isolated,
+    Mixed
+}
+
+public enum TargetFramerate
+{
+    Fps23_976,
+    Fps24,
+    Fps25,
+    Fps29_97,
+    Fps30,
+    Fps50,
+    Fps59_94,
+    Fps60
+}
+
+public enum TargetResolution
+{
+    R720p,
+    R1080p,
+    R4K
+}
diff --git a/src/tests/TeamsISO.Engine.Tests/Domain/EnumSanityTests.cs b/src/tests/TeamsISO.Engine.Tests/Domain/EnumSanityTests.cs
new file mode 100644
index 0000000..1af3d28
--- /dev/null
+++ b/src/tests/TeamsISO.Engine.Tests/Domain/EnumSanityTests.cs
@@ -0,0 +1,40 @@
+using TeamsISO.Engine.Domain;
+
+namespace TeamsISO.Engine.Tests.Domain;
+
+public class EnumSanityTests
+{
+    [Fact]
+    public void NdiSourceKind_HasExpectedMembers()
+    {
+        var values = Enum.GetValues<NdiSourceKind>();
+        values.Should().Contain(new[]
+        {
+            NdiSourceKind.Participant,
+            NdiSourceKind.ActiveSpeaker,
+            NdiSourceKind.Audio,
+            NdiSourceKind.ScreenShare
+        });
+    }
+
+    [Fact]
+    public void IsoState_HasExpectedMembers()
+    {
+        var values = Enum.GetValues<IsoState>();
+        values.Should().Contain(new[]
+        {
+            IsoState.Idle,
+            IsoState.Receiving,
+            IsoState.Sending,
+            IsoState.NoSignal,
+            IsoState.Error
+        });
+    }
+
+    [Fact]
+    public void TargetFramerate_HasAllSupportedRates()
+    {
+        var values = Enum.GetValues<TargetFramerate>();
+        values.Should().HaveCount(8);
+    }
+}
diff --git a/src/tests/TeamsISO.Engine.Tests/GlobalUsings.cs b/src/tests/TeamsISO.Engine.Tests/GlobalUsings.cs
new file mode 100644
index 0000000..7b25ddd
--- /dev/null
+++ b/src/tests/TeamsISO.Engine.Tests/GlobalUsings.cs
@@ -0,0 +1,2 @@
+global using FluentAssertions;
+global using Xunit;