diff --git a/.idea/.idea.WinAppCommunity.Sdk/.idea/.gitignore b/.idea/.idea.WinAppCommunity.Sdk/.idea/.gitignore
new file mode 100644
index 0000000..f1cd8f1
--- /dev/null
+++ b/.idea/.idea.WinAppCommunity.Sdk/.idea/.gitignore
@@ -0,0 +1,13 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Rider ignored files
+/.idea.WinAppCommunity.Sdk.iml
+/contentModel.xml
+/projectSettingsUpdater.xml
+/modules.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
diff --git a/.idea/.idea.WinAppCommunity.Sdk/.idea/encodings.xml b/.idea/.idea.WinAppCommunity.Sdk/.idea/encodings.xml
new file mode 100644
index 0000000..df87cf9
--- /dev/null
+++ b/.idea/.idea.WinAppCommunity.Sdk/.idea/encodings.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding" addBOMForNewFiles="with BOM under Windows, with no BOM otherwise" />
+</project>
\ No newline at end of file
diff --git a/.idea/.idea.WinAppCommunity.Sdk/.idea/indexLayout.xml b/.idea/.idea.WinAppCommunity.Sdk/.idea/indexLayout.xml
new file mode 100644
index 0000000..7b08163
--- /dev/null
+++ b/.idea/.idea.WinAppCommunity.Sdk/.idea/indexLayout.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="UserContentModel">
+    <attachedFolders />
+    <explicitIncludes />
+    <explicitExcludes />
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/.idea.WinAppCommunity.Sdk/.idea/vcs.xml b/.idea/.idea.WinAppCommunity.Sdk/.idea/vcs.xml
new file mode 100644
index 0000000..35eb1dd
--- /dev/null
+++ b/.idea/.idea.WinAppCommunity.Sdk/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/src/IModifiableProject.cs b/src/IModifiableProject.cs
index 4dd19b7..abc00e4 100644
--- a/src/IModifiableProject.cs
+++ b/src/IModifiableProject.cs
@@ -3,7 +3,7 @@
 /// <summary>
 /// Represents a project that can be modified.
 /// </summary>
-public interface IModifiableProject : IReadOnlyProject, IModifiableEntity, IModifiableImagesCollection, IModifiableUserRoleCollection, IModifiableAccentColor
+public interface IModifiableProject : IReadOnlyProject, IModifiableEntity, IModifiableImagesCollection, IModifiableUserRoleCollection, IModifiableAccentColor, IModifiableFeaturesCollection
 {
     /// <summary>
     /// Updates the publisher for this project.
diff --git a/src/IModifiableProjectRole.cs b/src/IModifiableProjectRole.cs
new file mode 100644
index 0000000..a354896
--- /dev/null
+++ b/src/IModifiableProjectRole.cs
@@ -0,0 +1,8 @@
+namespace WinAppCommunity.Sdk;
+
+/// <summary>
+/// Represents a project with a corresponding role that can be modified.
+/// </summary>
+public interface IModifiableProjectRole : IReadOnlyProjectRole, IModifiableProject
+{
+}
\ No newline at end of file
diff --git a/src/IReadOnlyProject.cs b/src/IReadOnlyProject.cs
index d3c4d85..a653f99 100644
--- a/src/IReadOnlyProject.cs
+++ b/src/IReadOnlyProject.cs
@@ -10,7 +10,7 @@ public interface IReadOnlyProject : IReadOnlyProject<IReadOnlyProjectCollection>
 /// <summary>
 /// Represents a project.
 /// </summary>
-public interface IReadOnlyProject<TDependencyCollection> : IReadOnlyEntity, IReadOnlyImagesCollection, IReadOnlyUserRoleCollection, IReadOnlyAccentColor
+public interface IReadOnlyProject<out TDependencyCollection> : IReadOnlyEntity, IReadOnlyImagesCollection, IReadOnlyUserRoleCollection, IReadOnlyAccentColor, IReadOnlyFeaturesCollection
     where TDependencyCollection : IReadOnlyProjectCollection
 {
     /// <summary>
diff --git a/src/IReadOnlyUserCollection.cs b/src/IReadOnlyUserCollection.cs
index e49e0d0..dc10f3d 100644
--- a/src/IReadOnlyUserCollection.cs
+++ b/src/IReadOnlyUserCollection.cs
@@ -13,7 +13,7 @@ public interface IReadOnlyUserCollection : IReadOnlyUserCollection<IReadOnlyUser
 /// Represents a collection of users with a corresponding role that can be modified.
 /// </summary>
 /// <typeparam name="TUser">The type of user in this collection.</typeparam>
-public interface IReadOnlyUserCollection<TUser>
+public interface IReadOnlyUserCollection<out TUser>
     where TUser : IReadOnlyUser
 {
     /// <summary>