diff --git a/Sources/OpenSwiftUICore/View/Trait/ViewTraitCollection.swift b/Sources/OpenSwiftUICore/View/Trait/ViewTraitCollection.swift
deleted file mode 100644
index 0c427b942..000000000
--- a/Sources/OpenSwiftUICore/View/Trait/ViewTraitCollection.swift
+++ /dev/null
@@ -1,67 +0,0 @@
-//
-//  ViewTraitCollection.swift
-//  OpenSwiftUI
-//
-//  Audited for iOS 15.5
-//  Status: WIP
-//  ID: 9929B476764059557433A108298EE66F
-
-package struct ViewTraitCollection {
-    package init() {
-        self.storage = []
-    }
-    
-    private var storage: [any AnyViewTrait]
-    
-    private struct AnyTrait<Key: _ViewTraitKey>: AnyViewTrait {
-        var value: Key.Value
-        
-        init(value: Key.Value) {
-            self.value = value
-        }
-        
-        var id: ObjectIdentifier { ObjectIdentifier(Key.self) }
-        
-        subscript<V>() -> V {
-            get { value as! V }
-            set { value = newValue as! Key.Value }
-        }
-    }
-    
-    subscript<Key: _ViewTraitKey>(_: Key.Type) -> Key.Value {
-        get {
-            value(for: Key.self)
-        }
-        set {
-            if let index = storage.firstIndex(where: { $0.id == ObjectIdentifier(Key.self) }) {
-                storage[index][] = newValue
-            } else {
-                storage.append(AnyTrait<Key>(value: newValue))
-            }
-        }
-    }
-    
-    func value<Key: _ViewTraitKey>(for _: Key.Type, defaultValue: Key.Value = Key.defaultValue) -> Key.Value {
-        storage.first { $0.id == ObjectIdentifier(Key.self) }?[] ?? defaultValue
-    }
-    
-    mutating func setValueIfUnset<Key: _ViewTraitKey>(_ value: Key.Value, for _: Key.Type) {
-        guard !storage.contains(where: { $0.id == ObjectIdentifier(Key.self) }) else {
-            return
-        }
-        storage.append(AnyTrait<Key>(value: value))
-    }
-    
-//    func insertInteraction(for: OnInsertInteraction.Strategy) -> OnInsertInteraction? {
-//        preconditionFailure("TODO")
-//    }
-//    
-//    var optionalTransition: AnyTransition? {
-//        preconditionFailure("TODO")
-//    }
-}
-
-private protocol AnyViewTrait {
-    var id: ObjectIdentifier { get }
-    subscript<V>() -> V { get set }
-}
diff --git a/Sources/OpenSwiftUICore/View/Trait/ViewTraitKey.swift b/Sources/OpenSwiftUICore/View/Trait/ViewTraitKey.swift
deleted file mode 100644
index 404bf6a46..000000000
--- a/Sources/OpenSwiftUICore/View/Trait/ViewTraitKey.swift
+++ /dev/null
@@ -1,11 +0,0 @@
-//
-//  ViewTraitKey.swift
-//  OpenSwiftUI
-//
-//  Audited for iOS 15.5
-//  Status: Complete
-
-public protocol _ViewTraitKey {
-    associatedtype Value
-    static var defaultValue: Value { get }
-}
diff --git a/Sources/OpenSwiftUICore/View/Trait/ViewTraitKeys.swift b/Sources/OpenSwiftUICore/View/Trait/ViewTraitKeys.swift
deleted file mode 100644
index 4b0da3483..000000000
--- a/Sources/OpenSwiftUICore/View/Trait/ViewTraitKeys.swift
+++ /dev/null
@@ -1,35 +0,0 @@
-//
-//  ViewTraitKeys.swift
-//  OpenSwiftUI
-//
-//  Audited for iOS 18.0
-//  Status: Complete
-
-package struct ViewTraitKeys {
-    package var types: Set<ObjectIdentifier>
-    package var isDataDependent: Bool
-    
-    package init() {
-        types = []
-        isDataDependent = false
-    }
-    
-    package func contains<T>(_ type: T.Type) -> Bool where T: _ViewTraitKey{
-        types.contains(ObjectIdentifier(type))
-    }
-    
-    package mutating func insert<T>(_ type: T.Type) where T: _ViewTraitKey {
-        types.insert(ObjectIdentifier(type))
-    }
-    
-    package mutating func formUnion(_ other: ViewTraitKeys) {
-        types.formUnion(other.types)
-        isDataDependent = isDataDependent || other.isDataDependent
-    }
-
-    package func withDataDependent() -> ViewTraitKeys {
-        var copy = self
-        copy.isDataDependent = true
-        return copy
-    }
-}
diff --git a/Sources/OpenSwiftUICore/View/Variadic/ViewTrait.swift b/Sources/OpenSwiftUICore/View/Variadic/ViewTrait.swift
new file mode 100644
index 000000000..ed1eee232
--- /dev/null
+++ b/Sources/OpenSwiftUICore/View/Variadic/ViewTrait.swift
@@ -0,0 +1,239 @@
+//
+//  ViewTrait.swift
+//  OpenSwiftUI
+//
+//  Audited for iOS 18.0
+//  Status: Blocked by ViewList
+//  ID: 9929B476764059557433A108298EE66F (SwiftUI)
+//  ID: 48526BA25CDCBF890FA91D018A5421B4 (SwiftUICore)
+
+import OpenGraphShims
+
+// MARK: - ViewTraitKey
+
+/// A type of key for a trait associated with the content of a
+/// container view.
+public protocol _ViewTraitKey {
+    /// The type of value produced by the trait.
+    associatedtype Value
+    
+    /// The default value of the trait.
+    static var defaultValue: Value { get }
+}
+
+// MARK: - _TraitWritingModifier [TODO]
+
+/// A view content adapter that associates a trait with its base content.
+@frozen
+public struct _TraitWritingModifier<Trait>: PrimitiveViewModifier where Trait : _ViewTraitKey {
+    public let value: Trait.Value
+
+    @inlinable
+    public init(value: Trait.Value) {
+        self.value = value
+    }
+
+    nonisolated public static func _makeView(
+        modifier: _GraphValue<Self>,
+        inputs: _ViewInputs,
+        body: @escaping (_Graph, _ViewInputs) -> _ViewOutputs
+    ) -> _ViewOutputs {
+        preconditionFailure("TODO")
+    }
+    nonisolated public static func _makeViewList(
+        modifier: _GraphValue<Self>,
+        inputs: _ViewListInputs,
+        body: @escaping (_Graph, _ViewListInputs) -> _ViewListOutputs
+    ) -> _ViewListOutputs {
+        preconditionFailure("TODO")
+    }
+
+    nonisolated public static func _viewListCount(inputs: _ViewListCountInputs, body: (_ViewListCountInputs) -> Int?) -> Int? {
+        preconditionFailure("TODO")
+    }
+
+    private struct AddTrait {
+        @Attribute var modifier: _TraitWritingModifier
+        @OptionalAttribute var traits: ViewTraitCollection?
+    }
+}
+
+@available(*, unavailable)
+extension _TraitWritingModifier: Sendable {}
+
+extension View {
+    /// Associate a trait `value` for the given `key` for this view content.
+    @inlinable
+    nonisolated public func _trait<K>(_ key: K.Type, _ value: K.Value) -> some View where K: _ViewTraitKey {
+        return modifier(_TraitWritingModifier<K>(value: value))
+    }
+}
+
+// MARK: - _ConditionalTraitWritingModifier [TODO]
+
+/// Conditionally writes a trait.
+@frozen
+public struct _ConditionalTraitWritingModifier<Trait>: PrimitiveViewModifier where Trait : _ViewTraitKey {
+    public var value: Trait.Value
+    public var isEnabled: Bool
+    
+    @_alwaysEmitIntoClient
+    public init(traitKey: Trait.Type = Trait.self, value: Trait.Value, isEnabled: Bool) {
+        self.value = value
+        self.isEnabled = isEnabled
+    }
+     
+    nonisolated public static func _makeView(
+        modifier: _GraphValue<Self>,
+        inputs: _ViewInputs,
+        body: @escaping (_Graph, _ViewInputs) -> _ViewOutputs
+    ) -> _ViewOutputs {
+        preconditionFailure("TODO")
+    }
+    nonisolated public static func _makeViewList(
+        modifier: _GraphValue<Self>,
+        inputs: _ViewListInputs,
+        body: @escaping (_Graph, _ViewListInputs) -> _ViewListOutputs
+    ) -> _ViewListOutputs {
+        preconditionFailure("TODO")
+    }
+
+    nonisolated public static func _viewListCount(inputs: _ViewListCountInputs, body: (_ViewListCountInputs) -> Int?) -> Int? {
+        preconditionFailure("TODO")
+    }
+}
+
+@available(*, unavailable)
+extension _ConditionalTraitWritingModifier: Sendable {}
+
+extension View {
+    @_alwaysEmitIntoClient
+    public func _trait<K>(_ key: K.Type = K.self, _ value: K.Value, isEnabled: Bool) -> some View where K: _ViewTraitKey {
+        modifier(_ConditionalTraitWritingModifier<K>(
+            value: value,
+            isEnabled: isEnabled
+        ))
+    }
+}
+
+// MARK: - TraitTransformerModifier [TODO]
+
+struct TraitTransformerModifier {
+    
+}
+
+extension View {
+    package func transformTrait<K>(_ key: K.Type = K.self, transform: @escaping (inout K.Value) -> Void) -> some View where K: _ViewTraitKey {
+        preconditionFailure("TODO")
+    }
+}
+
+// MARK: - ViewTraitCollection
+
+private protocol AnyViewTrait {
+    var id: ObjectIdentifier { get }
+    subscript<V>() -> V { get set }
+}
+
+package struct ViewTraitCollection {
+    package init() {
+        self.storage = []
+    }
+    
+    package func contains<Trait>(_ key: Trait.Type) -> Bool where Trait: _ViewTraitKey {
+        storage.contains { $0.id == ObjectIdentifier(key) }
+    }
+    
+    package func value<Trait>(for key: Trait.Type, defaultValue: Trait.Value) -> Trait.Value where Trait: _ViewTraitKey {
+        storage.first { $0.id == ObjectIdentifier(key) }?[] ?? defaultValue
+    }
+    
+    package func value<Trait>(for key: Trait.Type) -> Trait.Value where Trait: _ViewTraitKey {
+        value(for: key, defaultValue: key.defaultValue)
+    }
+        
+    package mutating func setValueIfUnset<Trait>(_ value: Trait.Value, for key: Trait.Type) where Trait: _ViewTraitKey {
+        guard !storage.contains(where: { $0.id == ObjectIdentifier(key) }) else {
+            return
+        }
+        storage.append(AnyTrait<Trait>(value: value))
+    }
+    
+    package subscript<Trait>(key: Trait.Type) -> Trait.Value where Trait : _ViewTraitKey {
+        get {
+            value(for: key)
+        }
+        set {
+            if let index = storage.firstIndex(where: { $0.id == ObjectIdentifier(key) }) {
+                storage[index][] = newValue
+            } else {
+                storage.append(AnyTrait<Trait>(value: newValue))
+            }
+        }
+    }
+    
+    package mutating func mergeValues(_ traits: ViewTraitCollection) {
+        for trait in traits.storage {
+            setErasedValue(trait: trait)
+        }
+    }
+    
+    private mutating func setErasedValue<ViewTrait>(trait: ViewTrait) where ViewTrait: AnyViewTrait {
+        if let index = storage.firstIndex(where: { $0.id == trait.id }) {
+            let value: Any = trait[]
+            storage[index][] = value
+        } else {
+            storage.append(trait)
+        }
+    }
+    
+    private var storage: [any AnyViewTrait]
+    
+    private struct AnyTrait<Trait>: AnyViewTrait where Trait: _ViewTraitKey {
+        typealias Value = Trait.Value
+        
+        var value: Value
+        
+        init(value: Trait.Value) {
+            self.value = value
+        }
+        
+        var id: ObjectIdentifier { ObjectIdentifier(Trait.self) }
+        
+        subscript<V>() -> V {
+            get { value as! V }
+            set { value = newValue as! Value }
+        }
+    }
+}
+
+// MARK: - ViewTraitKeys
+
+package struct ViewTraitKeys {
+    package var types: Set<ObjectIdentifier>
+    package var isDataDependent: Bool
+    
+    package init() {
+        types = []
+        isDataDependent = false
+    }
+    
+    package func contains<T>(_ type: T.Type) -> Bool where T: _ViewTraitKey{
+        types.contains(ObjectIdentifier(type))
+    }
+    
+    package mutating func insert<T>(_ type: T.Type) where T: _ViewTraitKey {
+        types.insert(ObjectIdentifier(type))
+    }
+    
+    package mutating func formUnion(_ other: ViewTraitKeys) {
+        types.formUnion(other.types)
+        isDataDependent = isDataDependent || other.isDataDependent
+    }
+
+    package func withDataDependent() -> ViewTraitKeys {
+        var copy = self
+        copy.isDataDependent = true
+        return copy
+    }
+}
diff --git a/Tests/OpenSwiftUICoreTests/View/AnyViewTests.swift b/Tests/OpenSwiftUICoreTests/View/AnyViewTests.swift
index 697423d93..b1d289443 100644
--- a/Tests/OpenSwiftUICoreTests/View/AnyViewTests.swift
+++ b/Tests/OpenSwiftUICoreTests/View/AnyViewTests.swift
@@ -1,6 +1,6 @@
 //
 //  AnyViewTests.swift
-//  OpenSwiftUITests
+//  OpenSwiftUICoreTests
 
 @testable import OpenSwiftUICore
 import Testing
diff --git a/Tests/OpenSwiftUICoreTests/View/Variadic/ViewTraitTests.swift b/Tests/OpenSwiftUICoreTests/View/Variadic/ViewTraitTests.swift
new file mode 100644
index 000000000..d31bfcbdc
--- /dev/null
+++ b/Tests/OpenSwiftUICoreTests/View/Variadic/ViewTraitTests.swift
@@ -0,0 +1,138 @@
+//
+//  ViewTraitTests.swift
+//  OpenSwiftUICoreTests
+
+@testable import OpenSwiftUICore
+import Testing
+import Numerics
+
+fileprivate struct IntTrait: _ViewTraitKey {
+    static let defaultValue: Int = .zero
+}
+
+fileprivate struct Int32Trait: _ViewTraitKey {
+    static let defaultValue: Int32 = .zero
+}
+
+fileprivate struct DoubleTrait: _ViewTraitKey {
+    static let defaultValue: Double = .zero
+}
+
+struct ViewTraitCollectionTests {
+    @Test("Test ViewTraitCollection contains API")
+    func contains() {
+        var collection = ViewTraitCollection()
+        #expect(collection.contains(IntTrait.self) == false)
+        #expect(collection.contains(DoubleTrait.self) == false)
+        
+        collection[IntTrait.self] = 1
+        #expect(collection.contains(IntTrait.self) == true)
+        
+        collection[DoubleTrait.self] = 1.0
+        #expect(collection.contains(DoubleTrait.self) == true)
+    }
+    
+    @Test("Test ViewTraitCollection value abd setValueIfUnset API")
+    func value() {
+        var collection = ViewTraitCollection()
+        
+        #expect(collection.value(for: IntTrait.self) == IntTrait.defaultValue)
+        #expect(collection.value(for: DoubleTrait.self).isApproximatelyEqual(to: DoubleTrait.defaultValue))
+        
+        collection[IntTrait.self] = 1
+        collection[DoubleTrait.self] = 1.0
+        
+        #expect(collection.value(for: IntTrait.self) == 1)
+        #expect(collection.value(for: DoubleTrait.self).isApproximatelyEqual(to: 1.0))
+        
+        collection.setValueIfUnset(2, for: IntTrait.self)
+        collection.setValueIfUnset(2.0, for: DoubleTrait.self)
+        
+        // Values should not change since they were already set
+        #expect(collection.value(for: IntTrait.self) == 1)
+        #expect(collection.value(for: DoubleTrait.self).isApproximatelyEqual(to: 1.0))
+        
+        collection[IntTrait.self] = 3
+        collection[DoubleTrait.self] = 3.0
+        
+        #expect(collection.value(for: IntTrait.self) == 3)
+        #expect(collection.value(for: DoubleTrait.self).isApproximatelyEqual(to: 3.0))
+    }
+    
+    @Test("Test ViewTraitCollection mergeValues API")
+    func mergeValues() {
+        var collection1 = ViewTraitCollection()
+        var collection2 = ViewTraitCollection()
+
+        collection1[IntTrait.self] = 1
+        collection1[DoubleTrait.self] = 1.0
+                
+        collection2[Int32Trait.self] = 2
+        collection2[DoubleTrait.self] = 2.0
+        
+        collection1.mergeValues(collection2)
+        #expect(collection1.value(for: IntTrait.self) == 1)
+        #expect(collection1.value(for: Int32Trait.self) == 2)
+        #expect(collection1.value(for: DoubleTrait.self).isApproximatelyEqual(to: 2.0))
+        
+        // Test merging with empty collection
+        let emptyCollection = ViewTraitCollection()
+        collection1.mergeValues(emptyCollection)
+        
+        // Values should remain unchanged
+        #expect(collection1.value(for: IntTrait.self) == 1)
+        #expect(collection1.value(for: Int32Trait.self) == 2)
+        #expect(collection1.value(for: DoubleTrait.self).isApproximatelyEqual(to: 2.0))
+    }
+}
+
+struct ViewTraitKeyTests {
+    @Test("Test ViewTraitKeys contains API")
+    func contains() {
+        var keys = ViewTraitKeys()
+        #expect(keys.contains(IntTrait.self) == false)
+        #expect(keys.contains(Int32Trait.self) == false)
+        #expect(keys.contains(DoubleTrait.self) == false)
+        
+        keys.insert(IntTrait.self)
+        #expect(keys.contains(IntTrait.self) == true)
+        #expect(keys.contains(Int32Trait.self) == false)
+        #expect(keys.contains(DoubleTrait.self) == false)
+    }
+    
+    @Test("Test ViewTraitKeys formUnion API")
+    func formUnion() {
+        var keys1 = ViewTraitKeys()
+        var keys2 = ViewTraitKeys()
+        
+        keys1.insert(IntTrait.self)
+        keys2.insert(Int32Trait.self)
+        keys2.insert(DoubleTrait.self)
+        
+        keys1.formUnion(keys2)
+        
+        #expect(keys1.contains(IntTrait.self) == true)
+        #expect(keys1.contains(Int32Trait.self) == true)
+        #expect(keys1.contains(DoubleTrait.self) == true)
+        #expect(keys1.isDataDependent == false)
+        
+        // Test union with data dependent keys
+        let dataDependent = keys2.withDataDependent()
+        keys1.formUnion(dataDependent)
+        #expect(keys1.isDataDependent == true)
+    }
+    
+    @Test("Test ViewTraitKeys withDataDependent API")
+    func withDataDependent() {
+        var keys = ViewTraitKeys()
+        keys.insert(IntTrait.self)
+        #expect(keys.isDataDependent == false)
+        
+        let dependent = keys.withDataDependent()
+        #expect(dependent.isDataDependent == true)
+        #expect(dependent.contains(IntTrait.self) == true)
+        
+        // Original should remain unchanged
+        #expect(keys.isDataDependent == false)
+    }
+}