diff --git a/src/UniTask/Assets/Plugins/UniTask/CompilerServices/AsyncUniTaskMethodBuilder.cs b/src/UniTask/Assets/Plugins/UniTask/CompilerServices/AsyncUniTaskMethodBuilder.cs
new file mode 100644
index 0000000..2acad7e
--- /dev/null
+++ b/src/UniTask/Assets/Plugins/UniTask/CompilerServices/AsyncUniTaskMethodBuilder.cs
@@ -0,0 +1,303 @@
+
+#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
+
+using System;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Security;
+
+namespace Cysharp.Threading.Tasks.CompilerServices
+{
+    [StructLayout(LayoutKind.Auto)]
+    public struct AsyncUniTaskMethodBuilder
+    {
+        // cache items.
+        AutoResetUniTaskCompletionSource promise;
+        IMoveNextRunner runner;
+
+        // 1. Static Create method.
+        [DebuggerHidden]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static AsyncUniTaskMethodBuilder Create()
+        {
+            return default;
+        }
+
+        // 2. TaskLike Task property.
+        public UniTask Task
+        {
+            [DebuggerHidden]
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                if (promise != null)
+                {
+                    return promise.Task;
+                }
+
+                if (runner == null)
+                {
+                    return UniTask.CompletedTask;
+                }
+
+                promise = AutoResetUniTaskCompletionSource.Create();
+                return promise.Task;
+            }
+        }
+
+        // 3. SetException
+        [DebuggerHidden]
+        public void SetException(Exception exception)
+        {
+            // runner is finished, return first.
+            if (runner != null)
+            {
+                runner.Return();
+                runner = null;
+            }
+
+            if (promise != null)
+            {
+                promise.TrySetException(exception);
+            }
+            else
+            {
+                promise = AutoResetUniTaskCompletionSource.CreateFromException(exception, out _);
+            }
+        }
+
+        // 4. SetResult
+        [DebuggerHidden]
+        public void SetResult()
+        {
+            // runner is finished, return first.
+            if (runner != null)
+            {
+                runner.Return();
+                runner = null;
+            }
+
+            if (promise != null)
+            {
+                promise.TrySetResult();
+            }
+        }
+
+        // 5. AwaitOnCompleted
+        [DebuggerHidden]
+        public void AwaitOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine)
+            where TAwaiter : INotifyCompletion
+            where TStateMachine : IAsyncStateMachine
+        {
+            if (promise == null)
+            {
+                promise = AutoResetUniTaskCompletionSource.Create();
+            }
+            if (runner == null)
+            {
+                runner = MoveNextRunner<TStateMachine>.Create(ref stateMachine);
+            }
+
+            awaiter.OnCompleted(runner.CallMoveNext);
+        }
+
+        // 6. AwaitUnsafeOnCompleted
+        [DebuggerHidden]
+        [SecuritySafeCritical]
+        public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine)
+            where TAwaiter : ICriticalNotifyCompletion
+            where TStateMachine : IAsyncStateMachine
+        {
+            if (promise == null)
+            {
+                promise = AutoResetUniTaskCompletionSource.Create();
+            }
+            if (runner == null)
+            {
+                runner = MoveNextRunner<TStateMachine>.Create(ref stateMachine);
+            }
+
+            awaiter.OnCompleted(runner.CallMoveNext);
+        }
+
+        // 7. Start
+        [DebuggerHidden]
+        public void Start<TStateMachine>(ref TStateMachine stateMachine)
+            where TStateMachine : IAsyncStateMachine
+        {
+            stateMachine.MoveNext();
+        }
+
+        // 8. SetStateMachine
+        [DebuggerHidden]
+        public void SetStateMachine(IAsyncStateMachine stateMachine)
+        {
+            // don't use boxed stateMachine.
+        }
+
+#if DEBUG || !UNITY_2018_3_OR_NEWER
+        // Important for IDE debugger.
+        object debuggingId;
+        private object ObjectIdForDebugger
+        {
+            get
+            {
+                if (debuggingId == null)
+                {
+                    debuggingId = new object();
+                }
+                return debuggingId;
+            }
+        }
+#endif
+    }
+
+    [StructLayout(LayoutKind.Auto)]
+    public struct AsyncUniTaskMethodBuilder<T>
+    {
+        // cache items.
+        AutoResetUniTaskCompletionSource<T> promise;
+        IMoveNextRunner runner;
+        T result;
+
+        // 1. Static Create method.
+        [DebuggerHidden]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static AsyncUniTaskMethodBuilder<T> Create()
+        {
+            return default;
+        }
+
+        // 2. TaskLike Task property.
+        [DebuggerHidden]
+        public UniTask<T> Task
+        {
+            get
+            {
+                if (promise != null)
+                {
+                    return promise.Task;
+                }
+
+                if (runner == null)
+                {
+                    return UniTask.FromResult(result);
+                }
+
+                promise = AutoResetUniTaskCompletionSource<T>.Create();
+                return promise.Task;
+            }
+        }
+
+        // 3. SetException
+        [DebuggerHidden]
+        public void SetException(Exception exception)
+        {
+            // runner is finished, return first.
+            if (runner != null)
+            {
+                runner.Return();
+                runner = null;
+            }
+
+            if (promise == null)
+            {
+                promise = AutoResetUniTaskCompletionSource<T>.CreateFromException(exception, out _);
+            }
+            else
+            {
+                promise.TrySetException(exception);
+            }
+        }
+
+        // 4. SetResult
+        [DebuggerHidden]
+        public void SetResult(T result)
+        {
+            // runner is finished, return first.
+            if (runner != null)
+            {
+                runner.Return();
+                runner = null;
+            }
+
+            if (promise == null)
+            {
+                this.result = result;
+                return;
+            }
+
+            promise.TrySetResult(result);
+        }
+
+        // 5. AwaitOnCompleted
+        [DebuggerHidden]
+        public void AwaitOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine)
+            where TAwaiter : INotifyCompletion
+            where TStateMachine : IAsyncStateMachine
+        {
+            if (promise == null)
+            {
+                promise = AutoResetUniTaskCompletionSource<T>.Create();
+            }
+            if (runner == null)
+            {
+                runner = MoveNextRunner<TStateMachine>.Create(ref stateMachine);
+            }
+
+            awaiter.OnCompleted(runner.CallMoveNext);
+        }
+
+        // 6. AwaitUnsafeOnCompleted
+        [DebuggerHidden]
+        [SecuritySafeCritical]
+        public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine)
+            where TAwaiter : ICriticalNotifyCompletion
+            where TStateMachine : IAsyncStateMachine
+        {
+            if (promise == null)
+            {
+                promise = AutoResetUniTaskCompletionSource<T>.Create();
+            }
+            if (runner == null)
+            {
+                runner = MoveNextRunner<TStateMachine>.Create(ref stateMachine);
+            }
+
+            awaiter.OnCompleted(runner.CallMoveNext);
+        }
+
+        // 7. Start
+        [DebuggerHidden]
+        public void Start<TStateMachine>(ref TStateMachine stateMachine)
+            where TStateMachine : IAsyncStateMachine
+        {
+            stateMachine.MoveNext();
+        }
+
+        // 8. SetStateMachine
+        [DebuggerHidden]
+        public void SetStateMachine(IAsyncStateMachine stateMachine)
+        {
+            // don't use boxed stateMachine.
+        }
+
+#if DEBUG || !UNITY_2018_3_OR_NEWER
+        // Important for IDE debugger.
+        object debuggingId;
+        private object ObjectIdForDebugger
+        {
+            get
+            {
+                if (debuggingId == null)
+                {
+                    debuggingId = new object();
+                }
+                return debuggingId;
+            }
+        }
+#endif
+
+    }
+}
\ No newline at end of file
diff --git a/src/UniTask/Assets/Plugins/UniTask/CompilerServices/AsyncUniTaskVoidMethodBuilder.cs b/src/UniTask/Assets/Plugins/UniTask/CompilerServices/AsyncUniTaskVoidMethodBuilder.cs
new file mode 100644
index 0000000..73cbabb
--- /dev/null
+++ b/src/UniTask/Assets/Plugins/UniTask/CompilerServices/AsyncUniTaskVoidMethodBuilder.cs
@@ -0,0 +1,121 @@
+
+#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
+
+using System;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Security;
+
+namespace Cysharp.Threading.Tasks.CompilerServices
+{
+    public struct AsyncUniTaskVoidMethodBuilder
+    {
+        IMoveNextRunner runner;
+
+        // 1. Static Create method.
+        [DebuggerHidden]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static AsyncUniTaskVoidMethodBuilder Create()
+        {
+            return default;
+        }
+
+        // 2. TaskLike Task property(void)
+        public UniTaskVoid Task
+        {
+            [DebuggerHidden]
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                return default;
+            }
+        }
+
+        // 3. SetException
+        [DebuggerHidden]
+        public void SetException(Exception exception)
+        {
+            // runner is finished, return first.
+            if (runner != null)
+            {
+                runner.Return();
+                runner = null;
+            }
+
+            UniTaskScheduler.PublishUnobservedTaskException(exception);
+        }
+
+        // 4. SetResult
+        [DebuggerHidden]
+        public void SetResult()
+        {
+            // runner is finished, return.
+            if (runner != null)
+            {
+                runner.Return();
+                runner = null;
+            }
+        }
+
+        // 5. AwaitOnCompleted
+        [DebuggerHidden]
+        public void AwaitOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine)
+            where TAwaiter : INotifyCompletion
+            where TStateMachine : IAsyncStateMachine
+        {
+            if (runner == null)
+            {
+                runner = MoveNextRunner<TStateMachine>.Create(ref stateMachine);
+            }
+
+            awaiter.OnCompleted(runner.CallMoveNext);
+        }
+
+        // 6. AwaitUnsafeOnCompleted
+        [DebuggerHidden]
+        [SecuritySafeCritical]
+        public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine)
+            where TAwaiter : ICriticalNotifyCompletion
+            where TStateMachine : IAsyncStateMachine
+        {
+            if (runner == null)
+            {
+                runner = MoveNextRunner<TStateMachine>.Create(ref stateMachine);
+            }
+
+            awaiter.OnCompleted(runner.CallMoveNext);
+        }
+
+        // 7. Start
+        [DebuggerHidden]
+        public void Start<TStateMachine>(ref TStateMachine stateMachine)
+            where TStateMachine : IAsyncStateMachine
+        {
+            stateMachine.MoveNext();
+        }
+
+        // 8. SetStateMachine
+        [DebuggerHidden]
+        public void SetStateMachine(IAsyncStateMachine stateMachine)
+        {
+            // don't use boxed stateMachine.
+        }
+
+#if DEBUG || !UNITY_2018_3_OR_NEWER
+        // Important for IDE debugger.
+        object debuggingId;
+        private object ObjectIdForDebugger
+        {
+            get
+            {
+                if (debuggingId == null)
+                {
+                    debuggingId = new object();
+                }
+                return debuggingId;
+            }
+        }
+#endif
+    }
+}
+