Metal 4 support in iOS simulator

Thank you for sharing your post. However, I believe you did not provide sufficient details for others to provide a meaningful response to your question. Could you please specify the version of Xcode, Simulator, or macOS you are using when targeting the simulator? Additionally, do you mean that the simulator is compatible with your device?

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I'm sure someone in the community will be able to help once you have a chance to update your post.

Resources about metal 4 from WWDC 25:

https://developer.apple.com/videos/play/wwdc2025/205/

Albert Pascual
  Worldwide Developer Relations.

Ah sorry for the lack of details, thanks for addressing this issue. Here's a swift code snippet to reproduce this issue:

import MetalKit

class MetalTestView: MTKView {
    var commandBuffer: MTL4CommandBuffer?
    var commandQueue: MTL4CommandQueue?
}

If you build with a real device selected, such as iPhone 14 with iOS 26 beta installed, the build succeeds, but if you build with iPhone 17 simulator with iOS 26, the build fails and complains that "Cannot find type 'MTL4CommandBuffer/MTL4CommandQueue' in scope". Any way to get the simulator to recognize metal 4 types?

Hello,

Metal 4 is expected to work on the Simulator with iOS 26.

Given that this compiles on device and only fails to compile on Simulator this is a regression.

Try importing Metal i.e. import Metal to see if that solves the problem.

You can also see if this compiles with Obj-C.

Otherwise please send us a bug report.

Thanks for the details regarding this. I tried import Metal in the swift test, as well as the following Objective C test code:

#import "ViewController.h"
#import "Metal/Metal.h"

@interface ViewController ()

@property id<MTL4CommandBuffer> commandBuffer;
@property id<MTL4CommandQueue> commandQueue;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

@end

No dice with this either. I'll file the bug, thanks for looking into this!

Thank you for letting us know and appreciate the bug report as this is a serious concern.

What is the current status of this issue? In the Xcode/iOS 26.4.1 SDK, attempting to use Metal 4 symbols still causes an error.

The code below works when targeting iOS Device, Designed for iPad, or mac, but for the Simulator, I get the error: “Cannot find protocol declaration for ‘MTL4CommandQueue’; did you mean ‘MTLCommandQueue’?”

#import <Foundation/Foundation.h>
#import <Metal/Metal.h>

@interface MyClass : NSObject

@end

@implementation MyClass

- (void)test {
    id <MTL4CommandQueue> queue;
}

@end

Sorry to bump, but this issue still seems to exist with the iOS 27.1 simulators. I'm trying to update my Metal 4 based app to work with iPhone Duo, and while it compiles fine on my physical iPhone 16 Pro, no dice on the simulator.

Getting similar errors as others have posted: "Cannot find type 'MTL4CommandQueue' in scope", "Cannot find type 'MTL4CommandBuffer' in scope" and other similar errors for other MTL4 types.

Any update on this? I did submit feedback (FB24868746), but haven't heard anything yet.

protocol MetalVisualizerRenderer: AnyObject {
  var device: MTLDevice { get }
  var commandQueue: any MTL4CommandQueue { get }
  var commandBuffer: any MTL4CommandBuffer { get }
  var sharedEvent: MTLSharedEvent { get }
.
.
.