// Create a controller class to handle the REST request:
[ApiController]
[Route("api/messages")]
public class MessagesController : ControllerBase
{
    [HttpPost]
    public IActionResult SendMessage([FromBody] string message)
    {
        // Create an instance of the SignalR hub context
        var hubContext = HttpContext.RequestServices.GetService<IHubContext<MyHub>>();

        // Process the message and prepare the data for the REST response
        string responseMessage = ProcessMessage(message);

        // Send the response to the connected SignalR clients
        hubContext.Clients.All.SendAsync("ReceiveResponse", responseMessage);

        // Return an appropriate REST response
        return Ok(responseMessage);
    }
}

// Create a controller class to handle the REST request:
[ApiController]
[Route("api/messages")]
public class MessagesController : ControllerBase
{
    [HttpPost]
    public IActionResult SendMessage([FromBody] string message)
    {
        // Create an instance of the SignalR hub context
        var hubContext = HttpContext.RequestServices.GetService<IHubContext<MyHub>>();

        // Process the message and prepare the data for the REST response
        string responseMessage = ProcessMessage(message);

        // Send the response to the connected SignalR clients
        hubContext.Clients.All.SendAsync("ReceiveResponse", responseMessage);

        // Return an appropriate REST response
        return Ok(responseMessage);
    }
}