NumberWorker.cs

public class NumberWorker: BackgroundService
{
    private readonly ILogger<TimeWorker> _logger;
    private readonly ChannelReader<int> _channel;
    public NumberWorker(ILogger<TimeWorker> logger, ChannelReader<int> channel)
    {
        _logger = logger;
        _channel = channel;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        _logger.LogInformation("NumberWorker running at: {time}", DateTimeOffset.Now);
        await foreach (var item in _channel.ReadAllAsync(stoppingToken))
        {
            try
            {
                _logger.LogInformation("Number sended to channel: {Item}", item);
            } catch (Exception ex)
            {
                _logger.LogError(ex, "Error in NumberWorker");
            }
        }
    }
}


[ApiController]
[Route("[controller]")]
public class SendNumberController: ControllerBase
{
    private readonly ChannelWriter<int> _channel;

    public SendNumberController(ChannelWriter<int> channel)
    {
        _channel = channel;
    }
    
    [HttpGet("{number}")]
    public async Task<IActionResult> SendNumber([FromRoute] int number=0)
    {
        await _channel.WriteAsync(number);
        return Ok();
    }
}

builder.Services.AddSingleton(Channel.CreateUnbounded<int>(new UnboundedChannelOptions() { SingleReader = true }));
builder.Services.AddSingleton(svc => svc.GetRequiredService<Channel<int>>().Reader);
builder.Services.AddSingleton(svc => svc.GetRequiredService<Channel<int>>().Writer);
builder.Services.AddHostedService<NumberWorker>();