public class IOMiddleware
{
    private readonly RequestDelegate _next;

    public IOMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task Invoke(HttpContext context)
    {
        await LogRequest(context.Request);

        await LogResponseAndInvokeNext(context);
    }

    private async Task LogRequest(HttpRequest request)
    {
        using (var bodyReader = new StreamReader(request.Body))
        {
            string body = await bodyReader.ReadToEndAsync();

            request.Body = new MemoryStream(Encoding.UTF8.GetBytes(body));
            System.Diagnostics.Debug.Print(body);
        }
    }

    private async Task LogResponseAndInvokeNext(HttpContext context)
    {
        using (var buffer = new MemoryStream())
        {
            //replace the context response with our buffer
            var stream = context.Response.Body;
            context.Response.Body = buffer;

            //invoke the rest of the pipeline
            await _next.Invoke(context);

            //reset the buffer and read out the contents
            buffer.Seek(0, SeekOrigin.Begin);
            var reader = new StreamReader(buffer);
            using (var bufferReader = new StreamReader(buffer))
            {
                string body = await bufferReader.ReadToEndAsync();

                //reset to start of stream
                buffer.Seek(0, SeekOrigin.Begin);

                //copy our content to the original stream and put it back
                await buffer.CopyToAsync(stream);
                context.Response.Body = stream;

                System.Diagnostics.Debug.Print($"Response: {body}");

            }
        }
    }
}

public async Task Invoke(HttpContext context)
    {
        //Workaround - copy original Stream
        var initalBody = context.Request.Body;

        using (var bodyReader = new StreamReader(request.Body))
        {
            string body = await bodyReader.ReadToEndAsync();
            //Do something with body
            //Replace write only request body with read/write memorystream so you can read from it later

               request.Body = new MemoryStream(Encoding.UTF8.GetBytes(body));

        //handle other middlewares
        await _next.Invoke(context);

        //Workaround - return back to original Stream
        context.Request.Body = initalBody;
    }