RequestDecompression.cs

interface IRequestDecompressionProvider
{
    bool TryDecompressRequest(HttpContext httpContext);
}

public sealed class GzipDecompressionProvider : IRequestDecompressionProvider
{
    bool TryDecompressRequest(HttpContext context)
    {
         // e.g. Content-Encoding: br, deflate, gzip
        var encodings = context.Request.Headers.ContentEncoding;
        if (encodings.Length == 1 && encodings[0] == "gz")
        {
            stream = SizeLimitedStream(httpContext.GetRequiredFeature<IHttpSizeLimitFeature>(), GzipStream(context.Request));
            context.Body = stream;
            context.Request.Headers.ContentEncoding = null;
            return true;
        }
        
        stream = null;
        return false;
    }
}

public class RequestDecompressionOptions
{
    IList<IRequestDecompressionProvider> DecompressionProviders { get; } =  new List<IRequestDecompressionProvider>
    {
        new GzipDecompressionProvider(),
        new BrotliCompressionProvider(),
        new DeflateCompressionProvider(),
    };
}

class RequestDecompressionMiddleware
{
    Task InvokeAsync(HttpContext context)
    {
        foreach (var provider in _providers)
        {
            if (TryDecompressRequest(context))
            {
                break;
            }
        }
        
        return _next();
    }
}