Instructions:

To create an AWS Lambda C# Package, type your function's code in the editor below and click the Download Package button.
NOTE: Ignore the Go button in the editor. 

using System;
using System.Threading.Tasks;
using System.Net.Http;
using Newtonsoft.Json;

public static async Task<HttpResponseMessage> Run(HttpRequestMessage req)
{
    return new HttpResponseMessage
    {
        Content = new StringContent(
            JsonConvert.SerializeObject(new { greeting = "Hello World!", uri = req.RequestUri })
        )
    };
}
Download Package