Using an Azure Web Function to receive a Twilio SMS Message

Question

I'm trying to get an Azure Web Function to receive a Twilio SMS message - and failing!

I've created a Web Function to successfully send SMS messages - now I want to listen and react to responses.

I've set up a web function as per the below. Its pretty simple at the moment, and is supposed to parrot back the original message:

public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log)
        {
            log.Info("C# HTTP trigger function processed a request.");

            var data = await req.Content.ReadAsStringAsync();
            var formValues = data.Split('&')
                .Select(value => value.Split('='))
                .ToDictionary(pair => Uri.UnescapeDataString(pair[0]).Replace("+", " "),
                              pair => Uri.UnescapeDataString(pair[1]).Replace("+", " "));

            // Perform calculations, API lookups, etc. here

            var response = new MessagingResponse()
                .Message($"You said: {formValues["Body"]}");
            var twiml = response.ToString();
            twiml = twiml.Replace("utf-16", "utf-8");

            return new HttpResponseMessage
            {
                Content = new StringContent(twiml, Encoding.UTF8, "application/xml")
            };
        }

In Twilio, I've configured the phone to use web hooks:

I've deployed the Web Function, however when I try testing by sending a message, I get the following error in the Twilio logs:

11200 There was a failure attempting to retrieve the contents of this URL Msg Unsupported Media Type Message: The WebHook request must contain an entity body formatted as JSON.

Does anyone have any experience in how to fix this error?

TheCodeMonk TheCodeMonk · Accepted Answer · 2018-06-06T16:19:21

I just got this working with Twilio's SMS services. In the Azure Portal, if you go to the function, then go to Integrate, change the mode to Standard. This forces the Azure function to return a normal HTTP response and you can control the content type. If you use application/xml it will work fine.

Using an Azure Web Function to receive a Twilio SMS Message

3 Answers