This text describes how to build a simple application using C#, ASP.NET, and Azure that responds to SMS messages from Twilio. The app will send back the names of federal representatives for a given ZIP code. The tools needed include Visual Studio 2015, an Azure account, a Twilio account, and an API key for the Sunlight Foundation's Congress API. Once set up, users can text their ZIP code to the designated phone number to receive the list of representatives. The app uses the Congress API to retrieve the data and formats it in a user-friendly way. The application is tested locally and deployed to Azure for production use.