How To Build a Voicemail with ASP.NET Core and NancyFX

This tutorial guides developers on how to create a voicemail application using Nexmo Voice APIs and ASP.NET Core, allowing customers to leave messages for a specific phone number. The project uses NancyFX to handle HTTP requests and creates a route to /webhook/answer, which responds with an NCCO returned by the GetVoiceMailNCCO() method. The tutorial also covers configuration steps such as linking a Nexmo account to a phone number, setting up an answer URL using Ngrok, and exposing the webhook endpoint for testing. With this application, customers can leave messages that will be stored in a recording and sent to another route for further processing.