Call Forwarding with Voicemail

This is a small Go app that shows how to forwards calls during a specific time window, and how to record voicemails if calls are unanswered, or are received outside that time window.

Find out more on Twilio Code Exchange.

Application Overview

The application forwards incoming calls to a specified number during business hours; by default, these are Monday to Friday 8:00-18:00 UTC. Otherwise, it directs the call to voicemail. If the call is directed to voicemail, a message can be recorded and a link of the recording sent via SMS to the configured phone number.

Requirements

To use the application, you'll need the following:

• Go 1.22 or above
• A Twilio account (free or paid) with a phone number. Click here to create one, if you don't have already.
• ngrok
• Two phone numbers; one to call the service and another to redirect your call to, if it's between business hours.

Getting Started

After cloning the code to wherever you store your Go projects, and change into the project directory. Then, copy .env.example as .env, by running the following command:

cp -v .env.example .env

After that, set values for TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN, TWILIO_PHONE_NUMBER. You can retrieve these details from the Account Info panel of your Twilio Console dashboard.

Then, set MY_PHONE_NUMBER to the phone number that you want to receive SMS notifications to. Ideally, also set as many of the commented out configuration details as possible.

When that's done, run the following command to launch the application:

go run main.go

Then, use ngrok to create a secure tunnel between port 8080 on your local development machine and the public internet, making the application publicly accessible, by running the following command.

ngrok http 8080

With the application ready to go, make a call to your Twilio phone number.