Learning Objective

After completing this lesson, you will be able to:

• use modules in KRL
• wrap an extermal API call and make it available from a module
• use the keys pragma for API keys

Prerequisites

You should have done the following before starting this lesson:

• Read the page on User Defined Modules
• Read the page on using keys
• Read the page on the built-in HTTP library
• Pico State Lesson

Modules

Modules make KRL programming easier. KRL has a powerful parameterized module facility. 

In this lesson, we're going to explore how modules can be used to wrap an external API and make it available inside a pico. 

## outline

1. Create a ruleset to serve as our module called twilio