mruby and mruby-cli makes it possible to ship single binary command-line tools that can be used without setup effort. How can we make these easy to write too? Existing libraries for making command-line tools are built for experienced rubyists. This makes them a poor choice for porting to mruby. In this talk we'll explore how to build a command-line tool with mruby-cli along with a design and philosophy that makes it easy to create new commands and maintain existing commands even for unfamiliar developers. Eric Hodel, @drbrain Eric Hodel is a ruby committer and maintainer of many gems. He works at Fastly on the API features team maintaining and building ruby services that customers use to configure their CDN services.