It's cool to have an API but at one point you will want you or other people to be able to use it. Also, we will use it as an opportunity to do integration testing.
Must have
A gem able to connect to our API and query at least some methods on it;
A test suite based on VCR that really test our API;
Documentation in the readme;
The gem must be available on rubygem;
CI/CD: circle CI build and if everything is alright send it to rubygem.
Why ?
It's cool to have an API but at one point you will want you or other people to be able to use it. Also, we will use it as an opportunity to do integration testing.
Must have
Reading list
bundle gem xxx
to create a new gem (https://bundler.io/man/bundle-gem.1.html)