The project file

A project is one <name>.cat.yaml file. Every CAT tool opens it, resolves the definitions it holds or points to, runs the tests and writes the outputs. You edit the file directly, so this skill is not a sequence of steps: it is what you must read before you write, and what to check after. Every fact is on the documentation page it links; the same page as markdown is at the URL with index.md appended, which is the form to read when your fetch tool summarizes HTML.

The shape