Skills Are Just Markdown
The first post in this series talked about /journal and /checkin — a daily journal and a 15-minute check-in loop that runs unattended on a schedule. I called them “skills” without explaining what that means. This post is about the mechanism. A skill is a markdown file. That’s the whole abstraction. Specifically: a directory under .claude/skills/<name>/ with a SKILL.md inside. The directory name is the slash command. The contents of SKILL.md are the instructions Claude reads when you invoke it. There’s no plugin API, no shell wrapper, no “register your command.” Drop a directory in, the command exists. Edit the file, the behavior changes. ...