Slash command

A slash command is a shortcut you type into the agent's input, /name, that either triggers a built-in action or expands into a stored prompt. Built-ins handle the harness itself: /clear to start a fresh session, /compact to trigger compaction, /init to draft an AGENTS.md, /help. Custom commands are prompt files you keep in the project; typing /review might paste a two-paragraph review checklist with the current diff attached, and the model takes it from there.

Custom commands solve the 'I keep typing the same thing' problem, and they solve it better than putting the text in a rules file. Anything in the rules file is loaded into every turn whether relevant or not, spending context on instructions the current task doesn't need. A slash command loads its text only when you call it. That makes it the right home for long, occasional prompts: the release checklist, the migration playbook, the 'write a field note about this' template.

Keep commands in the repo so the whole team gets them, give them arguments where it helps (/fix-issue 123), and let them reference files rather than inline everything. When a command needs supporting scripts or several steps, it has outgrown the format and should become a skill. A good test: if a new teammate would benefit from the shortcut on day one, commit it.