Rules / Instructions

What's a rule?

A rule is text that gets injected into every chat in a workspace. Use it for things the model should always know about your codebase.

Where they live

• .codexax/rules.md — single rule file
• .codexax/rules/*.md — multiple files, all loaded
• Front-matter glob field scopes rules to specific paths

Example

---
glob: ["src/**/*.tsx"]
---
# React conventions

- Use function components with hooks. No class components.
- Prefer composition over prop drilling. Reach for Context after 3 levels.
- Co-locate styles in the same file via styled-jsx.
- Tests live next to the file: foo.tsx → foo.test.tsx.

Personal vs team

• Repo rules (committed) — apply to everyone working on the project.
• User rules (~/.codexax/rules.md) — apply to all your projects, not shared.

What rules are good for

• "Always use early returns, never deep nesting."
• "This codebase uses pnpm, not npm."
• "Errors propagate via Result<T, E>, never thrown."
• "DB queries go through the repository layer, never raw SQL in routes."

What they're bad for: anything you'd put in a README. The model can read your README; it doesn't need rules to repeat it.