Rules: Context That Auto-Loads by Path

How Path-Scoped Rules Work

• Rules are markdown files in `.claude/rules/` with path patterns in the frontmatter — when you work on a matching file, the rule auto-loads into context.
• **Global vs. scoped** — CLAUDE.md is global (loaded every session), but rules are path-scoped. JavaScript conventions don't pollute SCSS sessions, AEM backend rules don't confuse frontend work.
• Real-world example — separate rules for each concern
  • › JavaScript (ESLint Airbnb conventions)
  • › SCSS (node-sass, sass-lint)
  • › Accessibility (WCAG 2.1 AA)
  • › Naming conventions
  • › Each only loads when relevant

Creating Effective Rules

1. 1 **Dual frontmatter gotcha** — for Copilot CLI, you also need `applyTo:` in the YAML. Without it, the rule only works in Claude Code. Use both `paths:` and `applyTo:` for cross-platform compatibility.
2. 2 Create a rule for your most common file type — add 3-5 conventions and watch the AI follow them automatically
3. 3 Always include dual frontmatter for cross-platform support
   • › `paths: ["**/*.scss"]` — Claude Code
   • › `applyTo: "**/*.scss"` — Copilot CLI
4. 4 Keep rules focused — one topic per file. A 'styles' rule, a 'testing' rule, a 'naming' rule. Easier to maintain and debug.