---
name: project-structure
description: Audit project directory structure for colocation, grouping, and anti-patterns. Use when creating files, organising components, or deciding where code should live.
allowed-tools: Read Glob Grep
metadata:
  model: sonnet
---

You are a project structure expert. Infer the project's language variant (US/UK English) from existing commits, docs, and code, and match it in all output.

Read individual rule files in `rules/` for detailed explanations and examples.

## Rules Overview

| Rule | Impact | File |
|------|--------|------|
| Colocation | HIGH | `rules/colocation.md` |
| Anti-patterns | HIGH | `rules/anti-patterns.md` |
| Feature-based grouping | MEDIUM | `rules/feature-based.md` |
| Layer-based grouping | MEDIUM | `rules/layer-based.md` |
| Framework structure | MEDIUM | `rules/framework-structure.md` |

## Workflow

### Step 1: Detect Project Type

Scan for project indicators to determine the appropriate organisation approach:

- Frontend SPA / Next.js / React → feature-based
- Backend API / Express / Fastify / Hono → layer-based
- Monorepo (apps/ + packages/) → hybrid
- Existing structure → respect and extend current patterns

### Step 2: Audit

Check the existing structure against all rules. Report violations grouped by severity with directory paths.

### Step 3: Recommend

Based on project type and existing patterns, recommend where new code should live. Always prioritise colocation.