project-index

name	project-index
description	Generate and maintain project structure index for fast AI navigation. Creates docs/structure.md with optimized file index. Load this skill when starting new project, after major changes, or when docs/structure.md is outdated.

Project Index Skill

Generate optimized project structure file for fast AI context loading.

When to Use

• First time: Project has no docs/structure.md
• After changes: Added/removed files, restructured folders
• Periodic refresh: Weekly or after major features
• On demand: User says "update structure", "refresh index", "scan project"

---

Output File

Location: docs/structure.md

Purpose: Single source of truth for AI to understand project layout without scanning entire codebase.

---

Cross-Platform Scripts (Recommended)

This skill includes pre-built scripts that work on all platforms:

Node.js Script

# Basic usage (from project root)
node .codex/skills/project-index/scripts/scan-structure.js . 4

# Output to file
node .codex/skills/project-index/scripts/scan-structure.js . 4 > docs/structure.md

# JSON format
node .codex/skills/project-index/scripts/scan-structure.js . 4 json

Python Script

# Basic usage
python .codex/skills/project-index/scripts/scan_structure.py . 4

# Output to file  
python .codex/skills/project-index/scripts/scan_structure.py . 4 > docs/structure.md

# JSON format
python .codex/skills/project-index/scripts/scan_structure.py . 4 json

Script Features

• ✅ Cross-platform (Windows, macOS, Linux)
• ✅ Auto-detect entry points (main., index., app., server.)
• ✅ Auto-detect config files (package.json, tsconfig.*, etc.)
• ✅ Auto-detect key files (README, CHANGELOG, LICENSE)
• ✅ File distribution by language/type
• ✅ Customizable depth and ignore patterns
• ✅ Output: Markdown or JSON

---

Generation Workflow

Step 1: Scan Project (Alternative Methods)

Option A: Use Built-in Scripts (Recommended)

# Node.js
node .codex/skills/project-index/scripts/scan-structure.js . 4

# Python
python .codex/skills/project-index/scripts/scan_structure.py . 4

Option B: VS Code Tools

# Use list_dir tool recursively
# Use file_search tool with glob patterns

Option C: Native Commands (Platform-specific)

# Linux/macOS
tree -L 4 -I 'node_modules|.git|dist|build' --dirsfirst

# Windows PowerShell
Get-ChildItem -Recurse -Depth 4 | Where-Object { $_.FullName -notmatch 'node_modules|\.git|dist|build' }

# Windows CMD (limited)
dir /s /b /ad

Step 2: Identify Key Files

Scan for these important files:

• Entry points: main.*, index.*, app.*, server.*
• Config: *.config.*, *.json, *.yaml, *.toml, .env*
• Docs: README*, CHANGELOG*, docs/*
• Routes/API: **/routes/**, **/api/**, **/controllers/**
• Components: **/components/**, **/views/**, **/pages/**
• Services: **/services/**, **/lib/**, **/utils/**
• Database: **/models/**, **/schema/**, **/migrations/**
• Tests: **/*.test.*, **/*.spec.*, **/tests/**

Step 3: Generate Structure File

Create docs/structure.md with this format:

# Project Structure Index
> Auto-generated by project-index skill. Last updated: YYYY-MM-DD HH:mm

## Quick Stats
- Total files: X
- Main language: TypeScript/Python/etc
- Framework: Next.js/Angular/Express/etc
- Package manager: npm/yarn/pnpm

## Directory Tree
\`\`\`
<tree output here>
\`\`\`

## Key Entry Points
| File | Purpose |
|:---|:---|
| src/index.ts | Main entry |
| src/app.ts | App initialization |

## Config Files
| File | Purpose |
|:---|:---|
| package.json | Dependencies |
| tsconfig.json | TypeScript config |

## Feature Map
| Feature/Domain | Location | Key Files |
|:---|:---|:---|
| Authentication | src/auth/ | login.ts, session.ts, middleware.ts |
| User Management | src/users/ | user.model.ts, user.service.ts |
| API Routes | src/api/ | routes.ts, handlers/ |
| Database | src/db/ | schema.prisma, migrations/ |
| UI Components | src/components/ | Button.tsx, Modal.tsx, Layout.tsx |

## File Patterns
| Looking for | Path pattern |
|:---|:---|
| Components | src/components/**/*.tsx |
| API handlers | src/api/**/*.ts |
| Database models | src/models/**/*.ts |
| Tests | **/*.test.ts, **/*.spec.ts |
| Styles | src/styles/**/*.css |

## Recent Changes (Optional)
- 2024-01-15: Added payment module at src/payment/
- 2024-01-10: Restructured auth to src/auth/

Step 4: Validate & Save

1. Ensure docs/ folder exists
2. Write to docs/structure.md
3. Confirm file created/updated

---

JSON Alternative (Optional)

If project prefers JSON, create docs/structure.json:

{
  "generated": "2024-01-15T10:30:00Z",
  "stats": {
    "totalFiles": 150,
    "language": "TypeScript",
    "framework": "Next.js"
  },
  "entryPoints": [
    {"path": "src/index.ts", "purpose": "Main entry"},
    {"path": "src/app.ts", "purpose": "App init"}
  ],
  "features": {
    "auth": {
      "location": "src/auth/",
      "files": ["login.ts", "session.ts", "middleware.ts"]
    },
    "api": {
      "location": "src/api/",
      "files": ["routes.ts", "handlers/"]
    }
  },
  "patterns": {
    "components": "src/components/**/*.tsx",
    "api": "src/api/**/*.ts",
    "tests": "**/*.test.ts"
  }
}

---

Update Triggers

Structure file should be updated when:

1. Manual trigger: User says "update structure"
2. New feature: After adding new module/feature folder
3. Restructure: After moving/renaming folders
4. Weekly maintenance: As part of regular cleanup
5. Before major task: Ensure index is fresh before big changes

---

Integration with AGENTS.md

After generating docs/structure.md, AI should:

1. Read structure first before searching for files
2. Use Feature Map to locate relevant code areas
3. Use File Patterns for glob searches
4. Skip full tree scan if structure file exists and is recent

---

Quick Commands

# Check if structure exists (cross-platform)
test -f docs/structure.md && echo "EXISTS" || echo "NEEDS GENERATION"

# Generate with Node.js script
node .codex/skills/project-index/scripts/scan-structure.js . 4 > docs/structure.md

# Generate with Python script
python .codex/skills/project-index/scripts/scan_structure.py . 4 > docs/structure.md

# Quick check last modified (Linux/macOS)
stat docs/structure.md | grep Modify

# Quick check last modified (PowerShell)
(Get-Item docs/structure.md).LastWriteTime

---

AI Agent Workflow

When generating structure as AI agent:

Method 1: Use Built-in Script (Fast)

node .codex/skills/project-index/scripts/scan-structure.js . 4 > docs/structure.md

Method 2: Use VS Code Tools (No Script Required)

1. Use list_dir tool to scan root
2. Use list_dir recursively on key folders
3. Use file_search with patterns like **/*.tsx, **/*.ts
4. Combine results into structure.md format

Method 3: Hybrid Approach

1. Run script for basic tree
2. Use read_file on package.json to detect framework
3. Manually add Feature Map based on codebase understanding

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Best Practices

1. Keep it updated: Stale index is worse than no index
2. Feature-focused: Group by business domain, not just folders
3. Include purpose: Don't just list files, explain what they do
4. Patterns over lists: For large folders, show patterns instead of listing all files
5. Version control: Commit structure.md so team shares same understanding
6. Use scripts: Prefer built-in scripts over platform-specific commands