ai-codex

This project was entirely designed, written, and published by Claude Code (Anthropic's AI coding assistant). The concept, implementation, documentation, and examples were all generated in a single conversation session.

Generate a compact codebase index that gives AI coding assistants instant context about your project structure. Instead of wasting 50K+ tokens on file exploration at the start of every conversation, your AI assistant reads a pre-built index and gets to work immediately.

Why

Every time you start a conversation with an AI coding assistant (Claude Code, Cursor, GitHub Copilot, etc.), it spends thousands of tokens exploring your codebase -- reading files, scanning directories, building a mental model. This happens every single conversation.

ai-codex solves this by generating compact, structured reference files that capture:

• Every API route with its HTTP methods
• Every page with its rendering strategy (client vs. server)
• Every library function signature
• Your database schema (key fields, relationships)
• Your component tree with props

The result: 5 small files that replace 50K+ tokens of exploration, every time.

Quick Start

Run it in your project root:

npx ai-codex

That's it. It auto-detects your framework and generates the index.

Output

By default, files are written to .ai-codex/ in your project root:

| File | What it contains | |------|-----------------| | routes.md | API routes grouped by resource, with HTTP methods | | pages.md | Page tree with client/server rendering tags | | lib.md | Library exports -- function signatures, classes | | schema.md | Database schema -- key fields, FKs, relationships | | components.md | Component index with props, grouped by feature |

Files that don't apply are skipped (e.g., no schema.md if you don't use Prisma).

Configuration

CLI Flags

npx ai-codex --output .claude/codex     # custom output directory
npx ai-codex --include src lib           # only scan these directories
npx ai-codex --exclude tests __mocks__   # skip these directories
npx ai-codex --schema prisma/schema.prisma  # explicit schema path

Config File

Create a codex.config.json in your project root:

{
  "output": ".ai-codex",
  "include": ["src", "lib", "app"],
  "exclude": ["tests", "__mocks__"],
  "schema": "prisma/schema.prisma"
}

CLI flags override config file values.

Output Format Examples

routes.md

## products
GET,POST     /api/products [auth,db]
GET,PUT,DELETE /api/products/:id [auth,db]
POST         /api/products/:id/images [auth]

## orders
GET,POST     /api/orders [auth,db]
GET          /api/orders/:id [auth,db]
POST         /api/orders/:id/refund [auth,db]

pages.md

[client]   /                                                  HomePage
[server]   /products                                          ProductsPage
[client]   /products/:id                                      ProductDetailPage
[server]   /cart                                               CartPage
[client]   /checkout                                           CheckoutPage

lib.md

## lib
cart-utils.ts
  fn calculateTotal
  fn applyDiscount
  fn formatPrice
auth.ts  fn validateSession
stripe.ts  fn createPaymentIntent

schema.md

## Product
  id                     String    PK
  categoryId             String
  -> Category, OrderItem[], Review[]

**Order** id(PK) | userId | status -> User, OrderItem[]
**User** id(PK) | email(UQ) -> Order[], Review[]

components.md

## components
(c) CartDrawer  items, onRemove, onCheckout
(c) ProductCard  product, onAddToCart
    PriceDisplay  amount, currency
(c) SearchBar  onSearch, placeholder

Integration with AI Assistants

Claude Code

Add this to your CLAUDE.md:

## Codebase Index
Pre-built index files are in `.ai-codex/`. Read these FIRST before exploring the codebase:
- `.ai-codex/routes.md` -- all API routes
- `.ai-codex/pages.md` -- page tree
- `.ai-codex/lib.md` -- library exports
- `.ai-codex/schema.md` -- database schema
- `.ai-codex/components.md` -- component tree

Cursor / Other AI IDEs

Add the .ai-codex/ directory to your AI assistant's context or rules file. Most AI coding tools support a way to include reference files.

Auto-Refresh

Git Pre-Commit Hook

# .git/hooks/pre-commit
npx ai-codex --quiet
git add .ai-codex/

npm Script

{
  "scripts": {
    "codex": "npx ai-codex --quiet",
    "precommit": "npx ai-codex --quiet && git add .ai-codex/"
  }
}

CI/CD

# GitHub Actions example
- name: Update codebase index
  run: npx ai-codex
- name: Commit index
  run: |
    git add .ai-codex/
    git diff --cached --quiet || git commit -m "chore: update codebase index"

Supported Frameworks

| Framework | Auto-detected | What it scans | |-----------|:------------:|---------------| | Next.js (App Router) | Yes | app/ or src/app/ (api/**/route.ts, **/page.tsx), lib/, components/ | | Next.js (Pages Router) | Yes | pages/ or src/pages/ (api/**/*.ts, **/*.tsx excl. _app/_document/_error), lib/, components/ | | SvelteKit | Yes | src/routes/ (+server.ts routes, +page.svelte pages), src/lib/, components | | Generic TypeScript | Yes | src/, lib/, utils/, components/ |

Schema sources are auto-detected from multiple ORMs:

• Prisma at prisma/schema.prisma (or nested under prisma/schema/)
• Drizzle at db/schema.ts, src/db/schema.ts, lib/db/schema.ts, src/lib/db/schema.ts, app/db/schema.ts, src/app/db/schema.ts, database/schema.ts, drizzle/schema.ts, or src/lib/server/db/schema.ts (SvelteKit convention) — including split-file layouts where <base>/schema/ is a directory of .ts files

Override with --schema <path> for either ORM (file extension determines the parser).

Supported Runtimes

| Runtime | Auto-detected | What it detects | |----------|:------------:|-----------------| | Node.js | Yes (default) | Standard Node project | | Cloudflare Workers | Yes (SvelteKit) | adapter-cloudflare in svelte.config.js, or wrangler.jsonc/wrangler.toml — extracts D1, R2, KV bindings. Next.js projects are always reported as Node.js. |

What Gets Skipped

• node_modules/, .next/, dist/, build/, .git/, .worktrees/, __pycache__/, .turbo/, .cache/, coverage/, .nyc_output/, .parcel-cache/, and ai-codex's own output (.ai-codex/, .claude/)
• .d.ts declaration files, .map source maps, .min.js / .min.css minified files
• Backup files (*.backup.*, *-backup-*)
• shadcn/radix UI primitives (button, dialog, etc.) in components/ui/

Contributing

1. Fork the repo
2. Create a feature branch: git checkout -b my-feature
3. Make your changes
4. Test on a real project: cd /path/to/your/project && npx tsx /path/to/ai-codex/src/generate-codex.ts
5. Submit a pull request

Ideas for Contributions

• Support for more frameworks (Remix, Astro)
• Support for more ORMs (TypeORM, Knex)
• Watch mode (--watch) for continuous regeneration
• Token count estimation in output
• Support for Python projects (FastAPI, Django)

License

MIT