The L4 cache#

This is my own image cdn built on cloudflare r2 mainly so I can have fast optimized images on my blog.

Docs#

bun install
wrangler r2 bucket create l4-images
wrangler kv namespace create L4

Update wrangler.toml with the KV namespace ID and set HOST to your domain as well as INDIKO_URL to your Indiko instance

Production#

wrangler secret put INDIKO_CLIENT_ID
wrangler secret put INDIKO_CLIENT_SECRET

bun run deploy

Development#

bun run dev

Create .dev.vars for local development:

INDIKO_CLIENT_ID=your_client_id
INDIKO_CLIENT_SECRET=your_client_secret

CLI Usage#

Install CLI#

cd cli
bun install
bun run build
npm link

Configure#

l4 config --api-key <your-api-key> --url https://l4.yourdomain.com

Upload Image#

l4 upload image.jpg
l4 upload image.jpg --key custom-name.jpg

List Images#

l4 list
l4 list --limit 50

Delete Image#

l4 delete image-key.jpg

Get Image URL#

l4 url image.jpg
l4 url image.jpg --width 800 --format webp --quality 85

Image Transformations#

Images are served via /i/:key with optional query parameters:

• w - Width (pixels)
• h - Height (pixels)
• f - Format (auto, webp, avif, jpeg)
• q - Quality (1-100, default 85)
• fit - Fit mode (scale-down, contain, cover, crop, pad)

Examples#

/i/photo.jpg?w=800&f=webp
/i/photo.jpg?w=400&h=400&fit=cover&q=90
/i/photo.jpg?f=auto

API Endpoints#

Authentication#

• GET /login - Login page
• GET /api/login - Initiate OAuth
• GET /api/callback - OAuth callback
• POST /api/logout - Logout
• GET /api/me - Get current user

Images#

• POST /api/upload - Upload image (multipart/form-data)
• GET /api/images - List images
• DELETE /api/images/:key - Delete image
• GET /i/:key - Serve image (public)

API Keys#

• GET /api/keys - List API keys
• POST /api/keys - Create API key
• DELETE /api/keys/:id - Delete API key

Architecture#

┌─────────────┐
│   Browser   │
└──────┬──────┘
       │
       ├─── HTML/JS (Indiko OAuth)
       │
       ├─── Upload/Manage Images
       │
       v
┌─────────────────┐
│ Cloudflare      │
│ Workers         │
│                 │
│ - Auth          │
│ - Transform     │
│ - Cache         │
└────────┬────────┘
         │
         ├─── Session/Metadata
         v
    ┌────────┐
    │   KV   │
    └────────┘
         │
         ├─── Original Images
         v
    ┌────────┐
    │   R2   │
    └────────┘

© 2025-present Kieran Klukas