@adaptive-ds/cfb2 - 🚀 Zero-Cost B2 Object Storage Cloudflare Proxy

A clever Cloudflare Worker that eliminates Backblaze B2 outbound bandwidth costs through using the Cloudflare Network of the Bandwidth Alliance.

• Zero bandwidth costs – leverage Cloudflare's Bandwidth Alliance with Backblaze B2 for free outbound traffic.
• Lightning fast – runs on Cloudflare's global edge network with automatic CDN capabilities.
• Dead simple – just point it at your B2 bucket and forget about expensive bandwidth bills.
• Production ready – handles CORS, proper headers, and multiple environments out of the box.

Stop paying for outbound bandwidth and start serving your media files smarter, not harder.

Quick Links

• code - https://github.com/david1gp/cfb2
• npm - https://www.npmjs.com/package/@adaptive-ds/cfb2
• cloudflare bandwidth alliance - https://www.cloudflare.com/bandwidth-alliance/

Features

• Proxies requests to Backblaze B2 storage through Cloudflare Workers
• Eliminates outbound bandwidth costs via Bandwidth Alliance
• Full CORS support with configurable origins
• Multi-project support – deploy multiple environments for different use cases
• Custom domain routing – clean URLs that hide your raw storage infrastructure

Architecture

The Worker acts as a transparent proxy between your users and Backblaze B2:

User Request → Custom Domain → Cloudflare Worker → Backblaze B2 → Cloudflare Worker → User Response

Since Cloudflare and Backblaze are Bandwidth Alliance partners, the data transfer between them is free, eliminating your outbound bandwidth costs.

Multi-Project Architecture

Deploy multiple environments for different projects:

cdn.yourdomain.com     → Production Environment (media, assets)
dev-storage.yourdomain.com → Development Environment

Each environment can point to different B2 buckets with customized CORS and caching settings.

Prerequisites

• Pnpm/Bun/Npm for package management
• Cloudflare account (for Workers deployment)
• Backblaze B2 bucket with public URL

Local Development

1. Clone the repository.
2. Install dependencies:

   bun install

Configuration

The Worker uses environment variables for configuration:

• B2_BUCKET_PUBLIC_BASE_URL: Your Backblaze B2 bucket public URL
• HEADER_CORS_ALLOW_ORIGIN: Comma-separated list of allowed origins (default: "*")
• HEADER_CORS_MAX_AGE: CORS max-age header value (default: "300")

Deployment to Cloudflare Workers

1. Login to Cloudflare:

   wrangler login

2. Configure Account ID (if needed, add to wrangler.jsonc):

   wrangler whoami

   Then update wrangler.jsonc with account_id = "your-account-id".

3. Deploy Single Environment:

   bun run deploy

4. Deploy All Environments:

   bun run ops/deploy.ts

   This will deploy all configured environments (production, staging, etc.).

5. Monitor:

   wrangler tail adaptive-cfb2

Environment Setup

The project supports multiple environments through wrangler.jsonc. See wrangler.example.jsonc for a comprehensive configuration example.

Security Considerations

• Root path (/) access is blocked against crawlers and bots
• CORS is configurable per environment
• No sensitive data is logged or exposed
• Custom domains hide storage infrastructure details
• Environment isolation prevents cross-contamination

License

MIT License - feel free to use this in your projects and save on bandwidth costs!