Backblaze B2 Reverse Proxy

A simple Next.js reverse proxy that forwards requests to Backblaze B2's native download API. Serve B2 files from your own domain with the exact same URL path structure.

Live Demo: https://b2-reverse-proxy.vercel.app

Features

• 🌐 Your Domain - Serve B2 files from your own domain
• ⚡ Simple Forwarding - Direct proxy to B2's native download API
• 🔄 Same URL Structure - Matches B2's /file/bucket/path format exactly
• 📦 Public Buckets - Works with public B2 buckets (no auth required)
• 🔒 Private Buckets - Supports private buckets via env credentials or URL token
• 🎯 Range Requests - Supports partial content / byte-range requests
• 🚀 Edge Ready - Deploy on Vercel's edge network

Usage

Just replace f005.backblazeb2.com with your domain:

# Original B2 URL
https://f005.backblazeb2.com/file/my-bucket/path/to/file.jpg

# Your Custom Domain
https://your-domain.com/file/my-bucket/path/to/file.jpg

That's it! No configuration needed for public buckets.

Setup

Local Development

pnpm install
pnpm dev

Test it:

curl http://localhost:3000/file/your-bucket/your-file.jpg

Deploy to Vercel

vercel

Or connect your GitHub repo to Vercel for automatic deployments.

Configuration

Set environment variables in .env.local (local) or Vercel dashboard (production):

# B2 download endpoint (default: https://f005.backblazeb2.com)
B2_DOWNLOAD_URL=https://f005.backblazeb2.com

# For private buckets: B2 credentials (optional)
# Get these from Backblaze B2 > App Keys
B2_KEY_ID=your_application_key_id
B2_APP_KEY=your_application_key

Private Buckets

Two ways to access private buckets:

1. Environment Variables (Recommended)

Set B2_KEY_ID and B2_APP_KEY in your environment. The proxy will automatically generate and cache auth tokens (valid 24h, cached 23h).

# Just use the same URL - auth is handled automatically
curl https://your-domain.com/file/private-bucket/secret-file.pdf

2. URL Parameter

Pass a B2 authorization token in the URL:

# Get a token from B2 API first, then:
curl "https://your-domain.com/file/private-bucket/secret-file.pdf?Authorization=YOUR_B2_TOKEN"

Priority: URL token > Environment credentials > Public access

API

Endpoint: /file/[bucket]/[...path]

Methods: GET, HEAD

Query Parameters:

• Authorization - B2 auth token (optional, for private buckets)

Request Headers Forwarded:

• Range (for partial content requests)

Response Headers Forwarded:

• Content-Type
• Content-Length
• Content-Disposition
• Cache-Control
• ETag
• Last-Modified
• Accept-Ranges
• Content-Range

Examples

# Public bucket
curl https://b2-reverse-proxy.vercel.app/file/my-public-bucket/image.jpg

# Private bucket (with env credentials configured)
curl https://b2-reverse-proxy.vercel.app/file/my-private-bucket/secret.pdf

# Private bucket (with URL token)
curl "https://b2-reverse-proxy.vercel.app/file/my-private-bucket/secret.pdf?Authorization=4_abc123..."

# Check file info
curl -I https://b2-reverse-proxy.vercel.app/file/my-bucket/file.jpg

License

MIT