format.hackclub.com

A paste-clean-copy tool: you paste any rich text; the app sanitizes and normalizes the HTML; images are rehosted on Hack Club's CDN (R2 + Cloudflare) with dedupe, intelligent conversion, and metadata stripping; you copy the Gmail-safe result and paste into Gmail.

Things to test:

• Image upload:
  • PNG with transparency
  • PNG no transparency (converts to jpeg)
  • JPEG
• Pasting rich HTML from Gmail with image attachments
• Pasting image directly from local fileystem
• Pasting image from a website
• Pasting from Gmail an email with multiple different images in it and make sure they all come through

Architecture

Browser (Next.js + Lexical)
        |
        | OAuth (Google One-Tap/Popup) → ID token
        v
Go API (chi)  ──>  Image pipeline (libvips via bimg + jpegli/mozjpeg + oxipng/libimagequant)
        |             └─ hash, dedupe, resize, convert, strip metadata
        |                        
        └─> R2 (S3 API)  <── Cloudflare CDN on custom domain (e.g., i.format.hackclub.com)

Development

Backend (Go)

cd backend
go run cmd/server/main.go

Frontend (Next.js)

cd frontend
npm run dev

Environment Variables

See .env.example for required environment variables.

Docker Deployment

Quick Start

# Copy and configure environment
cp .env.example .env
# Edit .env with your values...

# Start the application
docker-compose up -d app

Port Configuration

By default, the app runs on port 8080. You can customize the external port using environment variables:

# Use different external port
HOST_PORT=9000 docker-compose up -d app

# Or set in .env file
HOST_PORT=9000

Note: HTTPS is handled by your hosting platform's reverse proxy, not by the container.

Features

• Predictable Gmail formatting: basic, consistent HTML subset
• Bulletproof images: rehosted on our domain, scaled, optimized, deduped, and cached
• Speed: paste → clean → copy in < 10 seconds for typical documents
• Safety: sanitize HTML; strip tracking & scripting