⚡ PoopiePay

A fast, minimalist, and ultra-lightweight UPI QR Code Generator with a persistent file data saver. Designed to run as a single compiled binary or a tiny ~12MB Docker container, perfect for self-hosting on Unraid, Linux, or macOS.

✨ Features

• ⚡ Single Binary: Everything (web server, minimalist UI, and QR engine) is compiled directly into a single ~4.8MB binary with zero runtime dependencies.
• 📱 3 Simple Inputs:
  1. UPI ID: Payee address (e.g. merchant@okhdfcbank or 9876543210@paytm).
  2. Remarks: Transaction note (e.g. Groceries, Dinner, Invoice #12).
  3. Amount: Transaction amount in INR (₹).
• 💾 Automatic File Data Saver:
  • Automatically remembers and pre-populates your UPI ID and Remarks so you only have to type the amount for quick counter payments.
  • Changes to UPI ID or Remarks immediately persist to data/data.json (and browser localStorage).
  • Stores recent payment history in the same JSON file.
• 📷 1-Tap Customer Experience:
  • Generates standard upi://pay?pa=...&am=...&tn=...&cu=INR QR codes.
  • Customers scan with Google Pay, PhonePe, Paytm, BHIM, Cred, or Navi and just hit Pay.
• 🎨 Minimalist & Modern UI:
  • Live real-time QR generation as you type.
  • Quick amount chips (+₹50, +₹100, +₹500, +₹1000, Clear).
  • Copy UPI Deep-Link button for messaging or sharing.
  • Download High-Res QR button (PNG).
  • Clean collapsible transaction history.
• 📦 Hostable on Unraid:
  • Maps to /mnt/user/appdata/poopiepay:/data.
  • Docker container size is only ~12MB!

🚀 Quick Start

Option 1: Run Pre-compiled Binary Directly (No Docker required)

On macOS:

PORT=8080 ./poopiepay

On Linux (x86_64 / Unraid console):

PORT=8080 ./poopiepay-linux-amd64

On ARM Linux (Raspberry Pi / ARM Unraid):

PORT=8080 ./poopiepay-linux-arm64

Open your browser to: http://localhost:8080

Option 2: Docker / Docker Compose

Run with docker-compose:

docker compose up -d

Or run directly with Docker:

docker run -d \
  --name poopiepay \
  --restart unless-stopped \
  -p 8080:8080 \
  -v $(pwd)/data:/data \
  poopiepay

🖥️ Unraid Deployment Guide

In Unraid:

1. Open the Docker tab and click Add Container.
2. Fill in:
   • Name: poopiepay
   • Repository: Build locally or use your image tag.
   • Port: Host 8080 → Container 8080.
   • Path: Host /mnt/user/appdata/poopiepay → Container /data.
3. Click Apply.
4. Access via http://<your-unraid-ip>:8080.

Your settings and recent payment history are saved in /mnt/user/appdata/poopiepay/data.json.

🛠️ Building from Source

Requirements: Go 1.20+ (standard library only).

# Build native binary and Linux cross-compilations in one command:
./build.sh

This generates:

• poopiepay (Native macOS Mach-O executable)
• poopiepay-linux-amd64 (Static Linux ELF binary for Unraid/x86_64)
• poopiepay-linux-arm64 (Static Linux ELF binary for ARM64)

📂 Project Structure

PoopiePay/
├── main.go               # Single Go web server & file data saver (stdlib only)
├── static/
│   ├── index.html        # Modern minimalist single-page app
│   └── qrcode.min.js     # Bundled 19KB client QR engine (no CDN required)
├── data/
│   └── data.json         # Persistent JSON file storage
├── Dockerfile            # Multi-stage build producing ~12MB container
├── docker-compose.yml    # Ready for Docker / Unraid
├── build.sh              # Single-command cross-compiler
├── PLANNING.md           # Architecture and specification
└── README.md             # Documentation

🔒 Security & Performance

• Zero pip / npm bloat: 100% built on Go standard library.
• Atomic file writes: Uses temporary files and atomic renames to prevent file corruption during power cuts or server restarts.
• Air-gapped & Offline: All static assets are embedded into the binary. No external CDN requests needed at runtime.