💸 Kuber Mail

Kuber Mail is a lightweight, email-driven payment gateway that lets businesses, freelancers, or anyone accept UPI payments without needing a bank account or API integration.

Forget the hassle of connecting to banks, handling APIs, or complex payment SDKs. Kuber Mail works by:

1. Generating unique payment orders with tiny fractional amounts.
2. Scanning a configured email inbox for partner payment notifications.
3. Automatically matching received payments to pending orders.

Perfect for small businesses, freelancers, or informal services looking for a simple, automated, and secure payment solution.

[User] --> Create Order --> [Kuber Mail Backend]
                                |
                                v
                       Adds Fraction to Amount
                                |
                                v
                     Generates UPI QR Code & URI
                                |
                                v
                       Payer Scans QR & Pays
                                |
                                v
                     Email Notification Received
                                |
                                v
                     IMAP Polling & Payment Matching
                                |
                                v
                      Order Status Updated (PAID)

Step-by-Step Flow:

1. Create a payment order via /create_order or web form.
2. Kuber Mail generates the full amount (base + fractional).
3. A UPI URI and QR code are created for the payer.
4. Payer sends money via UPI.
5. Kuber Mail polls your email inbox using IMAP.
6. Payment emails are parsed and matched with pending orders.
7. Order status updates to PAID, and fractions are released for reuse.

💡 Tip: Each fractional amount ensures you can distinguish payments even if multiple payers send the same base amount.

Built in Python 3, Kuber Mail uses Flask for APIs and IMAP scanning for emails.

Modules at a glance:

Backend Highlights:

• Threaded IMAP polling detects incoming payments in real-time.
• Orders have unique fractional amounts.
• All orders are stored in a JSON file (orders.json).
• Payments are matched automatically via amount + payer name regex.
• Fractions are released once payments are confirmed or orders expire.

POST /create_order

Payload Example:

{
  "amount": 1000.0,
  "expected_payer": "John Doe",
  "upi_id": "receiver@upi" // optional, defaults to configured receiver UPI
}

Response Example:

{
  "txn_id": "uuid-generated-id",
  "upi_uri": "upi://pay?pa=receiver@upi&pn=ReceiverName&am=1000.12&cu=INR&tn=uuid-generated-id",
  "qr_data_uri": "data:image/png;base64,...",
  "full_amount": "1000.12",
  "expires_at": "2025-09-13T12:34:56Z",
  "message": "Order created. Waiting for payment."
}

GET /order/<txn_id>

Response Example:

{
  "txn_id": "uuid-generated-id",
  "base_amount": 1000.0,
  "full_amount": 1000.12,
  "fraction": 12,
  "expected_payer": "John Doe",
  "upi_id": "receiver@upi",
  "status": "PENDING",
  "created_at": "2025-09-13T12:00:00Z",
  "expires_at": "2025-09-13T12:05:00Z",
  "amount_received": null,
  "payer_name": null,
  "message": "Waiting for payment"
}

ORDERS_FILE=orders.json
LIVE_LIMIT=100
FRACTION_MIN=0
FRACTION_MAX=99
ORDER_TTL_SECONDS=300
MAIL_POLL_INTERVAL=10

RECEIVER_UPI_ID=receiver@upi
UPI_PARTNER_EMAILS=partner1@example.com,partner2@example.com

IMAP_HOST=imap.gmail.com
IMAP_USER=your-email@gmail.com
IMAP_PASS=your-app-password
IMAP_SSL=True
IMAP_MAILBOX=INBOX

git clone https://github.com/DevLord-Avijit/kuber-mail.git
cd kuber-mail
pip install -r requirements.txt

Create your .env file, then:

python app.py

Open your browser: http://localhost:5000 🚀

• WebSocket notifications for live updates
• Database integration (PostgreSQL/MySQL)
• Multi-partner email support with separate folders
• Admin dashboard for monitoring live payments & reports

MIT License