youpi-pg/YouPI-PG

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0% Gateway Fees • Direct-to-Bank Settlement • WhatsApp Pre-Checkout OTP • Bank SMS & Gmail Observers

Live Demos • Why YOUPI? • Architecture • Superpowers • Quickstart • Merchant Integration • Banking Observers • Port Topology • Docs

🎬 Live Product Demos

💡 Stop Paying 2–3% + 18% GST to Payment Aggregators

🏗️ Architecture at a Glance

🚀 Key Features & Superpowers

1. ⚡ 0% Transaction Fees Forever

2. 💬 WhatsApp Pre-Checkout Authentication (Berry Protocol)

3. 🔒 Deterministic Single-Slot FIFO Queue Engine

4. 📱 Native Android Observer APK (com.youpi.observer)

5. 📧 Automated Gmail & Google Messages Ingestion

6. 🏪 Dual Operational Modalities

7. 🎨 100% White-Label Customizer

8. 🚦 5 Standardized Merchant Outcome Pages

⚡ Quickstart in 60 Seconds

Prerequisites

1. Clone & Install Dependencies

git clone https://github.com/gxurav1710/YouPI-PG.git youpi-pg
cd youpi-pg
npm install

2. Configure Environment

cp .env.example .env

3. Zero-Config Launch (Auto-Initialized SQLite)

npm run dev
# or
npm start

4. Run the Full Regression Test Suite

npm test

============================================================
🧪 YOUPI PG V2 — FULL REGRESSION TEST RUNNER
Running 31 curated test suites...
============================================================
[1/31] Testing packages/common/src/__tests__/common.test.js... ✅ PASS (0.22s)
...
[31/31] Testing scripts/production-infrastructure.test.js... ✅ PASS (0.17s)
============================================================
🎉 ALL 31 TEST SUITES PASSED CLEANLY (Total: 17.68s)
============================================================

📦 Universal Merchant Integration

Step 1: Add the Universal Script to your <head>

<!-- Official YOUPI PG Universal Integration Script -->
<script src="https://pay.yourdomain.com/youpi.js" 
        data-youpi-key="YOUR_MERCHANT_PUBLIC_KEY" 
        data-currency="INR">
</script>

Step 2: Declarative Button (Zero JavaScript Required!)

<button data-youpi-pay
        data-order-id="ORDER-1001"
        data-amount="499.00"
        data-currency="INR">
  ⚡ Buy Now with YOUPI PG
</button>

Step 3: Programmatic API (For React, Vue, Next.js, Nuxt)

window.Youpi.pay({
  order_id: 'ORDER-1001',
  amount: 499.00,
  currency: 'INR',
  name: 'Acme Digital Store',
  description: 'Pro Subscription Top-Up',
  handler: function(response) {
    // response: { status: 'SUCCESS', order_id, amount_received, utr }
    console.log(`Payment confirmed! UTR: ${response.utr}`);
    window.location.href = `/order-success?order_id=${response.order_id}&utr=${response.utr}`;
  },
  onClose: function() {
    console.log('Customer closed payment modal');
  }
});

Step 4: Authoritative Server-to-Server Webhook Verification

Webhook Contract:

Polyglot Webhook Verification Snippets:

1. Node.js (Express)

import crypto from 'node:crypto';

app.post('/api/youpi-webhook', express.raw({ type: 'application/json' }), (req, res) => {
  const signature = req.headers['x-gateway-signature'] || '';
  const secret = process.env.YOUPI_WEBHOOK_SECRET;
  const expected = 'sha256=' + crypto.createHmac('sha256', secret).update(req.body).digest('hex');

  if (signature.length !== expected.length ||
      !crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(expected))) {
    return res.status(401).json({ error: 'Invalid webhook signature' });
  }

  const payload = JSON.parse(req.body.toString('utf8'));
  if (payload.event === 'SUCCESS') {
    // Fulfill order: payload.orderId, payload.utr, payload.amount, payload.amountPaise
  }
  res.status(200).json({ received: true });
});

2. Python (FastAPI)

import hmac, hashlib, json
from fastapi import FastAPI, Request, HTTPException

app = FastAPI()

@app.post("/api/youpi-webhook")
async def youpi_webhook(request: Request):
    raw_body = await request.body()
    signature = request.headers.get("X-Gateway-Signature", "")
    secret = request.app.state.webhook_secret.encode("utf-8")

    expected = "sha256=" + hmac.new(secret, raw_body, hashlib.sha256).hexdigest()
    if not hmac.compare_digest(signature, expected):
        raise HTTPException(status_code=401, detail="Invalid webhook signature")

    payload = json.loads(raw_body.decode("utf-8"))
    if payload.get("event") == "SUCCESS":
        # Fulfill order: payload["orderId"], payload["utr"], payload["amount"]
        pass
    return {"received": True}

3. PHP

<?php
$rawPayload = file_get_contents('php://input');
$signature = $_SERVER['HTTP_X_GATEWAY_SIGNATURE'] ?? '';
$secret = getenv('YOUPI_WEBHOOK_SECRET');

$expected = 'sha256=' . hash_hmac('sha256', $rawPayload, $secret);

if (!hash_equals($expected, $signature)) {
    http_response_code(401);
    exit(json_encode(['error' => 'Invalid webhook signature']));
}

$payload = json_decode($rawPayload, true);
if (($payload['event'] ?? '') === 'SUCCESS') {
    // Fulfill order: $payload['orderId'], $payload['utr'], $payload['amount']
}

http_response_code(200);
echo json_encode(['received' => true]);
?>

4. Go (net/http)

package main

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"io"
	"net/http"
	"os"
)

func youpiWebhookHandler(w http.ResponseWriter, r *http.Request) {
	rawBody, err := io.ReadAll(r.Body)
	if err != nil {
		http.Error(w, "Cannot read body", http.StatusBadRequest)
		return
	}
	defer r.Body.Close()

	signature := r.Header.Get("X-Gateway-Signature")
	secret := []byte(os.Getenv("YOUPI_WEBHOOK_SECRET"))

	mac := hmac.New(sha256.New, secret)
	mac.Write(rawBody)
	expected := "sha256=" + hex.EncodeToString(mac.Sum(nil))

	if !hmac.Equal([]byte(signature), []byte(expected)) {
		http.Error(w, "Invalid webhook signature", http.StatusUnauthorized)
		return
	}

	var payload struct {
		Event       string `json:"event"`
		OrderId     string `json:"orderId"`
		UTR         string `json:"utr"`
		Amount      string `json:"amount"`
		AmountPaise int64  `json:"amountPaise"`
	}
	if err := json.Unmarshal(rawBody, &payload); err == nil && payload.Event == "SUCCESS" {
		// Fulfill order: payload.OrderId, payload.UTR, payload.Amount
	}

	w.WriteHeader(http.StatusOK)
	w.Write([]byte(`{"received":true}`))
}

🔭 Tri-Channel Observation Mesh

              CUSTOMER SCANS & PAYS VIA UPI
                           │
                           ▼
                 RECEIVING BANK ACCOUNT
                           │
        ┌──────────────────┼──────────────────┐
        ▼                  ▼                  ▼
┌───────────────┐  ┌───────────────┐  ┌───────────────┐
│  CELLULAR SMS │  │   BANK PUSH   │  │  GMAIL CREDIT │
│  ALERT ON SIM │  │ NOTIFICATION  │  │  ALERT EMAIL  │
└───────┬───────┘  └───────┬───────┘  └───────┬───────┘
        │                  │                  │
        ▼                  ▼                  │
┌──────────────────────────────────┐          │
│    NATIVE ANDROID OBSERVER APK   │          │
│  com.youpi.observer (Foreground) │          │
│     HMAC-SHA256 Signed Payload   │          │
└─────────────────┬────────────────┘          │
                  │                           ▼
                  │                 ┌───────────────────┐
                  │                 │   GMAIL OBSERVER  │
                  │                 │ Google Cloud API  │
                  │                 └─────────┬─────────┘
                  │                           │
                  └─────────────┬─────────────┘
                                ▼
                   PAYMENT CORE REST ENGINE
               Exact Amount & UTR Normalization
                                │
                                ▼
                       SUCCESS CONFIRMED

🌐 Port Topology & Microservices Map

🔒 Security & Reliability Architecture

📚 Documentation Hub

⚖️ License

Take back control of your payments. Zero middleman fees. Direct settlement.

⭐ Star this repository if you believe in open, zero-fee payment infrastructure!