REST API · JSON responses

API Documentation

Name: fusioniuApi
Author: mespark

Integrate FamPay payment verification into your application in minutes with our simple REST API.

🔑 You need an API key

Every request to /genqr and /check requires ?key=YOUR_API_KEY. Sign up, then generate a key from your dashboard.

Generate API key →

Need a Gmail App Password?

The /check endpoint requires a 16-char Gmail App Password (not your normal password).

Get the guide →

Live API Playground

Try the API directly from your browser. No signup needed.

API Key

UPI ID

Amount (₹)

Merchant name

/api/public/genqr?key=&upi=yourname%40fam&amount=10&name=My+Store

Response

Response will appear here…

1. Generate UPI QR

Create a dynamic UPI QR code. Requires an API key.

GEThttps://fusioniuapi.mespark.in/api/public/genqr?key=YOUR_API_KEY&upi=YOURUPI@fam&amount=AMOUNT&name=MERCHANTNAME

Request Parameters

Parameter	Type	Description
key	Required	Your API key from /keys
upi	Required	Your UPI ID (e.g. `yourname@fam`)
amount	Required	Fixed amount in INR (user can't edit it)
name	Required	Merchant / payee name shown on the QR

Response

json

{
  "status": "success",
  "data": {
    "qr_image": "data:image/png;base64,iVBOR...",
    "upi_uri": "upi://pay?pa=yourname@fam&pn=My%20Store&am=10&cu=INR",
    "upi_id": "yourname@fam",
    "amount": "10",
    "name": "My Store",
    "created_at_ist": "16-05-2026 23:47:00"
  },
  "dev": "@btwspark"
}

2. Verify Payment

Scan your Gmail for FamPay "You received" emails and confirm payment.

For payments from other apps (Paytm / GPay / PhonePe → FamPay) use utr:

GEThttps://fusioniuapi.mespark.in/api/public/check?key=YOUR_API_KEY&mail=YOUREMAIL@gmail.com&apppass=APPPASSWORD&utr=UTRNUMBER&amount=AMOUNT

For FamPay → FamPay transfers use txnid:

GEThttps://fusioniuapi.mespark.in/api/public/check?key=YOUR_API_KEY&mail=YOUREMAIL@gmail.com&apppass=APPPASSWORD&txnid=FMPIBXXXXXXX&amount=AMOUNT

Request Parameters

Parameter	Type	Description
key	Required	Your API key from /keys
mail	Required	Your Gmail address (with or without @gmail.com)
apppass	Required	Gmail App Password (16 chars, not your normal password)
amount	Required	Expected amount in INR for validation
utr	Conditional	12-digit UTR (for non-FamPay payments)
txnid	Conditional	FamPay Txn ID like `FMPIB...` (FamPay → FamPay only)

Important: Use either utr OR txnid — not both. We only scan emails starting with "You received" to ensure valid payment confirmations.

Success Response

json

{
  "status": "success",
  "data": {
    "transaction_id": "FMPIB5255631361",
    "amount": 10,
    "utr": "301268197755",
    "sender_name": "Anuj Patel",
    "payment_time_ist": "16-05-2026 23:50:12",
    "verified": true
  },
  "dev": "@btwspark"
}

Error Responses

json

// 401 Missing or invalid key
{ "status": "error", "message": "API key required", "dev": "@btwspark" }

// 403 Blocked / disabled
{ "status": "error", "message": "Account blocked", "dev": "@btwspark" }

// 409 Already verified (each UTR / Txn ID can only be used ONCE)
{ "status": "error", "message": "Transaction already verified",
  "details": "This UTR / Txn ID has already been used.", "dev": "@btwspark" }

// 404 Not Found
{ "status": "error", "message": "Transaction not found",
  "details": "No matching payment found in email inbox", "dev": "@btwspark" }

// 409 Amount Mismatch
{ "status": "error", "message": "Amount mismatch", "expected": 10, "found": 5, "dev": "@btwspark" }

// 401 Gmail Auth failure
{ "status": "error", "message": "Invalid Gmail app password or authentication failed", "dev": "@btwspark" }

Integration Examples

Copy-paste ready snippets in your favorite language.

→ Generate QR

curl

curl "https://fusioniuapi.mespark.in/api/public/genqr?upi=yourname@fam&amount=10&name=My%20Store"

→ Verify Payment

curl

curl "https://fusioniuapi.mespark.in/api/public/check?mail=you@gmail.com&apppass=abcdefghijklmnop&utr=301268197755&amount=10"

Error Codes

Code	Status	Description
400	Bad Request	Missing or invalid parameters
401	Unauthorized	Invalid Gmail app password or authentication failed
403	Forbidden	IMAP access disabled or account restricted
404	Not Found	Payment not found in email inbox
409	Conflict	Amount mismatch or duplicate transaction
500	Server Error	Mailbox scan failed; try again