Overview

This webhook is triggered to notify merchants about lifecycle events of a debit transaction under an eNACH presentation. It includes all critical stages — from transaction creation to success/failure.

This helps the merchant reconcile payments, track processing, and take action (e.g., retry, notify customer) based on real-time transaction status.

Trigger Points

Webhook is triggered when any of the following events occur for a debit transaction:

Status	Description
`new`	Transaction is created but not yet submitted to the bank
`submitted_to_bank`	Transaction submitted to the sponsor/destination bank
`payment_success`	Debit successfully processed
`payment_failed`	Debit attempt failed; reason is sent in `remarks` field

Webhook Request Format

Method: POST
Content-Type: application/json
Authentication: Optional HMAC-SHA256 signature in header

🔹 Webhook Payload Fields

Field	Type	Description
`transactionId`	string	Unique Castler transaction ID
`presentationId`	string	Debit presentation ID this transaction belongs to
`customerName`	string	Name of the customer
`debitAmount`	number	Amount attempted to be debited
`createdAt`	datetime	ISO timestamp of when the transaction was created
`statementDate`	datetime	Date the transaction will reflect in bank statement
`nextPaymentDate`	datetime	Next scheduled payment date (for recurring mandates)
`transactionReference`	string	Unique reference sent to NPCI/bank
`status`	string	Transaction status: `new`, `submitted_to_bank`, `payment_success`, `payment_failed`
`remarks`	string	Present only if status is `payment_failed`. Reason for failure.
`paymentCount`	integer	Total number of payments scheduled
`paidCount`	integer	Number of payments already successfully completed

🔹 Sample Webhook Payloads

🟡 1. Transaction Created (`new`)

{
  "transactionId": "NPT250903111001079LB55PUGBWWZ2TH",
  "presentationId": "NSP2509031106081538R9E4R82462BWW",
  "customerName": "Abhinav Singh",
  "debitAmount": 50,
  "createdAt": "2025-09-03T11:11:37.049813267",
  "statementDate": "2025-09-04T00:00",
  "nextPaymentDate": "2025-09-04T00:00",
  "transactionReference": "LB55PUGBWWZ2TH",
  "status": "new",
  "paymentCount": 2,
  "paidCount": 1
}

📤 2. Submitted to Bank (`submitted_to_bank`)

{
  "transactionId": "NPT250903111001079LB55PUGBWWZ2TH",
  "presentationId": "NSP2509031106081538R9E4R82462BWW",
  "customerName": "Abhinav Singh",
  "debitAmount": 50,
  "createdAt": "2025-09-03T11:11:37.049813267",
  "statementDate": "2025-09-04T00:00",
  "nextPaymentDate": "2025-09-04T00:00",
  "transactionReference": "LB55PUGBWWZ2TH",
  "status": "submitted_to_bank",
  "paymentCount": 2,
  "paidCount": 1
}

✅ 3. Payment Success (`payment_success`)

{
  "transactionId": "NPT250903111001079LB55PUGBWWZ2TH",
  "presentationId": "NSP2509031106081538R9E4R82462BWW",
  "customerName": "Abhinav Singh",
  "debitAmount": 50,
  "createdAt": "2025-09-03T11:11:37.049813267",
  "statementDate": "2025-09-04T00:00",
  "nextPaymentDate": "2025-09-04T00:00",
  "transactionReference": "LB55PUGBWWZ2TH",
  "status": "payment_success",
  "paymentCount": 2,
  "paidCount": 1
}

❌ 4. Payment Failed (`payment_failed`)

{
  "transactionId": "NPT250903111001412E5996AIZKKPM6N",
  "presentationId": "NSP2509031106081538R9E4R82462BWW",
  "customerName": "Abhinav Singh",
  "debitAmount": 50,
  "createdAt": "2025-09-03T11:11:36.783545",
  "statementDate": "2025-09-04T00:00",
  "transactionReference": "E5996AIZKKPM6N",
  "status": "payment_failed",
  "remarks": "Transaction not allowed, Debit is already created for this UMRN",
  "paymentCount": 2,
  "paidCount": 2
}