API Reference
Callback API
Overview
The Callback API provides event-based notifications posted to the merchant's server for transaction-related events (success or failure). Responses are sent server-to-server using the POST method in name-value pair format to the merchant’s configured URL.
Process Flow
- The customer initiates a payment on the merchant’s website, redirecting to the NTT DATA payment page or using a seamless API request.
- The customer selects a payment option and authorizes the transaction.
- Upon transaction completion, the response is posted to the merchant’s return URL and callback URL (if configured).
- The merchant’s IP and domain URL must be whitelisted.
Prerequisites
- Callback Configuration: Must be set up at NDPS for the merchant.
- IP Whitelisting: Share details via email with integration support.
- Web Server: Callback URL must be accessible.
- HTTPS: Must be enabled with TLS v1.2 or higher.
- Duplicate Handling: Must be managed at the merchant’s end.
- Test Environment: Sandbox must be set up to verify webhook responses.
Status Codes
| S.No | Initial Status | Final Status | Timeframe | Description |
|---|---|---|---|---|
| 1 | Initiated | Success | Real-time | Transaction successful |
| 2 | Pending | Success | T day | Pending at NDPS but successful at bank |
| 3 | Success | Success | T+1 | Pending post-reconciliation |
| 4 | Failed | Failed | T+1 | Failed post-reconciliation |
| 5 | Initiated | Failed | T day | Transaction failed on T day |
| 6 | Success | Auto Reversal | T+2 | Successful but reversed after T+2 |
| 7 | Challan Generated | Pending | T day | Challan generated but unpaid |
| 8 | Challan Paid | Success | T day | Challan generated and paid |
Receive Transaction Callback
Receives event-based transaction notifications (success or failure) posted to the merchant’s configured URL.
Response Attributes
Attribute
Description
payInstrument
object (4 fields)
Optional
Payment Instrument