LinkPay API Migration Guide

1. API Domains

Environment	Domain
Production	`https://api.evonetonline.com`
Sandbox	`https://sandbox.evonetonline.com`

Operation	Legacy Version	New Version
Create LinkPay	`POST /g2/v0/payment/mer/{sid}/evo.e-commerce.linkpay`	`POST /interaction`
Retrieve LinkPay	`GET /g2/v0/payment/mer/{sid}/evo.e-commerce.linkpay/{merchantOrderID}`	`GET /interaction/{merchantOrderID}`

Item	Legacy Version	New Version
Signature Method	Requires building a signature string, hashing it with SHA256, and including the result in `Authorization`.	Simplified authentication — no manual signature construction required. Use the Secret Key at the store level directly in the `Authorization` header.
Key Configuration	N/A	The system provides a `KeyID`, and `SignType` is `Key-based`.

📘
The same authentication type used in requests is also applied to responses and asynchronous notifications.

The transInitiator object is added in both Retrieve Interaction responses and Interaction Notifications.
It appears when the frontend product collects and passes related information to LinkPay system.
This field identifies the transaction initiator, improving traceability and analytics.

When creating a LinkPay order using the Interaction API, the merchantTransID must follow this format: merchantTransID = "pay-" + 28-character random UUID
This ensures consistent order identification across requests and reconciliation.

The result object now includes a new field: category.
When the response code is not successful (not starting with S), the system adds a category field to indicate the error type.

Please refer to the documentation for the latest response code definitions: Result Code Reference

The new and old LinkPay APIs are 99% backward compatible.
Response structures and webhook formats remain consistent.
Google Pay has already been implemented in the new Get Interaction API for a smoother experience.

The new LinkPay (Interaction API) brings several major advantages:

Simpler integration: no more manual signature string construction.
Improved flexibility: easier configuration for subscription and card binding.
Future-ready design: upcoming features like Auth + Capture will first be available on this version.
Enhanced compatibility: almost identical structure to the legacy API, ensuring a smooth migration.