Developers

Test Scenarios for myPOS Web Checkout

Ready to test your integration? Here are the key scenarios to make sure everything works as expected.

Getting Started

Before you begin, make sure you have:

1Set up the myPOS Web Checkout integration
2Your test credentials from the Test Data page
3Configured your URL_Notify endpoint

Test Environment URL

https://www.mypos.com/vmp/checkout-test

Essential Test Scenarios

Go through these scenarios to validate your integration:

Scenario 1

Error in POST Request

Your integration should handle errors and show clear messages to users.

How to test: Send a request with missing parameters, wrong formats, or incorrect data types.

Scenario 2

Invalid Signature

Ensures the system rejects tampered or incorrect requests.

How to test: Change the signature value before sending your request.

Scenario 3

Verify Message Signature

Confirms the response from myPOS is authentic and hasn't been tampered with.

How to test: After a successful transaction, validate the signature in the response.

Scenario 4

Customer Cancels Payment

Your system should handle cancellations smoothly without errors.

How to test: Start a payment, then cancel on the myPOS Checkout page. Check your URL_Cancel receives the cancellation.

Scenario 5 · Most Important

Successful Payment

This is the main payment flow — complete a payment from start to finish.

How to test: Use a test card and confirm:

Payment is processed successfully
Customer is redirected to URL_OK
Notification is sent to URL_Notify
Your system records the transaction
Scenario 6

Successful Payment, Failed Notification

If your server doesn't respond correctly, the payment will be reversed.

How to test: Complete a payment but make your server:

  • • Not respond with HTTP 200 OK
  • • Not return OK in the body
  • • Be unreachable or timeout

Critical: Don't Skip This

Common Pitfall: Misconfigured URL_Notify

Even if your integration reaches the myPOS Checkout page, it does NOT mean your integration is complete.

What goes wrong:

  1. 1Customer enters card details
  2. 2Payment is processed
  3. 3myPOS cannot notify your system
  4. 4Payment is automatically reversed
  5. 5Customer is confused and you lose the sale

Common problems:

  • Notify URL is not publicly accessible (e.g., localhost)

  • Notify URL doesn't use HTTPS

  • Server doesn't return HTTP 200 OK with body "OK"

  • Public certificate is invalid or missing

How to Avoid This

Make sure your URL_Notify endpoint:

Uses HTTPS (not HTTP)
Is publicly accessible (not localhost or private IP)
Returns HTTP 200 OK status code
Returns "OK" in plain text as the response body
Validates the response signature from myPOS

Example correct response:

Status: HTTP 200 OK
Content-Type: text/plain
Body: OK

Tip: Use tools like webhook.site or requestbin.com to test your notification endpoint before going live.

Testing Checklist

Before you finish, make sure you have:

0/8

Next Steps

Response Codes

Understand all possible transaction outcomes

Contact Support

Need help with testing? We're here!