Testing

Before you go live, you should exercise every payment flow your integration supports — successful charges, declines, 3DS challenges, refunds, and webhook delivery — against the Axra sandbox environment. The sandbox uses the same API surface as production, so code that works in testing will work in production without modification. This page walks you through the test environment setup, available test cards, and a pre-launch checklist to make sure nothing is missed.

Test environment

Axra provides a fully isolated sandbox environment. Test mode does not process real payments and will never charge a real card.

Setting	Value
Test base URL	`https://staging-api.useaxra.com`
Production base URL	`https://api.useaxra.com/api/v1`
API key prefix	`bk_test_`

Obtain your sandbox API keys from the API Keys section of the Axra dashboard. Test keys are prefixed with bk_test_ to distinguish them from live keys (bk_live_).

Never use a live API key in a test or development environment, and never use a test API key in production. Test keys are rate-limited differently and will not process real funds.

Test cards

Use these card numbers in the sandbox to trigger specific payment outcomes. For all test cards, use any future expiry date and any 3-digit CVV.

Card number	Result
`4242 4242 4242 4242`	Successful charge, no 3DS required
`4000 0000 0000 0002`	Card declined
`4000 0025 0000 3155`	3DS authentication required — succeeds
`4000 0082 6000 3178`	3DS authentication required — fails
`4000 0000 0000 9995`	Insufficient funds
`4000 0000 0000 3220`	3DS2 required

In test mode, 3DS challenges are auto-completed by the sandbox — you are not redirected to a real bank page. This lets you test the full authentication flow without any manual steps.

Testing the full checkout flow

Use this flow to verify your end-to-end checkout session integration:

Create a checkout session

Call POST /business/payment/session with your test API key. Use a valid amount and currency.

Open the checkout URL

Open the checkoutUrl from the response in a browser. You will see Axra’s hosted payment page.

Enter a test card

Enter one of the test card numbers from the table above. Use any future expiry date and any 3-digit CVV.

Complete the payment

Submit the form. If you used a 3DS card, the sandbox will auto-complete the authentication challenge.

Verify the webhook

Confirm that your server receives a payment.completed webhook event. Check that you return a 2xx response within 30 seconds, and that your application correctly updates the order or fulfillment status.

Testing a direct charge

For server-to-server (S2S) charging, you can test the charge endpoint directly with curl:

# Test a successful charge
curl -X POST https://staging-api.useaxra.com/business/payment/charge \
  -H "x-api-key: bk_test_your_test_key" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 49.99,
    "currency": "usd",
    "card": {
      "number": "4242424242424242",
      "expiryMonth": 12,
      "expiryYear": 2028,
      "cvv": "123"
    },
    "email": "test@example.com"
  }'

Replace bk_test_your_test_key with your actual sandbox API key. Swap out the card number to trigger a different outcome — for example, use 4000000000000002 to test your declined-card handling.

S2S charging must be enabled for your business in the Axra dashboard before you can use the charge endpoint. If you receive a 400 with a message about S2S not being enabled, contact support@useaxra.com.

Testing webhooks locally

Your local development server is not reachable from the internet by default. Use ngrok to create a public tunnel to your local machine.

Install and start ngrok

Download ngrok from ngrok.com, then expose your local server:

ngrok http 3000

ngrok will print a public URL such as https://abc123.ngrok.io.

Set your webhook URL

In the Axra dashboard, open your business profile settings and set the Webhook URL to your ngrok tunnel with your webhook path appended — for example:

https://abc123.ngrok.io/webhook

Trigger a test payment

Create a checkout session or fire a test charge. Axra will send webhook events to your ngrok URL, which forwards them to your local server.

Inspect the delivery

The ngrok web interface at http://localhost:4040 shows every request and response in real time. Use it to inspect the payload and debug your signature verification logic.

ngrok URLs change each time you restart the tunnel (unless you have a paid plan with reserved domains). Update your webhook URL in the dashboard whenever your tunnel URL changes.

Verifying idempotency

Axra deduplicates charge requests within a 1-minute window based on the request parameters. To verify this is working:

Send the same charge request twice with identical parameters within 60 seconds.
Confirm that both responses return the same paymentId — this means the second request returned the cached result rather than creating a new charge.
Check that no duplicate payment appears in your dashboard.

This behavior protects against double-charges caused by network retries. Make sure your application handles idempotent responses correctly — do not treat a repeated paymentId as an error.

Pre-launch checklist

Before switching to your live API key, verify that your integration handles each of these scenarios correctly:

Scenario	What to verify
Successful payment flow	`payment.completed` webhook received; order fulfilled
3DS authentication flow	Customer redirected and authenticated; payment confirmed via webhook
Card declined	User shown an appropriate error; no order created
Insufficient funds	User shown an appropriate error; no order created
Webhook signature verification	Your endpoint rejects requests with an invalid `X-Axra-Signature`
Refund flow	Refund created via API; `payment.refunded` webhook received
Checkout session creation and redirect	Session created; `checkoutUrl` opens the hosted payment page correctly

Run through the full checklist with both a success card (4242424242424242) and a decline card (4000000000000002) to make sure your application responds correctly to both outcomes.

Overview

Reference

Test environment

Test cards

Testing the full checkout flow

Testing a direct charge

Testing webhooks locally

Verifying idempotency

Pre-launch checklist

​Test environment

​Test cards

​Testing the full checkout flow

​Testing a direct charge

​Testing webhooks locally

​Verifying idempotency

​Pre-launch checklist

Test environment

Test cards

Testing the full checkout flow

Testing a direct charge

Testing webhooks locally

Verifying idempotency

Pre-launch checklist