Quick Start

A pay-in takes four steps: get credentials, collect a wallet token, create the payment, confirm the final status.

1. Get credentials

Your integration manager issues:

Sdk-Partner-Token credentials in the form service_id:secret;
a Sign Key for the X-Signature header;
an allow-list entry for your server IP(s), per environment.

Apple Pay also requires domain registration — see Apple Pay onboarding.

2. Collect a wallet token

Collect the payment token on your frontend with the wallet's own API and pass it to your backend. pay_token is always Base64, and each wallet has its own payload inside:

Apple Pay — Base64 of the token.paymentData JSON. See Apple Pay.
Google Pay — Base64 of paymentData.paymentMethodData.tokenizationData.token. See Google Pay.

3. Create the payment

Send the token and the buyer's details from your backend. Sign the compact JSON body with your Sign Key — see Authentication & signature.

curl -X POST https://pay-in-api.mrcr.io/sdk-partner/alternative-mobile-pay/mobile-pay \
  -H 'Sdk-Partner-Token: 42:your-secret' \
  -H 'X-Signature: <hex HMAC-SHA256 of the compact JSON body>' \
  -H 'Content-Type: application/json' \
  -d '{"pay_system":"apple","pay_token":"<base64 payment token>","merchant_transaction_id":"order-8841","email":"john.doe@example.com","name":"John Doe","fiat_amount":"10.00","fiat_currency":"USD","ip":"203.0.113.10","billing_address":{"country_code":"DE","city":"Berlin","zip_code":"12345"}}'

{
  "status": 200,
  "data": { "id": "28a3c125a28075453", "status": "pending" }
}

Google Pay additionally requires success_url and failure_url in the request.

4. Confirm the final status

New payments start as pending. Assign your own merchant_transaction_id before the first request and reuse it for every retry of that payment — the rules for retries and unresolved outcomes are in Handling errors.

Track the result through webhooks or GET /mobile-pay/{id}/status. Follow Payment statuses for final outcomes, required actions, and handling an unknown or long-running status. A browser redirect to your success_url is not payment confirmation.

If a response contains redirect_data, follow it to complete 3DS. A Google Pay webhook with redirect_pending does not contain that object: first query GET status to obtain the current state and redirect_data.

Ready for the details? Continue with Sandbox & Testing.

Overview

Sandbox & Testing