# API Reference
source: https://developer.mastercard.com/payment-initiation-api/documentation/api-reference/index.md

## Environment Domains {#environment-domains}

* Sandbox
* Production

```Sandbox
https://sandbox.api.mastercard.com/commercial/payments
```

```Production
https://api.mastercard.com/commercial/payments
```

## Swagger UI {#swagger-ui}


API Specification: `https://static.developer.mastercard.com/content/payment-initiation-api/swagger/payment_initiation_api.yaml`

## Next Steps {#next-steps}

Now that you have a good understanding of all the services endpoints, proceed to the [Testing](https://developer.mastercard.com/payment-initiation-api/documentation/testing/index.md) section to learn about testing the service.