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

## Environment Domains {#environment-domains}

👉 Verify and update the domains that you expose your service in. Include your YAML file here. See [here](https://confluence.mastercard.int/x/u-qjFw) for important information about environments on Mastercard Developers.
* Sandbox
* Mtf
* Production

```Sandbox
https://sandbox.api.mastercard.com/your-service
```

```mtf
mtf.api.mastercard.com/your-service 
```

```Production
https://api.mastercard.com/your-service
```

👉 To configure your Swagger, follow our [Swagger tutorial](https://stage.developer.mastercard.com/jamstack/tutorial/configuring-swagger-ui/).

## Swagger UI {#swagger-ui}


API Specification: `https://static.developer.mastercard.com/content/mastercard-agent-pay/swagger/petstore.yaml`

## Next Steps {#next-steps}

👉 Direct the user to the Integration and Testing section.   

Now that you have a good understanding of all the services endpoints, proceed to the [Integration and Testing](https://developer.mastercard.com/mastercard-agent-pay/documentation/integration-and-testing/index.md) section to learn how to integrate and make sure you are ready to begin testing.