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

## Environment Domains {#environment-domains}

* Sandbox
* Production

```Sandbox
https://sandbox.api.mastercard.com/loyalty/eligibility
```

```Production
https://api.mastercard.com/loyalty/eligibility
```

## APIs {#apis}


API Specification: `https://static.developer.mastercard.com/content/eligibility-api/swagger/eligibility-spec.yaml`

## Next Steps {#next-steps}

Now that you have a good understanding of all the API services, proceed to the [Testing](https://developer.mastercard.com/eligibility-api/documentation/testing/index.md) section to learn how to test the API services.