# Transaction Notifications Service API
source: https://developer.mastercard.com/transaction-notifications/documentation/api-reference/inbound/index.md

## Environment Domains {#environment-domains}

| Environment | Base URL                                      |
|:------------|:----------------------------------------------|
| Sandbox     | `https://sandbox.api.mastercard.com/openapis` |
| Production  | `https://api.mastercard.com/openapis`         |

## API Specification {#api-specification}


API Specification: `https://static.developer.mastercard.com/content/transaction-notifications/swagger/inbound.yaml`

## Next Steps {#next-steps}

Review the use cases for the Transaction Notifications Service API:

* [Retrieve Undelivered Notifications](https://developer.mastercard.com/transaction-notifications/documentation/use-cases/retrieve-undelivered-notifications/index.md)
* [Search Clearing Transactions](https://developer.mastercard.com/transaction-notifications/documentation/use-cases/search-clearing-transactions/index.md)
* [Simulate a Test Transaction](https://developer.mastercard.com/transaction-notifications/documentation/use-cases/simulate-test-transaction/index.md)

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Follow step-by-step tutorials to get started:

* [Retrieve Undelivered Notifications](https://developer.mastercard.com/transaction-notifications/documentation/tutorials-and-guides/undelivered-notifications/index.md)
* [Retrieve Clearing Data](https://developer.mastercard.com/transaction-notifications/documentation/tutorials-and-guides/clearing-data/index.md)
* [Create a Test Transaction](https://developer.mastercard.com/transaction-notifications/documentation/tutorials-and-guides/test-transaction/index.md)