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

## Overview {#overview}

When a transaction occurs on an enrolled card, you receive a real-time notification on your Transaction Notifications Endpoint (Webhook URL). The notification contains the card reference, amount, merchant details, and the issuer decision (approval/decline).

## API Specification {#api-specification}


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

## Next Steps {#next-steps}

* [Receive Transaction Notification](https://developer.mastercard.com/transaction-notifications/documentation/use-cases/receive-transaction-notification/index.md): Review the end-to-end use case for receiving notifications on your webhook.
* [Set Up Your Webhook](https://developer.mastercard.com/transaction-notifications/documentation/tutorials-and-guides/webhook/index.md): Follow a step-by-step tutorial to configure and test your webhook endpoint.