#  Push API
source: https://developer.mastercard.com/ethoca-alerts-for-merchants/documentation/api-reference/push-api-ref/index.md

The Ethoca Alerts for Merchants Push API is a webhook (outbound API) that lets merchants and merchant partners receive alerts if they're on the Ethoca network.

### Security {#security}

Outbound calls are sent from Mastercard to an endpoint exposed by you to notify you of transactions that happened on the user's cards.

The defined endpoint needs to be capable of receiving an HTTPS POST of JSON data. You must also support the MSSL (mutual SSL/TLS authentication) protocol. If you already have SSL certificates issued by an external certification authority for your endpoints, you will need to provide those details as part of your integration to validate if it is supported by Mastercard.

When integrating with the Merchants Push API, contact the [Ethoca Customer Delivery Team](mailto:customerdelivery@ethoca.com) for details.

You will also need to trust the root certificate:
Entrust [L1k Root Cert](https://web.entrust.com/root-certificates/entrust_l1k.cer)

The Merchants Push API exposes one outbound endpoint.

### How it Works {#how-it-works}

* An issuer sends an alert about a problem transaction to the Alerts platform.
* We process and match the alert, and then push it to your registered endpoint.
* You send an acknowledgement response to us with the status of "success" and we pass that information on to the issuer.

Diagram how-it-works-push

### APIs {#apis}

Note: The API request below shows example data for each individual field. Test cases are available to use in the sandbox, which include sets of request data that return expected responses. Contact your [Ethoca Customer Delivery Team](mailto:customerdelivery@ethoca.com) for details.
API Specification: `https://static.developer.mastercard.com/content/ethoca-alerts-for-merchants/swagger/alert-push-specs_outbound.yaml`

### Error handling {#error-handling}

See [Code and Formats](https://developer.mastercard.com/ethoca-alerts-for-merchants/documentation/code-and-formats/index.md) for detailed information about error response handling for the Alerts for Merchants API.