# Use Cases
source: https://developer.mastercard.com/ethoca-consumer-clarity-for-merchants/documentation/use-cases/index.md

This section provides sample use cases for how the API you create interacts with the Merchant Transaction API, which provides merchant and transaction information to issuers that request it.

## Consumer Clarity Call Center and Digital Receipts {#consumer-clarity-call-center-and-digital-receipts}

1. A cardholder uses an issuer's banking app or their call center to inquire about a specific transaction they made at your company.
2. A request is sent through Ethoca's Merchant Transaction API for details about the purchase.
3. After the request is validated, it is sent to you for response.
4. You return a JSON response in real-time with details about the purchase and additional contact information.
5. Ethoca tailors this information so that it can be displayed most clearly in either the digital or call center channel. We then pass the information on to the issuer.
6. The issuer provides the detailed merchant and transaction information to the cardholder in the banking app, or to the call center agent's internal system, which is then communicated to the cardholder.

### Sequence Diagram {#sequence-diagram}

Diagram transactions
API Reference: `GET /api/orders`

## Consumer Clarity Smart Subscriptions {#consumer-clarity-smart-subscriptions}

1. A cardholder initiates an action and fills in information on the issuer banking app.
2. A request is sent through Ethoca's Merchant Transaction API with the cardholder's subscription information, as configured by you during onboarding.
3. After the request is validated, it's sent to you for a response.
4. You return a JSON response in real time with options available for that action, such as a *Retention Offer* , a *List of Plans* , or *Pause Options*. Or, you return a response that confirms the action is completed.
5. Ethoca tailors the information so that it can be displayed to the cardholder clearly, and passes it to the issuer.
6. The issuer provides the relevant information to the cardholder in the banking app, where the cardholder is notified whether their subscription was modified or if any retention offers have been sent.
7. If you provided the cardholder with a retention offer, they make their selection in the banking app.
8. The issuer sends the cardholder's choice to you through the Ethoca Merchant Transaction API.
9. You send a response back to the cardholder confirming that their subscription was modified.

### Sequence Diagram {#sequence-diagram-1}

Diagram transactions-sc
API Reference: `GET /api/merchants/actions`

## First-Party Trust {#first-party-trust}

1. A cardholder initiates a dispute with their issuer. The issuer reviews the disputed transactions with the cardholder and starts the dispute process.
2. The issuer sends the request to Mastercard/MCOM, which invokes the First-Party Trust Engine.
3. The First-Party Trust Engine looks up historical transactions and sends a request to the merchant for compelling evidence for the transaction in question and the supporting transactions.
4. The merchant responds to the request and provides the compelling evidence in the response.
5. The First-Party Trust Engine ingests this information and determines whether liability has shifted to the issuer or remains with the merchant.
6. This information is then passed on to the issuer, who can review it with the cardholder.

### Sequence Diagram {#sequence-diagram-2}

Diagram transactions-fpt
API Reference: `GET /api/orders`

## Next Steps {#next-steps}

Now that you have an understanding of the different use cases of the service, review [API Reference](https://developer.mastercard.com/ethoca-consumer-clarity-for-merchants/documentation/api-reference/index.md) to interact with our endpoints on the API explorer.