# Use Cases
source: https://developer.mastercard.com/authentication-facilitator/documentation/use-cases/index.md

## Cardholder Authentication Before Transaction {#cardholder-authentication-before-transaction}

### Available for Use By {#available-for-use-by}

* Issuers
* Issuer's Processors

### Regional Availability {#regional-availability}

* India

### Scenario {#scenario}

* Mahesh decides to use Wallet x to initiate an online transaction (e-commerce transaction) at a merchant site. Wallet x has an authentication policy, where the cardholder will be authenticated when a transaction is initiated.

### Web Services/APIs Used {#web-servicesapis-used}

* Deliver Authentication Code

### Integration {#integration}

Diagram yellow-path

1. When the cardholder initiates an online transaction, the wallet app (such as Samsung Pay, Google Pay, etc.) will prompt the cardholder to sign in.
2. Cardholder then enters the creadentials to login.
3. After successful login, the home screen is displayed, where the payment options are displayed.
4. The cardholder then selects a payment option.
5. The wallet app will require the cardholder to authenticate before continuing with the transaction.
6. The wallet provider then sends an authentication code request to MDES.
7. MDES will generate the authentication code and send it to the cardholder's issuer.
8. The issuer will then deliver the authentication code the cardholder through their preferred channel.
9. The cardholder will enter the authentication code in the wallet app.
10. The wallet app will then send the authentication request to the wallet provider and the wallet provider will send it to MDES.
11. MDES will validate the request and send the corresponding response to the wallet provider.
12. The wallet provider will send the appropriate response to the wallet app.
13. The wallet app will then prompt the cardholder to continue with the transaction after successful authentication.