# Pre-initiate a standalone authentication request

Pre-initiates a stand-alone 3D Secure authentication request for a transaction. This endpoint is for merchants who use PXP's service solely for authentication purposes. The pre-initiation step gathers necessary information and ensures that all required data is available and valid before proceeding with the actual authentication request. This process helps to streamline the authentication process and enhance security.

Endpoint: POST /threedsecure/standalone/authentications
Version: 1.0.0

## Request fields (application/json):

  - `amount` (object)
    Details about the authenticated transaction's amount.

  - `amount.transactionValue` (number, required)
    The amount of the authenticated transaction. The numbers after the decimal will be zero padded if they are less than the expected `currencyCode` exponent. For example, GBP 1.1 = GBP 1.10, EUR 1 = EUR 1.00, or BHD 1.3 = 1.300. The transaction will be rejected if numbers after the decimal are greater than the expected `currencyCode` exponent, for example, GBP 1.234, or if a decimal is supplied when the `currencyCode` exponent doesn't require it (e.g., JPY 1.0).

  - `amount.currencyCode` (string, required)
    The currency code associated with the transaction, in ISO 4217 format. This three-character code specifies the currency in which the transaction is processed, ensuring clarity and consistency across international transactions.
    Example: EUR

  - `fingerprintCallbackUrl` (string, required)
    The fingerprint callback URL.

  - `acquirerProfileId` (string, required)
    The unique identifier for the acquirer's profile.

  - `requestorAuthenticationIndicator` (string)
    Indicator used to specify the type of authentication request, such as payment authentication or account verification.
Possible values:
- `01`: Payment transaction
- `02`: Initial Recurring Transaction
- `03`: Initial Card-on-file transaction for subsequent MITs
- `04`: Initial Card-on-file transaction for subsequent CITs
- `05`: Store card details without purchase (card verification)
- `06`: Instalment transaction
- `07`: Billing agreement
- `08`: Split shipment
- `09`: Delayed shipment
- `10`: Split payment
    Example: 01

  - `merchantGroup` (string, required)
    The merchant group.

  - `card` (object, required)
    Details related to the card used for 3D Secure authentication. You can provide card details directly, use a stored gateway token, or use a scheme token.

  - `card.primaryAccountNumber` (string, required)
    The unique number assigned to a payment card, such as a credit or debit card.
    Example: 4111111111111111

  - `card.cardHolderName` (string)
    The full name of the individual who owns the payment card, printed on the physical card.

  - `card.expiryMonth` (integer, required)
    The expiry month [MM] of the card.
    Example: 3

  - `card.expiryYear` (integer, required)
    The expiry year [YYYY] of the card.
    Example: 2025

  - `card.cardVerificationCode` (string)
    A 3 or 4 digit security code found on the card, used for verification in non-face-to-face transactions.
    Example: 123

  - `card.gatewayTokenId` (string, required)
    A securely stored token representing a previously saved card.
    Example: 2357e042-2bf0-4886-8d9d-718fa5909761

  - `card.schemeTokenId` (string, required)
    A unique scheme token ID generated by PXP, used as a reference to extract the schemeTokenNumber.
    Example: 4837261112345678

  - `card.schemeTokenNumber` (string, required)
    An external scheme token issued by Visa or Mastercard.
    Example: 4837261112345678

  - `card.holderName` (string)
    The full name of the cardholder associated with the scheme token.
    Example: Mr John Doe

  - `card.expiryMonth` (integer, required)
    The expiry month [MM] of the scheme token.
    Example: 3

  - `card.expiryYear` (integer, required)
    The expiry year [YYYY] of the scheme token.
    Example: 2025

  - `card.verificationCode` (string)
    A 3 or 4 digit security code for the scheme token.
    Example: 123

## Response 200 fields (application/json):

  - `authenticationId` (string)
    A unique reference provided by PXP for the authentication request, represented as a GUID.
    Example: 550e8400-e29b-41d4-a716-446655440000

  - `state` (string)
    The current state of the authentication request. For pre-initiation, this can only be `PendingClientData` or null (if the card isn't enrolled for 3DS).
    Enum: "PendingClientData"

  - `scaMandated` (boolean)
    Whether Strong Customer Authentication (SCA) is mandated for this transaction.
    Example: true

  - `threeDSecureVersion` (string)
    The version of the 3D Secure protocol being used for the authentication.
    Example: 2.1.0

  - `threeDSecureFingerprintUrl` (string)
    The URL to which the 3D Secure method data should be sent.
    Example: https://example.com/3ds-method

  - `threeDSecureFingerprintData` (string)
    Data required for the 3D Secure method, typically a base64 encoded string.
    Example: eyJ0aHJlZURTU2VjdXJlTWV0aG9kRGF0YSI6IlhYWiJ9

  - `threeDSecureSupported` (boolean)
    Whether 3D Secure authentication is supported for this transaction.
    Example: true

  - `recommendedChallengeIndicator` (string)
    The recommended challenge indicator.

## Response 400 fields (application/json):

  - `errorCode` (string)

  - `errorReason` (string)

  - `correlationId` (string)

  - `details` (array)

## Response 401 fields (application/json):

  - `errorCode` (string)

  - `errorReason` (string)

  - `correlationId` (string)

  - `details` (array)

## Response 403 fields (application/json):

  - `errorCode` (string)

  - `errorReason` (string)

  - `correlationId` (string)

  - `details` (array)

## Response 404 fields (application/json):

  - `errorCode` (string)

  - `errorReason` (string)

  - `correlationId` (string)

  - `details` (array)

## Response 500 fields (application/json):

  - `errorCode` (string)

  - `errorReason` (string)

  - `correlationId` (string)

  - `details` (array)