The ingress message format expected is Array<Transaction> or just a single Transaction where Transaction contains at least the following fields. You can provide further fields inside the meta object that the engine will include in the egress message, but the engine itself will not use the fields.

Ingress message schema

Field	Type	Required	Description
transactionId	String (max 36)	Yes	Unique identifier for the transaction.
accountId	String (max 36)	Yes	Unique identifier for the account.
userId	String (max 36)	No	Unique identifier for the customer.
accountType	String (max 10)	Yes	The account type. Permitted values as follows:"cash" - current accounts; "card" - credit cards; "savings" - savings accounts; "investment" - investment accounts; "loan" - loan accounts; "mortgage" - mortgage accounts; "pension" - pension accounts
txCode	String (max 64)	Yes	The transaction code. Permitted values as follows:"DEB" - general debit card transaction; "CR" - general bank credit; "TFR" - general transfer to/from; ")))" - contactless purchase; "DD" - direct debit; "SO" - standing order; "BGC" - bank giro credit; "ATM" - cash withdrawal; "CHQ" - cheque; "CHG" - bank chargeFor credit card transactions or if unsure for a transaction set to the empty string "".Although we do accept more; please supply us a list of the transaction codes you'd like to use and we'll either let you know if they are supported or how you can map onto our transaction codes.
date	Date (max 35)	Yes	The date and time of the transaction in ISO 8601 format (date-time).
description	String (max 256)	Yes	The transaction description, or statement reference. It is commonly a combination of the merchant name and merchant location.
amount	Number	Yes	The transaction amount in major units.
currency	String (max 3)	Yes	The currency of the transaction, e.g. GBP, EUR
status	String (max 7)	No	The transaction status: `pending` or `posted`.
merchantCategoryCode	String (max 4)	No	MCC code for the merchant’s primary activities. A maximum 4 digit string which we will left pad with 0s to make 4 digits if necessary.
cardPresent	Boolean	No	Indicates if the cardholder was present when the transaction occurred. Note that, online purchases are considered card holder not present. Only card holder present transactions are eligible for geotagging. Commonly derived from the POS entry mode: e.g. “07” is contactless chip read so card present. Do not specify or set to true if unknown/unsure; the engine uses this field as part of the estimation of a more accurate card present flag.
meta	Object	No	Additional data for storage/pass-through.

Example

{
    "transactionId": "123456",
    "accountId": "5382358854398",
    "userId": "5382358854398",
    "accountType": "cash",
    "txCode": ")))",
    "date": "2025-10-20T13:46:57.329Z",
    "description": "Tesco BriLL 293484 SS",
    "amount": -10.99,
    "currency":"GBP",
    "status": "posted",
    "merchantCategoryCode": "5411",
    "cardPresent": true,
    "meta": {
        "sourceSystem": "hex",
        "authorisedBy": "PStibbons",
        "yearOfCreation": "Year of the Luminous Lemur"
    }
}