Sometimes information about a transaction (like the name, date, or amount) can change for many reasons, and detecting these changes can be difficult via the /transactions/get endpoint. A request needs to be made to the /transactions/get endpoint to pull the latest information, and the response would then need to be compared with the stored information from previous requests. The DEFAULT_UPDATE webhook, which signals a transaction update for an Item and provides the number of new transactions, does not provide insight into such changes in transaction information. The TRANSACTIONS_REMOVED webhook will signal when transaction(s) for an Item are deleted.
The /transactions/sync endpoint does provide insight into when transaction information changes and lists any transactions with modified information in the modified array of the response. When transactions are deleted, they are listed in the removed array of the response, and newly added transactions are listed in the added array. To be alerted when there is new, updated, or deleted data, listen for the SYNC_UPDATES_AVAILABLE webhook.