A system and method for assessing digital interactions with a digital third party accounts can include receiving user account credentials for authentication with an external computing system, storing the user account credentials in association with a authentication token and communicating the authentication token to a computing device of an external application service; receiving, through a programmatic communication interface, a request that references the authentication token and digital interaction details; programmatically authenticating, using the stored user account credentials, as a user account with the external computing system and retrieving account data; processing the account data in combination with the digital interaction details and thereby generating a digital interact assessment; and initiating execution of a digital interaction based in part on the digital interaction assessment.