A virtual agent that utilizes an in-house natural language understanding (NLU) service and integrates a third party NLU service. The third-party NLU service is integrated with the virtual agent via a transformation script that establishes a transformation boundary through which communications are directed for adjustment and conditioning. The third party NLU service communicates with the virtual agent via an application programming interface (API). The virtual agent receives an utterance from a user via a chat session and provides the utterance to the third party NLU service. The third party NLU service may return intents, entities, and confidence, generate and return a response, and/or take actions within the cloud-based platform via the API, dependent upon the degree of integration. The virtual agent then provides a response to the user via the chat session.