GenUI enables an LLM to determine an interface at runtime, but current practice puts all of the responsibility on the client. This comes with many drawbacks, including exposing access keys and network traffic and adding latency. Using Google's Agent Development Kit (ADK), we can move (almost) all of that responsibility back onto the server, minimizing exposure and network calls, while keeping our Flutter apps lightweight and secure. As a bonus, we gain access to the ADK's powerful tool, agent, and workflow composition APIs. Flutter is great at rendering beautiful interfaces and GenUI enables unique, personalized experiences. Google's ADK is what powers enterprise-grade agents at scale.