Generative UI for agents: Rhys Sullivan's MCP Night 4 lightning demo

Rhys Sullivan, founder of Executor, addressed a significant gap in agent capabilities regarding user interfaces during a demo at MCP Night 4. While agents can handle documentation and API calls effectively, they struggle to render product UIs, a gap Sullivan aims to close. He illustrated this with PostHog, demonstrating how agents can answer queries but fail to deliver the visual experience that UI components provide. Sullivan introduced a solution by allowing agents to generate UI through a tool called posthog.render UI, which can interpret data and render it in a meaningful way using components from PostHog's interface. This approach involves a TypeScript SDK that lets agents write code in a structured environment, improving reliability over ad-hoc tool calls. The strategy is adaptable to any product with an OpenAPI and component library, allowing agents to integrate deeply with products and enhance user interaction by rendering product UIs directly or through deep links.