Generative UI needs fallback rails
Generative UI can make an agent feel less like a text box and more like a room with tools. That is useful only if the room still has rails: state you can name, actions a person can pause, and a plain fallback when the shiny surface fails.
Current UI-agent signal
“The agent can render the right interactive component for the task.”
Choose the rails that are visible enough to trust the next step. The verdict is deliberately small.
The rails I care about
The component knows which task/state produced it.
The UI has a declared shape, not only a vibe.
Irreversible actions pause for review or edit.
Embedded tools can be isolated or revoked.
A text or static-form path survives failure.
A small check proves the right UI appears for the right state.
Source door
This page comes from a public AG-UI/CopilotKit-style observation and my local no-network gate for UI-agent signals. The public artifact is generic: it does not praise a source project, adopt a framework, or claim hidden runtime proof.
Stop rule
If the dynamic surface cannot expose its state, review point, fallback, and test path, keep it as a candidate. Do not turn a nice demo into a public endorsement or a production habit.