Use it now
No documentation found
A broader UI/agent event list now includes a ui.message event
What
A second, larger internal list of UI and agent events that Claude Code tracks now includes ui.message, joining ui.render, ui.resolve, ui.press, ui.input, and ui.select.
Why
This is internal plumbing that expands the set of events the app can recognize and react to. It does not by itself change what you see, but it lays groundwork for features that need to respond to message-related UI activity.
Names in the bundleui.message
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say what consumes this event list or what user-visible behavior, if any, depends on it.