> ## Documentation Index
> Fetch the complete documentation index at: https://docs.langstate.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Presenter in SUP

> Project state into an interaction without mutating authoritative values.

<Note>
  **Design note.** LangState defines `BaseProjectorUI`, but no presenter implementation or renderer is bundled.
</Note>

A presenter reads current state and produces a view: natural-language prompt, structured UI components, or both. Its output should refer to stable field paths so a later interaction can be applied to the intended state.

The presenter may choose what to ask next, how to explain ambiguity, and which control best fits a schema. Business writes and action execution should remain outside the presentation step unless the application explicitly combines those roles.

LangState's `UIProjectionResult` is a possible boundary model. The host is still responsible for rendering, accessibility, localization, and returning user events as structured input.