AI chat

The agent-native UI kit composed into one surface: a streaming chat thread, the “thinking” state, an auto-growing prompt input (Enter sends, Shift+Enter for a newline, Stop while generating), the AI output-disclosure label, and per-response feedback. Responses are a deterministic mock — no API key needed. A thumbs-down opens a pre-filled GitHub issue, closing the same feedback loop the FeedbackFAB uses.