Agent Studio Chat

Follow the data flow

• Start from src/components/features/chat/hooks/useChatLogic.ts (Vercel AI SDK useChat + DefaultChatTransport).
• Server route is src/app/api/chat/route.ts (OpenRouter provider + streamText).
• UI entry is src/components/features/chat/ChatInterface.tsx (Virtuoso list + ChatInput).

Know the state layers

• Conversation persistence: src/lib/store/useChatStore.ts
• UI-only transient state (editing/copy): src/lib/store/useChatUIStore.ts
• Model + sampling + system instructions: src/lib/store/useSettingsStore.ts and src/components/features/settings/SettingsPanel.tsx

Make safe changes

• Preserve UIMessage.parts when needed (reasoning parts may carry provider metadata; see src/app/api/chat/route.ts).
• Prefer adding new transient UI flags to useChatUIStore to avoid prop drilling.
• Keep feature code under src/components/features/chat/ and reuse src/components/ui/* primitives.