Store - ChatStore | paotharit

abstract

Global Zustand store for chat session management and LLM model selection. Persists selectedProvider and selectedModel to localStorage so the user's model choice survives page refresh. Session list (sessions) is also persisted, giving the sidebar instant render without a network round-trip.

File

frontend/src/hooks/use-chat-store.ts

State Shape

interface ChatState {
  // Session management
  currentSessionId: string | null;
  sessions: ChatSession[];
  setCurrentSessionId: (id: string | null) => void;
  setSessions: (sessions: ChatSession[]) => void;
  addSession: (session: ChatSession) => void;
  removeSession: (id: string) => void;
  updateSessionTitle: (id: string, title: string) => void;
 
  // LLM model selection (persisted to localStorage)
  selectedProvider: string;
  selectedModel: string;
  setSelectedProvider: (provider: string) => void;
  setSelectedModel: (model: string) => void;
}

State Fields

Field	Type	Initial	Persisted	Description
`currentSessionId`	`string \| null`	`null`	Yes	UUID of the active chat session
`sessions`	`ChatSession[]`	`[]`	Yes	Ordered list (newest first) from `GET /api/v1/chat/sessions`
`selectedProvider`	`string`	—	Yes	Active LLM provider (`"ollama"`, `"openai"`, etc.)
`selectedModel`	`string`	—	Yes	Model name sent in `ask-stream` query params

ChatSession type from frontend/src/types/chat.ts:

interface ChatSession {
  id: string;
  title: string;
  provider: string;
  model_name: string;
  created_at: string;
}

Actions

Action	Signature	Side Effects
`setCurrentSessionId`	`(id: string \| null) => void`	Navigates sidebar highlight
`setSessions`	`(sessions: ChatSession[]) => void`	Replaces full session list
`addSession`	`(session: ChatSession) => void`	Prepends + sets `currentSessionId` to new session
`removeSession`	`(id: string) => void`	Filters list; nullifies `currentSessionId` if it matched
`updateSessionTitle`	`(id: string, title: string) => void`	Updates title in-place in `sessions` array
`setSelectedProvider`	`(provider: string) => void`	Persisted immediately to localStorage
`setSelectedModel`	`(model: string) => void`	Persisted immediately to localStorage

Persistence

Uses zustand/middleware persist. All state is serialized to localStorage. Key: default Zustand persist key derived from store definition order.

warning

sessions in localStorage can diverge from the server if sessions are created/deleted from another tab or device. app-sidebar.tsx re-fetches GET /api/v1/chat/sessions on mount and calls setSessions() to reconcile.

Data Flow

Consumers

Component	What it reads	What it calls
`frontend/src/components/app-sidebar.tsx`	`sessions`, `currentSessionId`	`addSession`, `removeSession`, `setSessions`, `setCurrentSessionId`
`frontend/src/components/chat/chat-interface.tsx`	`currentSessionId`, `selectedProvider`, `selectedModel`	`setCurrentSessionId`
`frontend/src/components/chat/model-selector.tsx`	`selectedProvider`, `selectedModel`	`setSelectedProvider`, `setSelectedModel`
`frontend/src/components/nav-session.tsx`	`sessions`, `currentSessionId`	`updateSessionTitle`, `removeSession`

Role	Link
Frontend page consuming this store	Page - Home
Chat session API	`API-GET-v1-chat-sessions`
TypeScript types	`frontend/src/types/chat.ts`

Store - ChatStore