IPaper

A full-stack AI agent application for intelligent paper writing and editing, powered by the Claude Agent SDK. Run multi-step AI agents in your browser — desktop, tablet, and mobile PWA ready.

This repository is the IPaper monorepo. The published web package lives in packages/web as @ai4paper/ipaper.

Monorepo Structure

ipaper/
├── packages/
│   ├── web/        # React + Vite frontend (published as @ai4paper/ipaper)
│   └── server/     # Bun HTTP + WebSocket server + Claude agent runtime
├── package.json    # Bun workspace root
└── bun.lock

Tech Stack

Frontend — packages/web

Concern	Technology
Runtime & tooling	Bun
Language	TypeScript (strict)
Framework	React 19 + Vite
UI components	shadcn/ui + Tailwind CSS v4
Routing	TanStack Router
Server state	TanStack Query
Agent streaming	Native WebSocket (auto-reconnecting singleton)

Backend — packages/server

Concern	Technology
Runtime	Bun (Bun.serve upgrades to WebSocket)
HTTP framework	Hono for REST routes
Language	TypeScript (strict)
Agent runtime	@anthropic-ai/claude-agent-sdk
Streaming	WebSocket frames (one connection per browser session)
Validation	Zod

Agent Streaming Architecture

Each chat has a long-lived Session on the server that owns one Claude query() call. Subsequent user prompts are pushed onto the agent's input queue, so context, prompt cache, and tool state survive across turns. Events fan out to one or more browser WebSocket subscribers.

Browser WebSocket  ⇄  /ws  ⇄  Bun.serve
                              │
   {type:"subscribe",chatId}  ▶ SessionManager.getOrCreate(chatId)
                              │      └── AgentSession (long-lived query())
   {type:"chat",chatId,...}   ▶ session.sendMessage(content)
                              ◀ {type:"user_message", ...}
                              ◀ {type:"tool_use", toolName, toolInput}
                              ◀ {type:"assistant_message", ...}
                              ◀ {type:"result", success, cost, duration}

Persistent state — chats and message history — is served via REST:

• GET /api/chats — list chats
• POST /api/chats — create a chat
• GET /api/chats/:id — chat metadata
• DELETE /api/chats/:id — delete chat & close its agent session
• GET /api/chats/:id/messages — message history

No authentication is required — the Anthropic API key lives in packages/server/.env.

In development, Vite proxies /api/* and /ws to the Bun server.

License

MIT