OpenBrowserClaw

Browser-native personal AI assistant. Zero infrastructure — the browser is the server.

Built as a browser-only reimagination of NanoClaw. Same philosophy — small enough to understand, secure by default, built for one user — but running entirely in a browser tab.

Quick Start

cd openbrowserclaw
npm install
npm run dev

Open http://localhost:5173, paste your Anthropic API key, and start chatting.

Architecture

┌─────────────────────────────────────────────────────────┐
│  Browser Tab (PWA)                                       │
│                                                          │
│  ┌──────────┐  ┌──────────┐  ┌──────────────────────── │
│  │ Chat UI  │  │ Settings │  │ Task Manager           │ │
│  └────┬─────┘  └────┬─────┘  └──────┬─────────────── ┘ │
│       └──────────────┼───────────────┘                   │
│                      ▼                                   │
│              Orchestrator (main thread)                   │
│              ├── Message queue & routing                  │
│              ├── State machine (idle/thinking/responding) │
│              └── Task scheduler (cron)                    │
│                      │                                   │
│          ┌───────────┼───────────┐                       │
│          ▼           ▼           ▼                       │
│     IndexedDB      OPFS    Agent Worker                  │
│     (messages,   (group    (Claude API                   │
│      tasks,       files,    tool-use loop,               │
│      config)     memory)    WebVM sandbox)               │
│                                                          │
│  Channels:                                               │
│  ├── Browser Chat (built-in)                             │
│  └── Telegram Bot API (optional, pure HTTPS)             │
└──────────────────────────────────────────────────────────┘

Key Files

File	Purpose
src/index.ts	Entry point, bootstraps UI
src/orchestrator.ts	State machine, message routing, agent invocation
src/agent-worker.ts	Web Worker: Claude API tool-use loop
src/tools.ts	Tool definitions (bash, read/write files, fetch, etc.)
src/vm.ts	WebVM wrapper (v86 Alpine Linux in WASM)
src/db.ts	IndexedDB: messages, sessions, tasks, config
src/storage.ts	OPFS: per-group file storage
src/router.ts	Routes messages to correct channel
src/channels/browser-chat.ts	In-browser chat channel
src/channels/telegram.ts	Telegram Bot API channel
src/task-scheduler.ts	Cron expression evaluation
src/crypto.ts	AES-256-GCM encryption for API keys
src/ui/	Chat, settings, and task manager components

How It Works

1. You type a message in the browser chat (or send one via Telegram)
2. The orchestrator checks the trigger pattern, saves to IndexedDB, queues for processing
3. The agent worker (a Web Worker) sends your message + conversation history to the Anthropic API
4. Claude responds, possibly using tools (bash, file I/O, fetch, JavaScript)
5. Tool results are fed back to Claude in a loop until it produces a final text response
6. The response is routed back to the originating channel (browser chat or Telegram)

Tools

Tool	What it does
bash	Execute shell commands in a sandboxed Linux VM (Alpine in WASM)
javascript	Execute JS code in an isolated scope (lighter than bash)
read_file / write_file / list_files	Manage files in OPFS per-group workspace
fetch_url	HTTP requests via browser fetch() (subject to CORS)
update_memory	Persist context to CLAUDE.md (loaded on every conversation)
create_task	Schedule recurring tasks with cron expressions

Telegram

Optional. Works entirely via HTTPS — no WebSockets or special protocols.

1. Create a bot with @BotFather on Telegram
2. Open Settings in OpenBrowserClaw, paste the bot token
3. Send /chatid to your bot to get the chat ID
4. Add the chat ID in Settings
5. Messages from Telegram are processed the same as browser chat

Caveat: The browser tab must be open for the bot to respond. Messages queue on Telegram's side and are processed when you reopen the tab.

WebVM (Optional)

The bash tool runs commands in a v86-emulated Alpine Linux. To enable:

1. Download the v86 WASM binary and Alpine rootfs image
2. Place them in public/assets/:
   • public/assets/v86.wasm
   • public/assets/v86/libv86.js
   • public/assets/alpine-rootfs.ext2
3. The VM boots automatically on first use (~5-15 seconds)

Without these assets, the bash tool returns a helpful error. All other tools work without the VM.

Comparison with NanoClaw

	NanoClaw	OpenBrowserClaw
Runtime	Node.js process	Browser tab
Agent sandbox	Docker/Apple Container	Web Worker + WebVM
Database	SQLite (better-sqlite3)	IndexedDB
Files	Filesystem	OPFS
Primary channel	WhatsApp	In-browser chat
Other channels	Telegram, Discord	Telegram
Agent SDK	Claude Agent SDK	Raw Anthropic API
Background tasks	launchd service	setInterval (tab must be open)
Deployment	Self-hosted server	Static files (any CDN)
Dependencies	~50 npm packages	0 runtime deps

Development

npm run dev        # Vite dev server with HMR
npm run build      # Production build → dist/
npm run preview    # Preview production build
npm run typecheck  # TypeScript type checking

Deploy

npm run build
# Upload dist/ to any static host:
# GitHub Pages, Cloudflare Pages, Netlify, Vercel, S3, etc.

No server needed. It's just HTML, CSS, and JS.