Open Browser

AI-powered autonomous web browsing framework for TypeScript.

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Give an AI agent a browser. It clicks, types, navigates, and extracts data — autonomously completing tasks on any website. Built on Playwright with first-class support for OpenAI, Anthropic, and Google models.

Production-ready since v1.0. Contributions welcome.

Why Open Browser?

• Autonomous agents: Describe a task in natural language, and an AI agent navigates the web to complete it — clicking, typing, scrolling, and extracting data without manual scripting
• Multi-model support: Works with OpenAI, Anthropic, and Google out of the box via the Vercel AI SDK — swap models with a single flag
• Interactive REPL: Drop into a live browser session and issue commands interactively — great for debugging, prototyping, and exploration
• Sandboxed execution: Run agents in resource-limited environments with CPU/memory monitoring, timeouts, and domain restrictions
• Production-ready: Stall detection, cost tracking, session management, replay recording, and comprehensive error handling
• Open source: MIT licensed, fully extensible, bring your own API keys

Quick Start

# Install dependencies
bun install

# Set up your API keys
cp .env.example .env
# Edit .env with your API keys

# Run an agent
bun run open-browser run "Find the top story on Hacker News and summarize it"

# Or open a browser interactively
bun run open-browser interactive

Architecture

Open Browser is a monorepo with three packages:

Package	Description
open-browser	Core library — agent logic, browser control, DOM analysis, LLM integration
@open-browser/cli	Command-line interface for running agents and browser commands
@open-browser/sandbox	Sandboxed execution with resource limits and monitoring

CLI Commands

Run an AI Agent

open-browser run <task> [options]

Describe what you want done. The agent figures out the rest.

# Search and extract information
open-browser run "Find the price of the MacBook Pro on apple.com"

# Fill out forms
open-browser run "Sign up for the newsletter on example.com with test@email.com"

# Multi-step workflows
open-browser run "Go to GitHub, find the open-browser repo, and star it"

Option	Description
-m, --model <model>	Model to use (default: gpt-4o)
-p, --provider <provider>	Provider: openai, anthropic, google
--headless / --no-headless	Show or hide the browser window
--max-steps <n>	Max agent steps (default: 25)
-v, --verbose	Show detailed step info
--no-cost	Hide cost tracking

Browser Commands

open-browser open <url>              # Open a URL
open-browser click <selector>        # Click an element
open-browser type <selector> <text>  # Type into an input
open-browser screenshot [output]     # Capture a screenshot
open-browser eval <expression>       # Run JavaScript on the page
open-browser extract <goal>          # Extract content as markdown
open-browser state                   # Show current URL, title, and tabs
open-browser sessions                # List active browser sessions

Interactive REPL

open-browser interactive

Drop into a live browser> prompt with full control:

browser> open https://news.ycombinator.com
browser> extract "top 5 stories with titles and points"
browser> click .morelink
browser> screenshot front-page.png
browser> help

Using as a Library

import { Agent, createViewport, createModel } from 'open-browser'

const viewport = await createViewport({ headless: true })
const model = createModel('openai', 'gpt-4o')

const agent = new Agent({
  viewport,
  model,
  task: 'Go to example.com and extract the main heading',
  settings: {
    stepLimit: 50,
    enableScreenshots: true,
  },
})

const result = await agent.run()
console.log(result)

Sandboxed Execution

Run agents with resource limits and monitoring:

import { Sandbox } from '@open-browser/sandbox'

const sandbox = new Sandbox({
  timeout: 300_000, // 5 minute timeout
  maxMemoryMB: 512, // Memory limit
  allowedDomains: ['example.com'],
  stepLimit: 100,
  captureOutput: true,
})

const result = await sandbox.run({
  task: 'Complete the checkout form',
  model: languageModel,
})

console.log(result.metrics) // steps, URLs visited, CPU time

Configuration

Environment Variables

# LLM Provider Keys (at least one required)
OPENAI_API_KEY=sk-...
ANTHROPIC_API_KEY=sk-ant-...
GOOGLE_GENERATIVE_AI_API_KEY=...

# Browser
BROWSER_HEADLESS=true
BROWSER_DISABLE_SECURITY=false

# Recording & Debugging
OPEN_BROWSER_TRACE_PATH=./traces
OPEN_BROWSER_SAVE_RECORDING_PATH=./recordings

Agent Configuration

Setting	Default	Description
stepLimit	100	Maximum agent iterations
commandsPerStep	10	Actions per agent step
failureThreshold	5	Consecutive failures before stopping
enableScreenshots	true	Include page screenshots in agent context
contextWindowSize	128000	Token budget for conversation
allowedUrls	[]	Restrict navigation to specific URLs
blockedUrls	[]	Block navigation to specific URLs

Viewport Configuration

Setting	Default	Description
headless	true	Run browser without visible window
width / height	1280 / 1100	Browser window dimensions
relaxedSecurity	false	Disable browser security features
proxy	—	Proxy server configuration
cookieFile	—	Path to cookie file for persistent sessions

How It Works

                    ┌─────────────┐
  "Book a flight"   │             │
  ───────────────►  │    Agent    │  ◄── LLM (OpenAI / Anthropic / Google)
                    │             │
                    └──────┬──────┘
                           │
                    ┌──────▼──────┐
                    │   Commands  │  click, type, scroll, extract, navigate...
                    └──────┬──────┘
                           │
                    ┌──────▼──────┐
                    │  Viewport   │  Playwright browser instance
                    └──────┬──────┘
                           │
                    ┌──────▼──────┐
                    │  DOM / Page │  Snapshot, interactive elements, content
                    └─────────────┘

1. You describe a task in natural language
2. The Agent sends the current page state + task to an LLM
3. The LLM decides what commands to execute (click, type, navigate, extract...)
4. Commands execute against the Viewport (Playwright browser)
5. The agent observes the result, detects stalls, and loops until the task is complete

Model Support

Provider	Example Models	Flag
OpenAI	gpt-4o, gpt-4o-mini, o1	-p openai
Anthropic	claude-sonnet-4-5-20250929, claude-opus-4-6	-p anthropic
Google	gemini-2.0-flash, gemini-2.5-pro	-p google

Project Structure

packages/
├── core/                    # Core library (open-browser)
│   └── src/
│       ├── agent/           # Agent logic, conversation, stall detection
│       ├── commands/        # Action schemas and executor (25+ commands)
│       ├── viewport/        # Browser control, events, guards
│       ├── page/            # DOM analysis, content extraction
│       ├── model/           # LLM adapter and message formatting
│       ├── metering/        # Cost tracking
│       ├── bridge/          # IPC server/client
│       └── config/          # Configuration types
├── cli/                     # CLI (@open-browser/cli)
│   └── src/
│       ├── commands/        # CLI command implementations
│       └── index.ts         # Entry point
└── sandbox/                 # Sandbox (@open-browser/sandbox)
    └── src/
        └── sandbox.ts       # Resource-limited execution

Development

# Install dependencies
bun install

# Type check
bun run build

# Run tests
bun run test

# Lint
bun run lint

# Format
bun run format

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines.

License

MIT