Brow MCP Server

<p align="center"> <img src="docs/assets/brow-headline.png" alt="Brow" width="820" /> </p> <p align="center"> <strong>Brow</strong> is an experimental Chrome side-panel AI browser agent for builders who want <strong>LangGraph.js</strong>, <strong>MCP</strong>, <strong>WebMCP</strong>, and semantic browser automation inside a real Chrome session. </p> <p align="center"> <img alt="Status: Experimental" src="https://img.shields.io/badge/Status-Experimental-A855F7?style=for-the-badge" /> <img alt="Manifest V3" src="https://img.shields.io/badge/Chrome-Manifest%20V3-2F2F2F?style=for-the-badge&logo=googlechrome&logoColor=white" /> <img alt="LangGraph.js" src="https://img.shields.io/badge/Agent-LangGraph.js-1B1B1B?style=for-the-badge" /> <img alt="MCP and WebMCP" src="https://img.shields.io/badge/Tools-MCP%20%2F%20WebMCP-7C3AED?style=for-the-badge" /> <img alt="License: Apache 2.0" src="https://img.shields.io/badge/License-Apache%202.0-2FF801?style=for-the-badge&logo=apache&logoColor=111111" /> </p> <p align="center"> <img src="docs/assets/Brow-intro.webp" width="760" alt="Brow Demo"/> </p>

Why Brow

Brow is an open-source AI agent that operates directly in the browser.

• It runs inside the user's live Chrome session instead of spinning up a detached automation browser.
• It gives the agent semantic browser context through Browser Snapshots, form semantics, and structured refs instead of raw DOM dumping.
• It combines three tool worlds in one side panel: built-in browser tools, page-local WebMCP tools, and remote MCP server tools.
• It keeps browser-native workflows close to the model with workflow demonstrations, reusable skills, and local domain memory.

Core Capabilities

Capability	What Brow provides
Browser Snapshots	Compact, ref-based snapshots of the live DOM so the agent can reason over visible structure and act on fresh targets.
Whole-form semantics	Form snapshots with field purposes, safe current values, validation cues, and submit semantics for batch form work.
WebMCP page tools	Dynamic discovery of page-local tools exposed through navigator.modelContext on the active tab.
Remote MCP servers and MCP Apps	HTTP/SSE MCP connectivity, tool discovery, and inline rendering for approved app-backed tool results.
Real side-panel workflow	A Manifest V3 Chrome extension with chat, tool timeline, approvals, configuration, and tab-aware execution in the side panel.
Workflow demonstrations, skills, and memory	Recorded workflows, skill mentions, domain memory, and reusable operational knowledge that help Brow improve over time.

Architecture At A Glance

<p align="center"> <img src="docs/assets/schema.png" alt="Brow" width="820" /> </p>

For the maintainer-oriented runtime map, see docs/maintainer-architecture.md.

Quick Start

Prerequisites

• Node.js >= 20
• npm >= 9
• Chrome or another Chromium browser with extension developer mode

1. Install dependencies

npm install

2. Build Brow

# production build
npm run build

# or keep a watch build running during development
npm run dev

3. Load the extension

1. Open chrome://extensions.
2. Enable Developer mode.
3. Click Load unpacked.
4. Select the local dist/ folder generated by the build.
5. Open Brow from the extension icon or Chrome side panel.

4. Configure the model and tools

1. Open Brow's Options page or the in-sidepanel config surface.
2. Set your OpenAI-compatible base URL, API key, model, and context window.
3. Optionally configure a VLM endpoint, MCP servers, and feature toggles such as WebMCP or MCP Apps.

Useful Scripts

Command	Purpose
npm run dev	Webpack watch build for extension development
npm run build	Production build to dist/
npm run clean	Remove build output
npm run typecheck	TypeScript validation without emitting files
npm test	Prepare fixtures and run the Node test suite
npm run verify	Run typecheck, tests, and production build

Project Map

Path	Purpose
src/sidepanel/	Side-panel UI, LangGraph agent runtime, tool assembly, MCP client, skills, and chat flow
src/content-script/	Browser Snapshot engine, WebMCP bridge, DOM inspection, and workflow recording
src/background/	Tab lifecycle observation, message routing, and WebMCP discovery coordination
src/options/	Extension options page for endpoint, transport, and feature-level configuration
src/shared/	Shared contracts, storage helpers, config normalization, and reusable types
src/html-app-view/	Brow-hosted HTML app rendering surface
docs/	Feature guide, maintainer architecture, ADRs, and visual assets
tests/	Node-based test suite for architecture, tool shape, browser semantics, and UI formatting
test-page/	Local fixture pages for WebMCP and browser automation development

Documentation

• docs/extension-features.md for the implementation-backed feature inventory
• docs/maintainer-architecture.md for runtime flow and code ownership
• CONTEXT.md for Brow's canonical product vocabulary
• docs/adr/ for architectural decisions and design history
• docs/full-spectrum-automation-plan.md for deeper planning context around Brow's automation direction

Status

Brow is currently experimental and optimized for builders, contributors, and early adopters who are comfortable loading an unpacked extension and iterating locally. The README intentionally describes a self-hosted workflow; it does not assume Chrome Web Store distribution or a fully stabilized public API surface yet.

License

Brow is licensed under the Apache License 2.0.

Support

If this project saves you time, consider supporting development ❤️

https://github.com/sponsors/shijou87