Browy

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The browser agent that runs on the AI subscription you already pay for. A Chromium extension for Chrome, Edge, and Brave that drives your real, logged-in tabs through chat. Side panel for day-to-day work, DevTools panel CLI for power users. No second bill: it runs on your existing GitHub Copilot subscription.

⚠️ Early access (v0.1.x). Browy is in preview. APIs, tools, and on-disk schemas may change between minor releases. Breaking changes are documented in CHANGELOG.md.

Table of contents

• What Browy is
• Quick install
• What gets installed
• Two ways to talk to Browy
• Worked examples
• How Browy is different
• Browy vs alternatives
• Project layout
• Status
• Responsible AI
• Contributing
• Security
• License

What Browy is

Browy is a browser AI agent. You install it as a Chromium extension; it adds two UI surfaces (a side panel chat and a DevTools panel CLI) that talk to a small Node native-messaging host running on your machine. The host wraps the GitHub Copilot SDK, so every model call uses your existing Copilot subscription, no extra API keys.

The agent drives the active tab through the Chrome DevTools Protocol via chrome.debugger. It reads pages off the accessibility tree (the same tree screen readers use), clicks and types by index, captures network and console activity, and runs JavaScript when the structured tools are not enough.

Browy is a productivity tool for a single human operator, not a way to run unattended automation against other people's services. You point it at a tab; it reads and acts on that tab; you see every action stream back into the chat. There is no Browy server in the loop and no inbox that other people can flood by talking to it.

Think Claude Code or Aider, but in your browser. An open-source alternative to Browser-Use and Skyvern.

Quick install

Step 1: install the extension

Add Browy from the Chrome Web Store (one click). The same listing covers Chrome, Edge, and Brave.

✓ Validate: Pin the toolbar icon. Click it. The side panel opens and asks you to install the backend, with the command for your OS and a copy button. That's Step 2.

Step 2: install the native host

Windows (bundles Node and the Copilot CLI, ~140 MB):

irm https://github.com/BrowyHQ/browy/releases/latest/download/install.ps1 | iex

macOS / Linux:

curl -fsSL https://github.com/BrowyHQ/browy/releases/latest/download/install.sh | bash

✓ Validate: Go back to the side panel. It picks up the backend by itself within a few seconds and moves on to the chat (if it doesn't, close and reopen it). Still stuck? Check the host is on disk: ~/.browy/app/node ~/.browy/app/dist/cli-bin.js --version (Windows: & "$env:LOCALAPPDATA\Browy\app\node.exe" "$env:LOCALAPPDATA\Browy\app\dist\cli-bin.js" --version).

Updating: run the same command again. It updates in place and keeps your chats. When the Web Store updates the extension past your backend, the side panel shows a yellow browy backend is out of date banner with a button that copies the command for you.

Step 3: sign in to Copilot

Click Sign in to GitHub Copilot in the side panel. A terminal window opens with a device-flow link. Paste the code in your browser, authorise, the terminal closes itself.

✓ Validate: Send "what is the headline of this page" against any tab. You should see a snapshot tool call followed by a streamed reply.

That's it. Try your first chat for five concrete examples.

From mainland China? GitHub Releases and api.githubcopilot.com are both reachable but slow. See the China setup guide for the BROWY_RELEASE_URL mirror pattern and a latency note.

What gets installed

The installer is conservative; everything below survives reboots and updates in place.

Nothing in this list leaves your machine. Page content the agent reads goes to GitHub Copilot, exactly as if you ran gh copilot from a terminal. Full data-handling summary at browyhq.github.io/privacy/.

Two ways to talk to Browy

Both surfaces share session state, model selection, and chat history. The DevTools CLI exists for keyboard-driven workflows; the side panel exists for everything else.

Worked examples

Real tasks Browy handles well. Each links to the full transcript and a screenshot.

• Scrape the YC startup directory by batch: "List all Fall 2026 YC companies with their location and one-line pitch."
• Review a GitHub PR: "Summarise the changes in this PR and flag anything that looks risky."
• Set up a Gmail filter: "Auto-archive everything from no-reply@*.atlassian.net."
• Fill a sign-up form across multiple tabs: multi-step, multi-tab, stops before submit.

For a guided walkthrough with screenshots, see Your first chat.

How Browy is different

• Runs against your real browser profile. Not a headless puppet. Your cookies, your extensions, your password manager, your existing logins. Most "first, log in to X" steps disappear.
• Indexed accessibility-tree snapshot. Every turn, Browy gives the model a numbered list of every visible interactive element ([12]<button>Submit</button>). The agent clicks by index. No brittle CSS selectors, no XPath guesswork.
• DevTools-aware. Network requests, console logs, cookies, storage, and evaluate_js are first-class tools. Great for debugging the app you are building, not just operating apps that are already running.
• Bring your own model. Pick from any frontier model your Copilot subscription exposes (Claude, GPT, Gemini, Llama, Codex). Switch with /model in the DevTools CLI or in Settings.
• One subscription, no surprise bills. Browy is built on the GitHub Copilot SDK. There is no Browy meter. Whatever Copilot costs you, that is what Browy costs you.
• Open source, Apache-2.0. Audit the host. Audit the extension. Pin a known-good build. The agent loop is in one file (src/agent/loop.ts) and the tool registry is in another (src/agent/tools/browser.ts).

Browy vs alternatives

Project layout

browy/
├── extension/             ← Chromium extension (side panel + DevTools panel + options)
│   └── README.md          ← Side panel and DevTools CLI feature docs
├── src/                   ← Node native-messaging host (TypeScript)
│   ├── agent/             ← Copilot SDK driver, tool registry, page snapshot
│   ├── cli/               ← Standalone CLI entry point (`browy run`)
│   ├── transports/        ← Native messaging and WebSocket framing
│   └── README.md          ← Architecture and developing locally
├── scripts/               ← Build, stage, pack helpers
├── installer/             ← NSIS installer plus install.ps1 / install.sh
├── packaging/             ← Per-OS native-messaging-host manifests
├── tests/                 ← Vitest suite (page-snapshot, redaction, agent-loop smoke)
└── docs/                  ← Screenshots used in READMEs; site lives at browyhq.github.io

Status

Browy is v0.1.x, early access. The Chrome Web Store listing is live for Chrome, Edge, and Brave on Windows, macOS, and Linux. Native-host installers ship from GitHub Releases.

Known rough edges:

• Long-running multi-step automations on hostile single-page apps (LinkedIn, Notion, Discord, Figma) need better wait and retry strategies. File issues with reproductions.
• Translations beyond Simplified Chinese have not started.
• The DevTools CLI is keyboard-only; mouse selection in the REPL is still rough.

The roadmap and current open work live on the GitHub project board and in the docs roadmap page.

Responsible AI

Browy amplifies a human operator. It does not replace the operator.

• You see every action. Tool calls render inline in the side panel as they happen. Browy never executes a tool you cannot watch.
• Host-touching tools are off by default. Shell, filesystem, and web_fetch require an explicit Settings toggle, one tool at a time.
• No background activity. The agent only acts when you send a message. No polling, no scheduled runs, no off-screen automation.
• Page content goes to GitHub Copilot. Same path as gh copilot in a terminal. Governed by your Copilot subscription terms.
• No Browy server. The maintainer cannot read your chats or your page content. Telemetry is not collected.
• Chrome shows its standard debugger banner whenever the agent is driving. You always know when Browy is attached.

Detailed security and threat-model notes at browyhq.github.io/security/.

Contributing

PRs welcome. The dev loop is small and the codebase is intentionally readable.

• CONTRIBUTING.md: setup, dev loop, style, PR process
• Architecture: extension ↔ port ↔ native host ↔ Copilot SDK
• Good first issues
• Discussions: bigger questions and design proposals

Contributors are listed in CONTRIBUTORS.md.

Security

Found a vulnerability? Use GitHub's private vulnerability reporting at https://github.com/BrowyHQ/browy/security/advisories/new. Please do not open a public issue. Full policy in SECURITY.md.

License

Apache-2.0. See LICENSE and NOTICE.