⚡ ChromeBoost

Give Claude hands in your own browser.

Not a headless clone in a data centre — your Chrome, already signed into your accounts, driven by clicks, drags and keystrokes shaped like a person's.

chromeboost.vercel.app · Install · What to ask it · Tools · ☕ Buy me a coffee

MIT · no account · no telemetry

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ChromeBoost is a Chrome extension plus an MCP server. Together they let Claude Code drive the browser sitting in front of you — the one with your sessions, your cookies, your logged-in dashboards. You ask in plain English and watch it happen.

Anything irreversible stops and waits for you. Posts, payments, passwords and 2FA are yours to confirm; ChromeBoost fills in everything around them and hands back control.

Things people actually say to it

"Reply to the new comments on my last LinkedIn post — draft each one and I'll hit Post."

Opens the post, reads the thread, types a reply into the composer for each comment. It stops at Post every time: the button gets highlighted and it waits for your click, so nothing goes out in your name that you didn't read.

"Grab my Stripe test keys and put them in .env"

Navigates to the dashboard you're already logged into, opens Developers → API keys, reveals the secret, writes it straight to .env. The key never touches your clipboard.

"Walk through our signup flow and screenshot every step into ./docs"

Drives the flow like a new user — fills the form, submits, waits for each screen — saving a numbered screenshot at every step. Onboarding docs that rebuild themselves.

"Drag the seat slider to 50 and tell me what it costs"

A slider has no button to click. ChromeBoost presses, moves through real intermediate positions, releases, then reads the price back off the page.

"Download last month's invoices from the billing portal"

Signs in as you, filters the date range, pulls every PDF using your real session cookies — the files a logged-out scraper can't reach.

Why it works where scripts don't

It doesn't teleport. A normal automation script jumps a cursor to coordinates and fires a click event. ChromeBoost sends the whole gesture through Chrome's own input pipeline — a curved approach, a settle tremor before it lands, pressure on the way down, keystrokes that arrive as real key events. React, TipTap, ProseMirror, CodeMirror, Monaco and Stripe's contenteditable fields all register input that scripted events silently swallow.

Cookie banners don't stop it. This is what breaks most browser agents: a page paints a scrim, a modal backdrop, or an invisible catch-all <div> over the button, the click lands on that, and the agent gets told it worked. It then argues with a button it never pressed. ChromeBoost hit-tests the target first — aims at a part of it that's actually exposed, scrolls out from under fixed bars, steps the overlay aside for the duration of a single click and puts it straight back. When something genuinely can't be reached, it names the element in the way instead of claiming success.

Not everything is click-shaped. hover for menus and row actions that only exist while the pointer is on them. drag for sliders, canvas and WebGL apps, map panning, sortable lists, resize handles.

Install

You need Chrome and Claude Code. There's nothing to clone and no build step — the plugin ships both halves.

1. Add the plugin

In Claude Code, run these one at a time — not as a single paste:

/plugin marketplace add lordamdal/chromeboost

/plugin install chromeboost@chromeboost

Then restart Claude Code so the MCP server starts.

2. Load the extension

/chromeboost-setup

This copies the extension to ~/Downloads/ChromeBoost-Extension and opens the folder. It goes to Downloads on purpose — the plugin's own directory is buried under ~/.claude/plugins/cache/…, which is painful to reach in Chrome's folder picker and changes on every plugin update.

Then in Chrome:

1. Paste chrome://extensions into the address bar (chrome:// links can't be clicked).
2. Turn on Developer mode, top right.
3. Click Load unpacked and pick ChromeBoost-Extension — or drag the folder onto the page.

Leave that folder where it is. Chrome reads it on every launch, so moving or deleting it breaks the extension. Chrome will also flag it as a developer-mode extension — expected, since ChromeBoost isn't on the Web Store and runs from files you can read.

3. Point it at a window

Click the ChromeBoost icon in the toolbar. Your session appears with a green dot — hit Use this window to bind the Chrome window you want driven. Then try:

open news.ycombinator.com and give me the top 5 stories

If something goes wrong

The first command opens a dialog asking for a "marketplace source"

It wants the repo on its own, without the /plugin prefix:

lordamdal/chromeboost

Permission denied or host-key error when adding the marketplace

owner/repo shorthand clones over SSH. Use the HTTPS URL instead:

https://github.com/lordamdal/chromeboost.git

Or set CLAUDE_CODE_PLUGIN_PREFER_HTTPS=1 to make shorthand clone over HTTPS.

No green dot in the popup

The extension is loaded but hasn't connected. Hit the reload arrow on the ChromeBoost card in chrome://extensions — it reconnects on a backoff timer, and a reload forces it immediately.

After updating the plugin

Run /chromeboost-setup again. It overwrites ~/Downloads/ChromeBoost-Extension in place, so you only need to hit reload in chrome://extensions — no re-picking the folder.

Build from source instead

git clone https://github.com/lordamdal/chromeboost
cd chromeboost
npm install
npm run build

Load packages/extension/dist unpacked, then /plugin marketplace add /absolute/path/to/chromeboost.

To register the MCP server by hand instead of using the plugin:

{
  "mcpServers": {
    "chromeboost": {
      "command": "node",
      "args": ["/absolute/path/to/chromeboost/packages/plugin/server/chromeboost.mjs"]
    }
  }
}

You lose the bundled skill and permission allowlist, so you'll be prompted on every tool call.

The HUD

While Claude drives, a small panel sits on the page so you know a session is in control and which one.

Action	How
Move it	Drag the header — it snaps flush to an edge if you drop it near one
Collapse it	Double-click the header, or the – button
Hide it	The × button
Bring it back	Alt+Shift+B on any page, or Show in the toolbar popup

Position and state persist, so you only ever move it once. It lives in a closed shadow root — no page can restyle it or find it — and only the panel itself takes clicks, never the space around it. It's kept out of screenshots automatically.

Where it stops

An agent with your logins shouldn't be able to publish in your name, move your money, or pass your 2FA on its own — and this one can't.

• Publishing — posts, comments and replies are drafted into the composer; the Post button is highlighted and waits for your real click.
• Passwords & 2FA — never typed. It brings you to the field and pauses. Secrets visible on screen are redacted out of what Claude reads by default.
• Payments & captchas — yours to confirm. Captchas aren't solved or faked; ChromeBoost reports one is present and steps back.

Tool surface

35 tools. You won't type any of them — Claude picks them — but here's what it can do:

Tool	For
hover	Hover-only menus, row actions at opacity: 0, tooltips, chart crosshairs
drag	Sliders, canvas/WebGL, map panning, sortable lists, resize handles
probe_point	Report what's actually painted at a spot — diagnoses a click that went nowhere
hud	Move, dock, collapse or hide the on-page panel
click_element · click_at_coordinates	Trusted clicks that hit-test first and get past overlays
fill_input · fill_form · type_text	Real keystrokes through React, contenteditable, CodeMirror, Monaco, TipTap
get_page_text · find_text · get_form_fields	Read the page, including closed shadow DOM; secrets redacted
open_page · wait_for · list_tabs · switch_to_tab	Navigate, wait, work across tabs
take_screenshot · download_file · read_attachment	Capture steps, pull authenticated files, read PDFs
fetch_url · inspect_request_headers	Requests with your real cookies, bypassing page CSP
highlight_region · wait_for_click	Hand control back to you
write_to_env	Put a captured key straight into .env

Full agent-facing guide: packages/plugin/skills/chromeboost/SKILL.md.

Development

npm install
npm run build      # both halves; also syncs the extension into the plugin
npm run dev:ext    # extension, watch mode
npm run dev:mcp    # MCP server, tsc watch

Reload the extension at chrome://extensions after changing extension source. Restart Claude Code after changing MCP server source.

Path	What
packages/extension/src/content/hittest.ts	Occlusion-aware hit testing + overlay piercing
packages/extension/src/content/hud.ts	The draggable HUD (closed shadow root)
packages/extension/src/background.ts	CDP dispatch: click, hover, drag; pierce/restore
packages/mcp-server/src/tools/cursor.ts	hover, drag, probe_point, hud
packages/plugin/	Plugin manifest, skill, and the bundled extension payload
apps/website/index.html	Landing page — static, no build step
tests/overlays/	Occlusion regression fixture

CLAUDE.md is the repo-developer guide.

Support

ChromeBoost is free, MIT-licensed, and has no telemetry — the server only ever talks to your own browser. If it saved you an afternoon:

☕ Buy me a coffee

License

MIT — see LICENSE.