Local Browser

When to use

Reach for this skill whenever the task needs to act AS THE USER in a web context. The hallmark is: an unauthenticated browser can't do this because the page requires their cookies/session.

• "Post this to LinkedIn / Twitter / Reddit" — needs their logged-in

session.

• "Check my Gmail / Slack / Linear for X" — same.
• "Pull this from behind SSO."
• "Place this order on Amazon / book this flight" — payment + saved

cards + addresses.

• "Comment on this PR / file this Jira ticket" — authored as them.

If the page is public and unauthenticated, prefer a regular fetch / plain scraping tool — driving a real browser is overkill and the cookies are sensitive.

What it is

The local-browser plugin (@agentproto/plugin-local-browser) is a one-time setup that:

1. Clones one of the user's existing Chrome profiles into

~/.agentproto/chrome-profile/ (cookies + extensions + logins transfer).

1. Installs chrome-devtools-mcp into ~/.agentproto/chrome-mcp/.
2. Registers it in ~/.agentproto/imported-mcps.json so the

agentproto daemon proxies all 29 browser tools through /mcp to every tunnel-connected client.

The daemon spawns Chrome on demand against the cloned profile, so the user's daily Chrome keeps running undisturbed.

How to call it

Tools surface under the alias local-browser. From an agentproto MCP-proxy client they're invoked via the daemon's meta-tools:

// list everything available
mcp_imported_tool_list({ alias: "local-browser" })

// drive the browser
mcp_imported_call({
  alias: "local-browser",
  tool: "navigate_page",
  arguments: { url: "https://news.ycombinator.com" }
})

The 29 tools fall into these buckets:

| What you want | Tool(s) | |--------------------------------|---------------------------------------------------------------------| | Open / switch pages | new_page, navigate_page, select_page, list_pages, close_page | | See the page | take_snapshot (AX tree), take_screenshot, list_console_messages | | Click / type / fill | click, type_text, fill, fill_form, press_key, hover, drag | | Wait for something | wait_for | | Run JS | evaluate_script | | Network inspection | list_network_requests, get_network_request | | Perf / Lighthouse | performance_start_trace, performance_stop_trace, lighthouse_audit | | Files / dialogs / viewport | upload_file, handle_dialog, resize_page, emulate |

A typical flow:

1. navigate_page to the target URL.
2. take_snapshot — returns an AX tree where each element has a

uid.

1. Pass that uid to click / fill / etc. (do NOT pass CSS

selectors).

1. wait_for if the next step depends on a network response or DOM

change.

1. take_screenshot if you need to show the user what happened.

How to know it's installed

If mcp_imported_status doesn't list a local-browser import, the user hasn't set the plugin up yet. Suggest:

npx -y -p @agentproto/plugin-local-browser agentproto-browser setup

Then the user restarts the daemon (~/.agentproto/start-daemon-prod.sh) and the tools appear on the next mcp_imported_status.

Safety rails

The plugin drives a Chrome signed into the user's accounts. That means:

• Don't speculatively click things. Each call may post, pay, send,

or delete with the user's identity. Always state what you're about to do and get explicit confirmation for irreversible actions.

• Don't run evaluate_script with anything that could exfiltrate

(document.cookie, localStorage dumps, etc.) without an extremely clear ask. The result returns through the daemon → MCP → wherever you are.

• Sessions are real but a snapshot. Logins set up at clone-time

may have expired; if a page redirects to a login screen, fall back to "please sign in here once" rather than trying to fill credentials.

• Treat screenshots like screenshares. They can reveal unrelated

open tabs, account names, notifications. Show only what the user asked for and crop when you can.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: agentproto
• Source: agentproto/ts
• License: Apache-2.0
• Homepage: https://agentproto.sh

Install and usage instructions live in the source repository linked above.