br0wser

br0wser is a small CLI for launching Chrome/Chromium with a debug port or attaching to an existing browser over the Chrome DevTools Protocol.

It is primarily meant to be used as a skill or helper tool by an agent that needs to reconnect to a live browser session across steps, turns, or debugging loops. Humans can use it directly too, but the main design goal is agent-friendly browser reuse instead of one-shot automation.

It is designed for workflows where browser state should stick around between runs: signed-in sessions, open tabs, localStorage, cookies, or a browser that was started by VS Code debugging.

Why this exists

Most browser automation tools assume they own the browser lifecycle. br0wser is built for the opposite case:

• open a browser once
• keep it alive
• reconnect to it whenever you need to inspect, click, fill, evaluate, or screenshot

That makes it useful for agent skills, local app development, debugger-driven flows, and any workflow where starting from a fresh browser each time is annoying.

Install

Install the CLI:

npm install -g @albro3459/br0wser

Install the bundled Claude skill:

br0wser install --skills claude

Install the bundled Codex skill:

br0wser install --skills codex

Those commands copy the packaged skill bundle into the matching agent skill directory:

• Claude: ~/.claude/skills/br0wser
• Codex: $CODEX_HOME/skills/br0wser or ~/.codex/skills/br0wser when CODEX_HOME is not set

You can also run the CLI without a global install:

npx @albro3459/br0wser info

Use br0wser --help to see the install flow again and print the resolved paths for:

• the package README.md
• the bundled skill SKILL.md
• the bundled skill references/ directory
• the installed skill target directory

Optional convenience alias:

alias brwsr="br0wser --chrome-port 9222"

The helper defaults to Chrome debug port 9222, so --chrome-port is optional unless you need a different port. The alias is still handy if you want to make that default explicit.

Quick start

Launch or reuse a browser on the default port 9222:

br0wser open http://localhost:4200

See what tabs are available:

br0wser info

Target a specific tab and interact with it:

br0wser --chrome-port 9222 --page-url localhost:4200 click-text "Login"
br0wser --chrome-port 9222 --page-url localhost:4200 fill-selector 'input[name="email"]' 'user@example.com'
br0wser --chrome-port 9222 --page-url localhost:4200 eval "location.href"

Common commands

br0wser --chrome-port 9222 open https://example.com
br0wser --chrome-port 9222 info
br0wser --chrome-port 9222 goto https://example.org
br0wser --chrome-port 9222 --page-url example.org click-selector 'button[type="submit"]'
br0wser --chrome-port 9222 --page-url example.org click-text 'Continue'
br0wser --chrome-port 9222 --page-url example.org fill-selector 'input[name="email"]' 'user@example.com'
br0wser --chrome-port 9222 --page-url example.org eval "document.title"
br0wser --chrome-port 9222 --page-url example.org screenshot page.png
br0wser install --skills <claude|codex>

How it works

• open launches a debug browser if one is not already listening on the chosen port
• if a browser is already running on that port, open reuses it
• each command connects, does one job, and detaches cleanly
• the browser keeps running until you close it
• install --skills <claude|codex> copies the bundled skill files into the selected agent skills directory

That means session state persists naturally across commands.

Useful flags

• --chrome-port <port>: debug port to attach to or launch with; defaults to 9222
• --page-url <fragment>: select the tab whose URL includes the fragment
• --headless: launch in headless mode when using open
• --user-data-dir <path>: use a dedicated browser profile
• --endpoint <url>: connect directly to a CDP endpoint instead of building one from a port
• --help: print usage, install flow, and the local doc paths bundled with the package

VS Code example

If VS Code launches Chrome with a remote debugging port, br0wser can hop into that same session. This is especially useful when an agent needs to share the exact browser instance that your debugger owns.

Example launch config in your project's .vscode/launch.json:

{
  "name": "Launch Chrome",
  "type": "pwa-chrome",
  "request": "launch",
  "url": "http://localhost:4200",
  "webRoot": "${workspaceFolder}/client",
  "runtimeArgs": [
    "--remote-debugging-port=9222"
  ]
}

Once that browser is running, your agent can connect:

br0wser --chrome-port 9222 info
br0wser --chrome-port 9222 --page-url localhost:4200 eval "location.href"
br0wser --chrome-port 9222 --page-url localhost:4200 screenshot debug-session.png

Tips

• Provide the VsCodeDebugger-MCP to your agent to query and run your VSCode launch configs.
• Treat br0wser as an attach-first tool for agents: keep the browser alive and reconnect instead of opening fresh sessions unless you need a clean profile.
• Run info before interacting when multiple tabs may be open.
• Use --page-url when you want to avoid clicking in the wrong tab.
• Prefer stable selectors over repeated button text.
• After route-changing clicks, verify with info or eval "location.href".
• If a click appears to hang during a debugger-driven flow, check whether execution is paused at a breakpoint.
• screenshot writes into the OS temp directory under .br0wser/ and appends a timestamp and hash to the filename.

Headed vs Headless

open is headed by default. Pass --headless only when you do not need a visible browser window.

Command summary

• open [url]
• info
• goto <url>
• click-text <text>
• click-selector <selector>
• fill-selector <selector> <text>
• screenshot [filename]
• eval <expression>
• install --skills <claude|codex>

Docs layout

Repository docs live here:

• README.md

The npm package also bundles the Codex skill at skills/br0wser/ with:

• skills/br0wser/SKILL.md
• skills/br0wser/references/
• skills/br0wser/agents/openai.yaml
• skills/br0wser/assets/

br0wser install --skills <claude|codex> copies that bundled directory into the selected agent skills folder.

Notes

• br0wser does not try to close the browser for you.
• A dedicated --user-data-dir is a good idea when you launch your own debug browser.
• This tool is intentionally small and works best as an agent skill or persistent-browser helper, not a full test runner.