MCP SERVERWork in the Chrome you already have open — read the active tab as stripped-down HTML, run JavaScript, wait on a condition and screenshot it — instead of launching a fresh automated browser.
LABSCO SUMMARY
A freshly launched automation browser starts with no cookies, no extensions and no session; this one attaches to the Chrome you are already using, which is the difference between scripting a public page and scripting the app you actually work in. Page reads are shaped around what a model can afford rather than fidelity — stripped HTML, plain text, or nothing but the tab list. The flip side is worth saying plainly: it runs inside your real browser session, so connect it only to clients you trust.
A bridge into a running Chromium browser through a companion extension and the Chrome DevTools Protocol, addressing tabs that are already open rather than a browser it starts for you.
Python 3.10 or newer and uv, since clients start it as uvx cdp-bridge@latest. A Chromium browser with this project's extension loaded unpacked from src/cdp_bridge/tmwd_cdp_bridge; the extension connects back to the server's WebSocket on 127.0.0.1:18765 and keeps retrying about every five seconds, so a refused connection right after loading resolves itself. For a shared or remote setup, start it with --transport streamable-http --port 8000 and give the client's Bearer token and the extension's Token field the same value. MIT.
One command — uvx cdp-bridge@latest
USE CASES
List the open tabs, make the one you want active on the server side, and scan it as simplified HTML or plain text. Nothing has to be re-authenticated because it is the same browser session you were using.
Run the JavaScript directly in the page and get the DOM changes it caused back with the return value, then poll a condition of your own until it is true rather than sleeping and hoping.
Screenshot the tab and write the PNG somewhere you can attach it. Given a directory, the save step names the file by timestamp, which is what you want when a run produces several.
Switching the server-side tab leaves Chrome looking untouched, which is deliberate but unhelpful when someone needs to take over. This activates the tab and focuses its window.
Give each browser profile's extension a different token and the server keeps their tabs in separate sessions, so one agent run never acts in another account's tab.
CDP methods can be sent as command objects and several of them batched into one request, so a document fetch and the calls that depend on it are a single round trip.
Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.
browser_batchRun multiple extension/CDP commands in one request.
Args: commands: Command objects supported by the extension, such as {"cmd":"cdp","method":"DOM.getDocument","params":{"depth":1}}. tab_id: Optional tab ID inherited by commands that omit tabId. timeout: Seconds to wait for the batch result.
browser_execute_jsExecute JavaScript in the browser and capture results plus DOM changes.
Args: script: JavaScript code to execute (or JSON command for CDP operations). switch_tab_id: Switch to this tab before executing. no_monitor: Skip DOM change monitoring (faster, less info).
browser_focus_tabBring a Chrome tab to the foreground: activate the tab AND focus its window.
Unlike browser_switch_tab (which only changes the MCP-side active session without touching the visible Chrome UI), this actually makes the tab visible to the user. Use this when the user can't find the tab the agent is working on (e.g. across many windows / Spaces / minimized windows).
Goes through chrome.tabs.update + chrome.windows.update (extension-native APIs), avoiding the chrome.debugger CDP "Not allowed" restriction on Target.activateTarget.
Args: tab_id: The tab ID to focus (from browser_get_tabs).
browser_get_tabsGet all open browser tabs with their IDs, URLs, and titles.
browser_navigateNavigate the active tab to a URL.
Args: url: The URL to navigate to.
browser_save_imageSave base64 screenshot data to PNG file.
Args: screenshot_json_str_or_file: JSON output from browser_screenshot tool, or path to a JSON file containing the screenshot data. output_path: Output PNG file path or directory. Behavior:
Returns: JSON with status, saved_path, and size_bytes.
browser_scanGet simplified HTML content of the active tab plus tab list. The HTML is optimized for LLM consumption (stripped of scripts, styles, invisible elements).
Args: tabs_only: Only return tab list without page content (saves tokens). switch_tab_id: Switch to this tab before scanning. text_only: Return plain text instead of simplified HTML.
browser_screenshotTake a screenshot of the active tab (returns base64 PNG).
Args: tab_id: Optional tab ID to screenshot. Uses active tab if empty.
browser_switch_tabSwitch the active MCP browser tab without changing the visible Chrome tab.
Args: tab_id: The tab ID to switch to (from browser_get_tabs).
browser_waitWait until JavaScript condition returns a truthy value.
Args: condition_js: JavaScript expression or script. The return value is tested for truthiness. timeout: Maximum seconds to wait. interval: Seconds between checks. switch_tab_id: Optional tab ID to make active before waiting.
BEFORE YOU INSTALL
10 tools when we connected.
uvx on PATH
CONTEXT COST
Rated by the size of the 10 tool definitions that ride along on every turn, not by how many there are
INSTALLATION
uvx cdp-bridge@latest{
"mcpServers": {
"cdp-bridge": {
"command": "uvx",
"args": [
"cdp-bridge@latest"
]
}
}
}{
"mcpServers": {
"cdp-bridge": {
"type": "streamableHttp",
"url": "http://127.0.0.1:8000/mcp"
}
}
}Clients spell the "type" value differently: Claude Code and VS Code use "http", Cline uses "streamableHttp", and Roo Code uses "streamable-http". Claude Desktop does not accept a URL entry in its config file.
{
"mcpServers": {
"cdp-bridge": {
"type": "http",
"url": "http://127.0.0.1:8000/mcp"
}
}
}codex mcp add cdp-bridge uvx cdp-bridge@latest{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"cdp-bridge": {
"type": "local",
"command": [
"uvx",
"cdp-bridge@latest"
],
"enabled": true
}
}
}{
"mcp": {
"servers": {
"cdp-bridge": {
"command": "uvx",
"args": [
"cdp-bridge@latest"
]
}
}
}
}MCP servers
lxe
opentabs-dev
williamkapke
apireno