Features Browser Chrome Devtools Protocol

Browser Chrome Devtools Protocol

Control web browsers through the Chrome DevTools Protocol (CDP). This feature lets an AI agent list open browser tabs, navigate to URLs, execute JavaScript, take screenshots, and click elements — enabling automated web interaction, scraping, and testing directly through the desktop browser without requiring a separate WebDriver or headless setup.

Actions

browser.list_tabs

List all open tabs across detected browser instances.

Parameter	Type	Description
browser	string	Optional. Target browser: chrome, chromium, firefox. If omitted, auto-detects a running browser.

deskbrid browser.list_tabs '{ "browser": "chrome" }'

{"type": "browser.list_tabs", "browser": "chrome"}

Response: Returns an array of tab objects, each with tab_id (string), title (string), url (string), browser (string), and favicon_url (string).

browser.navigate

Navigate a specific browser tab to a URL.

Parameter	Type	Description
tab_id	string	The tab ID returned by browser.list_tabs.
url	string	The full URL to navigate to (must include protocol, e.g. https://example.com).

deskbrid browser.navigate '{ "tab_id": "tab-1", "url": "https://example.com" }'

{"type": "browser.navigate", "tab_id": "tab-1", "url": "https://example.com"}

Response: Returns {"success": true} once the page has started loading. Does not wait for full page load.

browser.evaluate

Execute arbitrary JavaScript in a browser tab and return the result.

Parameter	Type	Description
tab_id	string	The tab ID to execute JavaScript in.
expression	string	The JavaScript expression or script to evaluate. Returns the evaluated result (serializable values only).

deskbrid browser.evaluate '{ "tab_id": "tab-1", "expression": "document.title" }'

{"type": "browser.evaluate", "tab_id": "tab-1", "expression": "document.title"}

Response: Returns an object with result containing the evaluated JavaScript value (string, number, boolean, array, or object — must be JSON-serializable). Non-serializable values (e.g. undefined, DOM nodes, functions) return an error or null.

browser.screenshot_tab

Capture a screenshot of a browser tab's current viewport.

Parameter	Type	Description
tab_id	string	The tab ID to screenshot.
format	string	Optional. Image format: png (default) or jpeg.

deskbrid browser.screenshot_tab '{ "tab_id": "tab-1", "format": "jpeg" }'

{"type": "browser.screenshot_tab", "tab_id": "tab-1", "format": "jpeg"}

Response: Returns a base64-encoded string of the screenshot image. Decode and save to disk for viewing.

browser.click

Click on a DOM element in a browser tab identified by a CSS selector.

Parameter	Type	Description
tab_id	string	The tab ID to click in.
selector	string	A CSS selector matching the target element (e.g. "#submit-btn", ".nav-link", "button[type=submit]").

deskbrid browser.click '{ "tab_id": "tab-1", "selector": "#submit-btn" }'

{"type": "browser.click", "tab_id": "tab-1", "selector": "#submit-btn"}

Response: Returns {"success": true} if the element was found and clicked. Returns an error if no element matches the selector.

Safety Boundary

• CDP access requires the browser to be launched with a remote debugging port enabled (e.g. --remote-debugging-port=9222 for Chrome/Chromium). Deskbrid does not automatically start browsers with debugging enabled — the user must configure this.
• browser.evaluate can execute arbitrary JavaScript, which has full access to the page's DOM, cookies, localStorage, and network. This is privileged access — treat it with the same caution as a browser extension.
• Firefox requires the moz:debuggerAddress capability and may behave differently than Chrome-based browsers.
• Tabs are sandboxed by browser origin policies — browser.evaluate only has access to the current page's origin, not cross-origin content.
• Confirmation mode is recommended for browser.navigate and browser.click when operating on sensitive sites.

Local Development

1. Start Chrome/Chromium with remote debugging enabled:

   google-chrome --remote-debugging-port=9222 --user-data-dir=/tmp/chrome-debug

2. Ensure Deskbrid daemon is running: deskbrid daemon
3. List tabs:

   deskbrid browser.list_tabs '{ "browser": "chrome" }'

4. Navigate to a test page:

   deskbrid browser.navigate '{ "tab_id": "<id>", "url": "https://example.com" }'

5. Run a JS expression:

   deskbrid browser.evaluate '{ "tab_id": "<id>", "expression": "document.body.innerText.substring(0, 200)" }'

6. Take a screenshot:

   deskbrid browser.screenshot_tab '{ "tab_id": "<id>" }'

Configuration

No Deskbrid-specific configuration is required, but the browser must be launched with a remote debugging port. Typical flags:

• Chrome/Chromium: --remote-debugging-port=9222
• Chromium-based Edge: --remote-debugging-port=9222
• Firefox: Requires marionette enabled (about:config > marionette.enabled=true) or use geckodriver.

Multiple browsers can run simultaneously on different debugging ports; Deskbrid auto-discovers them via CDP's discovery endpoint.