Install Chrome Extension
Install
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Install Crawlio for Chrome from the Chrome Web Store.
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Pin the extension to your toolbar for quick access.
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Click the Crawlio icon and press Connect to link the current tab to the MCP server.
All browser tools will target the connected tab.
How it works
The extension injects a CDP bridge into Chrome. It uses Chrome's debugger API to execute commands through the Chrome DevTools Protocol, the same protocol used by Chrome DevTools and Playwright.
The WebSocket connection stays local (127.0.0.1:9333, first free port in the 9333-9342 range). Bridge info is written to ~/.crawlio/bridge/.
Unlike headless browser tools like Playwright MCP, the extension connects to your existing Chrome. Your logged-in sessions, cookies, and tabs are all available. No separate browser process, no re-authenticating.
What you get
96 tools across 13 categories:
| Category | Count | Examples |
|---|---|---|
| Tab management | 6 | connect_tab, list_tabs, disconnect_tab |
| Page capture | 13 | capture_page, detect_framework, take_screenshot |
| Browser interaction | 9 | browser_navigate, browser_click, browser_type |
| Accessibility and waiting | 2 | browser_snapshot, browser_wait_for |
| Network interception | 1 | browser_intercept |
| Frame management | 3 | get_frame_tree, switch_to_frame |
| Tab, cookie, and device | 26 | create_tab, set_cookie, set_viewport, print_to_pdf |
| Network and security | 8 | emulate_network, get_security_state |
| DOM manipulation | 4 | set_outer_html, set_attribute, remove_node |
| CSS and JS coverage | 10 | start_css_coverage, detect_fonts, get_computed_style |
| Target and memory | 6 | get_targets, force_gc, take_heap_snapshot |
| Visual debugging | 3 | highlight_element, show_layout_shifts |
| Session recording | 5 | start_recording, compile_recording, ocr_screenshot |
See the full Browser Tools Reference for parameters and return types.
Live browser vs headless
The Chrome extension is one of two browser modes. If you also have the headless agent installed, the aggregator routes automatically: Chrome when a tab is connected, headless when not. See the Browser Agent Overview for how routing works.