Verified Agent Skill record

Browser Harness · Browser Harness

A CLI harness that drives a real browser over CDP for clicking, typing, navigation, logged-in sessions, and JS-rendered or bot-protected pages. It attaches to a local Chrome daemon, offers isolated Browser Use cloud browsers, and supports background recordings. Plain HTTP fetches of public content are out of scope; use curl for those.

Tasks

Extract content from a JavaScript-rendered or bot-protected page after a plain fetch fails or returns a shell page
Complete an interactive flow (click, type, navigate) that depends on the user's logged-in Chrome session
Run isolated browsing tasks in Browser Use cloud browsers with start_remote_daemon(name) and stop them with stop_remote_daemon(name)
Capture a background recording of a browsing task with start_recording(name, title=...) and stop_recording() after verifying the result

Inputs

Python script passed to the browser-harness CLI via heredoc (helpers are pre-imported)
Target URL supplied to new_tab(url)
Environment variables: BH_DOMAIN_SKILLS, BH_TAB_MARKER, BH_RECORD, BU_NAME, BU_CDP_URL, BU_CDP_WS, BH_AGENT_WORKSPACE, BH_OPEN_LIVE_URL, BH_REQUIRE_EXISTING_DAEMON
API key piped to browser-harness auth login --api-key-stdin (e.g., from $BROWSER_USE_API_KEY)
Site-specific files under $BH_AGENT_WORKSPACE/domain-skills/<site>/ when BH_DOMAIN_SKILLS=1

Outputs

Script stdout such as page_info() results
Accessibility tree node data (roles, names, backendDOMNodeId) and computed box-center coordinates
DOM inspection and extraction results from js(...)
Screenshots taken while the attached tab works in the background
Local recording directories returned by start_recording(name, title=...)
Raw CDP responses via cdp("Domain.method", ...)

Limitations and checks

Not for plain HTTP fetches of public content such as public pages, APIs, or docs; use curl or a fetch tool instead
Local Chrome is one shared browser; parallel tasks fight over tabs and focus, so one cloud browser per task is recommended for isolation
Remote daemons bill until they stop or time out
Do not poll in a loop after the macOS permission popup; the daemon holds one connection
CDP target order is not Chrome's visible tab-strip order, and omnibox popups are not real work tabs
activate_tab(target) visibly switches Chrome's tab, so it must not be used when the user has forbidden foreground changes
goto_url(...) returning skill filenames (up to 10) only applies when BH_DOMAIN_SKILLS=1
The first navigation of the task used new_tab(url) rather than goto_url(url), and new_tab() was not called again in every script since the daemon preserves the attached tab across CLI invocations