The browser_subagent tool fails on all browser automation tasks with a Playwright installation error.
Error Message
failed to create browser context: failed to install playwright: $HOME environment variable is not set
Steps to Reproduce
Use Antigravity agent on Windows
Invoke any browser_subagent task (e.g., navigate to localhost:3000)
Task fails immediately with the above error
Expected
Browser opens, navigates to URL, and allows interaction/screenshots.
Actual
All browser automation fails. Multiple retries produce the same error.
Impact
Cannot visually verify UI changes
Cannot capture screenshots for walkthroughs
Cannot perform browser-based testing
Environment
OS: Windows
Date: January 29, 2026
Notes
This appears to be an infrastructure configuration issue where the container/environment running Playwright doesn’t have the $HOME environment variable set, which is required for Playwright installation.
This is a known Windows issue — Playwright expects a Linux-style $HOME variable that Windows doesn’t set by default (it uses %USERPROFILE% instead). Quick fix: open PowerShell and run [System.Environment]::SetEnvironmentVariable(‘HOME’, $env:USERPROFILE, ‘User’). Restart your IDE after that and browser automation should work. Someone else posted this as a tip in a separate thread and confirmed it resolves the issue. Would be nice if the Antigravity team just set this automatically on Windows installs.
Hi @Algis
Thanks for providing the solution in this thread! For anyone else running into the $HOME environment variable is not set error while using browser automation on Windows, the fix has been confirmed in the link below. It involves a quick PowerShell command to map your user profile correctly so Playwright can initialize.