Google Antigravity browser agent won't start: `could not install driver ... 404 (404 Not Found)` for `playwright-1.57.0-mac-arm64.zip`; install the driver offline into the playwright-go cache

发生场景

Source(s): https://discuss.ai.google.dev/t/antigravity-browser-agent-not-working-on-apple-silicon-mac-os-x/174752 Signal: 1,740 views, 16 likes; a community answer is accepted, and at least six other users replied that it worked (macOS and one Windows user), the latest on 2026-10-18. Status: reported working by source, not reproduced by us (workaround only; root fix not confirmed).

问题

In Antigravity IDE, clicking the browser icon next to settings does nothing, and any agent task that needs the browser (for example opening a local dev server URL) fails with "Failed to complete task because the browser environment failed to initialize. The open_browser_url tool failed with the following error:" followed by the error above. Reinstalling Playwright with npx did not help the original poster.

报错原文（已脱敏/规范化）

failed to create browser context: failed to run playwright manager: failed to install playwright: could not install driver: could not install driver: error: got non 200 status code: 404 (404 Not Found) from https://playwright.azureedge.net/builds/driver/playwright-1.57.0-mac-arm64.zip

适用环境

Antigravity IDE 2.1.1 on an M4 Mac mini, macOS 26.5.2 (original poster, July 2026); later confirmations include Antigravity 2.5.5 on macOS and one Windows user.

如何确认是这个问题

1. Ask the agent to open any URL in the browser tool. → expect: the 404 error above for playwright-<version>-<platform>.zip.
2. Look in the playwright-go cache folder (macOS ~/Library/Caches/ms-playwright-go/1.57.0/). → expect: empty or missing; the original poster's folder existed but was empty.

不是这个问题时 / 边界

The error names a different host or a status other than 404, for example a proxy or certificate error (our inference). The original poster still saw the agent opening empty incognito windows after the fix until they asked it to use the chrome-devtools-mcp tools, so a browser that starts but doesn't load the page may be a separate problem.

根因

Per the replies (not Antigravity staff): the browser agent uses playwright-go, which downloads its driver from the playwright.azureedge.net CDN when its local cache is empty, and that URL returns 404 for 1.57.0. Once the driver files are in the cache folder, playwright-go skips the download.

修复步骤

1. Get the driver zip that matches your version and platform, for example playwright-1.57.0-mac-arm64.zip (Apple Silicon), playwright-1.57.0-mac-x64.zip (Intel Mac) or playwright-1.57.0-linux.zip (Linux x64), preferably copied from another machine where it downloaded normally (a reply's suggestion; GitHub releases is the other source it names). The accepted answer and the users who confirmed it used a third-party mirror instead; see risks.
2. Create the cache folder: mkdir -p ~/Library/Caches/ms-playwright-go/1.57.0 (macOS; Linux uses ~/.cache/ms-playwright-go/1.57.0, Windows %USERPROFILE%\AppData\Local\ms-playwright-go\1.57.0\).
3. Unzip the driver into it: unzip -q -o <path-to-driver.zip> -d ~/Library/Caches/ms-playwright-go/1.57.0. → expect: the folder contains LICENSE, node and package/ (with package/cli.js).
4. Make the bundled Node executable: chmod +x ~/Library/Caches/ms-playwright-go/1.57.0/node.
5. If Chromium is also missing from ~/Library/Caches/ms-playwright/, install it with the restored CLI: ~/Library/Caches/ms-playwright-go/1.57.0/node ~/Library/Caches/ms-playwright-go/1.57.0/package/cli.js install chromium.
6. Restart Antigravity and open the browser from its browser icon with no other Chrome window or profile already open (the original poster found it failed again when a Chrome window was already running). → expect: the browser agent opens the URL.

如何验证

The browser agent opens a URL and takes a screenshot without the 404 error (the accepted answer and several replies).

试过没用的办法

Reinstalling the Playwright drivers manually with npx, with help from Google One support (the original poster).

如何回滚

Delete the 1.57.0 folder you created under ms-playwright-go (our inference).

风险提示

Do not run the bundled node from a mirror zip without checking it first: the accepted answer downloads the driver from a third-party mirror (registry.npmmirror.com), not from Google or the Playwright project, and Antigravity will run that binary (our inference). Do not paste the accepted answer's command list into the Antigravity agent unread; read each command before an agent runs it (our inference). One user asked whether to delete the existing ms-playwright and ms-playwright-go folders first and nobody answered, so do not rm -rf them on that basis.

验证范围

Antigravity IDE 2.x browser agent with playwright-go driver 1.57.0, July to October 2026.

何时失效

Antigravity ships the Playwright driver itself or downloads it from a host that works.