Claude in Chrome (Beta) never connects on macOS despite verified-correct setup — window flashes open/closed, reproduces across versions

Summary

The Claude in Chrome extension will not pair with Claude Code on my Mac. Every static piece of the setup is correct, but the connection never establishes. When I trigger a reconnect, a Chrome window flashes open for ~1 second and immediately closes, and the extension stays "not connected." This has persisted across a full machine power-cycle, an extension remove-and-reinstall, and a Claude Code version update.

Environment

• macOS 26.5.2 (build 25F84)
• Claude Code 2.1.202 (also reproduced earlier on 2.1.197)
• Google Chrome 150.0.7871.125
• Claude in Chrome extension ID: fcoeoabgfenejglbffodgkkbkcdhcgfn (installed + enabled)
• Chrome and Claude Code signed into the same Claude account

What happens

Running /chrome → "Reconnect extension" (or launching claude --chrome) opens a Chrome window that closes itself after about a second. The /chrome menu itself reports Status: Enabled, Extension: Installed, but the browser never actually connects. Any browser tool call returns:

Browser extension is not connected. Please ensure the Claude browser extension is installed and running...

Expected behavior

The extension should pair with Claude Code and appear as a connected browser.

Steps to reproduce

1. Install the Claude in Chrome extension; confirm it's enabled and signed in.
2. In Claude Code, run /chrome and select "Reconnect extension" (or run claude --chrome).
3. Observe the Chrome window flash open and close; connection is never established.

What I've verified / ruled out

• Extension installed + enabled; signed into Chrome with the same account as Claude Code.
• Native messaging host manifest present at

~/Library/Application Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json,
with allowed_origins matching the extension ID.

• The manifest's path points to the wrapper ~/.claude/chrome/chrome-native-host, which execs

/opt/homebrew/Caskroom/claude-code/2.1.202/claude --chrome-native-host — target binary exists and is executable.

• After the 2.1.197 → 2.1.202 update, the wrapper was regenerated to the correct current path, so this is not a stale-path issue.
• Already tried: full Cmd+Q Chrome restart, /chrome → "Reconnect extension", claude --chrome, full extension remove + reinstall, and a complete machine power-cycle. All fail identically.