claude-code - 💡(How to fix) Fix Chrome extension service worker never initiates MCP bridge connection (Linux/AUR) [6 comments, 3 participants]

Summary

The Claude Chrome extension installs and authenticates successfully in Google Chrome on Linux, but its service worker never executes the MCP bridge initialization code. The native messaging host crashes on startup due to missing DISABLE_AUTOUPDATER env var (AUR package issue), and even after fixing that, the extension's bridge logic never activates.

Environment

• OS: Linux 6.19.11-arch1-1 (Arch Linux)
• Chrome: Google Chrome 147.0.7727.55
• Claude Code: 2.1.105 (installed via AUR: https://aur.archlinux.org/packages/claude-code)
• Extension: Claude 1.0.68

Two issues found

1. Native host crashes due to auto-updater (AUR-specific)

The AUR package installs Claude Code at /opt/claude-code/bin/claude with a wrapper at /usr/bin/claude that sets DISABLE_AUTOUPDATER=1. However, claude --chrome generates ~/.claude/chrome/chrome-native-host pointing directly to /opt/claude-code/bin/claude, bypassing the wrapper. Without DISABLE_AUTOUPDATER, the native host crashes immediately after Chrome's native messaging connects to it.

Error in extension service worker: Unchecked runtime.lastError: Native host has exited.

Workaround: Setting DISABLE_AUTOUPDATER=1 in the user environment (via ~/.config/environment.d/) so Chrome passes it to the native host. Patching the script directly doesn't survive restarts since claude --chrome regenerates it.

Suggested fix: The generated chrome-native-host script should include export DISABLE_AUTOUPDATER=1, or it should call through /usr/bin/claude (or $(which claude)) instead of hardcoding the binary path.

2. Extension service worker never runs bridge logic

After fixing the native host crash, the extension's service worker remains completely dormant:

• Service worker DevTools console is empty (no logs even on Verbose)
• mcpConnected is never written to extension storage (or stays false)
• chrome.runtime.connectNative() from DevTools works — returns a port, no errors, native host stays alive
• But the extension never calls connectNative on its own
• chrome_ext_bridge_enabled feature flag is true (source: defaultValue)
• Extension has valid OAuth tokens (accessToken, refreshToken)
• Pairing was completed (bridgeDisplayName set)
• browserControlPermissionAccepted: true
• Claude Code has 10+ active connections to bridge.claudeusercontent.com
• Chrome has connections to the same bridge server
• But the extension never joins the bridge for MCP tool calls

Steps to reproduce

1. Install Claude Code via AUR package
2. Install Claude extension in Google Chrome
3. Log into claude.ai in Chrome
4. Complete extension pairing
5. Run claude --chrome
6. Invoke any mcp__claude-in-chrome__* tool → "Browser extension is not connected"

Diagnostic details

• Initially tried Chromium (known unsupported due to server-side feature flag). Switched to Google Chrome — same result for issue #2.
• The cloud bridge (wss://bridge.claudeusercontent.com) is the data path, not local unix sockets. Both sides connect to the bridge server but the extension never initiates the MCP handshake.
• No other Claude Code sessions running during final tests.
• Extension toggled off/on, Chrome restarted multiple times — no change.

Expected behavior

After pairing and authentication, the extension's service worker should automatically initiate the MCP bridge connection via native messaging, allowing Claude Code's mcp__claude-in-chrome__* tools to function.