[BUG] Claude in Chrome (1.0.79) never registers with relay — "extension not connected" despite fully healthy extension

Environment

• Claude Code CLI: 2.1.201 (macOS, Darwin 25.5.0)
• Chrome extension: Claude in Chrome (Beta) 1.0.79, ID fcoeoabgfenejglbffodgkkbkcdhcgfn (official Web Store install)
• Extension state: enabled, service worker active (visible in chrome://extensions), side panel opens and works normally
• Extension login: same account as Claude Code (verified on the extension's options page)

Symptom

list_connected_browsers (and every other mcp__claude-in-chrome__* tool) always returns:

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

The relay reports zero registered extension instances for this account, i.e. the extension never registers — this is not a flaky or in-use-by-another-session situation.

Timeline

• It worked the previous day (2026-07-04) — browser automation via the extension ran fine in Claude Code sessions.
• The extension auto-updated at some point (user also manually checked for updates: "already up to date", currently 1.0.79).
• Since 2026-07-05, registration never succeeds across many hours and multiple retests.

Ruled out (all verified today)

1. Wrong extension — it is the official one (ID above), not a third-party MCP extension.
2. Account mismatch — extension options page shows the same Google account as Claude Code (claude.ai session valid; side panel chat works).
3. Network / proxy — direct connectivity to api.anthropic.com / claude.ai verified OK from the same machine; the in-browser proxy manager (ZeroOmega) was switched to Direct mode and the failure reproduced identically. No OS-level proxy is configured.
4. Stale service worker — extension toggled off/on, and Chrome fully quit (Cmd+Q) and relaunched with proxy still on Direct; no change.
5. Chrome/extension disabled state — chrome://extensions shows enabled, service worker running ("Service Worker, +2 views").
6. Other automation extensions (OpenAI Codex 1.1.5) present but the failure persists regardless; they use separate infrastructure and were not involved in the working sessions either.
7. Service-worker errors — opened the SW DevTools console from chrome://extensions ("Inspect views: service worker"): zero errors logged, yet relay registration still never happens. The failure is completely silent — no error surfaces anywhere (extension UI, SW console, or CLI beyond "not connected"). Retested list_connected_browsers with the SW console open and the SW therefore guaranteed alive: still "not connected".

Expected

Extension registers with the relay after (re)start; list_connected_browsers lists the browser.

Actual

Relay-side registration never happens; every session since 2026-07-05 reports "not connected".

Suspicion

Regression in the 1.0.79 service-worker relay registration (silent WebSocket failure with no retry), since the same setup worked the day before and every local factor has been eliminated.