[BUG] claude.ai Gmail MCP auth flow broken in Claude Code CLI on Linux — Enter key does nothing after browser auth

Environment

• Claude Code CLI version: (run claude --version to fill in)
• OS: Linux (Arch, kernel 6.19)
• Shell: zsh
• Plan: (fill in)

Summary

The /mcp authentication flow for the claude.ai Gmail connector never completes in Claude Code CLI. The terminal prompts "Press Enter after authenticating in your browser" but pressing Enter has no effect — no error, no success, the Gmail tools never
become available.

Steps to Reproduce

1. Add Gmail MCP: claude mcp add --transport http gmail https://gmail.mcp.claude.com/mcp
2. Run /mcp in a Claude Code session
3. Select "claude.ai Gmail" → authenticate
4. Terminal shows: Authenticating with claude.ai Gmail… A browser window will open for authentication
5. Browser opens to https://claude.ai/settings/connectors
6. Gmail shows as connected ("Disconnect" button visible)
7. Return to terminal, press Enter
8. Nothing happens (I press esc to exit it eventually)

Key Observations

1. Wrong redirect URL. The CLI opens https://claude.ai/settings/connectors — a settings page, not an OAuth endpoint. There is no OAuth token exchange triggered.
2. Two separate connector systems. https://claude.ai/settings/connectors (old, used by CLI auth flow) and https://claude.ai/customize (new Customize page) appear to be separate systems. Connecting Gmail on the new Customize page does not propagate to

the old page. The CLI auth flow uses the old page.

1. Gmail IS connected in the web app. The connector works correctly on claude.ai web chat — confirming the OAuth token is valid. The failure is CLI-specific.
2. No OAuth page shown. Other reporters (e.g. #30166) describe seeing gmail.mcp.claude.com/google/install?metadata=.... That page never appears in the CLI flow on Linux — the browser goes straight to the connectors settings page.

Expected Behavior

After pressing Enter, the CLI should pick up the OAuth token and the Gmail tools should become available in the session.

Actual Behavior

Enter key has no effect. Gmail tools never appear. No error is shown.

Related Issues

• #30166 — OAuth hang in Claude Desktop (different surface, similar root cause)
• #25650 — Gmail tools not exposed in session after auth