[BUG] claude.ai MCP integrations (Gmail, Google Calendar) not available in -p mode or --resume sessions since v2.1.79

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Cloud-managed claude.ai MCP integrations (Gmail, Google Calendar) are no longer available as tools when running
Claude Code in non-interactive mode (-p, --print, or --resume sessions). They work correctly in interactive
mode.

claude mcp list shows them as connected, and they execute successfully in interactive mode, but claude -p
cannot see or use them. Other OAuth-based MCPs added via plugins (Notion, Supabase) work fine in both modes —
the only difference is that plugin MCPs have local config in the plugin cache, while claude.ai MCPs are purely
cloud-managed with no local config file.

What Should Happen?

claude.ai MCP tools should be available in -p / non-interactive mode, just as they are in interactive mode, and
just as plugin MCPs (Notion, Supabase) are.

Error Messages/Logs

No error — the tools simply don't appear. Claude reports "I don't have any Gmail tools available" when asked in
   -p mode, while the same query in interactive mode returns and executes the tools successfully.

Steps to Reproduce

1. Have claude.ai Gmail and/or Google Calendar MCPs connected (visible and working in /mcp in interactive mode)
2. Verify they work interactively: open claude, ask to list calendar events — works fine
3. Run: claude -p "Do you have access to Gmail tools? List any mcp tools with gmail in the name."
4. Claude reports no Gmail tools available
5. Compare with plugin MCPs: claude -p "list your Notion tools" — these appear correctly

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Not sure of the exact version — it was working before v2.1.79 was installed on March 19, 2026.

Claude Code Version

2.1.79

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_