[BUG] Claude Code VS Code extension does not read MCP server config from Claude Desktop MSIX virtualized path

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?

The Claude Code VS Code extension reads MCP server configuration from %USERPROFILE%\.claude.json (non-virtualized path), but Claude Desktop — when installed via MS Store, WinGet, or claude-setup.exe — writes its config to the MSIX virtualized path:
%LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\claude_desktop_config.json

As a result, MCP servers configured in Claude Desktop are not visible to the VS Code extension. Users must manually duplicate their MCP configuration in %USERPROFILE%\.claude.json as a workaround.

What Should Happen?

The Claude Code VS Code extension should discover MCP servers from the same location Claude Desktop uses on the current system, including the MSIX virtualized path when Claude Desktop is installed as an MSIX package.

Error Messages/Logs

No error messages or logs are produced. MCP servers configured via Claude Desktop are silently unavailable in the extension — there is no indication that a separate config file is expected.

Steps to Reproduce

1. Install Claude Desktop on Windows via MS Store, WinGet, or claude-setup.exe (all deploy as MSIX)
2. Open Claude Desktop → Settings → Edit Config
3. Add one or more MCP server entries to claude_desktop_config.json — this file is written to:

%LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\claude_desktop_config.json

1. Open VS Code with the Claude Code extension installed
2. MCP servers configured in step 3 are not available in the extension
3. Manually adding the same entries to %USERPROFILE%\.claude.json makes them appear — confirming the extension reads from a different path

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

anthropic.claude-code VSCode extension: 2.1.186

Platform

Other

Operating System

Windows

Terminal/Shell

Other

Additional Information

This is for Claude Code for VSCode extension, not Claude Code CLI