[BUG] Background sessions (Agent View) do not load MCP servers from ~/.claude/mcp.json

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?

MCP servers added via claude mcp add are stored in ~/.claude/mcp.json, but background sessions started from Agent View do not load this file. They appear to only read ~/.claude.json.

What Should Happen?

Expected: ~/.claude/mcp.json is loaded consistently in all session types.

Workaround: Manually add the MCP server to the global mcpServers key in ~/.claude.json.

Error Messages/Logs

Mcp not found on /mcp

Steps to Reproduce

1. Add an MCP server via claude mcp add --transport http my-server https://...
2. Verify it works in a normal terminal session
3. Start a background session from Agent View
4. The MCP server is not available in the background session

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

v2.1.187

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

_No response_