Windows mcp.json major bug with non-stdio servers

Hey, thanks for the report. Confirming a known issue on Windows with duplicated connections to non-stdio MCP servers (N×N instead of N). Related threads:

This bug is critical for public MCP server operators - you may see N^2 client connections.

Could you share details for escalation:

  • mcp.json contents (global ~/.cursor/mcp.json and project .cursor/mcp.json if both exist)
  • Server types and endpoint URLs (SSE/HTTP)
  • Server-side logs showing duplicated connections
  • Logs from Help > Toggle Developer Tools > Console when MCP starts
  • Whether it reproduces with one non-stdio server (no dupes) vs two+ (duplication appears)
  • Whether you tested earlier Cursor versions

Temporary workarounds:

  • Ensure a server isn’t defined in both ~/.cursor/mcp.json and .cursor/mcp.json
  • Prefer stdio over SSE where possible
  • Use a single Cursor window
  • Disable extra MCPs in Settings > MCP

I’ll forward this to the team with your details.