Forum Article

I work on a Mac and use Claude Code to drive Bfexplorer through its MCP server. Bfexplorer is Windows-only, so it runs in a Parallels VM. Getting the Mac to talk to the MCP server took some trial and error, so here's what worked.

1. Start Bfexplorer with the MCP flag

The MCP/REST server only starts when Bfexplorer is launched with a flag, and only after you log in. Add it to the end of the shortcut's Target:

"C:\Program Files\BeloSoft\Bfexplorer\Bfexplorer.exe" -mcp localhost:10043

Launch it from the normal shortcut, not as admin, so it keeps your saved settings. To check it's listening, run this in Windows:

netstat -ano | findstr :10043

You should see 127.0.0.1:10043 ... LISTENING.

2. Forward the port so the Mac can reach it

Bfexplorer listens on loopback only, so the Mac can't connect directly. Set the Parallels network to Shared Network and note the VM's IP from ipconfig (usually 10.211.55.x). Then run this in an Admin PowerShell inside the VM:

netsh interface portproxy add v4tov4 listenaddress=0.0.0.0 listenport=10044 connectaddress=127.0.0.1 connectport=10043
New-NetFirewallRule -DisplayName "Bfexplorer MCP (Mac)" -Direction Inbound -Protocol TCP -LocalPort 10044 -Action Allow

To test it from the Mac, run curl -i http://10.211.55.x:10044/. Any HTTP response means it works. The REST API is on the same port at /api/openapi.json.

3. Point Claude Code at it

Add a .mcp.json in the project folder:

{
  "mcpServers": {
    "bfexplorer": { "type": "http", "url": "http://10.211.55.x:10044/" }
  }
}

Run claude, approve the server, and /mcp should list the Bfexplorer tools.

Things that caught me out

- Parallels pauses idle VMs by default (Configure → Options → Startup and Shutdown → "Pause Windows after…"). Untick it, or Bfexplorer stops answering mid-session.
- Turn on market/order streaming in Bfexplorer Settings. Without it, markets you aren't actively viewing return frozen prices.
- Stop the Mac sleeping if you leave it running unattended: sudo pmset -a disablesleep 1. With the lid closed it sleeps even with Amphetamine running.
- macOS Local Network permission: anything on the Mac that calls the VM (Python, Node) needs it under Privacy & Security → Local Network, or you get "No route to host".
- Keep Bfexplorer open: a Windows scheduled task that relaunches it with -mcp if it isn't running helps after updates or restarts. You still have to log in by hand.

Happy to answer questions if anyone's trying the same setup.