Verifying LegendCTL makes no network connections

LegendCTL claims to be local-only: no accounts, no telemetry, no remote config, no auto-update — see SECURITY.md. That claim is testable, and you don’t have to take our word for it. This page shows how to confirm it yourself with TCPView, a free Microsoft Sysinternals tool that lists, in real time, every TCP/UDP endpoint each process owns.

What you’ll need

Steps

  1. Close LegendCTL if it’s running.
  2. Launch TCPView and let the list settle. Optionally use its filter (Options → Filter, or the search box) to make the list easier to read.
  3. Launch LegendCTL and use it normally — connect a controller, read state, change and apply settings, open the various tabs.
  4. In TCPView, find the row(s) for the LegendCTL process:
    • Released build: the process is ZD Ultimate Legend.exe.
    • Run from source: the process is pythonw.exe (or python.exe).
  5. Watch the State, Remote Address, and Sent/Rcvd columns for that process while you keep using the app.

Expected result: nothing

For the LegendCTL process, the expected network activity is none:

If the process appears in the list at all, it should only ever be with no remote endpoint. LegendCTL talks to the controller over USB/HID — those handles are not network sockets and will not show up in TCPView.

ℹ️ Windows itself, your antivirus, your browser, and other apps will of course show network activity in TCPView. This test is specifically about the LegendCTL process row — that’s the one that should stay quiet.

ℹ️ One deliberate handoff: the About screen’s GitHub buttons (repository and issue tracker) hand a URL to your default browser (webbrowser.open). The LegendCTL process itself opens no socket; any traffic that follows belongs to the browser process, not to the LegendCTL row you’re watching here.

Quick check with PowerShell (built in — no download)

Prefer not to download anything? Windows’ built-in PowerShell shows the same result in a couple of commands. With LegendCTL running (and a controller connected, if you have one), list every network connection the process owns:

# Find the LegendCTL process id (released build):
Get-Process "ZD Ultimate Legend" | Select-Object Id, ProcessName

# List the TCP connections + UDP endpoints it owns (replace 12345 with the Id):
Get-NetTCPConnection -OwningProcess 12345 -ErrorAction SilentlyContinue
Get-NetUDPEndpoint  -OwningProcess 12345 -ErrorAction SilentlyContinue

For the LegendCTL process both commands return nothing — no TCP connections, no UDP endpoints — even while you read controller state and apply settings:

Id    ProcessName
--    -----------
36276 ZD Ultimate Legend

# Get-NetTCPConnection / Get-NetUDPEndpoint  ->  no output (zero connections)

Running from source instead? Use the pythonw / python process id. The HID handles LegendCTL uses to talk to the controller are not network sockets, so they never appear here.

Going further