Viz Plug-ins User Guide

Version 5.0 | Published December 20, 2022 ©


The viz_command_over_websocket plug-in allows Viz Engine to interpret websocket messages as Viz Engine commands.

Open a websocket connection and send for each command one message. The extension then responds with the corresponding command response from Viz Engine. The command can be prepended with an integral number which is used as Command ID. This way the response can be associated with the request message. If left empty, the config parameter default-id is used instead.


To Configure this plugin create a file called {VizEngine-Config-dir}/extensions/CommandOverWebsocket.json. This file is used for every running instance of Viz Engine. To have a specific config for a running instance, you can create configuration files like {VizEngine-Config-dir}/extensions/CommandOverWebsocket-{Instance-Number}.json. For this extension, this is required if multiple instances are started, as it is not possible to open multiple websocket servers on the same port.

Supported config parameters:

  • port: Port where the websocket server will listen.

  • default-id: Default Command-ID used if the incoming message does not include it.

The CommandOverWebsocket.json file could then look like this:

"default-id": "-1",
"port": 6900


Currently, the websocket server uses the ws protocol which is not protected. Using this extension in OEM versions is not possible.