GraphWalker can be run as a WebSocket service. This page is an overview of the API that can be used to interact with the service.
The service will handle multiple connections. Every connection will a unique session. The models has to be uploaded using the Websocket start API call. It does not load any models on command line.
Command line example
Start GraphWalker Websocket service on default port 8887 and debug level set to ALL.
java -jar graphwalker-cli-3.4.2.jar --debug all online
Start GraphWalker Websocket service on port 9999 with no debug level.
java -jar graphwalker-cli-3.4.2.jar online --port 9999 --service WEBSOCKET
See more about command line options here.