Use vSphere SOAP-based (vSphere Management SDK) APIs to get the API sessions.
API: SessionManager
To get your API sessions, compare the client machine's IP address and application name with the IpAddress and UserAgent of the UserSession object.
Sample code:
public void printUserSessions(String vCenterServer, String userName, String password) {
try {
si = new ServiceInstance(new URL("https://" + vCenterServer + "/sdk"), userName, password, false);
SessionManager sm = si.getSessionManager();
UserSession[] usList = sm.getSessionList();
for (UserSession us : usList) {
System.out.println("Client IPAddress::" + us.getIpAddress());
System.out.println("Session Username::" + us.getUserName());
System.out.println("Application/UserAgent::" + us.getUserAgent());
System.out.println("--------------------------------------------------");
}
} catch (Exception e) {
System.err.println("Error ServiceInstance::" + e.getLocalizedMessage());
}
}