The next CLI is part of the vCSA, and you can use the api command. To see all available commands, you can use help api list:

Command> help api list
Supported API calls by this server:
com.vmware.appliance.version1.access.consolecli.get com.vmware.appliance.version1.networking.ipv6.list
com.vmware.appliance.version1.access.consolecli.set com.vmware.appliance.version1.networking.ipv6.set
com.vmware.appliance.version1.access.dcui.get com.vmware.appliance.version1.networking.proxy.delete
com.vmware.appliance.version1.access.dcui.set com.vmware.appliance.version1.networking.proxy.get
com.vmware.appliance.version1.access.shell.get com.vmware.appliance.version1.networking.proxy.set
com.vmware.appliance.version1.access.shell.set com.vmware.appliance.version1.networking.proxy.test
...

See the following example:

Command> api com.vmware.appliance.health.mem.get
Health: green 

In real life, a VMware administrator needs other commands on the vCSA to restart components, such as the vSphere Web Client:

Command> service-control --list
vmware-updatemgr (VMware Update Manager)
vmafdd (VMware Authentication Framework)
vmware-eam (VMware ESX Agent Manager)
vmcam (VMware vSphere Authentication Proxy)
…

Restarting the vSphere Web Client service is quite easy from the command line:

Command> service-control --stop vsphere-client
Command> service-control --start vsphere-client

You should also know basic Linux commands such as tail, vi, more, less, grep, and ls for the TRBL process.