You can call the API with curl which runs pretty fast, or you can use one of these built-in commands:

Windows
triggercmdagent -t calculator -c office

Linux in X-Windows:
triggercmdagent -t calculator -c office

Linux without X-Windows (SSH):
node /usr/share/triggercmdagent/resources/app/src/triggercmd -t calculator -c office

Raspberry Pi:
node /usr/share/triggercmdagent/app/src/triggercmd -t calculator -c office

Mac:
./TRIGGERcmdAgent.app/Contents/MacOS/TRIGGERcmdAgent -t calculator -c office

Also:
You can use --trigger instead of -t
You can use --computer instead of -c
If your trigger or computer names have spaces, use quotes, for example: triggercmdagent -trigger "reboot now" -computer "office pc"~~