HI have just installed yatse and it is working well. However what I would like to do is switch on my av amplifier as a custom command within yatse (through wifi obviously). Is this possible?
Thanks
Additional information:
You lack a mega tons of details to be able to answer that question actually 
If your receiver is supported by one of the A/V receiver plugin most support that natively, if your receiver have an API for that over HTTP.
So all I can say is probably
sorry for the lack of detail, I use a broadcom rm mini ir blaster to send a signal to switch the av receiver on, so I need to send a signal to that in order for it to work. The app for this is on the same device as yatse. So my thoughts were if I can capture the data sent by that app (somehow) and add that to a command on yatse directing it to the ip address + port of the blaster…
From a quick look it seems the app on the phone start a webserver that accept commands.
So you can add a custom command inside yatse to talk to that server by using 127.0.0.1 as the IP.
For the url you need to find the doc see Home automation with a Broadlink RM Mini 3 and Google Home | by Kat Hempstalk | Medium to find the ips (or similar google search).
Support for the specific device is out of Yatse support sorry.
Thanks so much, that gives me a good start anyway