By doing a GET
to /api/machines/all
you'll get a list of all the Machines registered in Octopus. Each of them will look a bit like this:
{
"Id": "Machines-28",
"Name": "T1Listening1",
"Thumbprint": "5B39B11EA8804D9E02E8D10189343074891BED21",
"Uri": "https://ny-tentacle1:10933/",
"IsDisabled": false,
"EnvironmentIds": [