How to list VSTS agent pools programmatically from PowerShell?

Question

I want to connect to VSTS and get a list of agent pools. I want to enumerate the agent pools and then delete agents on the VSTS server. I can't find any documentation for how to do this in the VSTS API reference.

I'm connecting to VSTS fine like this to list projects for example, but how to list agent pools?

$User = 'mark.allison@domain.com'
$PersonalAccessToken = '{PAT_TOKEN}'
$base64authinfo = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f  $User, $PersonalAccessToken)))
$vstsAccount = "{VSTS_ACCOUNT}"

# projects
$resource = 'projects'
$uri = "https://sabinio.visualstudio.com/DefaultCollection/_apis/$($resource)?api-version=3.0"
$projects = Invoke-RestMethod -Method Get -ContentType application/json -Uri $Uri -Headers @{Authorization=("Basic {0}" -f $base64authinfo)}

Answer 1

I did as well not find anything about it in the official documents.
However by checking the network traffic I figured out the following: https://xyz.visualstudio.com/_apis/distributedtask/pools/ is how to get the Agent Pools.
So with a GET request you will get a list of agent pools, that includes name, id and some more properties. If you send a DELETE request to that url with the ID of the pool you want to delete, it will be removed.
If at first you want to get the agents of an agent pool, you do a GET to:
https://xyz.visualstudio.com/_apis/distributedtask/pools/POOLID/agents
Then again you get the agents of that pool listed with name, id etc.
To delete that agent you send a DELETE request to https://xyz.visualstudio.com/_apis/distributedtask/pools/POOLID/agents/AGENTID

So in your PowerShell script you as well don't need to fetch anything "project-specific", as the AgentPools and Agents are available for all the projects of the collection.

Hope that helps