Atera : Dead client removal

Atera_DeadClientRemoval.ps1

#
## ORIGINAL POST : https://support.atera.com/hc/en-us/community/posts/360002992288-Atera-s-Support-Team-Hack-of-the-week-Delete-Offline-Agents-using-API-
#

####### Edit this section only ##########
$apiKey = "XX" # your API key , get it from: https://app.atera.com/Admin#/admin/api
$offlinePeriodIndays = 60
$deleteAgents = 0 # set to 1 only after you verify the list
####### edit this section only ##########

######################################################################################
## Please do not alter the script below, it can cause a real damage to your account ##
######################################################################################
try {
    $last = 0
    $inactiveAgents = @()
    $pageLink = 'https://app.atera.com/api/v3/agents?itemsInPage=50'
    $monthAgo = (Get-Date).AddDays(0 - $offlinePeriodIndays)
    while (!$last) {
        $request = Invoke-RestMethod -Headers @{"X-API-KEY" = $apiKey } -Method GET -Uri $pageLink -ContentType application/json
        $inactiveAgents += $request | Select-Object -Expand items | where { $_.Online -eq 0 -and [DateTime]$_.Modified -lt $monthAgo }
        if ($request.nextLink.Length -gt 0) {
            $pageLink = $request.nextLink;
            Start-Sleep -s 1
        }
        else {
            $last = 1
        }
    }

    if (!$deleteAgents) {
        #see the agents
        $inactiveAgents | select AgentName, IpAddresses, OSType, CustomerName, Modified, Online | Sort-Object -Property AgentName | ft
        $agentsCount = $inactiveAgents.Count
        Write-Host "$agentsCount agents were found in the last $offlinePeriodIndays days"
        Write-Host "###This is just a test, please verify if these are the agents you want to delete.###`nOnce verified, set the deleteAgents parameter to 1 (at the top of this script)."
        Break;
    }

    $retryCount = 0
    foreach ($agent in $inactiveAgents)
    {
        $retryCount = 0
        while ($retryCount -lt 3) {
            $retryCount += 1
            try {
                $url = "https://app.atera.com/api/v3/agents/$($agent.AgentId)";
                Invoke-RestMethod -Headers @{"X-API-KEY" = $apiKey } -Method DELETE -Uri $url -ContentType application/json
                write-host "$($agent.AgentName) Deleted :)"
                Start-Sleep -s 1
                Break
            }
            catch {
                Start-Sleep -s 6
                if ($retryCount -eq 3) {
                    write-host "$($agent.AgentName) Delete Agent Failed. Error: $_.Exception"
                    try {
                        $streamReader = [System.IO.StreamReader]::new($_.Exception.Response.GetResponseStream())
                        $ErrResp = $streamReader.ReadToEnd()
                        $streamReader.Close()
                    }
                    catch {
                    }
                }
            }
        }
    }
}

catch {
    if ($_.Exception.Response.StatusCode -eq "Unauthorized") {
        Write-Host "Failed to authenticate, make sure the correct api-key has been added"
    }
    else {
        Write-Host "Failed to get your account agents list"
        Write-Host "error:" $_.Exception
    }
}