BulkCancelDeleteQueuedBuilds.ps1

$env:API_TOKEN="<replace>" # https://ci.appveyor.com/api-keys
$env:APPVEYOR_ACCOUNT_NAME="<replace>" # from AppVeyor URL (after "project/")
$env:APPVEYOR_PROJECT_SLUG="<replace>" # from AppVeyor URL (after account name)
$env:recordsNumber = 20

$headers = @{
  "Authorization" = "Bearer $env:API_TOKEN"
  "Content-type" = "application/json"
}

$history=Invoke-RestMethod -Uri "https://ci.appveyor.com/api/projects/$env:APPVEYOR_ACCOUNT_NAME/$env:APPVEYOR_PROJECT_SLUG/history?recordsNumber=$env:recordsNumber" -Headers $headers  -Method Get

$queued = $history.builds | ? {$_.status -eq "queued"}

$queued | % {
  Write-Host "Cancelling build version $($_.version)"
  Invoke-RestMethod -Uri "https://ci.appveyor.com/api/builds/$($env:APPVEYOR_ACCOUNT_NAME)/$($env:APPVEYOR_PROJECT_SLUG)/$($_.version)" -Headers $headers  -Method Delete
  
  Write-Host "Deleting build version $($_.version)"
  Invoke-RestMethod -Uri "https://ci.appveyor.com/api/builds/$($_.buildId)" -Headers $headers  -Method Delete
}