A PowerShell script that posts a comment (public or private) to a Zendesk ticket. Supports rich and HTML comments and author impersonation.

ZendeskAPI-PostComment.ps1

param(
    [Parameter(Mandatory=$true)][Int32]$ticketID,
    [Parameter(Mandatory=$true)][String]$body,
    [Parameter(Mandatory=$true)][ValidateSet('rich', 'html')][String]$body_type,
    [Parameter(Mandatory=$true)][ValidateSet('private', 'public')][string]$scope,
    [String][ValidateSet('assignee', 'apiuser')]$author
)

if($body_type -eq "html"){
    $zd_body_type = "html_body"
}

elseif(($body_type -eq "rich") -or (!$body_type)){
    $zd_body_type = "body"
}

if($scope -eq "public"){
    $public = "True"
    }
elseif($scope -eq "private"){
    $public = "False"
   }

#Reference to another Zendesk script, see comments in the Gist.
$ticket = &ZendeskAPI-GetTicket.ps1 $ticketID

$assignee_id = $ticket.assignee_id

#Stupid hack to replace special character.
$body = $body.trim().replace("\","/").replace("`n","\n").replace("`r","\n").replace("    ","").replace("	","").replace("`"","`'").replace("*","").Replace("'","'")

#Zendesk API Connection Headers Referencing System Environmental Variables for username and API token.
$headers = @{Authorization = 'Basic ' + [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes("$($env:ZendeskAPI_Username):$($env:ZendeskAPI_Token)"));}

#Zendesk API: Update Ticket
$uri = "https://yourdomain.zendesk.com/api/v2/tickets/$ticketID.json"
if($author -eq "assignee"){
    $json = '{
        "ticket": {
            "comment": { "'+$zd_body_type+'": "'+$body+'", "public": "'+$public+'", "author_id": "'+$assignee_id+'" }
        }
    }'
}

else {
    $json = '{
        "ticket": {
            "comment": { "'+$zd_body_type+'": "'+$body+'", "public": "'+$public+'" }
        }
    }'
}

Invoke-RestMethod -Uri $uri -Method Put -Headers $headers -ContentType "application/json" -Body $json

ZendeskAPI-GetTicket.ps1 (referenced in the script above).