Send Slack alerts for low Zendesk CSAT scores using n8n

Prerequisites

Overview

Zendesk has no webhook or trigger for CSAT responses. When a customer rates a ticket "Bad," there's no event fired that you can listen for. The only way to detect new bad ratings is to poll the satisfaction ratings API on a schedule.

This workflow runs every 5 minutes, queries the Zendesk satisfaction ratings endpoint filtered to bad scores, checks for new ratings since the last poll, fetches ticket details for context, and sends a Slack Block Kit alert with a direct link to the ticket. This is the recommended approach because it provides near-real-time alerts with rich formatting and no code to maintain.

Step 1: Set up Zendesk credentials in n8n

Go to Credentials → Add credential → Zendesk API:

• Subdomain: your Zendesk subdomain (the xxx part of xxx.zendesk.com)
• Email: your agent email address
• API Token: the token from Admin Center → APIs → Zendesk API

Test the connection to verify access.

Step 2: Add a Schedule Trigger node

Add a Schedule Trigger node as the workflow entry point:

• Interval: Every 5 minutes

This is the polling frequency. Five minutes balances responsiveness with API rate limits.

Step 3: Poll the Zendesk satisfaction ratings API

Add an HTTP Request node:

• Method: GET
• URL: https://YOUR_SUBDOMAIN.zendesk.com/api/v2/satisfaction_ratings?score=bad&sort_order=desc&per_page=10
• Authentication: Predefined Credential Type → Zendesk API (or use Basic Auth with email/token:api_token)

The score=bad parameter filters to only unsatisfied ratings. The sort_order=desc returns newest first so you only need the first page.

Step 4: Filter to new ratings only

Add a Code node to deduplicate. Since we poll every 5 minutes, we only want ratings that appeared since the last poll:

const ratings = $input.first().json.satisfaction_ratings || [];
const fiveMinAgo = new Date(Date.now() - 5 * 60 * 1000).toISOString();
 
const newBadRatings = ratings.filter(r => r.updated_at > fiveMinAgo);
 
if (newBadRatings.length === 0) {
  return []; // No new bad ratings — stop workflow
}
 
return newBadRatings.map(r => ({
  json: {
    ratingId: r.id,
    ticketId: r.ticket_id,
    comment: r.comment || '(no comment)',
    createdAt: r.updated_at,
  }
}));

If no new bad ratings exist, the workflow stops here — no unnecessary Slack or Zendesk API calls.

Step 5: Fetch ticket details

Add an HTTP Request node to get context for each bad rating:

• Method: GET
• URL: https://YOUR_SUBDOMAIN.zendesk.com/api/v2/tickets/{'{'}$json.ticketId{'}'}.json
• Authentication: Same Zendesk credentials
• Batching: Process items individually (one request per bad rating)

This returns the ticket subject, requester name, assignee, tags, and other details you'll include in the Slack alert.

Step 6: Post a Slack Block Kit alert

Add an HTTP Request node (or Slack node) to post the alert:

• Method: POST
• URL: https://slack.com/api/chat.postMessage
• Headers: Authorization: Bearer YOUR_SLACK_BOT_TOKEN
• Body (JSON):

{
  "channel": "CSAT_CHANNEL_ID",
  "blocks": [
    {
      "type": "header",
      "text": {
        "type": "plain_text",
        "text": "Bad CSAT Rating Received",
        "emoji": true
      }
    },
    {
      "type": "section",
      "fields": [
        {"type": "mrkdwn", "text": "*Ticket:* #{{$json.ticketId}}"},
        {"type": "mrkdwn", "text": "*Subject:* {{$json.ticket.subject}}"},
        {"type": "mrkdwn", "text": "*Customer:* {{$json.ticket.requester.name}}"},
        {"type": "mrkdwn", "text": "*Assignee:* {{$json.ticket.assignee_id}}"}
      ]
    },
    {
      "type": "section",
      "text": {
        "type": "mrkdwn",
        "text": "*Customer comment:* {{$json.comment}}"
      }
    },
    {
      "type": "actions",
      "elements": [
        {
          "type": "button",
          "text": {"type": "plain_text", "text": "View in Zendesk"},
          "url": "https://YOUR_SUBDOMAIN.zendesk.com/agent/tickets/{{$json.ticketId}}"
        }
      ]
    }
  ]
}

Replace YOUR_SUBDOMAIN with your Zendesk subdomain and CSAT_CHANNEL_ID with your Slack channel ID.

Step 7: Reopen the ticket (optional)

If your team wants bad-rated tickets automatically reopened for follow-up, add another HTTP Request node:

• Method: PUT
• URL: https://YOUR_SUBDOMAIN.zendesk.com/api/v2/tickets/{'{'}$json.ticketId{'}'}.json
• Body:

{
  "ticket": {
    "status": "open",
    "tags": ["csat-bad", "needs-followup"]
  }
}

This reopens the ticket and adds tags so agents can filter to all bad-CSAT tickets in a Zendesk View.

Step 8: Activate and test

1. Set the workflow to Active
2. To test immediately, submit a bad CSAT rating on a solved ticket in your Zendesk sandbox
3. Wait for the next 5-minute poll cycle (or trigger the workflow manually)
4. Verify the Slack alert appears with the correct ticket details and link
5. Enable Retry On Fail on all HTTP Request nodes for resilience against temporary API errors

Cost

• n8n Cloud Starter: $0-24/mo depending on execution volume. This workflow uses approximately 4 node executions per poll cycle. At 5-minute intervals, that's ~1,152 executions per day — well within the Starter plan limits.
• n8n self-hosted: Free. Only costs are your hosting infrastructure.