Documentation

Webhooks and Zapier

Tessera can send a webhook every time a target changes status, so you can push alerts into Slack, Microsoft Teams, SMS, Google Sheets, PagerDuty, and hundreds of other apps. A webhook is simply an HTTP POST that Tessera sends to a URL you choose. The easiest way to connect it to other apps is Zapier.

What Tessera sends

When an alert fires, Tessera sends an HTTP POST with a Content-Type: application/json header and this JSON body:

{
  "target": "Company Website",
  "address": "https://example.com",
  "status": "DOWN",
  "timestamp": "2026-07-29T14:32:10.123Z",
  "error": "connection refused"
}

The fields:

  • target is the name you gave the monitored target.
  • address is the target's address or URL.
  • status is one of DOWN, RECOVERED, CERT_EXPIRING, or CERT_CLEARED.
  • timestamp is when the event happened, in UTC (ISO 8601).
  • error is a short reason (for example "connection refused" or "certificate expires in 6 days"), or null when there is nothing to report, such as a recovery.

Tessera expects a 2xx response. Anything else is recorded as a failed delivery in the diagnostic log.

Connect Tessera to Zapier

You will create a "Catch Hook" in Zapier, paste its URL into Tessera, then send one test event so Zapier learns the fields.

1. Create the Zap and copy your webhook URL

  1. In Zapier, click Create to start a new Zap.
  2. For the Trigger, choose Webhooks by Zapier.
  3. For the trigger event, choose Catch Hook, then continue.
  4. Zapier shows a custom webhook URL that looks like https://hooks.zapier.com/hooks/catch/.... Copy it.

2. Add the URL to Tessera

  1. In Tessera, open Settings, then the Notifications section.
  2. Turn on Webhook and paste the Zapier URL into the Webhook URL field.
  3. Click Save Settings.

3. Send a test event

Zapier needs to receive one real request before it can map the fields. Trigger an alert from Tessera:

  • The quickest way is to add a temporary target that will fail, for example a TCP target pointed at a port where nothing is listening. Give it a short "down after" time. When it goes DOWN, Tessera posts to Zapier. You can delete that target afterward.
  • Or simply wait for a real status change on an existing target.

Back in Zapier, on the Catch Hook step, click Test trigger. Zapier should find the request and show the parsed fields: target, address, status, timestamp, and error.

4. Add an action

  1. Add an Action step and choose the app you want, such as Slack, SMS by Zapier, Gmail, or Google Sheets.
  2. Map Tessera's fields into your message. For a Slack message you might use:
{{status}}: {{target}} ({{address}}) {{error}}
  1. Test the action, then Publish your Zap.

That is it. From now on every Tessera alert flows into your Zap.

Ideas

  • Slack or Teams: post outages to your operations channel.
  • SMS: text yourself when a critical target goes down. Add a Zapier Filter step so it only runs when status is DOWN.
  • Google Sheets or Airtable: log every event for reporting.
  • PagerDuty or Opsgenie: open an incident on DOWN and resolve it on RECOVERED.

Without Zapier

The payload is standard JSON, so you can point the webhook at anything that accepts a POST: a custom script, an automation platform like Make or n8n, or your own receiver. The body shown above is exactly what you will get.

Questions? Email support@gettessera.io.