Alerts & webhooks

Alerts tell you when a certificate's status changes — before it expires, not after. Everything here is configured on the Alerts page.

Channels

A channel is where alerts get delivered. Renew Radar currently supports:

• Email — sent to any address you add. Your account email is added automatically when you first visit the Alerts page.
• Webhook — an HTTP POST sent to a URL you control. See the payload format below.

Each channel can be enabled or disabled independently without deleting it, and you can add as many as you need.

Thresholds

A threshold defines how many days before expiry an alert should fire. New accounts start with four defaults, which you're free to edit or remove:

You can add your own thresholds with any label and day count from 0–365, and toggle any threshold active or inactive.

When alerts fire

During each hourly sweep, Renew Radar checks whether a certificate has crossed the closest threshold it hasn't already been alerted on for its current expiry, and sends one alert to every enabled channel at that point. You won't be paged again for the same threshold until the certificate is renewed and the countdown resets, or a closer threshold is crossed. A history of recent alerts is shown at the bottom of the Alerts page.

Webhook payload

Webhook alerts are delivered as an HTTP POST with a JSON body:

{
  "event": "certificate.alert",
  "domain": "shop.acme.com",
  "status": "expiring",
  "days_remaining": 7,
  "expires_at": "2026-07-21T00:00:00+00:00",
  "issuer": "R3",
  "threshold": {
    "label": "7 days before expiry",
    "days_before": 7
  },
  "url": "https://renewradar.com/certificates"
}

Requests time out after 5 seconds and are retried up to 3 times with a 30 second backoff if your endpoint errors or is unreachable. Respond with any 2xx status to acknowledge delivery.