Alert recipes

Three recipes for connecting SimpleDeploy alerts to common destinations.

Slack incoming webhook

Create an Incoming Webhook in your Slack workspace. Copy the URL.

In SimpleDeploy: Alerts > Webhooks > New. Paste the Slack URL. Save.

Then Alerts > Rules > New: e.g., CPU > 80 for 300 seconds, scope all apps, webhook = the one above.

The Slack webhook accepts SimpleDeploy’s default JSON shape. The message field becomes the post body. For richer formatting, point your webhook at a small relay that translates SimpleDeploy’s payload into Slack Block Kit.

Example translated message:

:warning: e2e-postgres CPU 87.4% (threshold 80%) for 5 min

Discord webhook

Create a Discord webhook on the target channel. Copy the URL.

Same setup as Slack: paste the URL, attach to a rule.

Discord ignores fields it does not understand; the default JSON renders as a raw post. For embeds, run a translator that produces:

{
  "embeds": [{
    "title": "CPU above threshold",
    "description": "e2e-postgres",
    "color": 16763904,
    "fields": [
      { "name": "Value", "value": "87.4%" },
      { "name": "Threshold", "value": "80%" },
      { "name": "Duration", "value": "5 min" }
    ]
  }]
}

Generic JSON to a custom endpoint with HMAC

For internal alert routers (PagerDuty, Opsgenie, your own incident bot), accept SimpleDeploy’s JSON directly:

{
  "rule_id": 12,
  "metric": "cpu",
  "op": ">",
  "threshold": 80,
  "value": 87.4,
  "app_slug": "e2e-postgres",
  "fired_at": "2026-04-17T14:31:00Z",
  "message": "CPU 87.4% above 80% for 5 min"
}

To verify the request came from your SimpleDeploy instance, configure a webhook secret. SimpleDeploy signs the body with HMAC-SHA256 and sends the digest in X-SimpleDeploy-Signature: sha256=<hex>. Verify in your handler:

expected := hmac.New(sha256.New, []byte(secret))
expected.Write(body)
got := r.Header.Get("X-SimpleDeploy-Signature")
if !hmac.Equal([]byte("sha256="+hex.EncodeToString(expected.Sum(nil))), []byte(got)) {
    http.Error(w, "bad signature", 401)
    return
}

Tuning

Start broad (CPU > 90 for 5 min). Tune as you learn the noise floor. Avoid alerts that fire more than a few times a day; either raise the threshold or lengthen the duration.