Uptime & synthetics
Send Oh Dear alerts to on-call with CallHeim.
Uptime, certificate & broken-link monitoring — typed events. CallHeim maps the payload, collapses repeats within five minutes, and pages whoever is on call for the service it belongs to.
Recovery
CallHeim recognises Oh Dear's recovery payload and closes the incident automatically when it arrives.
Setting it up
Create an Integration in CallHeim and choose Oh Dear from the Catalog. You get an ingest URL for that integration — paste it into Oh Dear’s webhook configuration. The snippet beside this is the shape it expects, with {{WEBHOOK_URL}} replaced by your real URL.
If you enable request signing on this integration, CallHeim requires a valid HMAC-SHA256 signature in the X-ItOnCall-Signature or X-Hub-Signature-256 header on every request to it. Without a signing secret, the ingest URL itself is the credential.
CallHeim includes a payload mapping for Oh Dear’s webhook format, built and tested against sample payloads.
# Oh Dear → Site → Notifications → Webhook
# URL: {{WEBHOOK_URL}}
# Body includes {type ("uptimeCheckFailed"|...), site:{url}, notification:{text}}.After it arrives
What CallHeim does with Oh Dear alerts.
Check failures from the same probe collapse onto one incident inside a five-minute window. Failures with different titles from the same source can still be grouped onto an open, unacknowledged incident within ten minutes, when the sender does not supply its own dedup key.
CallHeim maps Oh Dear’s own severity to a P1–P5 level and shows a separate, explainable severity suggestion — a published keyword ruleset plus your own resolved-incident history — that a person can apply. How severity is suggested →
Each alert source is bound to a service, and the service’s escalation policy (or its team’s) sets who is paged. Alerting and escalation →
CallHeim closes an incident on a recovery event only for sources whose recovery payload it recognises (or that you map). For the others, a person resolves the incident.
The thresholds it passes through
- Dedup window
- 300s
- Flap threshold
- 4 transitions / 600s
- Title correlation
- similarity ≥ 0.6, same source and service
- Group window default
- 600s
All defaults are published. You can turn title correlation off or change its threshold, and set the window on your own noise rules; the dedup window and the flap settings are fixed. How alerts are processed →
Point Oh Dear at CallHeim and see what it does with your alerts.
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