Does Alertmanager support phone calls?

Not directly. It supports receivers such as email, chat and generic webhooks. Edesy OnCall's alert webhook URL works as a webhook receiver and turns each firing alert into an escalating phone call.

Why do I need send_resolved?

Without it, Alertmanager doesn't tell OnCall when an alert clears, so the incident stays open until someone resolves it in the dashboard. With send_resolved: true it closes by itself.

Will grouped notifications call me many times?

No. OnCall keys each incident by the alert's fingerprint, so repeat and grouped notifications for the same alert update the open incident instead of starting new calls.

Can I send only critical alerts?

Yes. Use an Alertmanager route that matches your critical label and points at the OnCall receiver. Everything else keeps going to your existing receivers.

How much does it cost?

One alert webhook monitor counts as one monitor; the Free plan includes 3. Alert calls are billed per minute from your Edesy wallet.

Integration: Prometheus Alertmanager

Prometheus Alertmanager Phone Call Alerts

Alertmanager has no phone call receiver of its own. Add Edesy OnCall as a webhook_configs receiver and route critical alerts to it: each firing alert opens an incident that calls your team in English or Hindi until someone presses 1, and send_resolved closes it again. Detection and routing stay in your Prometheus setup.

Start free: 3 monitors

See the config

webhook_configs

Receiver type

send_resolved

Closes incidents

Fingerprint

Groups repeats

Free

For 3 monitors

Webhook v4 payload

Repeats grouped by fingerprint

Calls in English or Hindi

Alertmanager integration at a glance

How OnCall reads the webhook payload

Item	Edesy OnCall
Receiver	webhook_configs with url = your alert webhook monitor's URL and send_resolved: true
Payload	Alertmanager webhook (version 4): status, alerts[] with status, labels, annotations and fingerprint
Grouping	One incident per fingerprint; without one, alertname + instance + job
Spoken text	annotations.summary, or the alertname label
Incident detail	annotations.description, annotations.message or the instance label
Responses	202 with the number of alerts accepted; 400 for a payload that isn't JSON or has no alerts; 404 for an unknown URL
Limits	120 requests a minute per IP, 1 MB body

Connect Alertmanager to OnCall

One receiver and one route

Step 1 of 5: Create an alert webhook monitor
In OnCall, add an Alert webhook monitor, attach an escalation policy and copy its URL.
Step 2 of 5: Add the receiver
Add an edesy-oncall receiver with webhook_configs, the URL and send_resolved: true.
Step 3 of 5: Add a route
Match your critical alerts (for example severity = "critical") and send them to edesy-oncall.
Step 4 of 5: Reload Alertmanager
Reload the config and check that the receiver loads without errors.
Step 5 of 5: Fire a test alert
Send a test alert with amtool or a temporary rule, and watch the incident and call in OnCall.

alertmanager.yml

Critical alerts go to OnCall; everything else stays on your existing receiver. Replace the URL with the one from your OnCall monitor.

# alertmanager.yml
route:
  receiver: default-chat
  routes:
    - matchers:
        - severity = "critical"
      receiver: edesy-oncall
receivers:
  - name: default-chat
    # your existing email or chat receiver
  - name: edesy-oncall
    webhook_configs:
      - url: https://oncall.edesy.in/ingest/<token>
        send_resolved: true

What a good alert rule looks like

The on-call engineer hears your summary annotation, so keep it short and speakable:

- alert: CheckoutErrorRateHigh
  expr: sum(rate(http_requests_total{job="checkout",code=~"5.."}[5m])) / sum(rate(http_requests_total{job="checkout"}[5m])) > 0.05
  for: 5m
  labels:
    severity: critical
  annotations:
    summary: Checkout error rate above 5 percent
    description: More than 5% of checkout requests returned 5xx for 5 minutes

The description is shown in the incident and the email. Full field mapping: Alertmanager ingest docs.

Alertmanager phone call alerts: FAQ

Explore Edesy OnCall

Explore more comparisons, alternatives, and resources

Edesy OnCall

Uptime monitoring with phone call alerts OnCall features OnCall pricing OnCall docs

Use cases

Website down alert call Cron job failure alert Prometheus and Grafana alerts by phone Client site monitoring for agencies

Integrations

Grafana phone call alerts Uptime Kuma phone call alerts

Free tools

Cron heartbeat URL generator Downtime cost calculator Cron expression builder HTTP status code reference

Running Prometheus across several clusters?

Tell us how your alerting is set up. We reply within one working day with a suggested setup.

Give Alertmanager a phone

Create an alert webhook monitor on the Free plan and add it as a receiver. Prices exclude 18% GST.

Start free: 3 monitors See pricing