Set up Prometheus Alertmanager ingestion

What you will configure

• Generate a Prometheus / Alertmanager endpoint in the HowlOps Integration Hub (gives you a token)
• Point Alertmanager's built-in OpsGenie receiver (opsgenie_configs) at HowlOps
• Verify a real alert flows through to HowlOps

Time: ~5 minutes · Requires: a running Prometheus Alertmanager. Works on any plan, including Free On-call — external alert ingestion is free.

Step 1 — Generate the endpoint in HowlOps

1. In HowlOps, open Integrations in the sidebar (the Integration Hub).
2. Under Bring alerts into HowlOps, click the Prometheus / Alertmanager source card.
3. Click Generate endpoint.
4. Copy the Token shown in the drawer — it starts with howl_. This is your Alertmanager api_key.

Step 2 — Add the HowlOps receiver to alertmanager.yml

Add an opsgenie_configs receiver whose api_url points at HowlOps and whose api_key is the token from Step 1:

receivers:
  - name: howlops
    opsgenie_configs:
      - api_url: https://api.howlops.com/api/v1/prometheus/
        api_key: howl_YOUR_TOKEN_HERE
        send_resolved: true
        # Map your Prometheus `severity` label to an OpsGenie priority so HowlOps
        # gets the right incident severity. Without this, everything arrives as P3.
        priority: '{{ if eq .CommonLabels.severity "critical" }}P1{{ else if eq .CommonLabels.severity "warning" }}P3{{ else }}P5{{ end }}'

• api_url must end with a trailing slash — Alertmanager appends v2/alerts to it.
• send_resolved: true lets HowlOps auto-close the alert when it clears (matched by the Alertmanager alias).
• The priority template is optional but recommended; see Severity mapping below.

Alternative: deliver via webhook_configs

Prefer Alertmanager's generic webhook? HowlOps exposes a native webhook receiver too. Generate an Alertmanager token in Integrations (the Alertmanager tokens section), then add a webhook_configs receiver that authenticates with it as a Bearer token:

receivers:
  - name: howlops
    webhook_configs:
      - url: https://api.howlops.com/api/v1/webhook/alertmanager
        send_resolved: true
        http_config:
          authorization:
            type: Bearer
            credentials: howl_YOUR_TOKEN_HERE

• This endpoint takes Alertmanager's standard webhook JSON, so there is no api_url trailing-slash rule here.
• The credential is a separate Alertmanager token (sent as Bearer), not the OpsGenie api_key from Step 1. Generate it in the Alertmanager tokens section of Integrations.
• Severity is read from each alert's own severity label (critical / warning / info). The OpsGenie priority template shown above does not apply to this path.

Pick one receiver, not both, or a single alert would arrive twice.

Step 3 — Route alerts to HowlOps

route:
  receiver: howlops
  group_by: ['alertname']
  group_wait: 10s
  group_interval: 30s
  repeat_interval: 4h

Reload Alertmanager on your Alertmanager host (this example assumes the command runs on that host itself — swap in the real hostname if it doesn't):

curl -X POST http://localhost:9093/-/reload

Step 4 — Test it

Fire a test alert straight into the Alertmanager API on your Alertmanager host:

curl -X POST http://localhost:9093/api/v2/alerts \
  -H 'Content-Type: application/json' \
  -d '[{"labels":{"alertname":"HowlOpsTest","severity":"critical","instance":"web-01"},
        "annotations":{"summary":"Test alert from the HowlOps setup guide"},
        "startsAt":"2026-07-07T10:30:00Z"}]'

Within a few seconds the alert appears under Alerts in HowlOps. Because it carries severity: critical, the priority template maps it to P1 → critical, and a critical alert is promoted to an Incident.

Severity mapping

HowlOps reads the OpsGenie priority that Alertmanager sends and maps it to an incident severity:

Priority is controlled entirely by the priority field in your receiver. If you omit it, every alert arrives as P3 (warning). Use the template shown in Step 2 to derive the priority from your alert-rule labels (for example, severity: critical → P1).

Troubleshooting

• No alert appears — confirm Alertmanager can reach api.howlops.com, that api_url ends with a trailing slash, and that the token is correct (click Regenerate token if unsure). Check the Alertmanager logs for a 401 (bad token) or 404 (wrong URL).
• Everything shows as warning — you haven't set a priority in the receiver, so all alerts default to P3. Add the priority template from Step 2.
• Alert never resolves — make sure send_resolved: true is set; HowlOps matches the resolve to the open alert by the Alertmanager alias.

See also

• Integrations reference
• Alert & incident flow