alertmanager

Prometheus Alertmanager API v2 -- alerts, silences, receivers, alert groups, status, and operational health

Credits: Dunkel Cloud GmbH -- maintainer Updated: 2026-04-13

Coverage

100% (14 of ~14 endpoints)

Focus: alerts (list, create/update, groups), silences (CRUD), receivers (list), status, health/ready/reload

Missing: metrics and pprof debug endpoints (not useful for API consumers)

Last reviewed: 2026-04-13

Alertmanager has no built-in auth by default. If --web.config.file is configured with basic_auth_users:
1. Open the web.config.yml used by your Alertmanager instance
2. Find or add your username under basic_auth_users
3. Generate a bcrypt hash of your password: htpasswd -nBC 10 '' | tr -d ':\n'
4. Add the username: bcrypt_hash pair to basic_auth_users
5. Reload Alertmanager config (POST /-/reload or send SIGHUP)
If no auth is configured, leave credentials empty or use a reverse proxy for auth

Environment variable: ALERTMANAGER_URL

Default port is 9093. Set ALERTMANAGER_URL to http(s)://host:9093. For HA setups, point to any cluster member or a load balancer.

Add to your backends.yaml:

alertmanager.dadl

Set the credential:

ALERTMANAGER_URL=your-token-here

GET get_status Get Alertmanager status including version, config, uptime, and cluster state

GET get_health Health check — returns 200 if Alertmanager is running (liveness probe)

GET get_ready Readiness check — returns 200 when Alertmanager is ready to serve traffic

GET list_alerts List alerts with optional filters by state, receiver, and label matchers

POST post_alerts Create new alerts or update existing ones. Alerts are matched by label fingerprint. Set endsAt to resolve.

GET list_alert_groups Get alerts grouped by the routing tree configuration

GET list_silences List all silences, optionally filtered by label matchers

GET get_silence Get a single silence by its ID

POST post_silence Create a new silence or update an existing one. Include id to update, omit to create.

DELETE delete_silence Expire (delete) a silence by its ID. This immediately stops the silence from suppressing alerts.

GET list_receivers List all configured notification receiver names

POST reload_config Trigger a configuration reload (equivalent to sending SIGHUP to the process)