Notifications

18 event types across Email, Slack, and Microsoft Teams. Templates with Go variables, dead-letter handling, quiet hours, and per-project routing.

01Event catalog

Every notifiable event has a stable name. Subscribe channels to event names with optional severity filters.

02Channels

Configure under Settings → Notifications → Channels.

• Email — SMTP host, port, STARTTLS / TLS, auth. Per-recipient lists.
• Slack — incoming webhook URL or Bot OAuth token.
• Microsoft Teams — Workflow URL (Power Automate) or legacy connector.

03Templates

Each event has a default template you can override. Variables are exposed via Go templating:

Subject: [{{.severity | upper}}] {{.event}} — {{.cert.cn}}

The certificate {{.cert.cn}} (issued by {{.cert.issuer}}) is now
{{.cert.status}}.

Project:   {{.project}}
Fingerprint: {{.cert.fingerprint_sha256}}
Expires:   {{.cert.not_after | date "2006-01-02"}}
Detail:    {{.url.cert}}

Functions: upper, lower, date, truncate, relative. Per-channel overrides allow distinct formatting for Slack vs email.

04Routing

A route binds events to channels with optional filters:

• Severity at least — warn filters out info noise.
• Project — only match events from production.
• Tag — match certs tagged tier:tier-0.

Multiple routes can match the same event; each fires independently.

05Quiet hours

Per-route schedule to suppress non-critical events during off-hours. Critical events always fire. Useful for renewal-success spam — fine to suppress, but you still want to hear about cert.renewal.stalled at 3 AM.

06Dead-letter

If a channel fails (Slack 5xx, SMTP refusal), the message is queued to a dead-letter buffer with exponential retry up to 24 h. After 24 h the message is dropped and a notification.delivery.failed audit event records it. Failed deliveries surface under Settings → Notifications → History with their final status and last error.

07Testing a channel

Each channel has a Send test button — fires a fixture event and reports the channel's response. Always click it after creating or editing a channel.