Notifications & alert channels

NetPulse sends an alert when a connection crosses into an unhealthy state (a run of consecutive failed or threshold-breaching measurements) and a recovery when it comes back. Delivery fans out to whichever generic channels you enable — email, chat (Slack / Telegram / Discord / …) and webhook.

Everything here is configured from the UI at Settings → Notifications — no restart, no editing env files. Saved values are stored in the database (secrets encrypted at rest) and override the NOTIFY_* / MAILER_DSN environment defaults documented in Configuration.

Where to click

Sign in, then go to Settings → Notifications. Configure a channel, Save, then Send test to verify it before you rely on it.

Turn it on

• Send notifications — the master switch. Off by default.
• Alert after N consecutive failures — the debounce window (default 3). An alert fires the moment a connection has N consecutive unhealthy measurements; a recovery fires when a healthy result follows such a run. This prevents a single blip from paging you.

Then enable one or more channels below.

Email

Field	What to enter
Recipients	Comma-separated addresses, e.g. ops@example.com, oncall@example.com.
Mailer DSN	A Symfony Mailer DSN — usually SMTP.

A typical SMTP DSN:

smtp://user:password@smtp.example.com:587

The DSN is a write-only secret (stored encrypted, never shown back). Leave it blank to keep the existing one.

Chat (Slack / Telegram / Discord / …)

The chat channel is generic: it takes a Symfony Notifier chatter DSN, so any provider with a notifier bridge works. NetPulse ships the Slack, Telegram and Discord bridges.

Provider	DSN format
Slack	slack://BOT-TOKEN@default?channel=CHANNEL
Telegram	telegram://BOT-TOKEN@default?channel=CHAT_ID
Discord	discord://default?webhook_id=ID&token=TOKEN

How to get the credentials:

• Slack — create a Slack app, add the chat:write scope, install it to the workspace, and use the Bot User OAuth Token (xoxb-…). CHANNEL is the target channel name or ID. See the Slack notifier docs.
• Telegram — create a bot via @BotFather for the BOT-TOKEN, then use the numeric chat id of the destination as CHAT_ID.
• Discord — create a channel Webhook in Discord; its URL contains the webhook_id and token.

The DSN is a write-only secret (encrypted at rest). Leave it blank to keep the existing one.

More providers

Any Symfony Notifier chatter works if its bridge is installed (composer require symfony/<provider>-notifier). The DSN field accepts any of them.

Webhook

Enter a URL and NetPulse POSTs a JSON body to it on every alert/recovery:

{
  "kind": "alert",
  "severity": "critical",
  "subject": "…",
  "body": "…",
  "context": { "probe": "…", "connection": "…", "reason": "…", "downloadBits": 0, "pingMs": 0 },
  "timestamp": "2026-06-08T12:00:00+00:00"
}

The URL is a write-only secret (it can embed a token), encrypted at rest. A non-2xx response is treated as a failed delivery (logged, with the URL redacted).

Send test

The Send test button dispatches a sample alert through the currently saved enabled channels and reports a per-channel result (sent / skipped / failed). Save first, then test. It never touches the metrics counter.

Secrets & encryption

The mailer/chat DSN and the webhook URL are encrypted at rest with SETTINGS_ENCRYPTION_KEY (falling back to TOTP_ENCRYPTION_KEY). Without a key set, channel secrets can't be saved — the page shows a clear warning. Generate one with:

php -r "echo bin2hex(random_bytes(32));"

Resilience

• A channel that's enabled but not configured is skipped with a logged warning — never a crash.
• If one channel fails, the others still deliver; the failure is logged (with secrets redacted) and counted on netpulse_notifications_sent_total{status="failed"}.

Digest

Separately from alerts, NetPulse can send a periodic digest of every connection's health. It is not self-scheduled — run it from the host cron (it honours the same enabled channels):

docker compose exec -T app php bin/console app:notifications:digest --period=daily

Environment fallback

If you prefer config-as-code, the same settings have ENV fallbacks (used until an admin saves a value in the UI): NOTIFY_ENABLED, NOTIFY_CONSECUTIVE_THRESHOLD, NOTIFY_CHANNELS, NOTIFY_EMAIL_TO, MAILER_DSN, NOTIFY_CHAT_DSN, NOTIFY_WEBHOOK_URL — see Configuration.