Notifications — e-mail, Telegram, webhook
Updated 08 Oct 2026Castreon can tell you by itself when something goes wrong with a channel: it went down, switched to a backup source, shows a black or frozen picture, lost its sound. Messages go out by e-mail, on Telegram or to a webhook, and you also get a message when the problem is over.
Available from Castreon 1.2.0, on all plans.
Setup
Open Settings → Notifications, switch on Send notifications, then switch on the destinations you want. Each destination has its own Send a test button, which sends a message right away with the data in the form (before saving) and shows the result or the exact error.
E-mail (SMTP)
- SMTP server and Port, Security: STARTTLS (587), TLS (465) or No encryption (25).
- User and Password — leave User empty if the server needs no authentication. The password is only sent over an encrypted connection.
- From — the sender address; To — one or more addresses separated by commas (at most 10).
Telegram
- In Telegram, create a bot with @BotFather — you get the Bot token.
- Add the bot to the group or channel where you want the messages (to a channel as an administrator), or write to it once yourself.
- Chat ID: your own ID for a private chat, the group's ID (it starts with
-100…) or the channel's name (@name).
Webhook (JSON)
Castreon sends a POST with a JSON body to the Webhook address. The body also contains the ready-written message in the text and content fields, so it works directly with chat services that only show a text.
{
"source": "castreon",
"server": "node-1",
"sent_at": "2026-10-08T10:01:20Z",
"test": false,
"title": "Channel down",
"events": [
{"type": "down", "family": "down", "channel_id": "…", "slug": "channel-1", "channel": "Channel 1",
"message": "…", "since": "2026-10-08T10:00:00Z", "at": "2026-10-08T10:01:20Z", "duration_s": 80}
],
"text": "…",
"content": "…"
}
type is down, up, failover, primary, alert or resolved; for alerts, code says which one (for example black_picture).
Signature. With a Signing secret (16–200 characters, Generate makes one), every request carries the headers X-Castreon-Timestamp and X-Castreon-Signature: sha256=…. The signature is the HMAC-SHA256 of timestamp + "." + body with your secret. Check it on your side and reject requests that are too old.
The webhook address is kept on the server and not shown again: many services put the access key in the address.
What gets announced
Under What to announce you choose the families:
| Family | When |
|---|---|
| Channel down | the channel is not running for longer than the threshold (error, restarts, the source down and the “no signal” image on air) — and when it is back |
| Switch to backup | the channel runs on a backup source — and when it is back on the main one |
| Picture and sound | black or frozen picture, silent audio, output without new segments — see Picture and sound quality |
| DVB source | the operator's programme gaps, a service gone from the mux |
| Push outputs | RIST / SRT / UDP / RTMP outputs that do not reach their destination |
| Resources and stability | high memory, falling behind real time, restarts too often |
| Information | the same programme on several channels, HDR transcoded to SDR — off by default |
A channel you stop from the panel, switch off or delete announces nothing.
No flood of messages
- Announce only what lasts longer than — 60 seconds by default. Short gaps and quick restarts send nothing.
- Also announce the recovery — only for problems that were announced.
- Same problem on the same channel at most once every — 30 minutes by default.
- What happens within the same 20 seconds goes out as one grouped message (for example “17 channels: …”).
- At most 20 messages per hour per destination. Messages held back are counted and mentioned in the next one.
Language and links
- Message language: Same as the panel, or English, Romanian, German, Italian, Spanish.
- Server name in messages — empty = the machine name. Useful when you have several servers.
- Panel address (optional) — with it, each message has a link straight to the channel's page.
Latest messages shows the last 20 sendings: time, destination, what was sent and whether it went out. Each destination also shows its last error and how many messages it sent in the last hour.
Security
The SMTP password, the Telegram token, the webhook address and the signing secret are kept on the server and never shown again: after saving, the field shows that a value is saved. Leave it empty to keep it, or type a new value. They don't appear in API responses, in the audit log or in the diagnostic report.
Common problems
- E-mail: the server refuses the login or closes the connection: check the port and Security pair — 587 with STARTTLS, 465 with TLS. Many providers require an app password.
- Telegram:
chat not found: the bot hasn't been added to the group or channel, or nobody has written to it yet in a private chat. - Webhook: HTTP 4xx / 5xx: the message shows the status code returned by your service; the test sends exactly what a real message sends.
- The test works, but nothing comes during an outage: check that the family is ticked and that the problem lasted longer than the threshold.