The Notifier service delivers alerts to chat, email, and webhook destinations. This guide explains supported channels, configuration, and testing workflows.

## Accessing the Notifier UI
- URL: `http://127.0.0.1:${NOTIFIER_WEB_PORT:-8087}` (or via your reverse proxy)
- Default auth: none (protect with reverse proxy auth in production)
- Capabilities: manage destinations, configure credentials, view delivery history, trigger test messages

## Supported channels

| Channel | Required fields | Notes |
|---------|-----------------|-------|
| **Email (SMTP)** | Host, port, username/password or OAuth token, from address, TLS settings | Supports STARTTLS and SMTPS. Use app passwords for Gmail/Office365. |
| **Slack** | Webhook URL or Bot token + channel | Webhooks are simplest. For bot tokens, grant `chat:write` scope. |
| **Discord** | Webhook URL | Create in Server Settings -> Integrations. |
| **Telegram** | Bot token, chat ID | Use [@BotFather](https://core.telegram.org/bots#botfather) to create token. Retrieve chat ID via `getUpdates` or @RawDataBot. |
| **Gotify** | Server URL, app token | Self-hosted push notifications. |
| **Generic Webhook** | URL, HTTP method, optional headers/body | Supports templated payloads (JSON, form data, etc.). |

## Adding a destination
1. Open the Notifier UI -> Destinations.
2. Choose a channel type and fill in the fields.
3. Save.

## Message format
- Alert Engine sends a JSON payload to Notifier containing the rule name, message text, container details (if available), and timestamp.
- The Notifier currently renders a plain text message from those fields and passes that text to every enabled destination.
- Webhook destinations receive an HTTP request whose body is the same formatted text message. Apprise handles the request details for each provider.
- To deliver structured JSON or heavily customised content today, route notifications to a custom webhook endpoint that you control and perform the transformation there, or trigger automation scripts from the Alert Engine instead.

## Delivery reliability
- Notifier retries transient failures with exponential backoff. Default: 5 attempts over ~10 minutes.
- Persistent errors (401, 403, 404, TLS failure) mark the delivery as failed and surface in the UI.
- Use the delivery history table to inspect payloads and response codes.