docs: notification agent docs added

docs/SUMMARY.md

@@ -1,17 +1,21 @@
 # Table of contents
 
-* [Introduction](README.md)
+- [Introduction](README.md)
 
 ## Getting Started
 
-* [Installation](getting-started/installation.md)
+- [Installation](getting-started/installation.md)
+
+## Using Overseerr
+
+- [Notifications](using-overseerr/notifications/README.md)
+  - [Custom Webhooks](using-overseerr/notifications/webhooks.md)
 
 ## Support
 
-* [Frequently Asked Questions](support/faq.md)
-* [Asking for Support](support/asking-for-support.md)
+- [Frequently Asked Questions](support/faq.md)
+- [Asking for Support](support/asking-for-support.md)
 
 ## Extending Overseerr
 
-* [Reverse Proxy Examples](extending-overseerr/reverse-proxy-examples.md)
-
+- [Reverse Proxy Examples](extending-overseerr/reverse-proxy-examples.md)

docs/using-overseerr/notifications/README.md

@@ -0,0 +1,28 @@
+# Notifications
+
+Overseerr already supports a good number of notification agents, such as **Discord**, **Slack** and **Pushover**. New agents are always considered for development, if there is enough demand for it.
+
+## Currently Supported Notification Agents
+
+- Email
+- Discord
+- Slack
+- Telegram
+- Pushover
+- [Webhooks](./webhooks.md)
+
+## Setting up Notifications
+
+Configuring your notifications is _very simple_. First, you will need to visit the **Settings** page and click **Notifications** in the menu. This will present you with all of the currently available notification agents. Click on each one individually to configure them.
+
+You must configure which type of notifications you want to send _per agent_. If no types are selected, you will not receive any notifications!
+
+Some agents may have specific configuration gotchas that will be covered in each notification agents documentation page.
+
+{% hint style="danger" %}
+Currently, you will **not receive notifications** for any auto-approved requests. However, you will still receive a notification when the media becomes available.
+{% endhint %}
+
+## Requesting new agents
+
+If we do not currently support a notification agent you would like, feel free to request it on our [GitHub Issues](https://github.com/sct/overseerr/issues). Make sure to search first to see if someone else already requested it!

docs/using-overseerr/notifications/webhooks.md

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+# Webhooks
+
+Webhooks let you post a custom JSON payload to any endpoint you like. You can also set an authorization header for security purposes.
+
+## Configuration
+
+The following configuration options are available:
+
+### Webhook URL (Required)
+
+The URL you would like to post notifications to. Your JSON will be sent as the body of the request.
+
+### Authorization Header
+
+Custom authorization header. Anything entered for this will be sent as an `Authorization` header.
+
+### Custom JSON Payload (Required)
+
+Design your JSON payload as you see fit. JSON is validated before you can save or test. Overseerr provides several [template variables](./webhooks.md#template-variables) for use in the payload which will be replaced with actual values when the notifications are sent.
+
+You can always reset back to the default custom payload setting by clicking the `Reset to Default JSON Payload` button under the editor.
+
+## Template Variables
+
+### Main
+
+- `{{notification_type}}` The type of notification. (Ex. `MEDIA_PENDING` or `MEDIA_APPROVED`)
+- `{{subject}}` The notification subject message. (For request notifications, this is the media title)
+- `{{message}}` Notification message body. (For request notifications, this is the media's overview/synopsis)
+- `{{image}}` Associated image with the request. (For request notifications, this is the media's poster)
+
+### Notify User
+
+These variables are usually the target user of the notification.
+
+- `{{notifyuser_username}}` Target user's username.
+- `{{notifyuser_email}}` Target user's email.
+- `{{notifyuser_avatar}}` Target user's avatar.
+
+### Media
+
+These variables are only included in media related notifications, such as requests.
+
+- `{{media_type}}` Media type. Either `movie` or `tv`.
+- `{{media_tmdbid}}` Media's TMDB ID.
+- `{{media_imdbid}}` Media's IMDB ID.
+- `{{media_tvdbid}}` Media's TVDB ID.
+- `{{media_status}}` Media's availability status. (Ex. `AVAILABLE` or `PENDING`)
+- `{{media_status4k}}` Media's 4K availability status. (Ex. `AVAILABLE` or `PENDING`)
+
+### Special Key Variables
+
+These variables must be used as a key in the JSON Payload. (Ex, `"{{extra}}": []`).
+
+- `{{extra}}` This will override the value of the property to be the pre-formatted "extra" array that can come along with certain notifications. Using this variable is _not required_.
+- `{{media}}` This will override the value of the property to `null` if there is no media object passed along with the notification.