Message extras

Additional extras are used to pass extra information, change client behavior, etc. Extras are stored in a key-value schema and are only accepted in POST /message requests with content type application/json.

Namespaces

Keys under .extras must be in the following format: <top-namespace>::[<sub-namespace>::]<action>. Some namespaces are used by official clients:

Namespace	Description
client::*	Reserved
client::display	Changes how the client displays information
client::notification	Configures the notification
android::*	Reserved
android::action	Reacts to events
ios::*	Reserved
server::*	Reserved
All others	Defined by end users

client::display

contentType

Definition

contentType	description
text/markdown	Default; the message should be rendered as markdown. HTML must be ignored.
text/plain	The message will be displayed as plain text. Links may be highlighted and interactive.

Note: Notifly renders messages as markdown by default. Markdown supports displaying images via ![](img url), and those images will be automatically fetched when viewing a message. Similar to why remote content is blocked by default in mail clients, automatically fetching remote images can be used to gather information about the user.

Also, if part of the message is interpolated from a malicious external source, an attacker can inject malformed markdown that leads to information disclosure.

If a message is constructed from external sources (e.g., script output), it is recommended to explicitly set text/plain — plain text does not interpret markdown and reduces potential security issues.

Example

{
  "extras": {
    "client::display": {
      "contentType": "text/plain"
    }
  }
}

Support

Client	since	description
Notifly Web UI	v2.0.5	Uses GitHub Flavored Markdown
Notifly Android	v2.0.7	Uses commonmark-spec

client::notification

click.url

click.url (string): opens a URL when the notification is clicked.

Example

{
  "extras": {
    "client::notification": {
      "click": {"url": "https://notifly.net"}
    }
  }
}

Support

Client	since	description
Notifly Android	v2.0.10	Prevents opening the Notifly app by default

bigImageUrl

bigImageUrl (string): shows a large image in the notification.

Example

{
  "extras": {
    "client::notification": {
      "bigImageUrl": "https://placekitten.com/400/300"
    }
  }
}

Support

Client	since	description
Notifly Android	v2.3.0	May require expanding the notification.

android::action

onReceive.intentUrl

onReceive.intentUrl (string): opens an intent after the notification is delivered.

Example

{
  "extras": {
    "android::action": {
      "onReceive": {"intentUrl": "https://notifly.net"}
    }
  }
}

Support

Client	since	description
Notifly Android	v2.0.11	”Intent Action Permission” must be enabled in the app settings, otherwise this feature only works when the app is active.