Seelen UI — Plugin Guidelines
Reference guide for creating plugins. A plugin is a declaration file that extends the functionality of a specific widget. The plugin itself only declares who it targets and provides a data payload — the target widget is entirely responsible for loading, parsing, and deciding what to do with that data.
Read resource guidelines first for concepts shared across all resource kinds.
Table of Contents
1. What is a Plugin?
A plugin targets a widget by ID and provides it with arbitrary data. The widget discovers installed plugins at runtime, reads the ones that target it, and uses the data however it sees fit. A plugin has no logic of its own — it is a pure declaration.
What a plugin means depends entirely on the widget it targets. A toolbar plugin might define a new button. A calendar widget plugin might add a new event source. Whatever schema the widget expects is what the plugin must provide.
2. Plugin Structure — metadata.yml
id: "@yourname/my-plugin"
metadata:
displayName: My Plugin
description: A short description of what this plugin adds.
tags:
- toolbar
# Icon shown in the Seelen UI settings panel.
# Must be a valid react-icons name (https://react-icons.github.io/react-icons/).
# Defaults to PiPuzzlePieceDuotone if omitted.
icon: PiPuzzlePieceDuotone
# The widget this plugin is for
target: "@someuser/some-widget"
# The plugin data — structure depends entirely on the target widget
plugin:
someField: someValue
The only required fields are id, target, and plugin.
3. Plugin Data
The plugin field is free-form — it can be any valid YAML value (a map, a list, a string, anything). There is no schema
enforced at the resource level. The target widget receives it as-is and is responsible for validating and using it.
Read the documentation of the widget you are targeting to know what structure it expects.
You can use !include in the plugin block just like anywhere else in a resource file:
plugin:
template: !include plugin/template.js
tooltip: !include plugin/tooltip.js
scopes:
- Power