joplin/readme/api/references/plugin_manifest.md

Plugin Manifest

The manifest file is a JSON file that describes various properties of the plugin. If you use the Yeoman generator, it should be automatically generated based on the answers you've provided. The supported properties are:

Name	Type	Required?	Description
manifest_version	number	Yes	For now should always be "1".
name	string	Yes	Name of the plugin. Should be a user-friendly string, as it will be displayed in the UI.
version	string	Yes	Version number such as "1.0.0".
app_min_version	string	Yes	Minimum version of Joplin that the plugin is compatible with. In general it should be whatever version you are using to develop the plugin.
description	string	No	Detailed description of the plugin.
author	string	No	Plugin author name.
keywords	string[]	No	Keywords associated with the plugins. They are used in search in particular.
homepage_url	string	No	Homepage URL of the plugin. It can also be, for example, a link to a GitHub repository.
repository_url	string	No	Repository URL where the plugin source code is hosted.
categories	string[]	No	Categories that describes the functionality of the plugin.
screenshots	Screenshot[]	No	Screenshots are used for listing on Joplin Plugin website.
icons	Icons	No	If Icons is not supplied, a standard extension icon will be used by default. You should supply at least a main icon, ideally 48x48 px in size. This is the icon that will be used in various plugin pages. You may, however, supply icons of any size and Joplin will attempt to find the best icon to display in different components. Only PNG icons are allowed.

Categories

Category	Description
appearance	dealing with appearance of some element/s of the app. For example line numbers, layout, etc.
developer tools	built for the developers.
editor	enhancing note editor.
files	dealing with files. For example import, export, backup, etc.
integrations	integrating third party services or apps.
personal knowledge management	managing and organizing notes.
productivity	making Joplin more productive to use.
search	enhancing search inside the app.
tags	dealing with note tags.
themes	changing theme of the app.
viewer	enhancing the rendering of a note.

Screenshot

Properties	Description
src	a path or URL to a screenshot. If a path, src should be relative to the root of the repository (e.g. screenshots/a.png).
label	description of the image. This label will be used by screen readers or if the image cannot be loaded.

Note: If src is a path and not a URL, either repository_url or homepage_url must point to a GitHub repository for the screenshot to appear on the Joplin Plugins Website. See the relevant issue.

Icons

Properties	Description
16	a relative path to a PNG icon.
32	a relative path to a PNG icon.
48	a relative path to a PNG icon.
128	a relative path to a PNG icon.

Manifest example

{
    "manifest_version": 1,
    "name": "Joplin Simple Plugin",
    "description": "To test loading and running a plugin",
    "version": "1.0.0",
    "author": "John Smith",
    "app_min_version": "1.4",
    "homepage_url": "https://joplinapp.org",
    "screenshots": [
      {
        "src": "path/to/image.png",
        "label": "image description"
      },
      {
        "src": "https://example.com/path/to/the/screenshot.png",
        "label": "image description"
      }
    ],
    "icons": {
      "16": "path/to/icon16.png",
      "32": "path/to/icon32.png",
      "48": "path/to/icon48.png",
      "128": "path/to/icon128.png"
    }
}