create-canvas-extension

Create a canvas extension

Use this skill only for the github/awesome-copilot repository. Canvas extensions are reusable source components. They do not have a plugin.json under extensions/.

Required decisions

Before creating files, ask for each missing value:

1. Extension ID: lowercase kebab-case, matching the source folder and plugin name.
2. Display metadata:
   • description
   • version (default 1.0.0)
   • author name and optional URL
   • keywords (lowercase, hyphenated, maximum 10)
   • repository and license (default to the repository URL and MIT when appropriate)
3. Canvas entrypoint: confirm whether the extension already has extension.mjs. If not, create a minimal entrypoint only when the user provides enough implementation details; otherwise create the directory and leave an explicit TODO.
4. Preview image: obtain an existing assets/preview.png path or ask the user to add it. Do not invent a binary image or silently use a misleading placeholder.
5. Plugin registration:
   • For a standalone installable canvas plugin, create plugins/<extension-id>.
   • For an extension that belongs to an existing plugin, ask for the parent plugin ID and add ./extensions/<extension-id> to that plugin's extensions.com.github.awesome-copilot.extensions.
   • If the extension should be shipped by multiple plugins, collect all plugin IDs and add the same extension ID to each mapping file.

Files to create

For a new extension plugin, create this structure:

extensions/<extension-id>/
├── extension.mjs
└── assets/
    └── preview.png

plugins/<extension-id>/
├── plugin.json
└── README.md

The extension source may contain additional files such as package.json, canvas assets, or supporting modules. Keep all reusable implementation files under extensions/<extension-id>/.

Create plugins/<extension-id>/plugin.json with this shape:

{
  "$schema": "https://agent-plugins.org/schemas/1.0.0/plugin.schema.json",
  "name": "<extension-id>",
  "description": "<description>",
  "version": "1.0.0",
  "author": {
    "name": "<author>"
  },
  "repository": "https://github.com/github/awesome-copilot",
  "license": "MIT",
  "keywords": [
    "<keyword>"
  ],
  "extensions": {
    "com.github.copilot": {
      "logo": "assets/preview.png"
    },
    "com.github.awesome-copilot": {
      "extensions": [
        "./extensions/<extension-id>"
      ]
    }
  }
}