Creating Add-ons

Build reusable extensions for the Crow platform. Add-ons package panels, MCP servers, skills, or combinations of these into installable units.

What is this?

A Crow add-on is a packaged extension that other users can install. It follows a standard format with a manifest file, so the platform knows what it contains and how to set it up.

Why would I want this?

• Share your work — Package a custom panel, server, or skill for others to use
• Reusable bundles — Combine related components (e.g., a server + skill + panel) into one installable package
• Community ecosystem — Contribute to the Crow add-on registry

Add-on Types

Type	What it contains	Installed to
panel	Dashboard panel	~/.crow/panels/
mcp-server	MCP server (factory + stdio)	~/.crow/servers/
skill	Skill markdown file	~/.crow/skills/
bundle	Multiple components	Each to its respective location

manifest.json

Every add-on has a manifest.json at its root:

{
  "name": "crow-weather-panel",
  "version": "1.0.0",
  "type": "panel",
  "description": "Weather dashboard panel showing local forecast",
  "author": "Your Name",
  "license": "MIT",
  "crow": {
    "minVersion": "1.0.0"
  },
  "components": [
    {
      "type": "panel",
      "id": "weather",
      "entry": "panel/index.js"
    }
  ],
  "dependencies": {
    "node-fetch": "^3.0.0"
  },
  "envVars": [
    {
      "name": "WEATHER_API_KEY",
      "description": "API key from openweathermap.org",
      "required": true
    }
  ]
}

Manifest Fields

Field	Required	Description
name	Yes	Package name (lowercase, hyphens ok)
version	Yes	Semver version string
type	Yes	One of: panel, mcp-server, skill, bundle
description	Yes	Short description (under 200 characters)
author	Yes	Author name or handle
license	Yes	SPDX license identifier
crow.minVersion	No	Minimum Crow version required
components	Yes	Array of component definitions
dependencies	No	npm dependencies (installed automatically)
envVars	No	Required environment variables

File Structure

Panel add-on

crow-weather-panel/
  manifest.json
  panel/
    index.js          # Panel manifest + handler
    assets/           # Optional static files

MCP server add-on

crow-task-server/
  manifest.json
  server/
    server.js         # Factory function
    index.js          # Stdio entry point
  schema/
    init.sql          # Database tables (run during install)
  skills/
    tasks.md          # Optional companion skill

Skill add-on

crow-pomodoro-skill/
  manifest.json
  skills/
    pomodoro.md       # Skill file

Bundle add-on

crow-project-manager/
  manifest.json
  server/
    server.js
    index.js
  panel/
    index.js
  skills/
    project-manager.md
  schema/
    init.sql

Testing Locally

1. Create your add-on directory with a manifest.json
2. For panels: symlink or copy to ~/.crow/panels/
3. For servers: add to scripts/server-registry.js temporarily
4. For skills: copy to skills/
5. Restart the gateway and verify everything works

Test the manifest:

node -e "const m = JSON.parse(require('fs').readFileSync('manifest.json')); console.log(m.name, m.version, m.type);"

Publishing

Once your add-on is tested:

1. Push it to a public Git repository
2. Tag a release with the version from your manifest
3. Submit it to the Add-on Registry for listing

See the Registry documentation for the full submission process.

Guidelines

• Keep add-ons focused — one purpose per add-on
• Use environment variables for secrets, never hardcode them
• Follow the Zod .max() constraint pattern for any MCP tool parameters
• Use sanitizeFtsQuery() for any FTS5 queries
• Include a LICENSE file
• Test with both dark and light dashboard themes if you're building a panel