Starlight Plugin Extension Guide

Plugin System Overview

Starlight’s plugin system is built on Astro integration, allowing modular extension of documentation site functionality. All plugins are distributed through npm packages, supporting both official and community plugins.

Core Concepts

1. Feature Extension: Add new components, optimize build process, or integrate third-party services
2. Configuration Inheritance: Plugin configuration deeply integrates with Starlight main configuration
3. Type Safety: Complete TypeScript type support provided

Plugin Management

Installing Plugins

Using the official image plugin as an example:

npm install @astrojs/starlight-image @astrojs/image

Configuration File

Create starlight.plugins.mjs in the project root:

import imagePlugin from '@astrojs/starlight-image';

/** @type {import('@astrojs/starlight').StarlightPlugins} */
export default {
  image: imagePlugin({
    defaultLocale: 'en',
    imageService: 'sharp',
  }),
};

Applying Configuration

Update astro.config.mjs:

import { defineConfig } from 'astro/config';
import starlight from '@astrojs/starlight';
import plugins from './starlight.plugins.mjs';

export default defineConfig({
  integrations: [
    starlight({
      // ... existing configuration ...
      plugins: Object.values(plugins),
    }),
  ],
});

Common Plugin Examples

1. Image Optimization Plugin

Configuration example:

// starlight.plugins.mjs
export default {
  image: imagePlugin({
    responsive: {
      deviceSizes: [640, 750, 828, 1080, 1200],
      imageSizes: [16, 32, 48, 64],
    },
  }),
};

2. Analytics Plugin

Installation:

npm install starlight-google-analytics

Usage:

// starlight.plugins.mjs
import analytics from 'starlight-google-analytics';

export default {
  analytics: analytics({
    trackingID: 'UA-XXXXX-Y',
  }),
};

Plugin Development Basics

1. Create Plugin Template

mkdir starlight-plugin-example
cd starlight-plugin-example
npm init -y

2. Basic Structure

// index.js
/** @type {import('@astrojs/starlight').StarlightPlugin} */
export default {
  name: 'example-plugin',
  hooks: {
    setup({ config, updateConfig }) {
      // Plugin logic
      updateConfig({
        head: [
          ...config.head,
          { tag: 'meta', attrs: { name: 'plugin-added' } },
        ],
      });
    },
  },
};

3. Local Testing

Temporarily install in your project:

npm install ./path/to/starlight-plugin-example

Troubleshooting

1. Version Conflicts: Ensure plugin version is compatible with Starlight version
2. Configuration Validation: Use astro check to validate configuration
3. Cache Issues: Run npm run clear to clear build cache