Extension Functions Best Practices

Implementation guidance for browser extension features across 13 categories. Each category includes reference open-source projects and links to detailed implementation guides.

When to Use

• Building extension features in any supported category
• Looking for proven patterns and reference implementations
• Choosing libraries and APIs for specific functionality
• Understanding permission requirements

How Reference Projects Are Chosen

• Verifiable: Prefer projects you can install from a store, or build into a loadable extension from GitHub, with real Issues/Releases.
• Behavior-aligned: Table Highlights describe user-visible behavior (e.g. “merge HLS segments”) rather than only “call the downloads API”.
• Download / streaming: Tutorial-style chrome.downloads + an m3u8 URL is often not enough for a playable file; treat rules/download.md (“Reality check & common pitfalls”) and repos such as Cat Catch, Live Stream Downloader, and Video DownloadHelper as the ground truth.