ExtensionKit Will Sunset on April 1, 2026
After building ExtensionKit over the last few years, I wanted to share an important update: ExtensionKit will sunset on April 1, 2026.
It has been a lot of fun building this product and supporting everyone using it to ship browser extensions faster. Thank you for the support, feedback, and ideas along the way.
Why we are sunsetting
The current state of AI has changed how quickly developers can generate extension boilerplate and iterate on new ideas. The original value of a paid starter-kit library is no longer as necessary as it once was, and I want to be direct about that.
Download every template in one click
If you have access to ExtensionKit, you can still grab everything quickly from the dashboard.
- Sign in to the dashboard.
- Click Download all templates.
- Save the ZIP so you have all templates locally.
Keep using the templates with AI
Even after sunset, the templates are still useful as high-signal context for AI-assisted development.
Instead of asking AI to start from a blank file, give it a template and
manifest.json so it can work with some starter context easily (or tag
additional templates if you want a quick merged concept).
Here are three practical ways to use them:
- Start from a working template, then add your product logic.
Example prompt: "Use this popup template as the base. Add a task planner with local storage, keyboard shortcuts, and a filter UI while keeping the existing file structure."
- Feed AI both the template and manifest, then ask for MV3-safe edits.
Example prompt: "Refactor this content-script template to run only on docs.google.com and notion.so. Keep MV3 compatibility and explain each manifest permission you add."
- Use templates as architecture references before writing code.
Example prompt: "Compare this sidepanel template and this new-tab template, then propose a unified folder structure and implementation plan for a tab manager extension."
I hope ExtensionKit has been useful for your work. Thanks again for being part of it.