Plugins rely on certain packages contained within the HomeSeer installation directory. Before you can begin developing a plugin for HS4, you will need to make sure that you have a registered copy of the latest version of the platform installed on your computer.
Download the latest installer from the forums.
HS4 Alpha installations will currently only work with trial licenses.
If you are looking for instructions on how to create a new plugin for the HS4 platform, check out the Creating a Plugin guide.
There are a few sample plugins developed by HomeSeer, open-sourced, and available for your use in developing plugins. You can find a list of the available samples and instructions on how to use them on the Sample Plugins page.
See the HS3 to HS4 API Reference guide to get started finding the new signatures for the various classes and methods.
More documentation on this subject will be coming soon.
The Plugin SDK has been open-sourced and is available on GitHub: HomeSeer/Plugin-SDK
Please report any issues you are experiencing there. Contributions are welcome; create a pull request.