Mac and iOS development team Panic announced today in a company blog post that the next major version of its Coda web development tool would not be coming to the Mac App Store. The reason? App Store apps need to be sandboxed (a security feature in OS X that doesn’t let apps modify data outside of their designated “sandboxes”), and Coda 2.5 simply doesn’t work as a sandboxed app.

According to Panic, Apple worked with the developers as much as possible to provide temporary exemptions and workarounds that could help alleviate some of the issues encoutered, but ultimately the decision was made to only release the update through the Panic website.

There’s nothing for App Store users to worry about, though. Panic has created an easy transition path to get from the App Store version (2.0.14) to the upcoming 2.5 build. Customers who currently have the App Store version installed just need to leave it in place. When version 2.5 is released through the Panic website, those customers just need to download it and run it. The app will automatically detect the previously-purchased App Store version and activate itself.

The update is also introducing a new syncing mechanism called Panic Sync that will replace iCloud in all of Panic’s apps. This is because iCloud compatiblity is only available to apps sold through Apple’s official channels. Since Coda 2.5 won’t be able to use iCloud to sync with other devices, the company has built its own syncing solution.

The developers are hopeful that someday the app will be able to return to the App Store, but until they’ve found a way to work around all of the issues sandboxing creates, the app will only be available on the company website. Since the upgrade path for App Store users is in place, you can get the current App Store build of Coda 2 for $79.99 now and get the upgrade from Panic when it becomes available.