Skyline Emulator, the popular emulator that ran Nintendo Switch games for Android, is officially shutting down due to the threat of legal action by Nintendo.

For those unaware, Skyline is an open-source experimental emulator for Android devices that emulates the functionality of a Nintendo Switch system. It is a Switch emulator that is built by dumping keys from the developer’s own Switches.

Skyline team, the developers behind the Skyline Emulator, shared the news via an announcement on the official Discord Server last Friday, and stated that they will be ceasing all further development on Skyline with immediate effect following a DMCA takedown notice from Nintendo against an adjacent project and homebrew software called “Lockpick”.

In order to emulate Nintendo Switch games, you require two main components: the game itself and keys dumped from your console that can decrypt the game.

Lockpick is a commonly used tool for dumping console keys and digital game keys from your own Nintendo Switch console.

However, Nintendo sent a DMCA request to GitHub to take down the Lockpick project, as it believes that the software circumvents their copy protection (TPMs) and therefore violates their copyright.

The Japanese game company claimed that “the use of Lockpick with a modified Nintendo Switch console allows users to bypass Nintendo’s Technological Measures for video games; specifically, Lockpick bypasses the Console TPMs [Trusted Platform Modules] to permit unauthorized access to, extraction of, and decryption of all the cryptographic keys, including product keys, contained in the Nintendo Switch.”

It added, “The decrypted keys facilitate copyright infringement by permitting users to play pirated versions of Nintendo’s copyright-protected game software on systems without Nintendo’s Console TPMs or systems on which Nintendo’s Console TPMs have been disabled.”

Skyline requires the keys obtained from Lockpick to function. Prior to Nintendo’s DMCA request, Skyline’s team had believed that dumping keys from your own Switch console was completely legal to emulate games that were legally purchased.

Fearing that Nintendo’s mentioned reasons for taking down Lockpick would be applicable to them also, Skyline developers immediately decided to cease work on the project.

“It is with great sadness that we bring you this news. We find ourselves in a position where we are potentially violating their copyright by continuing to develop our project, Skyline, by dumping keys from our own Switches,” the Skyline team said in the announcement.

“After much internal discussion, we have made the difficult decision to immediately cease all further development on Skyline. The risks associated with a potential legal case are too high for us to ignore, and we cannot continue knowing that we may be in violation of copyright law.”

The Skyline team says the emulator itself is entirely legal and it won’t be taking down the repository (which will be made read-only) or software builds in the foreseeable future.

However, they would not continue to develop or update the emulator. Additionally, all incomplete source code for ‘texman’ and ‘nnvk’ will be made public.