Creating Skyline Plugins

Skyline is an environment for linking, runtime hooking and code patching originally designed for Super Smash Bros Ultimate but can be used with other Nintendo Switch games.

This is a great tool for modders who want to create mods that require code changes, as it allows you to write your mods in Rust or C++.

Note

This guide is for advanced users who are already familiar with reverse engineering and coding in general, if you don’t know what reverse engineering is or don’t know how to code we recommend starting with a more introductory guide.

Installing Skyline

ACNH needs its own Skyline build: skyline-acnh, a Skyline fork made for Animal Crossing: New Horizons.

1. Go to the latest skyline-acnh release.
2. Download skyline.zip.
3. Extract it and copy the exefs directory to atmosphere/contents/01006F8002326000/ on your Switch SD card.

Tip

If you are testing your mods on an emulator instead of hardware, the path structure inside atmosphere/ remains identical, but starts from the emulator’s virtual SD card root:

• Ryujinx: Ryujinx/sdcard/atmosphere/contents/01006F8002326000/.
• Eden: eden/sdmc/atmosphere/contents/01006F8002326000/.

Logging

Skyline

1. Set your Switch’s IP address with cargo skyline set-ip <SWITCH_IP_ADDRESS>.
2. Run cargo skyline listen to start listening for logs.

Note

Replace <SWITCH_IP_ADDRESS> with your Nintendo Switch’s actual local IP address (found in your console’s Internet Settings). If you are using an emulator on the same computer, you can use localhost.

Netcat (Linux)

1. Run the following command in your terminal while the game is running:

   nc <SWITCH_IP_ADDRESS> 6969

2. Look for the logs in the console output.

Note

Replace <SWITCH_IP_ADDRESS> with your Nintendo Switch’s actual local IP address (found in your console’s Internet Settings). If you are using an emulator on the same computer, you can use localhost.

PuTTY (Windows)

1. Open PuTTY.
2. Enter your Switch/PC IP address and set the Port to 6969.
3. Select Raw as the Connection Type and click Open.

Writing mods with Rust

1. Install cargo-skyline with cargo install cargo-skyline.
2. Create a new project with cargo skyline new <project_name>.
3. To build a project simply run cargo skyline build.
4. Once built, your compiled plugin will be located in the target/aarch64-skyline-switch directory. This is to be copied over to atmosphere/contents/01006F8002326000/romfs/skyline/plugins/