S1Interop

S1Interop is an alpha .NET toolchain for Schedule I mod developers working across Mono and IL2CPP. It analyzes projects, reports known interop risks, plans reversible migrations, and can generate selected backend-neutral helpers.

It is low-level tooling. Use S1API, MAPI, networking libraries, and dedicated-server APIs for the workflows they already own. Use S1Interop for direct ScheduleOne.* and Il2CppScheduleOne.* seams that would otherwise need duplicated runtime code.

Licensed under GPL-3.0-only.

Start here

Use the Start here guide. It gives new modders a complete first-mod route, lets experienced mod authors begin with read-only analysis, and sends tool authors directly to the relevant reference.

Your situation	First route
New to Schedule I modding	Install, build, and load a small mod
Already maintaining a mod	Inspect it without changing files
Already know the S1Interop feature you need	Jump to a task or reference

The default new-project path produces explicit Mono and IL2CPP builds. Generated backend-neutral facades are experimental. Keep a dual-runtime fallback until the shipped assembly has in-game evidence on both runtime branches.

Install

Install the current alpha with .NET SDK 8 or newer:

dotnet tool install --global S1Interop --version 0.1.0-alpha.1
s1interop --help

Use dotnet tool update --global S1Interop --version 0.1.0-alpha.1 when the tool is already installed. See Install S1Interop for local tool installation and contributor package builds.

Safety model

• analyze, lint, and doctor do not change the project.
• File-changing commands show a dry-run plan until you add --apply.
• Applied migrations write backups and a rollback manifest under s1interop-runs/<run-id>/.
• verify-migration works in a temporary copy instead of the source project.
• Game installs stay local. Do not commit assemblies, generated IL2CPP wrappers, decompiled output, game assets, or local.build.props.

Documentation

The documentation starts with one route by experience and outcome: Start here.

• Core concepts
• Common tasks
• Commands
• Troubleshooting
• Contributing

Repository layout

src/S1Interop.Cli/          command parsing and user-facing reporting
src/S1Interop.Core/         analysis, migration, generation, rollback, verification
tests/S1Interop.Tests/      portable and local integration coverage
docs/docfx/                 public documentation site