About S1MAPI
From ThunderstoreS1MAPI is a mapping and construction library for Schedule 1 mods. Create procedural meshes, build structures, and load GLTF assets without depending on game assemblies.
S1MAPI - Schedule 1 Mapping API
S1MAPI is a mapping and construction library for Schedule 1 mods. Create procedural meshes, build structures, and load GLTF assets without asset bundles.
Documentation • GitHub Repository
What S1MAPI Does
- Procedural Meshes: Generate 3D shapes at runtime such as boxes, spheres, cylinders, and capsules
- Building Construction: Create buildings with walls, floors, roofs, windows, and furniture
- GLTF Loading: Import external 3D models without extra runtime dependencies
- Update Resilience: Avoid ScheduleOne types so mods survive game updates more cleanly
Installation
For Players
If a mod you want to use requires S1MAPI:
- Download the S1MAPI package from Thunderstore
- Extract the package - it includes
UserLibs/S1MAPI_Mono.dllandUserLibs/S1MAPI_Il2Cpp.dll - Copy the correct DLL for your Steam branch into your game's
UserLibsfolder:
- Regular Steam branch (default): Use
S1MAPI_Il2Cpp.dll - Alternate Steam branch: Use
S1MAPI_Mono.dll
- Launch the game - S1MAPI will load automatically with MelonLoader
To check your Steam branch: Right-click Schedule 1 in Steam -> Properties -> Betas. If it shows "None" or no selection, you are on the regular branch and should use the Il2Cpp DLL.
For Developers
To use S1MAPI in your mod project:
- Add the Mono S1MAPI DLL as a reference to your mod project
- Build your mod against the Mono DLL - it works for both runtimes
- Tell users to install S1MAPI separately with the correct DLL for their Steam branch
Building From Source
- Clone the repository
- Copy
local.build.props.exampletolocal.build.props - Edit
local.build.propsand set your game installation paths - Build with
dotnet build S1MAPI.csproj -c Monoordotnet build S1MAPI.csproj -c Il2cpp
Requirements
- Schedule 1
- MelonLoader 0.7.0+
- .NET Framework 4.7.2+ or .NET 6.0+
Learn More
License
GNU GPL v3 License - see the LICENSE file.
Highlights
From source dataLoaders
Runs on BepInEx.
Footprint
Rated a light load on a server.
Dependencies
Needs 1 other project installed alongside it.
S1MAPI on Nxeon
From our catalogue- One-click install
- Not available. One-click install isn't available for this game's mods yet. Download it and upload it to your server in Files.
- Server type needed
- BepInEx
- Server load
- light
- Latest build
- 2.0.1, released 2026-07-23
Game versions by loader
| Loader | Game versions | Newest |
|---|---|---|
| BepInEx |
From 3 recorded builds of S1MAPI.
Recent builds
| Build | Released | Game versions | Loaders |
|---|---|---|---|
| 2.0.1 | 2026-07-23 | n/a | BepInEx |
| 2.0.0 | 2026-03-31 | n/a | BepInEx |
| 1.0.0 | 2026-01-08 | n/a | BepInEx |
Dependencies
- Required: MelonLoader
Declared by the newest build that lists any. Required ones are installed with it on one-click installs.
What kind of mod it is
From the catalogLibraries & compatibility
Foundations and fixes other mods build on. Usually installed because something else needs it.
Compatibility
- Game
- Schedule I
- Loaders
- BepInEx
- Requires
- One-click install needs a BepInEx server. 1 other project installed alongside it.
Verified at the source
- ✓ThunderstoreOfficial listing, checked 2026-10-02Open ↗
- ✓AuthorifBars, as published on Thunderstore
- ✓LicenseNot published by the sourceFree



