Source-checkedLibraries & compatibility

S1MAPI

by ifBars · for Schedule I

S1MAPI is a mapping and construction library for Schedule 1 mods. Create procedural meshes, build structures, and load GLTF assets without depending on game assemblies.

22KDownloads
3 mo agoLast updated
BepInExLoaders
ThunderstoreSource

About S1MAPI

From Thunderstore

S1MAPI 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:

  1. Download the S1MAPI package from Thunderstore
  2. Extract the package - it includes UserLibs/S1MAPI_Mono.dll and UserLibs/S1MAPI_Il2Cpp.dll
  3. Copy the correct DLL for your Steam branch into your game's UserLibs folder:
  • Regular Steam branch (default): Use S1MAPI_Il2Cpp.dll
  • Alternate Steam branch: Use S1MAPI_Mono.dll
  1. 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:

  1. Add the Mono S1MAPI DLL as a reference to your mod project
  2. Build your mod against the Mono DLL - it works for both runtimes
  3. Tell users to install S1MAPI separately with the correct DLL for their Steam branch

Building From Source

  1. Clone the repository
  2. Copy local.build.props.example to local.build.props
  3. Edit local.build.props and set your game installation paths
  4. Build with dotnet build S1MAPI.csproj -c Mono or dotnet 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 data

Loaders

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

LoaderGame versionsNewest
BepInEx

From 3 recorded builds of S1MAPI.

Recent builds

BuildReleasedGame versionsLoaders
2.0.12026-07-23n/aBepInEx
2.0.02026-03-31n/aBepInEx
1.0.02026-01-08n/aBepInEx

Dependencies

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 catalog
Listed on Thunderstore as “Core”

Libraries & 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

S1MAPI, answered

Generated from the mod’s own source data.

Which loaders does it support?

BepInEx.

Is it free?

Yes. S1MAPI is free to download from Thunderstore.

How do I add it to my Nxeon server?

NxLabs doesn’t install Schedule I mods for you. Download S1MAPI free from Thunderstore.

NxLabs

Run S1MAPI on a Schedule I server.

Free to download from Thunderstore.