Contents

• What is SMAPI?
• For players
• For mod developers
• For SMAPI developers
  • Compiling from source
  • Debugging a local build
  • Preparing a release
• Advanced usage
  • Configuration file
  • Command-line arguments

What is SMAPI?

SMAPI is an open-source modding API for Stardew Valley that lets you play the game with mods. It's safely installed alongside the game's executable, and doesn't change any of your game files. It serves five main purposes:

1. Load mods into the game.
   SMAPI loads mods when the game is starting up so they can interact with it. (Code mods aren't possible without SMAPI to load them.)

2. Provide APIs and events for mods.
   SMAPI provides low-level APIs and events which let mods interact with the game in ways they otherwise couldn't.

3. Rewrite mods for crossplatform compatibility.
   SMAPI rewrites mods' compiled code before loading them so they work on Linux/Mac/Windows without the mods needing to handle differences between the Linux/Mac and Windows versions of the game.

4. Rewrite mods to update them.
   SMAPI detects when a mod accesses part of the game that changed in a recent update which affects many mods, and rewrites the mod so it's compatible.

5. Intercept errors.
   SMAPI intercepts errors that happen in the game, displays the error details in the console window, and in most cases automatically recovers the game. This prevents mods from accidentally crashing the game, and makes it possible to troubleshoot errors in the game itself that would otherwise show a generic 'program has stopped working' type of message.

For players

• How to install SMAPI & use mods
• Release notes
• Need help? Come chat on Discord or post in the support forums.
  Please don't submit issues on GitHub for support questions.

For mod developers

• How to develop mods
• How to update mods
• Release notes
• Chat on Discord with SMAPI developers and other modders

For SMAPI developers

This section is about compiling SMAPI itself from source. If you don't know what that means, this section isn't relevant to you; see the previous sections to use or create mods.

Compiling from source

Using an official SMAPI release is recommended for most users.

SMAPI uses some C# 7 code, so you'll need at least Visual Studio 2017 on Windows, MonoDevelop 7.0 on Linux, Visual Studio 2017 for Mac, or an equivalent IDE to compile it. It uses build configuration derived from the crossplatform mod config to detect your current OS automatically and load the correct references. Compile output will be placed in a bin folder at the root of the git repository.

Debugging a local build

Rebuilding the solution in debug mode will copy the SMAPI files into your game folder. Starting the StardewModdingAPI project with debugging from Visual Studio (on Mac or Windows) will launch SMAPI with the debugger attached, so you can intercept errors and step through the code being executed. This doesn't work in MonoDevelop on Linux, unfortunately.

Preparing a release

To prepare a crossplatform SMAPI release, you'll need to compile it on two platforms. See crossplatforming info on the wiki for the first-time setup.

1. Update the version number in GlobalAssemblyInfo.cs and Constants::Version. Make sure you use a semantic version. Recommended format:

   build type	format	example
   dev build	<version>-alpha.<timestamp>	1.0-alpha.20171230
   prerelease	<version>-prerelease.<ID>	1.0-prerelease.2
   release	<version>	1.0

2. In Windows:

   1. Rebuild the solution in Release mode.
   2. Rename bin/Packaged to SMAPI <version> (e.g. SMAPI 1.0).
   3. Transfer the SMAPI <version> folder to Linux or Mac.
      This adds the installer executable and Windows files. We'll do the rest in Linux or Mac, since we need to set Unix file permissions that Windows won't save.

3. In Linux or Mac:

   1. Rebuild the solution in Release mode.

   2. Copy bin/internal/Packaged/Mono into the SMAPI <version> folder.

   3. If you did everything right so far, you should have a folder like this:

      SMAPI-1.x/
         install.exe
         readme.txt
         internal/
            Mono/
               Mods/*
               Mono.Cecil.dll
               Newtonsoft.Json.dll
               StardewModdingAPI
               StardewModdingAPI.AssemblyRewriters.dll
               StardewModdingAPI.config.json
               StardewModdingAPI.exe
               StardewModdingAPI.pdb
               StardewModdingAPI.xml
               steam_appid.txt
               System.Numerics.dll
               System.Runtime.Caching.dll
            Windows/
               Mods/*
               Mono.Cecil.dll
               Newtonsoft.Json.dll
               StardewModdingAPI.AssemblyRewriters.dll
               StardewModdingAPI.config.json
               StardewModdingAPI.exe
               StardewModdingAPI.pdb
               StardewModdingAPI.xml
               steam_appid.txt
      

   4. Open a terminal in the SMAPI <version> folder and run chmod 755 internal/Mono/StardewModdingAPI.

   5. Copy & paste the SMAPI <version> folder as SMAPI <version> for developers.

   6. In the SMAPI <version> folder...

      • edit internal/Mono/StardewModdingAPI.config.json and internal/Windows/StardewModdingAPI.config.json to disable developer mode;
      • delete internal/Windows/StardewModdingAPI.xml.

   7. Compress the two folders into SMAPI <version>.zip and SMAPI <version> for developers.zip.

Advanced usage

Configuration file

You can customise the SMAPI behaviour by editing the StardewModdingAPI.config.json file in your game folder. It contains these fields:

field	purpose
DeveloperMode	Default false (except in SMAPI for developers releases). Whether to enable features intended for mod developers. Currently this only makes TRACE-level messages appear in the console.
CheckForUpdates	Default true. Whether SMAPI should check for a newer version when you load the game. If a new version is available, a small message will appear in the console. This doesn't affect the load time even if your connection is offline or slow, because it happens in the background.
ModCompatibility	A list of mod versions SMAPI should consider compatible or broken regardless of whether it detects incompatible code. Each record can be set to AssumeCompatible or AssumeBroken. Changing this field is not recommended and may destabilise your game.
VerboseLogging	Whether SMAPI should log more information about the game context.

Command-line arguments

SMAPI recognises the following command-line arguments. These are intended for internal use or testing and may change without warning.

argument	purpose
--log-path "path"	The relative or absolute path of the log file SMAPI should write.
--no-terminal	SMAPI won't write anything to the console window. (Messages will still be written to the log file.)

Compile flags

SMAPI uses a small number of conditional compilation constants, which you can set by editing the <DefineConstants> element in StardewModdingAPI.csproj. Supported constants:

flag	purpose
EXPERIMENTAL	Enables preview features that aren't officially released yet.
SMAPI_FOR_WINDOWS	Indicates that SMAPI is being compiled on Windows for players on Windows. Set automatically in crossplatform.targets.