← [README](../README.md)

This file provides more technical documentation about SMAPI. If you only want to use or create
mods, this section isn't relevant to you; see the main README to use or create mods.

This document is about SMAPI itself; see also [mod build package](mod-package.md) and
[web services](web.md).

# Contents
* [Customisation](#customisation)
  * [Configuration file](#configuration-file)
  * [Command-line arguments](#command-line-arguments)
  * [Compile flags](#compile-flags)
* [Compile from source code](#compile-from-source-code)
  * [Main project](#main-project)
  * [Custom Harmony build](#custom-harmony-build)
* [Prepare a release](#prepare-a-release)
  * [On any platform](#on-any-platform)
  * [On Windows](#on-windows)
* [Release notes](#release-notes)

## Customisation
### Configuration file
You can customise some SMAPI behaviour by editing the `smapi-internal/config.json` file in your
game folder. See documentation in the file for more info.

### Command-line arguments
The SMAPI installer recognises three command-line arguments:

argument | purpose
-------- | -------
`--install` | Preselects the install action, skipping the prompt asking what the user wants to do.
`--uninstall` | Preselects the uninstall action, skipping the prompt asking what the user wants to do.
`--game-path "path"` | Specifies the full path to the folder containing the Stardew Valley executable, skipping automatic detection and any prompt to choose a path. If the path is not valid, the installer displays an error.

SMAPI itself recognises two arguments **on Windows only**, but these are intended for internal use
or testing and may change without warning. On Linux/macOS, see _environment variables_ below.

argument | purpose
-------- | -------
`--no-terminal` | SMAPI won't write anything to the console window. (Messages will still be written to the log file.)
`--mods-path` | The path to search for mods, if not the standard `Mods` folder. This can be a path relative to the game folder (like `--mods-path "Mods (test)"`) or an absolute path.

### Environment variables
The above SMAPI arguments don't work on Linux/macOS due to the way the game launcher works. You can
set temporary environment variables instead. For example:
> SMAPI_MODS_PATH="Mods (multiplayer)" /path/to/StardewValley

environment variable | purpose
-------------------- | -------
`SMAPI_NO_TERMINAL` | Equivalent to `--no-terminal` above.
`SMAPI_MODS_PATH` | Equivalent to `--mods-path` above.

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

flag | purpose
---- | -------
`SMAPI_FOR_WINDOWS` | Whether SMAPI is being compiled for Windows; if not set, the code assumes Linux/macOS. Set automatically in `common.targets`.

## Compile from source code
### Main project
Using an official SMAPI release is recommended for most users, but you can compile from source
directly if needed. Just open the project in an IDE like [Visual
Studio](https://visualstudio.microsoft.com/vs/community/) or [Rider](https://www.jetbrains.com/rider/),
and build the `SMAPI` project. The project will automatically adjust the build settings for your
current OS and Stardew Valley install path.

Rebuilding the solution in debug mode will copy the SMAPI files into your game folder. Starting
the `SMAPI` project with debugging from Visual Studio or Rider should launch SMAPI with the
debugger attached, so you can intercept errors and step through the code being executed.

### Custom Harmony build
SMAPI uses [a custom build of Harmony](https://github.com/Pathoschild/Harmony#readme), which is
included in the `build` folder. To use a different build, just replace `0Harmony.dll` in that
folder before compiling.

## Prepare a release
### On any platform
**⚠ Ideally we'd have one set of instructions for all platforms. The instructions in this section
will produce a fully functional release for all supported platfrms, _except_ that the application
icon for SMAPI on Windows will disappear due to [.NET runtime bug
3828](https://github.com/dotnet/runtime/issues/3828). Until that's fixed, see the _[on
Windows](#on-windows)_ section below to create a build that retains the icon.**

#### First-time setup
1. On Windows only:
   1. [Install Windows Subsystem for Linux (WSL)](https://docs.microsoft.com/en-us/windows/wsl/install).
   2. Run `sudo apt update` in WSL to update the package list.
   3. The rest of the instructions below should be run in WSL.
2. Install the required software:
   1. Install the [.NET 5 SDK](https://docs.microsoft.com/en-us/dotnet/core/install/linux-ubuntu).  
      _For Ubuntu-based systems, you can run `lsb_release -a` to get the Ubuntu version number._
   2. [Install Steam](https://linuxconfig.org/how-to-install-steam-on-ubuntu-20-04-focal-fossa-linux).
   3. Launch `steam` and install the game like usual.
   4. Download and install your preferred IDE. For the [latest standalone Rider
      version](https://www.jetbrains.com/help/rider/Installation_guide.html#prerequisites):
      ```sh
      wget "<download url here>" -O rider-install.tar.gz
      sudo tar -xzvf rider-install.tar.gz -C /opt
      ln -s "/opt/JetBrains Rider-<version>/bin/rider.sh"
      ./rider.sh
      ```
3. Clone the SMAPI repo:
   ```sh
   git clone https://github.com/Pathoschild/SMAPI.git
   ```

### Launch the game
1. Run these commands to start Steam:
   ```sh
   export TERM=xterm
   steam
   ```
2. Launch the game through the Steam UI.

### Prepare the release
1. Run `build/unix/set-smapi-version.sh` to set the SMAPI version. Make sure you use a [semantic
   version](https://semver.org). Recommended format:

   build type | format                   | example
   :--------- | :----------------------- | :------
   dev build  | `<version>-alpha.<date>` | `4.0.0-alpha.20251230`
   prerelease | `<version>-beta.<date>`  | `4.0.0-beta.20251230`
   release    | `<version>`              | `4.0.0`

2. Run `build/unix/prepare-install-package.sh` to create the release package in the root `bin`
   folder.

### On Windows
#### First-time setup
1. Set up Windows Subsystem for Linux (WSL):
   1. [Install WSL](https://docs.microsoft.com/en-us/windows/wsl/install).
   2. Run `sudo apt update` in WSL to update the package list.
   3. The rest of the instructions below should be run in WSL.
2. Install the required software:
   1. Install the [.NET 5 SDK](https://dotnet.microsoft.com/download/dotnet/5.0).
   2. Install [Stardew Valley](https://www.stardewvalley.net/).
3. Clone the SMAPI repo:
   ```sh
   git clone https://github.com/Pathoschild/SMAPI.git
   ```

### Prepare the release
1. Run `build/windows/set-smapi-version.ps1` in PowerShell to set the SMAPI version. Make sure you
   use a [semantic version](https://semver.org). Recommended format:

   build type | format                   | example
   :--------- | :----------------------- | :------
   dev build  | `<version>-alpha.<date>` | `4.0.0-alpha.20251230`
   prerelease | `<version>-beta.<date>`  | `4.0.0-beta.20251230`
   release    | `<version>`              | `4.0.0`

2. Run `build/windows/prepare-install-package.ps1` in PowerShell to create the release package
   folders in the root `bin` folder.

3. Launch WSL and run this script:
   ```bash
   # edit to match the build created in steps 1-2
   # In WSL, `/mnt/c/example` accesses `C:\example` on the Windows filesystem.
   version="4.0.0"
   binFolder="/mnt/e/source/_Stardew/SMAPI/bin"
   build/windows/finalize-install-package.sh "$version" "$binFolder"
   ```

## Release notes
See [release notes](../release-notes.md).