Portable Minecraft Launcher

An easy-to-use command line Minecraft launcher in only one Python script! This launcher is compatible with the directory structure of the official Minecraft Launcher. It aims to be fast and reliable for all Minecraft versions in a stateless manner, it also supports addons, official ones can be found below.

Install now!

Fabric and Forge addons

This launcher is tested for Python 3.6, 3.7, 3.8, 3.9, 3.10.

Table of contents

• Installation
• Sub-commands
  • Start the game
    • Authentication
    • Offline mode
    • Custom JVM
    • Auto connect to a server
    • LWJGL version and ARM support
    • Miscellaneous
  • Search for versions
  • Authentication sessions
  • Addon sub-command
• Addons
  • Fabric ⇗
  • Forge ⇗
  • Console ⇗
  • Archives ⇗
• Log4J Exploit
• Contribute
  • Setup environment
  • Contributors
• API Documentation ⇗
• Addon API Documentation ⇗

Installation

Before starting, please check if your Python version is valid for the launcher by doing python -V, the version must be greater or equal to 3.6 according to semver specification, this launcher's version is also following the semver specification.

The easiest way to install the launcher is to use the pip tool of your Python installation. On some linux distribution you might have to use pip3 instead of pip in order to run it on Python 3. You can also use python -m pip if the pip command is not in the path and the python executable is.

pip install --user portablemc

We advise you to keep --user because this allows to install the launcher for your current user only, it is implicit if you are not an administrator and if you are, it allows not to modify other users' installations.

After that, you can try to show the launcher help message using portablemc in your terminal. If it fails, you must ensure that the scripts directory is in your user path environment variable. On Windows you have to search for a directory at %appdata%/Python/Python3X/Scripts and add it to the user's environment variable Path. On UNIX systems this should work properly because the script is put in ~/.local/bin.

Sub-commands

Arguments are split between multiple sub-commands. For example portablemc <sub-command>. You can use -h argument to display help (also works for every sub-commands).

You may need to use --main-dir <path> if you want to change the main directory of the game. The main directory stores libraries, assets, versions. By default the location of this directory is OS-dependent, but always in your user's home directory, check wiki for more information.

You may also need --work-dir <path> to change the directory where your saves, resource packs and all "user-specific" content is stored. This can be useful if you have a shared read-only main directory (--main-dir) and user-specific working directory (for example in ~/.minecraft, by default it's the location of your main directory). This launcher also stores the authentication credentials in this directory (since launcher version 1.1.4).

The two arguments --main-dir and --work-dir may or may not be used by sub commands, then you can alias the command and always set the main and work directory like you want.

An advanced argument --timeout <seconds> can be used to set a global timeout value that can be freely used by the launcher or addons. You can use the special value 0 to force using local caches, is supported. For now, it's used by the launcher only for the version manifest fetching as it is now locally cached.

Start the game

The portablemc start [arguments...] [version] sub-command is used to prepare and launch the game. A lot of arguments allow you to control how to game will behave. The only positional argument is the version, which can be either a full version id (which you can get from the search sub-command), or a type of version to select the latest of this type (release (default) or snapshot), if you omit the version argument, it's equivalent to release.

Authentication

Online mode is supported by this launcher, use the -l <email_or_username> (--login) argument to log into your account (login with a username is deprecated by Mojang). If your session is not cached nor valid, the launcher will ask for the password.

You can use the the -m (--microsoft) to authenticate a Microsoft account if you already had migrated your account. In this case the launcher will open a page in your web browser with the Microsoft login page.

You can disable session caching using the argument -t (--temp-login). If your session is not cached nor valid, you will be asked for the password on every launch.

You can also use --anonymise in order to hide most of your email when printing it to the terminal. For example, [email protected] will become f*****r@g***l.com, this is useful to avoid leaking it when recording or streaming. However, if you use this, make sure that you either use an alias or a variable with the -l argument, for exemple -l $PMC_LOGIN.

Check below for more information about authentication sessions.

Offline mode

If you need fake offline accounts you can use -u <username> (--username) to define the username and/or -i <uuid> (--uuid) to define your player's UUID.

If you omit the UUID, a random one is chosen. If you omit the username, the first 8 characters of the UUID are used for it. These two arguments are overwritten by the -l (--login) argument.

Custom JVM

The launcher uses Java Virtual Machine to run the game, by default the launcher downloads and uses the official JVM distributed by Mojang which is adapted to the running version. The JVM is installed in a sub-directory called jvm inside the main directory. You can change it by providing a path to the java binary with the --jvm <path_to/bin/java> argument. By default, the launcher starts the JVM with default arguments, these are the following and are the same as the Mojang launcher:

-Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M

You can change these arguments using the --jvm-args=<args>, please always quote your set of arguments, this set must be one argument for PMC. For example portablemc start "--jvm-args=-Xmx2G -XX:+UnlockExperimentalVMOptions".

Auto connect to a server

Since Minecraft 1.6 we can start the game and automatically connect to a server. To do that you can use -s <addr> (--server) for the server address (e.g. mc.hypixel.net) and the -p (--server-port) to specify its port, by default to 25565.

LWJGL version and ARM support

With --lwjgl {3.2.3,3.3.0,3.3.1} you can update the LWJGL version used when starting the game. This can be used to support ARM architectures, but this may only work with modern versions which are already using LWJGL 3. This argument works by dynamically rewriting the version's metadata, the new metadata is dumped in the version directory. Using these versions on ARM is unstable and can show you an error with GLXBadFBConfig, in such cases you should export the following environment variable export MESA_GL_VERSION_OVERRIDE=4.5 (more info here).

Miscellaneous

With --dry, the game is prepared but not started.

With --demo you can enable the demo mode of the game.

With --resol <width>x<height> you can change the resolution of the game window.

With --no-better-logging flag you can disable the better logging configuration used by the launcher to avoid raw XML logging in the terminal.

The two arguments --disable-mp (mp: multiplayer), --disable-chat respectively to disable multiplayer button and disable in-game chat (since 1.16).

Search for versions

The portablemc search [-l] [version] sub-command is used to search for versions. By default, this command will search for official versions available to download, you can instead search for local versions using the -l (--local) flag. The search string is optional, if not given all official or local versions are displayed.

Authentication sessions

Two subcommands allow you to store or logout of sessions: portablemc login|logout <email_or_username>. These subcommands don't prevent you from using the -l (--login) argument when starting the game, these are just here to manage the session storage.

A new argument -m (--microsoft) is available for both subcommands since 1.1.4 for migrated Microsoft accounts. The launcher will open the Microsoft login page (with your email pre-typed in) in your web browser and wait until validated.

Your password is not saved! Only a token is saved (the official launcher also does that) in the file portablemc_auth.json in the working directory. In older version of the launcher (< 1.1.4), this file was portablemc_tokens in the main directory, the migration from the old file is automatic and irreversible (the old file is deleted).

Addon sub-command

The portablemc addon list|show sub-commands are used to list and show addons.

Addons

The following official add-ons are supported and maintained, since version 3.0.0 you can install them from from PyPI as shown in the following pages:

• Fabric ⇗
• Forge ⇗
• Console ⇗
• Archives ⇗

See the Addon Sub-command for more information on how to list and show which add-ons are installed.

Log4j Exploit

The launcher is safe to Log4j exploit since v2.2.0, if you are running an older version, please update or read the following issue for a temporary fix: #52.

Contribute

Setup environment

This project is currently a monorepo based on Poetry, each official module is stored in the src directory, the main and mandatory module is core. The other modules are official add-ons.

We also suggest Conda (or Miniconda) for easy development together with Poetry. If you want to try you can use the following commands:

# You can use any version of Python here from 3.6 to test compatibility of the launcher.
conda create -n pmc python=3.10 pip
# This line is optional if you don't have any user site-packages in your host installation, if not it allows to isolate pip. This is useful to avoid conflicts with conda-installed packages.
conda env config vars set PYTHONNOUSERSITE=1 -n pmc

On you have a conda environment setup, you can use on each module you want to test.

# Assume we are in the project's directory.
# First, we need to activate the environment.
conda activate pmc
# If poetry isn't installed, or outdated.
# Note that this project requires poetry 1.2.0 or greater to allow dependency groups.
# If this doesn't work, try to roll back to Poetry 1.2.0b1 which is the currently tested version.
pip install poetry --upgrade --pre
# Then, go to the module you want to install in development mode, and then install it.
cd src
# Here we use the workspace script that is just a wrapper that launch a poetry command on all modules.
python workspace.py install
# Now, you can test the development version of the launcher.
portablemc --help

You can call this development version from everywhere using:

conda run -n pmc portablemc

Contributors

This launcher would not be as functional without the contributors, and in particular the following for their bug reports and suggestions to make the launcher better: GoodDay360, Ristovski and GooseDeveloper.

There must be a lot of hidden issues, if you want to contribute you just have to install and test the launcher, and report every issue you encounter, do not hesitate!