async-mc-launcher-core 🚀

A Modern Async Python Library for Building Minecraft Launchers

中文說明請見 README-Chinese.md

This project is a fork of JakobDev/minecraft-launcher-lib.

A Python library for building custom Minecraft launchers. Supports installing, launching Minecraft, and interacting with Mojang/Microsoft accounts.

Features

• Easy installation
• Generate Minecraft launch commands
• Microsoft account login support
• Supports Forge, Fabric, Quilt, and Liteloader
• Supports alpha/beta and legacy versions
• All functions are type-annotated and documented
• PyPy support
• Full online documentation and tutorials
• Vanilla launcher profiles read/write support
• mrpack modpacks support
• All public APIs are statically typed
• Rich examples
• Open source

Installation

Using pip:

pip install async-mc-launcher-core

Or using uv (recommended for faster installation):

uv pip install async-mc-launcher-core

Microsoft Account Login Example

import logging
from launcher_core import microsoft_account
import asyncio
from launcher_core.setting import setup_logger
from launcher_core.mojang import have_minecraft

logger = setup_logger(enable_console=False, level=logging.INFO, filename="microsoft_account.log")

async def login_microsoft_account():
    AZURE_APP = microsoft_account.AzureApplication()
    Login = microsoft_account.Login(azure_app=AZURE_APP)
    login_url = await Login.get_login_url()
    print(f"Please open {login_url} in your browser and copy the URL you are redirected into the prompt below.")
    code_url = input()
    code = await microsoft_account.Login.extract_code_from_url(code_url)
    auth_code = await Login.get_ms_token(code)
    print(f"Refresh token: {auth_code['refresh_token']}")
    xbl_token = await microsoft_account.Login.get_xbl_token(auth_code["access_token"])
    xsts_token = await microsoft_account.Login.get_xsts_token(xbl_token["Token"])
    uhs = xbl_token["DisplayClaims"]["xui"][0]["uhs"]
    mc_token = await microsoft_account.Login.get_minecraft_access_token(xsts_token["Token"], uhs)
    await have_minecraft(mc_token["access_token"])
    login_data = {
        "access_token": mc_token["access_token"],
        "refresh_token": auth_code["refresh_token"],
        "expires_in": auth_code["expires_in"],
        "uhs": uhs,
        "xsts_token": xsts_token["Token"],
        "xbl_token": xbl_token["Token"]
    }
    return login_data["access_token"]

if __name__ == "__main__":
    access_token = asyncio.run(login_microsoft_account())
    print(f"Access token: {access_token}")

Documentation & More Examples

• Online Documentation
• More Examples

Comparison: This Fork vs. JakobDev/minecraft-launcher-lib

Feature/Design	This Fork	JakobDev Original
Python Version Support	3.10+, more complete type annotations	3.7+, partial type annotations
Logging System	Built-in setup_logger, file & console output	No built-in logging, user must implement
Microsoft Login Flow	Example & API fully async/await	All sync
Dependencies	aiofiles, aiohttp, requests, requests-mock	requests
Documentation	Primarily in Chinese, tailored for TW/Chinese users	English
Branch Strategy	main/dev auto-sync (GitHub Actions)	Single main branch
Others	Optimized for async/await and type annotations	Focus on broad compatibility

Please refer to both the original and this fork to choose the version that best fits your needs!

Contributing

PRs and issues are welcome!

Acknowledgements

Thanks to tomsik68 for documenting Minecraft launcher internals.

Thanks to JakobDev for the original code (BSD-2).