/MinecraftLauncher-core

Lightweight module that downloads and runs Minecraft using javascript / NodeJS

Primary LanguageJavaScriptMIT LicenseMIT

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This project is complete for now.

Build Status License: MIT version badge

MCLC (Minecraft Launcher Core) is a NodeJS solution for launching modded and vanilla Minecraft without having to download and format everything yourself. Basically a core for your Electron or script based launchers.

Getting support

Since people seem to use this, I've created a Discord server for anyone who needs to get in contact with me or get help!

chat on Discord

Installing

npm i minecraft-launcher-core

Standard Example

const { Client, Authenticator } = require('minecraft-launcher-core');
const launcher = new Client();

let opts = {
    clientPackage: null,
    // For production launchers, I recommend not passing 
    // the getAuth function through the authorization field and instead
    // handling authentication outside before you initialize
    // MCLC so you can handle auth based errors and validation!
    authorization: Authenticator.getAuth("username", "password"),
    root: "./minecraft",
    version: {
        number: "1.14",
        type: "release"
    },
    memory: {
        max: "6G",
        min: "4G"
    }
}

launcher.launch(opts);

launcher.on('debug', (e) => console.log(e));
launcher.on('data', (e) => console.log(e));

Documentation

Client Functions

Function Type Description
launch Promise Launches the client with the specified options as a parameter. Returns child the process
launch
Parameter Type Description Required
options.clientPackage String Path or URL to the client package zip file. Do not rehost Minecraft, it's against ToS. False
options.removePackage Boolean Option to remove the client package zip file after its finished extracting. False
options.installer String Path to installer being executed. False
options.root String Path where you want the launcher to work in. like C:/Users/user/AppData/Roaming/.mc, True
options.os String windows, osx or linux. MCLC will auto determine the OS if this field isn't provided. False
options.customLaunchArgs Array Array of custom Minecraft arguments you want to add. False
options.customArgs Array Array of custom Java arguments you want to add. False
options.version.number String Minecraft version that is going to be launched. True
options.version.type String Any string. The actual Minecraft launcher uses release and snapshot. True
options.version.custom String The name of the folder, jar file, and version json in the version folder. False
options.memory.max String Max amount of memory being used by Minecraft. True
options.memory.min String Min amount of memory being used by Minecraft. True
options.forge String Path to Forge Jar. (Versions below 1.13 should be the "universal" jar while versions above 1.13+ should be the "installer" jar) False
options.javaPath String Path to the JRE executable file, will default to java if not entered. False
options.server.host String Host url to the server, don't include the port. False
options.server.port String Port of the host url, will default to 25565 if not entered. False
options.proxy.host String Host url to the proxy, don't include the port. False
options.proxy.port String Port of the host proxy, will default to 8080 if not entered. False
options.proxy.username String Username for the proxy. False
options.proxy.password String Password for the proxy. False
options.timeout Integer Timeout on download requests. False
options.window.width String Width of the Minecraft Client False
options.window.height String Height of the Minecraft Client. False
options.window.fullscreen Boolean Fullscreen the Minecraft Client. False
options.overrides Object Json object redefining paths for better customization. Example below. False

IF YOU'RE NEW TO MCLC, LET IT HANDLE EVERYTHING! DO NOT USE OVERRIDES!

let opts = {
   otherOps...,
   overrides: {
       gameDirectory: "", // where the game process generates folders like saves and resource packs.
       minecraftJar: "",
       versionJson: "",
       directory: "", // where the Minecraft jar and version json are located.
       natives: "", // native directory path.
       assetRoot: "",
       libraryRoot: "",
       cwd: "", // working directory of the java process.
       detached: true, // whether or not the client is detached from the parent / launcher.
       classes: [], // all class paths are required if you use this.
       minArgs: 11, // The amount of launch arguments specified in the version file before it adds the default again
       maxSockets: 2, // max sockets for downloadAsync.
       // The following is for launcher developers located in countries that have the Minecraft and Forge resource servers
       // blocked for what ever reason. They obviously need to mirror the formatting of the original JSONs / file structures.
       url: {
           meta: "https://launchermeta.mojang.com", // List of versions.
           resource: "https://resources.download.minecraft.net", // Minecraft resources.
           mavenForge: "http://files.minecraftforge.net/maven/", // Forge resources.
           defaultRepoForge: "https://libraries.minecraft.net/", // for Forge only, you need to redefine the library url
                                                                // in the version json.
           fallbackMaven: "https://search.maven.org/remotecontent?filepath="
       }
   }
}

Notes

Custom

If you are loading up a client outside of vanilla Minecraft or Forge (Optifine and for an example), you'll need to download the needed files yourself if you don't provide downloads url downloads like Forge and Fabric. If no version jar is specified, MCLC will default back to the normal MC jar so mods like Fabric work.

Installer

This runs an executable with specified launch arguments. Was used to support Forge 1.13 before ForgeWrapper.

Authenticator Functions

getAuth
Parameter Type Description Required
username String Email or username True
password String Password for the Mojang account being used if online mode. False
validate
Parameter Type Description Required
access_token String Token being checked if it can be used to login with (online mode). True
client_token String Client token being checked to see if there was a change of client (online mode). True
refreshAuth
Parameter Type Description Required
access_token String Token being checked if it can be used to login with (online mode). True
client_token String Token being checked if it's the same client that the access_token was created from. True
selected_profile Object Json Object that was returned from Mojang's auth api. True
invalidate
Parameter Type Description Required
access_token String Token being checked if it can be used to login with (online mode). True
client_token String Token being checked if it's the same client that the access_token was created from. True
signOut
Parameter Type Description Required
username String Username used to login with True
password String Password used to login with True
changeApiUrl
Parameter Type Description Required
url String New URL that MCLC will make calls to authenticate the login. True

Events

Event Name Type Description
arguments Object Emitted when launch arguments are set for the Minecraft Jar.
data String Emitted when information is returned from the Minecraft Process
close Integer Code number that is returned by the Minecraft Process
package-extract null Emitted when clientPackage finishes being extracted
download String Emitted when a file successfully downloads
download-status Object Emitted when data is received while downloading
debug String Emitted when functions occur, made to help debug if errors occur
progress Object Emitted when files are being downloaded in order. (Assets, Forge, Natives, Classes)

What should it look like running from console?

The pid is printed in console after the process is launched. gif

Contributors

These are the people that helped out that aren't listed here!

  • Pyker - Forge dependency parsing.
  • Khionu - Research on how Minecraft'snatives are handled.
  • Coding-Kiwi - Pointed out I didn't pass clientToken in initial authentication function.
  • maxbsoft - Pointed out that a certain JVM option causes OSX Minecraft to bug out.
  • Noé - Pointed out launch args weren't being passed for Forge 1.13+.