Cosmic is a server emulator for Global MapleStory (GMS) version 83.
Cosmic launched on March 2021. It is based on code from a long line of server emulators spanning over a decade - starting with OdinMS (2008) and ending with HeavenMS (2019).
This is mainly a Java based project, but there are also a bunch of scripts written in JavaScript.
Head developer and maintainer: Ponk.
Contributors: a lot of people over the years, and hopefully more to come. Big thanks to everyone who has contributed so far!
Join the Discord server where most of the discussions take place: https://discord.gg/JU5aQapVZK
What we are working towards.
- Vanilla gameplay - stay as close to the original game as possible (within reason).
- Ease of use - getting started should be frictionless and contributing to the project straightforward.
- Reduce technical debt - making changes should be easy without causing unintended side effects.
- Modern tools & technologies - stay appealing by continuously improving the code and the project as a whole.
Explicitly excluded from the scope of the project.
- Custom gameplay features - existing custom features will be removed over time and new ones are unlikely to be added.
- Client development - this project is focused on the server. Please go elsewhere for client related questions.
- Public server - there will not be an official Cosmic server open to the public. Feel free to launch your own server at your own risk. No support will be provided.
You may contribute to the project in various ways, mainly through GitHub:
- Providing improvements to the code through a Pull Request from your own fork.
- Reporting a bug by creating an Issue.
- Providing information to existing issues or reviewing pull requests that others have made.
- ...and in other ways that I haven't thought of!
A GitHub Actions pipeline is set up to run the build automatically when a new pull request is opened or commits are pushed to an existing one. This ensures that the code compiles and all the tests pass.
Once a pull request is merged, a tag with the new version is automatically created.
Most GitHub activity is pushed to a Discord channel for visibility. This works by leveraging a webhook. The activity includes (but is not limited to): merged commits, created PRs, comments, and new tags.
The project follows the semantic versioning scheme using git tags.
- Bug fixes are treated as PATCH: 1.2.3 -> 1.2.4
- General changes or improvements are treated as MINOR: 1.2.3 -> 1.3.0
- Major changes are treated as MAJOR: 1.2.3 -> 2.0.0
Follow along as I go through the steps to play the game on your local computer from start to finish. I won't go into extreme detail, so if you don't have prior experience with Java or git, you might struggle.
We will set up the following:
- Database - the database is used by the server to store game data such as accounts, characters and inventory items.
- Server - the server is the "brain" and routes network traffic between the clients.
- Client - the client is the application used to play the game, i.e. MapleStory.exe.
You will start by installing the database server and client, and then run some scripts to prepare it for the server.
- Download and install MySQL Community Server 8+. You will have to set a root password, make sure you don't lose it because you will need it later.
- Download and install HeidiSQL.
- Open HeidiSQL and connect to the database ("New" -> "Session in root folder" -> fill in password -> "Open").
- Run all four scripts located in database/sql in order. Starting with
1-db_database.sqland ending with4-db-admin.sql. In HeidiSQL: "File" -> "Run SQL File...". - The database is ready!
You will start by cloning the repository, then configure the database properties and lastly start the server.
- Java 21+ (I recommend Amazon Corretto)
- IDE (I recommend IntelliJ IDEA)
- Clone Cosmic into a new project. In IntelliJ, you would create a new project from version control.
- Open config.yaml. Find "DB_PASS" and set it to your database root user password.
- Start the server. The main method is located in
net.server.Server. - If you see "Cosmic is now online" in the console, it means the server is online and ready to serve traffic. Yay!
Below, I list other ways of running the server which are completely optional.
Support for Docker is also provided out of the box, as an alternative to running straight in the IDE. If you have Docker Desktop installed it's as easy as running docker compose up.
Making changes becomes a bit more tedious though as you have to rebuild the server image via docker compose up --build.
On the first launch, the database container will run the scripts which may take so long that the server fails to start. In that case, just wait until the database is done running the scripts and then retry (Ctrl+C and re-run the command).
Another option is to start the server from a terminal by running a jar file. You first need to build the jar file from source which requires Maven.
Building the jar file is as easy as running mvn clean package. The project is configured to produce a "fat" jar which contains all dependencies (by utilizing the maven-assembly-plugin). Note that the WZ XML files are not included in the jar.
To run the jar, a launch.bat file is provided for convenience. Simply double-click it and the server will start in a new terminal window.
Alternatively, run the jar file from the terminal. Just remember to provide the wz-path system property pointing to your wz directory.
You will start by installing the game with the old installer, then overwrite some WZ files with our custom ones, and lastly get the localhost executable in place.
- Download MapleGlobal-v83-setup.exe from my Google Drive. This is the official installer from back then.
- Install it in a directory of your choice.
- Delete the following files from the installation directory: HShield (entire directory), ASPLnchr.exe, MapleStory.exe, and Patcher.exe.
- Download CosmicWZ-v1-2021.05.10.zip from my Google Drive.
- Unzip it and copy all .wz-files into the installation directory. Replace the existing ones.
- Download HeavenMS-localhost-WINDOW.exe from hostr.co. This is a client modified to connect to your localhost instead of Nexon's server (along with some fixes and custom changes).
- Your antivirus will likely detect the file as a trojan or similar and automatically delete it. To prevent this from happening, add your Downloads directory and the installation directory as exclusions in your antivirus software. On W11, this is under "Virus & threat protection settings" -> "Add or remove exclusions".
- Move HeavenMS-localhost-WINDOW.exe into the installation directory.
- Done! Double-click the exe and the game should start.
- The client may be a bit fiddly. Sometimes it won't start, but if you see "Client connected" in the server console it's a good indication. Try spam-clicking it like 10+ times, that usually works for me.
Important note about localhost clients: these executables are red-flagged by antivirus tools as potentially malicious software. This happens due to the reverse engineering methods that were applied onto these software artifacts. The one provided here has been in use for years already and posed no harm so far, so it is assumed to be safe.
The client has started, and you're looking at the login screen.
At this point, you can log in to the admin account using the following credentials:
- Username: "admin"
- Password: "admin"
- Pin: "0000"
- Pic: "000000"
Or create a regular account by typing in your desired username & password and attempting to log in. This "automatic registration" feature lets you create new accounts to play around with. It is enabled by default (see config.yaml).
Create a new character as you normally would, and then select it to enter the game. Hooray, finally we're in!
If you log in to the "Admin" character, you'll notice that the character looks almost invisible. This is hide mode, which is enabled by default when you log in to a GM character. You won't be visible to normal players and no mobs will move if you're alone on the map. Toggle hide mode on or off by typing "@hide" in the in-game chat.
Hide is one of many commands available to players, type "@commands" to see the full list. Higher ranked GMs have access to more powerful commands.
That's it, have fun playing around in game!
Some slightly more advanced concepts that might be useful once you're up and running.
You don't have to host the server on your local machine to play. It's possible to host on a remote server such as a VPS or even a dedicated server.
I leave it to you to figure out the server hosting part, but once you have that running you'll need to edit the client exe to point to your remote server ip.
- Download and install a hex editor: HxD
- Start HxD and open your client exe (I recommend making a copy of it first). At this point you should see a bunch of hex codes and a "Decoded text" column to the right of it.
- Ctrl+f and search for Text-string "127.0.0.1". You should find three occurrences right above each other.
- Place your cursor before the first "127" and start typing the desired ip, overwriting what is already there. Do the same on the other two and click on Save.
- Done! Now the client will attempt to connect to that ip address instead when you launch it.
WZ files are the asset/data files required by the client and server. Typically, HaRepacker-resurrected is used to handle (view, edit, export) the .wz files.
The client can read the .wz files directly, but the server requires them in XML format. The server also does not make use of the sprites, which is the motivation for different kinds of exporting. HaRepacker allows you to export to "Private server", which is the .img files packaged in the .wz stripped of sprites and converted to XML. This takes much less disk space.
This server requires custom .wz files (unfortunately), as you may have noted during installation of the client. The intention is for these to be removed eventually and to solely run on vanilla .wz files.
- Use the HaRepacker-resurrected editor, encryption "GMS (old)".
- Open the desired .wz for editing and use the node hierarchy to make the desired changes (copy/pasting nodes may be unreliable in rare scenarios).
- Save the changed .wz, overwriting the original content at the client folder.
- Finally, re-export (using the "Private Server" exporting option) the changed XMLs into the server's .wz XML files (found in the "wz" directory), overwriting the old contents.
Make sure to always export from the client .wz files to the server XML, and not the other way around.
Editing the client .wz without exporting to the server may lead to strange behavior.
For more information about the client and its features, see HeavenMS on GitHub.
Some notable features:
- Opens in window mode by default
- Uncapped max speed