Groove-Coaster-2OS-Server

A small local server for Groove Coaster 2: Original Style, implemented with Python and Flask Starlette.

一个基于Python和FlaskStarlette的微型Groove Coaster 2: Original Style本地服务器。

English

Introduction

This project is for game preservation purposes only. Creative liberty and conveniences have been taken when it comes to specific implementation. The goal is not to ensure 1:1 behavior, but to guarrantee the minimum viability of playing this game. It is provided as-is, per the GPLv2 license.

It has been rewritten multiple times to nuke my poor code optimize and improve. The latest iteration is 7003. For migration, visit the Version Migration section directly.

You shall bare all the responsibility for any potential consequences as a result of running this server. If you do not agree to these requirements, you are not allowed to replicate or run this program.

Inspiration: Lost-MSth/Arcaea-server

Special thanks: Walter-o/gcm-downloader

Warning: Do not put personal files under the folders in the private server directory files - all files within these sub-folders will be accessible by anyone with your server address! Security and performance are not guaranteed, and it is not recommended to host this server on the internet. You have been warned.

Supported Features

Features	Degree of support
Asset delivery	.pak, stage and music zip files
Shop	Purchase individual songs, avatars, and items using GCoin. GCoins are earned by playing the game. Does not support music preview. Does not support song pack.
Ranking	Individual song-difficulty ranking. Support total score ranking, but does not support regional ranking. Does not support viewing player profile.
Save backup	Support save/load via an Account system. Support password and username changes. Support logging out.
Titles	Static full-unlock and setting titles via "Status".
Mission	Basic automatic song unlock after reaching in-game levels. Everything else is not supported.
Friend	Not supported.
Progress Grid	Not supported.
Additional features	Account/device whitelisting and banning, batch download API, user center, admin panel, MFA authentication modes

Download

Server download: Download the project as zip. To do so, click the green Code button on the top, then Download ZIP at the bottom of the popup.

Asset download: MEGA Google Drive Baidu(code: aaaa)

If you'd like to upload it somewhere else and contribute the link, please contact #AnTcfgss or QQ 3421587952， thanks!

Download common.zip and a platform of your choosing. Unzip the folders within to the private server root directory. If in doubt, check the File Structure section at the end.

GC4MAX Expansion and Extra Challenge Expansion

To install the GC4MAX Expansion (which includes the Extra Challenge Expansion), which ports arcade exclusive tracks, avatars, and skins to 2OS, download the 4max expansion folder's common.zip and a platform of your choosing. Unzip the folders within to the privates server root directory. Overwrite existing files. Note that the included installation apk or ipa must be used for correct avatar rendering.

Edit config.py's MODEL, TUNEFILE, and SKIN value to match the pak's timestamp. paks can be found at /files/gc2/.

Important: You must use the common.zip inside the 4max expansion folder, not the common.zip in the root directory.

⚠️For players/servers already equipped with the 4MAX expansion, updating to the EX expansion means that your play results will be offsetted. While the server side can be corrected with a script in various-tools, your local save can't. The only way to fix this would be to clear your local and cloud save. Please beware.

Details

Because of a duplicate song, and 2 AC Alts being misplaced into 4MAX normal roster, the song list has changed order. As a result, your old play result would no longer match the song list. There is another solution - that is, to leave the 3 songs blank and hide them on both client and server side. However, since the remaining song list capacity is minimal (12 left), and the resulting code changes will pigeon-hole the 4max server code, resulting in discomfort in development later down the line. As a result, I chose to sacrifice the old user's save file. Sorry about that.

Updates

The GC4MAX expansion will receive updates to fix bugs. You can check the latest version by going to the ingame shop - songs page - GC4MAX banner after purchasing the expansion. A server restart is required to fetch the latest update.

The server owner must install the update on their instance. They can download it through the usual links. Simply download the update-vx.zip and unzip the content to the server root directory. Make sure to check the timestamp of the latest pak files and update them accordingly inside the config.py. A server restart is required after the installation.

Dependencies

• Python

• Flask Starlette

• Crypto (pycryptodome)

• bcrypt

• requests

• openpyxl (For data export feature)

At the Start

First, you need to set up the server. Use the Setup the Server First section.

Next, there are 2 ways to set up the connection. Pick one.

1. Proxy. Requires more setup, but the install package can remain unmodified.

2. File modification. Easier setup, but file edit is necessary.

For method 1, use the Instruction for Use (for official client) section.

For method 2, use the Instruction for Use (For modified client) section.

Setup the Server First

PC/MAC (Easier)

Download the server and assets, and extract everything according to the Download section.

Install python and pip on your PC/MAC.

Note that MAC uses python3. Code examples in this document will use the default of Windows, which is python. After the installation, install dependencies using pip install ....

Open command on Windows (MAC open terminal). Type ipconfig (MAC ifconfig), and obtain your IPV4 address. This assumes that you are connected to a WIFI, and it should start with 192 or 172.

Open the config.py of the private server, and change the IP accordingly.

Type cmd in the file directory on the top of the file explorer, and press enter. A command prompt will be opened for that directory.

Type pip install -r requirements.txt to install all the dependencies.

Type python 7002.py to start the server. If an error pops up, resolve it now – did you install all the dependencies? Is the IP correct?

Android (Harder)

Details

Install Termux.

Type the following commands.

termux-setup-storage

pkg install python

Use

pip install ...

to install rust, starlette, passlib, pycryptodome, requests.

If ssl errors pop up, you might need to pkg up ssl -y.

Copy the server to phone, or upzip the server files on the phone. (Skip the iOS files if not needed, it takes up a lot of space)

change config.py's IP to 127.0.0.1 (this is loopback. Feel free to use your android device's IPv4 via ifconfig if you are connected to a WIFI, to enable the server to the entire network).

cd storage/shared/.... (server location on android file system)

python 7002.py to start the server.

iOS (Hard)

Details

I did some research on Pythonista and it seems possible, but you are on your own for this one.

Instruction for Use (for official client)

Details

Android

For android 9+ devices, you need to bypass https in order to MITM the connection between game client and server. If you have root, you can install Certificate Authorities to system level, allowing the device to trust it. If you don't have root, I don't think it is possible and you might have to modify the client.

I will demonstrate the VProxid + Charles method.

Install VProxid on your android device.

Install Charles on your Windows PC. Charles has a free trial period, but there are ways to register it for free. Please do your own research on that subject.

Your server should already be running.

Install Charles Certificate Authority on your android device by going to Charles UI top bar: Help – SSL Proxying – Install Charles Root Certificate on a mobile device. Follow its instructions. Install the downloaded certificate on the android device. Follow this guide to move the user-level certificate to system level. Once done, go to the android device's system setting – certificates, and double check that Charles certificate appears at the bottom of the system certificates.

In Charles, open top bar: Proxy – Proxy Settings. Enable SOCKS proxy on port 8889. Enable http proxying over socks, include default ports.

Then, in top bar: Tools – Map Remote, map a URL to your Server IP address:port, under http. The URL is: https://gc2018.gczero.com.

On your android device, open VProxid. Create a new profile, with the server being your computer’s IP, port 8889, type socks5, and select GROOVE 2 using the app selector. Once created, click the play button on the profile to activate it.

Make sure the private server is running on your PC. Make sure Charles acknowledges the connection from the device. Make sure VProxid is running. Make sure your phone and laptop are under the same network. Start the game, and ovserve the server.

iOS

I did not test this method on iOS. If you know how to proxy stuff there, feel free read the Android guide and try the equivalent on iOS.

Instruction for Use (For modified client)

Details

Android

Download the apk file from the link's install packages folder. Install it. For Android 14+ devices, you might need to use lucky patcher to rebuild the app (Menu of Patches - Create Modified APK File - APK with changed permissions and activities - toggle Removes integrity check and signature verification and Re-sign with original signature for android patch "Disable .apk Signature Verification").

This apk has been modified. If you'd like to edit it on your own, see the last paragraph.

Open the game's obb with password eiprblFFv69R83J5, and extract all the files. Or, download the extracted folder from the link's install packages/main.76.jp.co.taito.groovecoasterzero.obb.

Open settings.cfg with your text editor, and change serverUrl to your server's http://ip:port/.

Use WinRAR or 7-zip to compress everything within the folder with the original password. Use ZIP legacy encryption for WinRAR, ZipCrypto for 7-zip。Name the compressed zip to main.76.jp.co.taito.groovecoasterzero.obb.

Paste (overwrite) the obb already inside Android/obb/jp.co.taito.groovecoasterzero. If the folder does not exist yet, you need to create it manually.

Open the game and observe the server output.

(The provided apk has the following modifications. Skip if you are not interested in it)

By modifying the apk's obb verification function and obb's settings.cfg, you can connect to the server without using any proxy software. To do so, decompile classes.dex using your favorite smali decompiler, and go to jp.co.taito.groovecoasterzero/BootActivity. Delete the part in e() where the loop is checking for a size, and, if mismatch, override a variable that causes the code to branch into DownloadActivity. We want the game to load the obb regardless of its size.

iOS

Download the ipa package from the link's install packages folder.

Open the ipa file with your favorite zip viewer。Go intoPayload,GROOVE 2. extract settings.cfg.

Open settings.cfg with a text editor，Edit serverUrl to your server's http://ip:port/.Dragsettings.cfg back into the ipa。

Sideload the ipa. Open the game, and observe the server.

Admin Functionalities

Database can be opened with DB Browser.

If you want to make your service only available to whitelisted devices, turn on AUTHORIZATION_NEEDED in config.py and add the device id after the .php request to the whitelist table. If you want to ban a device/taito ID, add the device ID or the username of the taito ID to the blacklist table. The reason column is for your own reference. If a device is logged in to that Taito ID, they cannot download asset, cannot log out, and cannot change name. If a device is not in the whitelist (if enabled) or is banned by device ID, they will not be able to download anything.

getCrypt.py is a standalone script used to decrypt the mass inside the GET requests.

QOL Features

Save file migration

A save_id will be generated upon saving the data to the server. It is available at your user page. You can share it, or input someone else's save_id, to have their save file applied to your record.

Note that your old record is not backed up. Thus, this feature should only be used to migrate your own save file, or some save file that you trust.

Web User Center

A simple web center can be accessed at host:port/login. Log in with your in-game account username and password.

A row will be created in webs table. Configure the permission to 2 to gain the ability to access the admin panel host:port/admin. There will be a redirection button in the user center.

The user center is fairly crude for now, and only support one feature: User data migration. You can download your own account, devices, results, and bind if any, via an excel sheet. These data can then be manually imported into other databases, or stored for safekeeping.

The admin panel supports basic CRUD actions to the database tables. Perfect for maintenance in a pinch.

Coin Multiplier

A coin multiplier [0, 5] can be set by the user in the user center.

That's about it actually

Asset Batch Downloading

Since this game features tons of downloadable music and stage files that cannot be natively acquired, a flutter app has been programmed to download all the files using a server API endpoint. the package can be resigned to have the same app id and signature, thus allowing overwrite installation with the game. It supports both Android and iOS.

In the database's batch-token table, create a token manually.

Implementation Detail

Account System

For 7003:

While ownership is stil tied to devices, the ability to log in to multiple devices means that the ownership data (stage, avatar) is now aggregated across devices. Coins and items are still device-specific.

For 7002 and prior:

Account is only used for save file saving/loading (song ownership and coins are tied to devices. However, songs unlocked in the save file will remain unlocked on a new device). Unlike the official version, you can rename and log out of your account. However, only one device may be connected to an account at a time. The old device will be logged off if a new device logs in.

Ranking System

I speculate that the official server's behavior hinges upon the fact that you cannot log out of your account, and that there is a maximum device count (6). This means that each account is connected to 5 devices via foreign keys, and the owned entitlements (stages, avatars, etc) and play records can be tallied.

In the private server, you can log out of devices with ease. This means that song ownership and results are not possible to remain consistent, unless we treat account as devices, which is clearly not the offical behavior.

Update for 7003: The above is true, and to make multiple device login possible, I had to make the choice to either disable guest result submission & ranking, or disable logouts.

With changes to the data structure, if you are not logged in to an account while submitting a score, your result will not be saved.

Title is still tied to account, if possible. While accounts can have avatars, in individual song ranking, the result's play avatar is used (since avatars have effects).

For 7002 and below:

With the current setup, if a device is playing with an associated account, the account information is saved at the same time and will continue to be shown on ranking in the future. The Avatar information is saved with the play records and will not follow the account or device. The Title information is not in the play records, nor in the account, so it will be tied to the Title of the device.

Ranking Data

A rather comprehensive data scrape was conducted prior to the server shutdown, containing at least first 99950 ranks of any given song. The data and metadata can be acquired at Google Drive

Note that this data is for analytics only, and the functionality to embed this data inside the private server is not and will not be supported by me. Feel free to Fork and create your own implementation.

Migration from 7002 to 7003

This is still experimental, always make backups!!

1. Get db-conv.py, copy your 7002 player.db, put it in a new folder with the script, and name it player_d.db.

2. Run db-conv.py. Depending on the amount of records, this could take a while.

3. Place the generated player.db and save folder into the 7003 server directory.

4. Move the asset files according to the folder structure.

Done.

Features and improvements:

1. Multi-device logins are supported. Configure in config.py.

2. Asset and API authentication via device ID, email, and discord verification (discord bot not included)

3. Client-rendered shop, ranking, and status for more features, robust caching, and user experience.

4. Save data outside of database (massive size savings)

5. Web user center (more features to come)

6. Enhanced performance and security, and more that I cannot remember at the time of writing.

Features lost:

1. Guest result will not be recorded, ranked, and displayed.

中文

简介

此项目的目标是保持游戏的长远可用性 (game preservation)。在具体实施上，我采取了一些便利及创意性的措施（偷懒）。此项目的目标不是确保 1:1 还原官服，而是保证游戏长久可玩。此项目在GPLv2许可证的“按现状” (as-is) 条件下提供。

此服务器已经重写多次，以让屎山代码消失提升性能和功能。最新版为7003. 如想迁移，请直接参考版本迁移章节。

你应对因运行本服务器而产生的任何潜在后果承担全部责任。如果您不同意这些要求，则不允许您复制或运行该程序。

灵感: Lost-MSth/Arcaea-server

鸣谢: Walter-o/gcm-downloader

警告：不要将私人文件放至私服内的文件夹里。自带的文件夹内所有文件都可被私服抓取！安全性和效率无法保证，不建议在公网上搭建。这不是强制要求，不过别怪我没提醒过你。

支持的功能

功能	支持程度
文件下载	.pak, 谱面及音频zip文件
商店	用GCoin购买单独的歌曲，头像，和道具。 GCoins可通过玩游戏来获得。不支持音频预览。不支持曲包。
排行榜	每首歌曲/难度的单独排行榜。总分排行榜。不支持地区排行榜。不支持查看其他玩家的详细信息。
存档备份	支持通过账号系统的保存/加载。支持修改密码和用户名。支持登出。
Titles	通过Status观看并使用全解锁的Titles。
任务	支持达到游戏内经验等级后歌曲自动解锁。其他功能均不支持。
好友	不支持。
进度表	不支持。
其他功能	账号/设备白名单和封禁，批量下载API，网页用户中心和管理员面板，多重验证模式。

下载

服务器下载：将此repo以zip形式下载。点击上栏绿色的Code按钮，然后点击弹窗下面的Download ZIP按钮。

资源下载：MEGA Google Drive Baidu(密码aaaa)

如果你想将资源备份到别的网盘并贡献链接，请联系#AnTcfgss or QQ 3421587952，感谢！

下载 common.zip 和您设备的平台。将里面的所有文件夹解压到服务器根目录。如有疑惑，请参照文末文件结构章节。

GC4MAX扩展包和Extra Challenge扩展包

如想下载GC4MAX扩展包（内含Extra Challenge扩展包）（包含了街机独占曲目，皮肤，和角色），下载4max expansion里的common.zip和和您设备的平台。将里面的所有文件夹解压到服务器根目录。如有重复，覆盖所有文件。请注意，必须使用包含的apk或ipa安装包来正确渲染角色。

修改config.py的MODEL, TUNEFILE, and SKIN 值至现有pak文件的时间戳. paks文件的位置在/files/gc2/.

重要: 必须使用4max expansion文件夹里的common.zip，而不是根目录里的common.zip.

⚠️针对已安装游玩4MAX扩展包的服务器/用户，更新至EX扩展包会造成歌曲游玩记录偏移。服务器端可使用tools里的脚本进行更正，但是本地存档将无法更正。唯一解决方法为清空本地和云存档。敬请注意。

细节

由于一首歌曲重复，两首AC Alt误放至4MAX正常曲目中，歌曲列表发生了偏移。你的游玩记录会跟着偏移。其实有一个解决办法，就是把这三首位置留空，然后在本地文件和服务器端隐藏他们。不过，鉴于总曲目限制所剩无几（仅剩12首），以及所带来的代码更新会将4MAX服务器陷入自己的鸽子洞，造成开发的不愉快，我选择了牺牲老用户的存档。非常抱歉。

更新

GC4MAX 扩展包会不定期接受bug修复更新。你可以在购买扩展包之后，通过游戏内的 shop - songs 页面 - GC4MAX 标题图片 来查看最新的版本。为获取最新的版本更新，服务器应当不定期重启。

服务器拥有者需要在TA的系统上安装更新。他们可以通过以往的链接下载更新文件。下载 update-vx.zip 并将所有内容解压至服务器根目录。确保最新的 pak 时间戳已在 config.py 里更新。安装完成后，需要重启服务器。

环境依赖

• Python

• FlaskStarlette

• Crypto (pycryptodome)

• bcrypt

• requests

• openpyxl (用于用户数据导出)

如何开始

首先，你需要配置服务器。请使用配置服务器。

接下来，有两种方式来设置连接。选一个吧。

1. 代理。需要更多配置，不过安装包不需要修改。

2. 修改文件。配置更加简单，不过。。必须修改文件。

方法1，请使用原版安装包的使用说明。

方法2，请使用改版安装包的使用说明。

配置服务器

PC/MAC(简单)

按照下载章节来下载解压服务器和资源。

PC/MAC安装 python，安装 pip。

注意 MAC 默认为 python3。往后的示例默认用 windows 的默认，即 python。安装完成后，使用 pip install ...安装所有依赖项。

PC打开 cmd 输入 ipconfig。MAC 打开 terminal 输入 ifconfig。获得你的IPV4,一串为192或172开头的数字。

PC用文本编辑器打开服务器文件夹的 config.env，将IPV4填写至IP。PORT(端口)也可以更改。

文件管理器上方的文件夹路径清空，输入 cmd。命令行窗口会弹出。

输入 python 7002.py来开启服务器。如果出现错误，就解决他们吧。检查依赖项是否安装，网络配置是否正确。

安卓(稍难)

细节

安装 Termux.

输入下面的命令。

termux-setup-storage

pkg install python

用

pip install ...

来安装 rust, starlette, bcrypt, pycryptodome, requests.

如果出现ssl问题，可能需要pkg up ssl -y.

将服务器拷到手机上，或者在手机上解压服务器文件。（如不需要iOS文件，就省点手机空间，别拷贝ios的东西了）

修改 config.py 的 IP 至 127.0.0.1 (这是 本地回环。如果连接了WIFI，可以使用ifconfig 获取手机的 IPv4 并填入，以在整个网络下支持私服).

cd storage/shared/.... (服务器在安卓文件系统的位置)

python 7002.py 来运行服务器。

iOS (难)

细节

Pythonista貌似可用，不过我祝你好运。

原版安装包的使用说明

细节

安卓

对于 Android 9+ 设备，您需要绕过 https才能对游戏客户端和服务器之间的连接进行中间人攻击。如果您拥有 root 权限，则可以将证书安装到系统级别，从而允许设备信任中间人软件。若您没有root，此方法可能不可用。

这里展示VProxid加Charles方法。 在您的Android设备上安装VProxid。 在Windows PC上安装Charles。 Charles有免费试用期，但有多种方法可以免费注册。 请对此主题进行自己的研究。

你的服务器应该已经在运行。

在您的Android设备上安装Charles 根证书：Charles用户界面顶栏：Help – SSL Proxying – Install Charles Root Certificate on a mobile device. 按照其说明进行操作。Android设备上安装下载的证书。请按照此指南将用户级证书移至系统级。 完成后，转到系统设置 - 证书，仔细检查Charles证书是否出现在系统证书页面底部。

在Charles中，打开顶部栏：Proxy – Proxy Settings。 在端口8889上启用SOCKS代理。打开http proxying over socks，配置默认端口。

然后，在顶部栏中： Tools – Map Remote，将如下URL映射到服务器IP:端口（http协议）。URL为：https://gc2018.gczero.com。

在您的Android设备上，打开VProxid。创建一个新的配置文件，服务器为您计算机的IP，端口为8889，类型为socks5，然后使用应用程序选择器选择GROOVE 2。 创建后，单击配置文件上的播放按钮将其激活。

确保您的PC上正在运行私服。 确保Charles提示并正在接收来自设备的连接。 确保VProxid正在运行。 确保您的设备和电脑在同一网络下。 开始游戏吧。

iOS

我不了解iOS系统，如果你了解ios的代理软件，可以阅读安卓部分，然后照葫芦画瓢（

改版安装包的使用说明

细节

安卓

下载网盘里install packages里的apk文件。安装。安卓14+ 设备可能需要用幸运破解器重构APK (Menu of Patches - Create Modified APK File - APK with changed permissions and activities - 打开 Removes integrity check and signature verification 和 Re-sign with original signature for android patch "Disable .apk Signature Verification" 有人反馈中文路径如下：点 破解菜单 然后点 已更改权限和活动项的APK文件 )。

(已获得授权，感谢@SaltNyaako)

此apk被修改过。若想自己修改,请看最后一段。

打开游戏的obb，密码是eiprblFFv69R83J5。提取全部文件。或者，从网盘下载install packages/main.76.jp.co.taito.groovecoasterzero.obb.

用文本编辑器打开settings.cfg，将serverUrl改成私服的http://ip:端口/。

用WinRAR或者7-zip压缩全部文件至zip，用密码加密。用ZIP legacy encryption/ZipCrypto。名称为main.76.jp.co.taito.groovecoasterzero.obb.

覆盖Android/obb/jp.co.taito.groovecoasterzero里的obb文件。如文件夹不存在，需要手动创建。

打开游戏，观察私服的输出。

（提供的apk已经执行了如下的修改，可以忽略）

你可以通过修改apk里的obb校验函数然后修改obb里的settings.cfg来直连私服，无需中继软件。用顺手的smali反编译器来反编译classes.dex，然后去jp.co.taito.groovecoasterzero/BootActivity。删除e()里循环检查文件大小的部分。这部分会检查obb文件的大小，如果不一致会修改一个变量跳至DownloadActivity。我们想强制游戏读取。

iOS

下载网盘里install packages里的ipa文件。

将ipa用压缩包软件打开。进Payload,GROOVE 2. 将settings.cfg提出。

文本编辑器打开settings.cfg，将serverUrl改成私服的http://ip:端口/。将settings.cfg拖回ipa。

侧载ipa即可。打开游戏，观察私服的输出。

管理员功能

数据库可以用DB Browser打开。

如果你想只对在白名单里的设备提供服务，开启config.py里的AUTHORIZATION_NEEDED，并将.php请求后面的设备ID加入whitelist列表。如果你想封禁设备或者Taito ID，将设备ID或者用户名加入blacklist列表。reason列可供你记录封禁原因。如果设备登陆该Taito ID，它将无法下载数据，不能登出，而且不能改名。如果设备在白名单开启后不在白名单里，或者设备被封禁，它将无法下载任何东西。

getCrypt.py 是一个用来单独解密GET请求后缀的脚本.

质量更新

存档迁移

一个 save_id 会在保存数据时生成，可在用户中心复制。你可以分享它，也可以输入别人的 save_id 来将他们的存档覆盖到你自己的账号下。

小心，你的旧存档不会被备份。因此，此功能仅适合来迁移自己的存档，或者迁移受信任的存档。

网页用户中心

及其原始的用户中心，可通过host:port/login访问。使用游戏内账号和密码登录。

webs表将自动填充。将permission设为2来给予在host:port/admin的管理员面板访问权限。用户中心也会多出一个跳转按钮。

目前功能单一，只支持用户数据导出功能。你可以通过一张xlsx表获得自己的账户，设备，结果，绑定信息(如有)。这些数据可以手工加入其他的数据库，或者用于备份。

管理员面板支持数据库表基础CRUD，可以解燃眉之急。

管理员平台

一个数据库增删改查网页在/Login。先在数据库admins表创建自己的账号和bcrypt密码哈希。

金币倍数调整

你可以在用户中心调整获得的金币倍数 [0, 5]。

嗯就这些（

资源批量下载

由于这款游戏包含大量无法通过程序自身自动获取的可下载音乐和谱面文件，因此已开发了一个 flutter 应用程序，通过服务器 API 接口下载所有文件。该包可重新签名以使用相同的应用程序 ID 和签名，从而实现与游戏的覆盖安装。该应用支持 Android 和 iOS 系统。如想添加下载token，请至batch_token表添加。

系统实装

账号系统

7003新增:

虽然歌曲和头像依然和设备绑定，因为支持多设备登录，单账号的解锁项将从所有已登入的设备集合。金币和items依然和设备绑定。

7002及之前版本:

账号仅用于保存/同步存档。Gcoin和歌曲所有权和设备绑定。不过，存档中已经解锁的曲目将在新的设备上可用。官方版不允许重命名及登出账号。私服则可以进行这些操作。不过，一个账号只能同时登陆一台设备，如果登录第二台设备，第一台设备将被挤掉。

排行榜系统

我推测官方服务器的行为取决于一个事实，即你不能注销你的账号，而且有一个最大设备数（6）。这意味着每个账户通过 foreign key 连接到 5 个设备，这样就可以统计所有拥有的 解锁（曲目、头像等）和游玩记录。

在私服，用户可以任意注销设备。这意味着解锁和游玩记录不可能保持一致，除非我们把账户当作设备，而这显然不是官服的行为。

7003新增：

以上推论基本属实。在实装多设备登录时，必须做出妥协：停止游客的成绩上传和排行，或者禁止登出。

此版本修改了数据结构，在没有登入时，游玩结果不会被保存。

Title的获取位置依然是账户，头像依然和游玩记录，因为其特殊效果。

7002及之前版本：

目前的设置下，假如一台设备游玩时有关联账户，账户信息会同时保存，并且未来将持续显示当时连接的账户信息。头像信息随游玩记录保存，将不跟随账户或者设备。Title信息不在游玩记录里，也不在账户里，所以将和该设备的Title绑定。

排行榜数据

在停服前完成了一次较完整的数据抓取。每个难度的前99950位均被保留。数据和元数据可在这里下载。 Google Drive

请注意，此数据仅用于分析，私服内置不会被实现。如果有需求，请Fork然后自行设计。

版本升级（7002到7003）

仍在试验中，谨记备份！！

1. 获得db-conv.py, 把7002的 player.db 复制到同一个文件夹并重命名 player_d.db.

2. 运行db-conv.py. 如果数据较多，可能需要一段时间执行。

3. 将生成的player.db和save文件夹放至7003服务器文件夹。

4. 将新的数据文件根据文件夹结构移入。

完成。

功能和改善：

1. 支持多设备登录，可在config.py配置。

2. 基于设备ID，电子邮件，和Discord的素材和API鉴权 (不包含discord机器人)

3. 客户端渲染的商店，排行榜，和状态页面。提供了更多功能，更强大的缓存，和更好的体验。

4. 存档外置，缩小数据库。

5. 网页用户中心(更多功能TBD)

6. 改善性能和安全性，以及现在想不起来的一些东西

失去的功能:

1. 游客游玩记录将不记录，不排行，不显示。

File Structure 文件结构

server/
├─ files/
│  ├─ gc2/
│  │  ├─ audio/ (found in android/ios.zip)
│  │  │  └─ ogg and m4a zips
│  │  │ 
│  │  ├─ stage/ (found in android/ios.zip)
│  │  │  └─ zip files for stage
│  │  │ 
│  │  └─ pak/ (found in android/ios.zip)
│  │     └─ model/skin/tunefile.pak(found in common.zip)(actual paks)
│  │  
│  ├─ gc/
│  │  └─ model1/skin1/tunefile1.pak(found in common.zip)(placeholder/unauthenticated paks)
│  │  
│  ├─ image/ (found in common.zip)
│  │  ├─ icon
│  │  └─ title
│  ├─ web/ (found in common.zip)
│  │  └─ webpage assets, including javascript/css found in this repo
│  │  
│  ├─ 4max_ver.txt (for 4max pack versioning, optional)
│  └─ various xml templates (found in this repo)
│ 
├─ 7003.py (main script)
├─ config.py (configuration script)
│ 
├─ api/ 
│  ├─ config/ (various configuration files)
│  └─ various .py (API scripts)
│  
└─ old_servers (old server (depricated))

Journal

I've been forcing myself to document the process for personal project. So here goes.

English

Project Taiyo started on Feb. 19, 2024, as the effort to create a private server for Groove Coaster 2: Original Style. No prior effort was spent on the game, since the save file acquired from lp did unlock the majority of the track.

However, as updates slowed down and Groove Coaster 4max is scheduled to shut down, time were allocated to investigate the viability of a private server. Asset scraping was tedius as each song has multiple downloadable files, and there is no naming convention. Every zip file was acquired by hand(!) via manual downloading, which was soon proven unnecessary with the discovery of gcm-downloader.

The obb's decryption key was discovered in the android executable's lib file, and, during investigation of a config file within the obb, the server's address is directly editable. On the iOS, this config file is within the ipa. A proxy can be setup to mitm traffic for the same result. A simple server that handles asset delivery and static full-unlock profile was quickly developed.

An account system was developed that facilitates the save/load feature. The server request's GET field is encrypted, and, initially, the key and encryption method was not found. However, due to CBC encryption's flaw, part of the encrypted mess can still be used to identify users. Later, the key and IV to decrypt request was found in gcm-downloader, and used to implement a correct implementation of the server.

Besides the above features, all other functionality remains unimplemented. This was completed within a week (shorter than what is ideal, given project OverRide's priority). Some effort was spent on documenting the scraping, setup, and scripting, uploaded to a github repo, and the MVP is shelved.

In Janurary 2025, renewed effort was put on the project as Taito announced the cease of additional DLC, after a lackluster 2024 season. Groove Coin, a removed feature in-game, has been revived to facilitate a shop system. No longer is the server delivering static full-unlock save file, but the user can now acquire their own content in a balanced progression.

Additional effort was put on researching and REing various aspect of the game. 5 removed songs were re-enabled by lib editing, later via stage_param edit. Effort was spent on scripting a .pak unpacker and packer, which is successful and allow us to create own .pak files for delivery.

Effort was spent on the PC and Switch (waiwai) port, investigating the possiblilty of chart porting to Mobile. Switch version uses a significantly different system, charts lack critical elements and music is stored in header-removed opus. Porting from switch is deemed hard.

The PC version has exclusive songs/packs, and the chart/model files are an exact match from mobile asset. Music is in header-appended OGG, which is also compatible with Mobile. Porting is technically feasible if the format of stage_param can be RE'd.

On Jan. 24, 2025, Taito announced the end of service of the game. This prompted the creation of this repo and release of private server.

Effort was spent on porting charts from the arcade port (4max) to 2OS, and this process has been automated. The work and related tools has been added to the repo.

Additional avatars and skins were ported, but a 256 hard amount limit was encountered for avatar, after addressing a 200 soft limit.

Leaderboard ranking was scraped as a dataset just prior to the server shutdown and added to the repo.

Taito shutted down the server on March 31st, 2025, marking the completion of project Taiyo.

Overall, the project was a resounding success. The initial goal of creating a feature-rich private server was accomplished, with bonus points such as the toolchain, 4MAX expansion, and leaderboard dataset. If we were to nitpick, the save data hard limit was not addressed, various promotional material was not acquired from the server, and the leaderboard was not completely scraped.