
Sync Client Server (SCS)
A mod that simplifies server management by keeping client mods and configs in sync with one in-game update button.
Screenshots

About this Mod
Sync Client Server (SCS)
With a single in-game Update button directly in the multiplayer server list, players can download the mods and configs required by the server in a simple and reliable way.
📸 Preview

🎯 Goal
SCS aims to simplify server administration and improve player experience by making modpack updates clear, predictable, and user-friendly, without requiring external launchers or manual file management.
✨ What SCS Can Do
- In-game Update button in the multiplayer server list
- Confirmation screen with update summary and Clear cache option
- modId-based synchronization to prevent duplicated or outdated mods
- Optional synchronization of
/configalongside/mods - Optional mirror mode for
/modsand/config - Server-enforced removal of specific client mods
- Per-server isolated cache
- Built-in lightweight file server to host
mods.zipandconfig.zip
⚠️ Important:
- Mod updates require a game restart to take effect
- Config updates do NOT require a restart and are applied immediately
🎮 Client Usage (Simple & Automatic)
The client workflow is intentionally minimal.
1️⃣ Add the server
- Add the server normally in the Multiplayer screen
- The Download URL field is automatically filled using the server address and port
- You may override it manually if needed
Example:
http://myserver.com:25566
2️⃣ Update the client
- Select the server in the list
- Click Update
- Review the summary and confirm
That’s it.
Restart the game only if mods were updated.
🧹 Clear Cache
Use Clear cache from the confirmation screen if:
- A download fails
- The client becomes out of sync
- ZIP contents changed but no update is triggered
- Other unexpected behaviors
Cache is isolated per server and safe to clear.
🖥️ Server Usage (Admin Guide)
1️⃣ Install and start
- Install SCS on the server
- Start the server once to generate the config file
2️⃣ Common Configuration
Config file:
config/scs-common.toml
Default values:
fileServerPort = 25566
updateConfig = true
mirrorMods = false
mirrorConfig = false
Explanation:
fileServerPort
Port used by the built-in file server (default:25566)updateConfig
Enables client config updates (enabled by default)mirrorMods/mirrorConfig
Disabled by default. When enabled, client folders are forced to exactly match the ZIP files
Because updateConfig is enabled by default, server admins can push new configuration changes to clients, such as enabling or disabling mirror options.
3️⃣ Creating the update packages
Option A: Using in-game commands
On the server, run:
/scs save-mods
/scs save-config
This generates:
mods.zipconfig.zip
Option B: Manual ZIP creation (advanced / recommended for control)
Admins may manually create or edit:
mods.zipconfig.zip
This allows:
- Shipping only specific mods or configs
- Full control over update contents
Both methods are fully supported.
4️⃣ Removing client mods (server-enforced)
To force the removal of specific client mods:
- Create a file named:
modsToRemoveFromTheClient.json
- Place it inside
mods.zip - List the
.jarfilenames to remove
Example:
[
"examplemod1.jar",
"examplemod2.jar"
]
These mods will be deleted from the client during the update.
5️⃣ Built-in File Server
When the server is running, SCS automatically hosts:
mods.zipconfig.zip
On:
<server-ip>:fileServerPort
Default:
<server-ip>:25566
No external web server is required.
📦 Modpack Usage
Feel free to include this mod in your modpack — credits are appreciated but not required.
❤️ Credits & Fork Notice
This project is a fork of the mod MMMMM by Place-Boy.
Original project: https://www.curseforge.com/minecraft/mc-mods/mmmmm
All credit for the original concept and foundation goes to the original author.
Available Versions
How to Install Sync Client Server (SCS) on Your Server
Order Server
Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).
Set fabric Loader
In the panel under "Egg", select the fabric loader and matching Minecraft version (1.21.1).
Install Mod
Open the mod browser in the dashboard and search for "Sync Client Server (SCS)". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
1.21.1, 1.20.1
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
Sync Client Server (SCS) server crashes on startup – what to do?
Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.21.1). You can switch loaders with one click in the panel.
Is Sync Client Server (SCS) compatible with fabric and forge and neoforge?
Sync Client Server (SCS) officially supports fabric, forge, neoforge for Minecraft 1.21.1, 1.20.1. Note: Forge and Fabric mods are NOT cross-compatible – pick one loader and stick with it. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with Sync Client Server (SCS) – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Sync Client Server (SCS) consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.
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