SerendiModGuarder
by Sanno
Servers that want to block unauthorized client mods can use SerendiModGuarder, a Fabric mod that checks each joining player's client during login and play.
What it does
SerendiModGuarder is a Fabric mod that detects players who run client-side mods the server forbids. The check combines three layers: a SHA256-signed query at login, a push of the mod list during play, and a delayed scan of plugin channels. The mod list is signed with SHA256 and a server nonce, so a client that alters the list is flagged as tampered.
Both the server and every client must install the mod, because the environment is client and server. Its configurable login query timeout defaults to 10 seconds, and clients that do not answer in time are kicked. Kick and timeout messages can be set separately. The configuration can be reloaded with a command, so changes apply without a restart, and an inspection command shows the verification state and plugin channels of each player.
The mod is open source under the GNU General Public License v3.0 only. It is published for Fabric alone, with 18 release versions covering 1.20.6 – 26.3. The latest file is 1.5.3 for 26.3, released 2026-10-04.
Key features
Three-layer detection
Login query, play-phase push and a delayed channel scan work together to catch forbidden client mods.
Signed mod list
The client's mod list is signed with SHA256 and a server nonce, so altered lists are detected as tampering.
Login query timeout
A configurable timeout, 10 seconds by default, kicks clients that do not answer the login query.
Hot reload
A reload command applies configuration changes to the running server without a restart.
Manual inspection
An inspection command shows the verification state and plugin channels of connected players.
Custom messages
Kick messages for a missing mod and for a timeout can be written separately.
Gallery
Compatibility
Latest build for each game version and loader.
26.x5 of 5 versions with builds
1.21.x12 of 12 versions with builds
1.20.x1 of 1 version with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Who it’s for: Server administrators who want to enforce a client mod list on a Fabric server. Players need the mod too, so the rule applies to every joining client.
How it compares
ValiMod is a Fabric mod for client and server, under the MIT License, with files for 1.20.4 – 1.20.6, and it is not open source. Sentinel&ModGuard is a client-side only Fabric mod with All rights reserved, published for 1.21 – 1.21.11. Serverauth Mod runs on the server alone, is under the MIT License and covers 1.20 – 26.1.2.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| SerendiModGuarder | Fabric | 1.20.6 – 26.3 | Client and server | 2026-10-04 |
| ValiMod | Fabric | 1.20.4 – 1.20.6 | Client and server | 2026-07-25 |
| Sentinel&ModGuard | Fabric | 1.21 – 1.21.11 | Client-side only | 2026-03-08 |
| Serverauth Mod | Fabric | 1.20 – 26.1.2 | Server-side only | 2026-07-20 |
Questions
Does SerendiModGuarder need to be installed on the client?
What happens when a client does not answer the login query?
Which game versions does SerendiModGuarder support?
In the catalog
SerendiModGuarder is one of 8,016 Management mods on ModsFinder, and one of 5,930 Management mods for Fabric. 8,071 mods support Minecraft 26.3.
More from Sanno
Similar mods
What the author says
SerendiModGuarder is a Fabric mod that detects and blocks players using forbidden client-side mods. Both server and client must install this mod. SerendiModGuarder 是一款 Fabric Mod，用于检测并拦截使用了违规客户端 Mod 的玩家。服务端和客户端都必须安装本 Mod。
Official listing
- Modrinth page
- modrinth.com/mod/serendimodguarder
- Owner
- Sanno
- Published
- 2026-07-12
- Updated on Modrinth
- 2026-10-04
- Facts verified
- 2026-10-15