ProtocolExtension
by Olafcio1
ProtocolExtension gives server owners and players a set of custom packets, sent alongside vanilla traffic, for mods that need a channel the game does not provide.
What it does
Packets are sent in both directions. The server announces ProtocolExtension support to a connected client, and the client replies, so each side knows whether the other can handle the extra data. Once that handshake is done, the mod reports client actions such as key presses outside of special keys, mouse movement on screens, and opening or closing the chat screen. It can also make a click on the F1 key on behalf of the client.
The mod is built on CustomPayload packets and needs Fabric API. It is published for Fabric and for the Paper server platform, so it can run on a Fabric server or on a Paper server. HUD elements that the server creates are removed automatically when a player leaves the server. The project is open source under the zlib License, and a single JAR is used on both the server and the client.
Key features
Server-to-client handshake
The server sends a notice of ProtocolExtension support, and the client answers so both sides confirm the link before extra packets flow.
Simulated F1 click
The mod can send a click on the F1 key on behalf of the client, which lets a server trigger the key action.
HUD cleanup on leave
HUD elements created by the server are removed automatically after a player leaves, so no stale overlays remain.
Compatibility
Latest build for each game version and loader.
26.x4 of 4 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.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Who it’s for: Server owners and mod developers who need custom packets on Fabric or Paper. Players only need the mod when a server or another mod requires it.
How it compares
Firewall is a client or server optional mod under the MIT License, published for Fabric 1.21 – 26.2, and it does not need to be on both sides. ProtocolExtension needs the client and server environment and has files for 1.20.6 – 26.2 on Fabric. PacketDump is client-side only under the GNU Lesser General Public License v3.0 or later, for 1.21.8 – 26.2, so it covers a narrower version range.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| ProtocolExtension | Fabric | 1.20.6 – 26.2 | Client and server | 2026-07-09 |
| Firewall | Fabric | 1.21 – 26.2 | Client or server, optional | 2026-08-27 |
| PacketDump | Fabric | 1.21.8 – 26.2 | Client-side only | 2026-08-04 |
Questions
Does ProtocolExtension need Fabric API?
Do players have to install ProtocolExtension?
Which Minecraft versions have files?
Can older Minecraft versions be requested?
In the catalog
ProtocolExtension is one of 8,016 Management mods on ModsFinder, and one of 5,930 Management mods for Fabric. 13,894 mods support Minecraft 26.2.
More from Olafcio1
Similar mods
What the author says
🏛️ P r o t o c o l E x t e n s i o n extends server possibilities by adding more packets* to the game. Note: If you're using my mods, please do not buy Minecraft.
Official listing
- Modrinth page
- modrinth.com/mod/protocolextension
- Owner
- Olafcio1
- Published
- 2025-11-23
- Updated on Modrinth
- 2026-07-09
- Facts verified
- 2026-10-15