Marmot

Name: Marmot
Author: chxll

Marmot is a Fabric library by chxll that gives server creators tools for customizing their servers and gives mod developers a camera and input API on the client.

FabricClient or server, optionalMIT LicenseOpen source1.21.8 – 1.21.10

What it does

Marmot provides server-side and client-side hooks for building custom UI rendering, camera control and accurate mouse click events. Developers can change camera pitch, yaw and roll, adjust the field of view on the client, and lock the F5 third-person toggle. Click events are sent from the client to the server, which allows real-time click tracking systems to be built on top of the library.

The library is meant for server owners and mod developers who need more control over what the player sees and how input is read. Either side can run it, and neither needs it, so it works on a client alone, a server alone or both. It requires Fabric Language Kotlin, and it is open source under the MIT License. Builds exist for Fabric only, for 1.21.8 and 1.21.10, with 1.3.4 for 1.21.10 as the latest file, published on 2025-11-30.

Key features

Custom screen rendering
Custom UI rendering on the server and client lets mods draw their own screens and overlays.
Camera control
Camera pitch, yaw and roll can be set on the client, along with the field of view.
Precise click events
Mouse click events are reported accurately, and clicks can be forwarded to the server for tracking.
Locked third-person view
The F5 camera toggle can be locked, so a mod can keep the player in one view.
Developer API
A documented API exposes these camera, input and rendering hooks to other Fabric mods.

Gallery

An example of forced keybinds on a server.

Compatibility

Latest build for each game version and loader.

Version

1.21.101.3.4

1.21.81.2.15

ReleaseBetaAlphaNot available

Only full game releases are shown. This mod publishes no snapshot builds.

Requirements

Dependencies declared by the latest file for each loader.

Required 1

Fabric Language KotlinThis is a mod that enables usage of the Kotlin programming language for Fabric mods.

Required

Use cases

Server customization

Server owners can build custom interfaces and click-driven systems that players interact with directly.

Real-time click tracking

Click updates sent to the server allow tracking systems that react as players click.

Who it’s for: Mod developers building Fabric content that needs camera or input control, and server creators who want custom client-facing interfaces. Players on vanilla-style servers can ignore it.