WebAssembly in MineCraft Fabric Mod

Requirements:

• Minecraft 1.17.1
• Fabric https://fabricmc.net

Setup

Download the file fabric-wasmcraft-mod-1.0.0.jar from releases and copy to your MineCraft mods folder.

Using

To run a WASM module in MineCraft first place a wasmcraft block.

Once the block has been placed you can right click on the block to bring up the configuration menu.

In this menu configure the name of the module you would like to load (filepaths are relative to the MineCraft folder).

Set the module name if using multiple modules.

Configure your parameters, If the parameter is a string, Wasmcraft will automatically attempt to write this to the modules memory. This feature requires the module to expose the functions allocate and deallocate, please see the example Go ABI for more info (./examples/go_complex/abi/abi.go)

Configure the expected value, all functions that are executed by WasmCraft require that the function has a return value. This can either be a String pointer or a simple I32.

Finally press the run button and esc to dismiss the menu. If the function executed correctly and the exepected value matches the value returned from the function the block will change to a green smily face.

Example modules

Go

Go Simple ./examples/go_simple

Simple Go module with Wasi compiled with TinyGo

Go String ./examples/go_string

Example showing how to interact with Wasm memory allowing complex types

Go Complex ./examples/go_complex

Example implementing AES encyption and decryption as a WASM module. Leverages WASI filesystem.

AssemblyScript

./examples/assemblyscript

Various examples including writing and reading to WASM memory and complex types

Rust

./examples/rust

Various examples showing complex types, host functions and imported module functions

References

• wasmtime-java https://github.com/kawamuray/wasmtime-java
• TinyGo https://tinygo.org
• Wasmtime docs https://docs.wasmtime.dev
• WASI - https://github.com/WebAssembly/WASI
• WASI Networking - WebAssembly/WASI#312