Creating a new project

Pumpkin plugins use the Cargo build system.

The complete code for this plugin can be found as a template on GitHub.

Installing the toolchain

Before we can compile a plugin, we have to have the wasm32-wasip2 target installed. You can install the target by running:

rustup target add wasm32-wasip2

Initializing a new crate

First we need to create a new project folder. You can do this by running this command in the folder you created:

cargo new <project-name> --lib

After adding this, we want to create a new directory called .cargo and add in a config.toml file with the following contents

[build]
target = "wasm32-wasip2"

Altogether your new folder structure should look like this:

├── .cargo/
│   └── config.toml
├── src/
│   └── lib.rs
├── Cargo.toml
└── Cargo.lock

Configuring the crate

Since Pumpkin plugins are loaded at runtime as dynamic libraries, we need to tell Cargo to build this crate as one.

Cargo.toml

[package]
name = "hello-pumpkin-wasm"
version = "0.1.0"
edition = "2024"

[lib] 
crate-type = ["cdylib"]

[dependencies]

Next we need to add some basic dependencies. Since Pumpkin is still in early development, the internal crates aren't published to crates.io, so we need to tell Cargo to download the dependencies directly from GitHub.

Cargo.toml

[package]
name = "hello-pumpkin"
version = "0.1.0"
edition = "2024"

[lib]
crate-type = ["cdylib"]

[dependencies]
# This is the api crate that makes creating plugins easier, and has wit definitions
pumpkin-plugin-api = { version = "0.1.0", git = "https://github.com/Pumpkin-MC/Pumpkin", package = "pumpkin-plugin-api" }
tracing = "0.1"

For improved performance and smaller file sizes, we recommend enabling Link-Time Optimization (LTO).
Be aware that this will increase compilation time.

Cargo.toml

[profile.release] 
lto = true

Enables LTO only for release builds.