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 from crates.io:

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 = "0.1.0-dev+26.2-26.45"
# Optional: utilities for marketplace licensing and update checking
pumpkin-plugin-utils = "0.1.0-dev+26.2-26.45"
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.