Setting up the development environment

TypeScript

Golem’s TypeScript toolchain uses npm as the underlying build tool. Install Node.js 24.11 or newer and npm 11.6.2 or newer by following the official instructions .

Effect

Golem’s Effect toolchain uses npm, TypeScript, and Rollup. Install Node.js 24.11 or newer and npm 11.6.2 or newer by following the official instructions .

Generated projects include compatible versions of effect and @golemcloud/effect-golem. Keep those versions aligned when updating dependencies; the Effect SDK currently uses Effect 4 APIs.

Rust

Setup Rust

Developing Golem agents in Rust requires a stable Rust compiler (rustc and cargo 1.94 or newer) and the WASM target used by Golem 1.6.

Installing Rust

Use the official guide  to install the latest stable version of the Rust compiler.

$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Enabling WebAssembly targets

With Rust and rustup installed, the next step is to enable the WebAssembly target used by Golem builds:

$ rustup target add wasm32-wasip2

To verify if this step was successful, run:

$ rustup target list --installed | grep wasm32-wasip2
wasm32-wasip2

Golem 1.6 uses the standard cargo build toolchain, so no additional cargo subcommands need to be installed.

Scala

Setup Scala

Developing Golem agents in Scala requires a Java Development Kit and sbt, because Golem 1.6 compiles Scala agents through Scala.js using an sbt plugin.

Installing Java

Install Java 17 or newer (JDK) using your preferred distribution.

Installing sbt

Install sbt by following the official installation guide .

Once Java and sbt are installed, golem build will drive the full Scala.js-based build pipeline for Scala components.

MoonBit

Setup MoonBit

Developing Golem agents in MoonBit requires the MoonBit toolchain and wasm-tools, because Golem 1.6 compiles MoonBit agents to WebAssembly using moon and packages them as components with wasm-tools.

Installing MoonBit

Install the latest stable version of the MoonBit toolchain by following the official instructions .

Installing wasm-tools

Install wasm-tools 1.227.1 or newer by following the official installation guide .

Once moon and wasm-tools are installed, golem build will install the required MoonBit dependencies and drive the full MoonBit-to-WASM build pipeline for MoonBit components.

Go

Setup Go

Golem 1.6 ships Go SDK 0.1.0. Go agents are compiled to WebAssembly components with componentize-go, which each generated component pins through a tool directive in its go.mod.

The Golem Go toolchain

componentize-go needs a Go runtime with patches that upstream Go does not have yet, so Go components are not built with the go you have installed. On the first Go build, the Golem CLI downloads Golem’s patched Go toolchain (based on Go 1.27.1) from golemcloud/go  and uses it for every Go command in the build. Prebuilt toolchains are published for Linux (x86_64 and ARM64), macOS (x86_64 and ARM64), and Windows (x86_64).

Offline builds require the toolchain to be installed already, or the GOLEM_GO_TOOLCHAIN environment variable to point at a Go toolchain built from golemcloud/go .

Installing Go

A regular Go 1.27.1 or newer installation is recommended for your editor, go test, and go vet, but it is not required to build. Install it from go.dev/dl .

Installing wasm-tools

Install wasm-tools 1.227.1 or newer by following the official installation guide . The release build preset uses it to strip components.