Installation

rut is a self-hosting-free, from-source toolchain: one Rust build gives you the rut binary (run / format / pack / dump) plus the language’s in-tree packages, which the engine mounts automatically when you run a standalone file.

Prerequisites

Rust (nightly) — the repo pins an exact nightly in rust-toolchain.toml; rustup installs it on the first build. Any recent rustup works.
git — for the checkout.
Node.js 20+ — only if you want to build or drive the wasm playground (the rest of the book does not need it).

Build the toolchain

From a checkout of the repository:

cargo build --release -p rut-cli

This produces the rut binary at target/release/rut. Put it on your PATH (or call it by path — the pages here use the bare name):

cargo build --release -p rut-cli
export PATH="$PWD/target/release:$PATH"
rut
# usage: rut — run <file.rut | dir | mod.rutbundle> [--fuel N] | fmt <file.rut | dir> [--check] | pack <dir> [-o out.rutbundle] | dump <file.rut>

The binary embeds the whole engine: lexer, parser, compiler, typed bytecode, and the VM. It also carries the vendored packages from the repo’s rut/ directory (core, pouch, ink, json, …) — a standalone hello.rut that says use ink::{ Logger }; just works, no manifest required.

Smoke-test it

cat > hello.rut <<'EOF'
use ink::{ Logger };

pub fn main() {
    let log = Logger.new("hello");
    log.info(f"hello, rut!");
}
EOF
rut run hello.rut

hello, rut!

If that printed, your toolchain is complete. Continue to your first rut program.

Optional: the wasm playground

The playground runs the same engine compiled to WebAssembly. Building it needs one extra target:

rustup target add wasm32-unknown-unknown
cargo build -p rut-wasm --target wasm32-unknown-unknown --release

or, from demo/, the one-command lane that also copies the artifact into place:

cd demo && npm install && npm run build:wasm

Optional: build this book

The documentation is an mdbook site:

cargo install mdbook --locked
mdbook serve docs     # live-reload preview at http://localhost:3000
mdbook build docs     # static site in docs/book/