Getting Started

Installation

Fatou runs on Linux, macOS, and Windows (x86_64 and arm64), and is available from several sources.

Cargo

Install from crates.io with Cargo:

cargo install fatou

npm

The fatou-cli package bundles a prebuilt binary:

npm install -g fatou-cli

PyPI

Install the binary as a Python tool:

uv tool install fatou
# or
pipx install fatou

AUR

On Arch Linux, install the prebuilt fatou-bin package with an AUR helper:

paru -S fatou-bin

Prebuilt binaries

Download an archive for your platform from the releases page and put the fatou binary on your PATH.

From source

Clone the repository and build a release binary:

git clone https://github.com/jolars/fatou
cd fatou
cargo build --release

The binary is written to target/release/fatou.

dprint

To format Julia files with dprint, add the Fatou dprint plugin. It bundles the formatter and requires neither Julia nor the Fatou CLI:

dprint config add jolars/fatou

First Run

Format a file in place:

fatou format file.jl

Check formatting without writing changes (prints a diff, exits non-zero if any file would change):

fatou format --check file.jl

To make formatting fail unless Fatou can verify that the parsed program and comments are preserved, opt in with --safe. A multi-file safe run checks the whole batch before writing any file:

fatou format --safe file.jl
fatou format --safe --check src

Lint a file; exits non-zero if there are any findings:

fatou lint file.jl

Run the language server over stdio (for editor integration):

fatou lsp

See the CLI Reference for the full set of commands and options, and Editor Setup to wire the language server into your editor.