Fatou

rust

julia

cli

Fatou is a Rust-based language server, formatter, and linter for Julia, providing code completion, navigation, and automatic fixes without running Julia itself.

Authors

Johan Larsson

Published

16 June 2026

Links

Docs Code crates.io PyPi npm

Fatou formats and analyzes Julia code without starting Julia. It combines an opinionated formatter, a configurable linter with automatic fixes, and a language server that provides completion, hover information, code navigation, rename, and signature help.

Fatou uses a lossless syntax tree and incremental computation to update its analysis as you edit. It works from the command line and integrates with editors through the Language Server Protocol, with extensions for VS Code and Zed. It is named after Pierre Fatou, whose Fatou set is the complement of the Julia set.

Citation

BibTeX citation:

@software{larsson2026,
  author = {Larsson, Johan},
  title = {Fatou: {A} {Language} {Server,} {Formatter,} and {Linter} for
    {Julia}},
  version = {0.22.0},
  date = {2026-06-16},
  url = {https://fatou.dev},
  langid = {en}
}

For attribution, please cite this work as:

Larsson, Johan. 2026. Fatou: A Language Server, Formatter, and Linter for Julia. Rust. V. 0.22.0. Released June 16. https://fatou.dev.