Panache

Panache is a language server, formatter, and linter for Quarto and other Markdown flavors, built in Rust with a lossless CST parser and support for external formatters and linters on code blocks.

Installation

Panache is available from several sources:

• crates.io: cargo install --locked panache
• Homebrew: brew install panache
• npm: npm install -g @panache-cli/panache (or npx @panache-cli/panache)
• PyPI: uv tool install panache-cli/pipx install panache-cli
• mise/Aqua: see the installation guide
• NixOS: the panache package on Nixpkgs
• Arch Linux: from the AUR: panache-bin (prebuilt), panache (built from source)
• Prebuilt binaries: tarballs, .deb, and .rpm from the releases page
• VS Code/Open VSX: the Panache extension, from the VS Code Marketplace or Open VSX (also works in Positron), which installs the CLI and starts the language server automatically

Install Script

The installer scripts pick the right release artifact for your platform and install to a user-local directory by default. They download the matching Panache CLI release asset. If you prefer, download and inspect the script before running it.

For macOS and Linux:

curl --proto '=https' --tlsv1.2 -sSf https://panache.bz/install | sh

For Windows PowerShell:

powershell -NoProfile -ExecutionPolicy Bypass -Command "irm https://panache.bz/install.ps1 | iex"

Set PANACHE_INSTALL_DIR to change the destination and PANACHE_TAG to pin a version.

See getting started for per-platform detail and the development version.

Usage

Panache provides a single CLI interface for formatting, linting, and running the LSP server.

Formatting

To format a file in place, simply run:

panache format document.qmd

You can also format from stdin by piping content into panache format:

cat <file> | panache format

panache format supports glob patterns and recursive directory formatting:

panache format **/*.{qmd,md}

You can use Panache as a linter via the --check flag to check if files are already formatted without making changes:

panache format --check document.qmd

External Code Formatters

Panache supports external formatters for code blocks. For example, you can configure it to run arity on R code blocks and ruff on Python code blocks:

[formatters]
r = "arity"
python = "ruff"
javascript = "prettier"
typescript = "prettier" # Reuse same formatter

You can setup custom formatters or modify built-in presets with additional arguments:

[formatters]
python = ["isort", "black"]
javascript = "myformatter"

[formatters.isort]
args = ["--profile=black"]

[formatters.myformatter]
cmd = "foobar"
args = ["--print-width=100"]
stdin = true

Linting

Panache also features a linter that can report formatting issues and optionally auto-fix them. To run the linter, use:

panache lint document.qmd

As with panache format, you can use glob patterns and recursive formatting:

panache lint **/*.{qmd,md}

External Linters

As with formatting, Panache supports external linters for code blocks. These are configured in the [linters] section of the configuration, but due to the complexity of linting, including dealing with auto-fixing, external linters cannot be customized and only support presets:

# Enable R linting
[linters]
r = "jarl" # R linter with JSON output

Language Server

Panache implements the language server protocol (LSP) to provide editor features like formatting, diagnostics, code actions, and more. See the language server documentation for guides on how to connect Panache to your editor and configure LSP features.

The list of LSP features supported by Panache includes, among others:

• Document formatting (full document, incremental and range)
• Diagnostics with quick fixes
• Code actions for refactoring
  • Convert between loose/compact lists
  • Convert between inline/reference footnotes
• Document symbols/outline
• Folding ranges
• Go to definition for references and footnotes
• Quarto and Bookdown project awareness

The development R package also provides RStudio addins for formatting documents and selected blocks.

Configuration

Panache looks for a configuration in:

1. An explicit --config <path>
2. .panache.toml, panache.toml, or .config/panache.toml in the current directory or a parent directory
3. The user configuration directory:
   • Linux: $XDG_CONFIG_HOME/panache/config.toml or ~/.config/panache/config.toml
   • macOS: ~/Library/Application Support/panache/config.toml
   • Windows: %APPDATA%\panache\config.toml

Example

# Markdown flavor and line width
flavor = "quarto"

# Formatting style
[format]
wrap = "reflow"
line-width = 80
line-ending = "auto"

# External code formatters (opt-in)
[formatters]
python = ["isort", "black"] # Sequential formatting
latex = "badness"           # Built-in preset
javascript = "prettier"     # Reusable definitions
typescript = "prettier"

# Customize formatters
[formatters.prettier]
prepend-args = ["--print-width=100"]

# External code linters
[linters]
julia = "fatou" # Enable Julia linting
python = "ruff"

See the configuration reference for a complete list of configuration options and their defaults.

Integrations

GitHub Actions

For CI, use the dedicated GitHub Action:

- uses: jolars/panache-action@v1

See the Integrations documentation for configuration options.

Pre-commit Hooks

Panache integrates with pre-commit to automatically format and lint your files before committing.

Installation:

First, install pre-commit if you haven't already:

pip install pre-commit
# or
brew install pre-commit

Then add Panache to your .pre-commit-config.yaml:

repos:
  - repo: https://github.com/jolars/panache-pre-commit
    rev: v3.14.0
    hooks:
      - id: panache-lint
      - id: panache-format

Note: The hooks live in jolars/panache-pre-commit, a thin shim repo.

Install the hooks:

pre-commit install

The lint hook reports findings; add args: [--fix] to apply safe fixes before formatting. The format hook rewrites files in place. See the integration guide for file patterns, check-only mode, and updates.

See examples/pre-commit-config.yaml for more configuration options.

Motivation

I wanted a formatter that understands Quarto and Pandoc syntax. I have tried to use Prettier as well as mdformat, but both fail to handle some of the particular syntax used in Quarto documents, such as fenced divs and some of the table syntax.

For a side-by-side overview of how Panache compares to Prettier, Pandoc, rumdl, mdformat, mado, markdownlint, markdownlint-cli2, and marksman, see the comparison page. For benchmarks against the same set of tools, see the performance page.

Design Goals and Scope

• Full LSP implementation with formatting, diagnostics, code actions, and more
• Standalone CLI for both formatting and linting
• Support for Quarto, Pandoc, R Markdown, MyST, and other Markdown flavors
• Lossless CST-based parsing
• Idempotent formatting
• Semi-opinionated defaults with configurable style options for common formatting decisions
• Support for running external formatters and linters on code blocks, with built-in presets for popular languages and tools

Acknowledgements

The development of Panache has simplified considerably thanks to the extensive documentation, well-structured code, and testing infrastructure provided by Pandoc. We also owe significant debt to the rust-analyzer project, on which Panache is heavily inspired.