chroma

CLI, syntax highlighter, and terminal-UI companion for the tree-sitter-manager Crystal runtime. The runtime owns grammar installation, loading, parsing, and cache management; chroma owns the presentation layer: themes, renderers, and Tree-sitter query assets.

Features

• Syntax highlighting for 306 languages via per-language Tree-sitter queries.
• 63 built-in color themes.
• Interactive terminal UI with incremental reparsing (chroma-tui).
• Grammar status, query inspection, installation statistics, diagnostics.
• Shell completion scripts for bash, zsh, and fish.

Install

Prerequisites: Crystal >= 1.21.0 and Shards, plus the tree-sitter-manager runtime checked out as ../tree-sitter-manager next to this repository (path dependency). See docs/development.md for the full checkout guide.

shards build                 # build bin/chroma and bin/chroma-tui
make install PREFIX=/usr/local

Installs binaries to $PREFIX/bin and query assets to $PREFIX/share/chroma/queries, so highlighting does not depend on the current working directory.

Usage

CLI

chroma highlight FILE          Highlight a source file.
chroma languages               List supported languages.
chroma themes                  List available themes.
chroma queries LANG            Show preprocessed queries for a language.
chroma groups                  List semantic language groups.
chroma stats                   Show installation statistics.
chroma doctor                  Check grammar, query, and cache health.
chroma completions SHELL       Generate completions (bash, zsh, fish).
chroma version                 Print version information.

highlight accepts an explicit language, theme, and output format:

chroma highlight path/to/file.cr
chroma highlight path/to/file.cr -l crystal -t catppuccin::frappe
chroma highlight path/to/file.cr -f html

Terminal UI

chroma-tui                                  # pick a file to open
chroma-tui path/to/file.cr

Shell completions

eval "$(chroma completions bash)"           # bash
source <(chroma completions zsh)            # zsh
chroma completions fish | source            # fish

Configuration

• CHROMA_QUERIES_DIR overrides the query assets directory.

Documentation

• Architecture
• Development
• Coding guidelines
• Testing
• PR workflow

License

MIT.