Awesome Crystal

A curated list of awesome Crystal code and resources. Inspired by awesome and awesome-awesomeness. The goal is to have projects mostly stable and useful for the community.

Search shards at shards.info or follow announcements Crystal [ANN] for more.

Contributions are welcome. Please take a quick look at the contribution guidelines first.

Awesome Crystal
Community
- Unofficial
Resources
- Official Documentation Translations
Services and Apps
Tools

Algorithms and Data structures

bisect - Inserting values into a sorted array
blurhash.cr - BlurHash implementation
crie - Compile-time Trie
CrOTP - HOTP and TOTP implementation for two factor authentication
crystal-linked-list - Implementation of Linked List
crystaledge - A pure Vector Math library
crystalg - A Generic Algorithm Library
crystalline - A collection of containers and algorithms
csuuid - A Chronologically Sortable UUID
edits.cr - Collection of edit distance algorithms
fzy - A Crystal port of awesome Fzy project fuzzy finder algorithm
Goban - A fast and efficient QR Code implementation
graphlb - Collection of graph datastructure and algorithms
haversine - An Implementation of the Haversine formula
HKDF - HMAC-based Extract-and-Expand Key Derivation Function rfc5869
kd_tree - An implementation of "K-Dimensional Tree" and "N-Nearest Neighbors"
ksuid.cr - K-Sortable Globally Unique IDs
markov - Build Markov Chains and run Markov Processes
multiset.cr - Implementation of a multiset
named_information - Naming Things with Hashes rfc6920
qr-code - QR Code generator
radix - Radix Tree implementation
s2_cells - S2 Geometry for spatial indexing
secure-remote-password - SRP-6a protocol for authentication over an insecure network
SPAKE2+ - Password Authenticated Key Exchange (PAKE) protocol, comparable to SRP-6a
splay_tree_map - Splay Tree implementation that conforms to the Hash ducktype
verhoeff - Implementation of the Verhoeff checksum algorithm

Blockchain

Axentro - A custom blockchain platform
Cocol - A minimal blockchain testbed
secp256k1.cr - Elliptic curve used in the public-private-key cryptography

C bindings

augeas.cr - Bindings for Augeas
clang.cr - Libclang bindings
crt.cr - Bindings for libncursesw and crt
crystal-gsl - Bindings for GNU Scientific Library
crystal-hunspell - Bindings for Hunspell
duktape.cr - Bindings for the Duktape javascript engine
fftw.cr - Bindings for FFTW library
gphoto2.cr - Bindings for the libgphoto2 library
gpio.cr - Bindings for the gpiod library (general purpose IO control and feedback)
icu.cr - Bindings for the ICU library
libnotify.cr - Bindings for Libnotify
nlopt.cr - Bindings for NLOpt
pcap.cr - Bindings for libpcap
pledge.cr - Bindings for OpenBSD's pledge(2)
ssh2.cr - Bindings for libssh2 library
syslog.cr - Bindings for syslog
v4l2.cr - Bindings for Video4Linux2
wasmer-crystal - Bindings for the wasmer WebAssembly runtime
win32cr - Bindings for Win32 API
x_do.cr - Bindings for libxdo (xdotool)

Caching

crystal-memcached - Implementation of a memcached client

CLI Builders

admiral - A robust DSL for writing command line interfaces
Athena Console - Allows for the creation of CLI based commands
clicr - A simple declarative command line interface builder
clim - Slim command line interface builder
Cling - A modular, non-macro-based command line interface library
commander - Command-line interface builder
Keimeno - A lightweight text user interface library in Crystal
OptionParser - command-line options processing (Crystal stdlib)
Phreak - A highly flexible Crystal CLI builder in the style of OptionParser

CLI Utils

climate - Tiny tool to make your CLI output 🌈 coloured
coin - Command-line application that performs currency conversion via the Fixer API
cride - A light CLI text editor/IDE
git-repository - A git cli wrapper querying and cloning remote repositories with minimal data transfer
hetzner-k3s - A CLI tool to quickly create and manage Kubernetes clusters in Hetzner Cloud
lff - Simple and straightforward large files finder utility in command line
meet - Start a jitsi meeting quickly from the comfort of your command line
oq - A performant, and portable jq wrapper to facilitate the consumption and output of formats other than JSON; using jq filters to transform the data
progress_bar.cr - A simple and customizable progress bar
tablo - A flexible terminal table generator
tallboy - Generate ASCII character tables with support for spanning cells over multiple columns

Code Analysis and Metrics

ameba - A static code analysis tool
linguist.cr - Using multiple ways to find programming language used in files, based on Github's Linguist

Compression

Crystar - Readers and writers of Tar archive format
Gzip - readers and writers of gzip format (Crystal stdlib)
polylines.cr — compression of series of coordinates
snappy - Snappy compression format reader/writer for Crystal
Zip - readers and writers of zip format (Crystal stdlib)
Zlib - readers and writers of zlib format (Crystal stdlib)
zstd.cr - Bindings for Zstandard compression library

Configuration

cr-dotenv - Loads .env file
Envy - Load environment variables from YAML
envyable - A simple YAML to ENV config loader
habitat - Type safe configuration for your classes and modules
totem - Load and parse a configuration in JSON, YAML, dotenv formats

Converters

base62.cr - Base62 encoder/decoder, well suited for url-shortening
crunits - Tool for converting units of measure (miles to kilometers, celsius to fahrenheit etc)
money - Handling money and currency conversion with ease (almost complete port of RubyMoney)
sass.cr - Compile SASS/SCSS to CSS (libsass binding)

Cryptography

cmac - Crystal implementation of Cipher-based Message Authentication Code (CMAC)
ed25519 - the Ed25519 elliptic curve public-key signature system described in [RFC 8032]
monocypher.cr - Crystal wrapper for the Monocypher crypto library
sodium.cr - Crystal wrapper for the libsodium crypto API