💎 A collection of awesome Crystal libraries, tools, frameworks and software
Switch branches/tags
Nothing to show
Clone or download
vladfaust and veelenga My repos chores (#324)
* Remove tele.cr due to deprecation

* Remove tele-broadcast.cr due to deprecation

* Fix Core URL

* Update Prism description
Latest commit f43da53 Aug 13, 2018



Awesome Crystal

Awesome Build Status

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 Crystal Shards or follow announcements Crystal [ANN] for more.

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

Algorithms and Data structures

Api Builders


C bindings


  • bloom_filter - Implementation of Bloom filter
  • bojack - A non-reliable in-memory key-value store
  • cache-hash - A key/value store where entries expire after a specified interval
  • crystal-memcached - Implementation of a memcached client
  • Nuummite - A tiny persistent embedded key-value store

Cli Builders

  • admiral - A robust DSL for writing command line interfaces
  • cli - Library for building command-line interface applications
  • clicr - A simple declarative command line interface builder
  • clim - Slim command line interface builder
  • commander - Command-line interface builder
  • completion - Easy command line completion engine
  • optarg - Yet another library for parsing command-line options and arguments
  • OptionParser - command-line options processing (Crystal stdlib)

Cli Utils

  • cride - A light CLI text editor/IDE
  • dl - Simple utility for download files by URLs from list
  • noteesh - Notes and Todo list in command line
  • progress - [==..] Progress bar
  • progress_bar.cr - A simple and customizable progress bar
  • spinner - Terminal Spinner
  • terminal_table.cr - Simple ASCII table generator
  • todo - Todo list working in command line

Code Analysis and Metrics

  • ameba - A static code analysis tool
  • trashman - A simple memory profiler for Crystal applications


  • cr-dotenv - Loads .env file
  • habitat - Type safe configuration for your classes and modules
  • totem - Load and parse a configuration in JSON, YAML, dotenv formats


  • base62.cr - Base62 encoder/decoder, well suited for url-shortening
  • human_file_size.cr - JSON & YAML mapping converter for human file sizes in serialized data
  • money - Handling money and currency conversion with ease (almost complete port of RubyMoney)
  • moola - Library for dealing with money and conversion (inspired by RubyMoney)
  • ms - Library to easily convert various time formats to milliseconds and milliseconds to human readable format
  • sass.cr - Compile SASS/SCSS to CSS (libsass binding)
  • time_format.cr - Convert time in human readable format with ease
  • turkish-number - Turn integers into the Turkish words
  • wkhtmltopdf-crystal - Bindings / wrapper for libwkhtmltox (HTML to PDF / image converter)

Data Formats

  • config.cr - Easy to use configuration format parser
  • crinder - Class based json renderer
  • crystal-toml - TOML parser
  • CSV - parsing and generating for comma-separated values (Crystal stdlib)
  • dockerfile.cr - Dockerfile Parsing Library
  • front_matter.cr - Separates a files front matter from its content
  • Gzip - readers and writers of gzip format (Crystal stdlib)
  • INI - INI file parser (Crystal stdlib)
  • JSON - parsing and generating JSON documents (Crystal stdlib)
  • maxminddb.cr - parsing MaxMindDB files, including the GeoIP2
  • XML - parsing and generating XML documents (Crystal stdlib)
  • YAML - parsing and generating YAML documents (Crystal stdlib)
  • Zip - readers and writers of zip format (Crystal stdlib)
  • Zlib - readers and writers of zlib format (Crystal stdlib)
  • zq - Command-line ZPL processor

Data Generators

  • faker - A library for generating fake data
  • hashids.cr - A library to generate YouTube-like ids from one or many numbers

Database Drivers/Clients

Database Tools

  • crecto-admin - Admin dashboard for Crecto and your database
  • micrate - Database migration tool
  • migrate - A simpler database migration tool with transactions
  • migro - A database migration tool that allows migrations to be specified in either YAML or raw SQL

Development Tools

  • guardian - File change watcher for Crystal and Non-Crystal libs
  • kemal-watcher - Kemal plugin to watch files and live-reload the browser
  • sentry - Watches src files, rebuilds/reruns application on file changes
  • sentry-run - Reload code changes using Sentry.run
  • Warden - Watches files, run command and a git command if succeed on file changes
  • watcher - Watch file changes using File.stat


  • carbon - Fun, testable, and adapter-based email library
  • crystal-email - Simple e-mail sending library
  • CrystalEmail - A RFC compliant Email validator
  • devmail - A combined SMTP/POP3-server with volatile mail storage
  • sendgrid.cr - Simple Sendgrid Client

Environment Management

Examples and funny stuff

Feature Flipping

  • flipper - Feature flipping/flags/rollouts. Supports multiple backends

Framework Components

Game Development

  • cray - Bindings for raylib, an easy-to-use game development library
  • CrSFML - Bindings to SFML multimedia/game library
  • crystal-chipmunk - Bindings for Chipmunk, a fast and lightweight 2D game physics library
  • glove - A library for gaming development
  • inari - A collection of games using Glove as the game engine
  • mos_game - Mini Offline Singleplayer game

GUI library

  • hedron - An extendable GUI library, with markup language capabilities
  • libui.cr - Bindings for libui
  • qt5.cr - Qt5 bindings for Crystal, based on Bindgen

HTML/XML Parsing


Image processing


  • charly - Charly Programming Language
  • cltk - A crystal port of the Ruby Language Toolkit
  • cppize - Crystal-to-C++ transpiler
  • crisp - Lisp dialect implemented with Crystal
  • crow - Transpile/compile Crystal to Flow
  • LinCAS-lang - A programming language for scientific computation
  • mint-lang - A refreshing programming language for the front-end web
  • myst-lang - A practical, dynamic language designed to be written and understood as easily and efficiently as possible
  • NuummiteOS - An OS written in Crystal as a Proof of Concept
  • runic-lang - In-design toy language
  • zir - Realizes to write macros in any scripts into any languages

Logging and monitoring

Machine Learning

Markdown/Text Processors

  • html-pipeline - HTML processing filters and utilities
  • markd - Yet another markdown parser built for speed, Compliant to CommonMark specification
  • remarkdown - GFM for Crystal


  • aasm.cr - Easy to use finite state machine for Crystal classes
  • accord - Sharable validations for Crystal objects
  • any_hash.cr - Recursive Hash with better JSON::Any included
  • atomic_write.cr - Library for writing or apppending files atomically
  • burocracia.cr - burocracia.cr the dependecyless shard to validate, generate and format Brazilian burocracias such as CPF, CNPJ and CEP
  • circuit_breaker - Implementation of the circuit breaker pattern
  • crystal-binary_parser - Binary parser
  • crz - Functional programming library
  • denetmen - Useful micro validator / check library
  • emoji.cr - Emoji library
  • hoop - Building native OSX apps
  • html_builder - DSL for creating HTML
  • i18n.cr - Internationalization shard
  • immutable - Implementation of thread-safe, persistent, immutable collections
  • inflector.cr - Singularize, pluralize, camelize, etc (port from ActiveSupport)
  • lirith - Graphics engine
  • m3u8 - Generate and parse m3u8 playlists for HTTP Live Streaming
  • manual-generator - Tool to generate PDF manuals from documentation sites
  • raytracer - CPU Raytracer with examples
  • syscall.cr - Raw syscall interface
  • tren - Give your SQL some love
  • ulid - Universally Unique Lexicographically Sortable Identifier (ULID)
  • wikicr - Wiki using git to manage revisions

Network Protocols


ORM/ODM Extensions

  • active_record.cr - Active Record pattern implementation
  • clear - ORM specialized to PostgreSQL only but with advanced features
  • core - Pure, transparent and efficient ORM
  • crecto - Database wrapper, based on Ecto
  • granite - ORM for Postgres, Mysql, Sqlite
  • jennifer.cr - Active Record pattern implementation with flexible query chainable builder and migration system
  • ohm-crystal - Object-hash mapping library for Redis
  • record - Type safe querying, saving and updating
  • redis-tsv.cr - Import and export data from Redis in TSV format
  • stal-crystal - Set algebra solver for Redis
  • topaz - A simple and useful db wrapper

Package Management

  • CRelease - Version and git tag manager that makes shard releases easy
  • shards - Dependency manager for the Crystal

Processes and Threads

  • await_async - Add keywords await & async in Crystal Lang
  • crystal-futures - Future type implementation
  • neph - A modern command line job processor that can execute jobs concurrently
  • promise - A Promise Implementation

Project Generators

  • bindgencr - Generator of bindings based on castxml output
  • crystal_lib - Automatic binding generator for native libraries
  • fez - A Kemal application generator
  • kgen - Kemalyst command line tool for console, init, generate (scaffolding), and watch.
  • libgen - Automatic bindings generator configured using JSON/YAML files
  • wasp - Static Site Generator

Queues and Messaging

  • amqp.cr - AMQP 0.9.1 client with RabbitMQ extensions
  • dispatch - In memory asynchronous job processing
  • mosquito - Redis backed periodic and ad hoc job processing
  • sidekiq.cr - Simple, efficient job processing


  • crouter - A standalone router
  • orion - A minimal, rails-esque routing library
  • router.cr - Minimum but powerful http router for HTTP::Server
  • toro - Tree Oriented Routing


Science and Data analysis

  • linalg - Linear algebra library inspired by MATLAB and SciPy.linalg
  • predict.cr - Satellite prediction library using the sgp4 model
  • scorystal - Scoring API for PMML - supports RF and GBM
  • stats - An expressive implementation of statistical distributions


  • hermes - Data Mapper pattern implementation for ElastiSearch
  • query-builder - Sql Query Builder library
  • query.cr - Query abstraction
  • soegen - Elasticsearch client for Crystal similar to the stretcher gem for ruby

Serverless Computing

  • gcf.cr - Managed execution of Crystal in Google Cloud Functions


  • baked_file_system - Virtual file system implementation
  • hardware - Get CPU, Memory and Network informations of the running OS and its processes
  • rcpu - A virtual machine emulator and assembler

Task management

  • cake - Production-ready Make-like utility tool
  • sam - Another one Rake-like task manager with namespacing and arguments system

Template Engine


  • coverage – Generate cover report for your crystal code
  • crotest - A tiny and simple test framework
  • LuckyFlow - Automated browser tests similar to Capybara
  • mass-spec - Web API testing library
  • microtest - Small opinionated testing library focusing on power asserts
  • minitest.cr - Library for unit tests and assertions
  • mocks.cr - Mocking library for Crystal
  • Spec - spec framework (Crystal stdlib)
  • spec2-mocks - An adapter of mocks.cr for spec2.cr
  • spec2.cr - Enhanced testing library
  • timecop.cr - Library for mocking with Time.now. Inspired by timecop ruby gem
  • webmock.cr - Library for stubbing HTTP::Client requests

Third-party APIs

Web Frameworks

  • amber - Open source efficient and cohesive web application framework
  • kemal - Lightning Fast, Super Simple web framework. Inspired by Sinatra
  • lattice-core - A WebSocket-first object-oriented framework (based on Kemal)
  • lucky - Catch bugs early, forget about most performance issues, and spend more time on code instead of debugging and writing tests
  • prism - Lightspeed web framework with typed params
  • raze - Modular, light web framework
  • spider-gazelle - A Rails esque web framework with a focus on speed and extensibility

Web Servers

  • fast-http-server - Super fast, zero configuration command line HTTP Server
  • prax.cr - Rack proxy server for development
  • salt - A Human Friendly Interface for HTTP server
  • serve - Command line static HTTP server




Official Documentation Translations

Services and Apps

  • carc.in - A web service that runs your code and displays the result
  • Crank - A Procfile-based application manager (like Foreman)
  • cry - Ability to execute crystal code in a fashion similar to Ruby's pry edit
  • Crystal [ANN] - Announce new project, blog post, version update or any other Crystal work
  • crystalshards.herokuapp.com, crystalshards.xyz - Web services that list all available Crystal shards
  • Crystular - Regular expression tester
  • DeBot - IRC bot written in Crystal
  • Ficha - A super secret chat app, for any body who needs privacy
  • Firegrid - Click anywhere with only a few key strokes
  • icr - Interactive console for Crystal (like IRB for Ruby)
  • JSON to Crystal - Paste in a JSON object and get Crystal mappings in response
  • mpngin - A URL shortener with simple stats
  • nes - A NES emulator
  • shards.rocks - Service that manages dependencies inspired by Gemnasium and David
  • torrent - A BitTorrent client



Editor Plugins

Shell plugins