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.
- Awesome Crystal
- Algorithms and Data structures
- Blockchain
- C Bindings
- Caching
- CLI Builders
- CLI Utils
- Code Analysis and Metrics
- Compression
- Configuration
- Converters
- Cryptography
- Data Formats
- Data Generators
- Database Drivers/Clients
- Database Tools
- Debugging
- Dependency Injection
- Environment Management
- Examples and funny stuff
- Feature Flipping
- Framework Components
- Game Development
- HTML Builders
- HTML/XML parsing
- HTTP
- Image Processing
- Implementations/Compilers
- Logging and monitoring
- Machine Learning
- Markdown/Text Processors
- Misc
- Network Protocols
- Networking
- ORM/ODM Extensions
- Package Management
- Processes and Threads
- Project Generators
- Queues and Messaging
- Routing
- Scheduling
- Science and Data analysis
- Search
- Serverless Computing
- System
- Task management
- Template Engine
- Testing
- Third-party APIs
- Validation
- Web Frameworks
- Community
- Resources
- Services and Apps
- Tools
- bisect - Inserting values into a sorted array
- 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
- edits.cr - Collection of edit distance algorithms
- fzy - A Crystal port of awesome Fzy project fuzzy finder algorithm
- graphlb - Collection of graph datastructure and algorithms
- haversine - An Implementation of the Haversine formula
- 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
- radix - Radix Tree implementation
- ternary_search_tree - Ternary Search Tree
- Cocol - A minimal blockchain testbed
- secp256k1.cr - Elliptic curve used in the public-private-key cryptography
- SushiChain - A custom blockchain platform
- clang.cr - Libclang bindings
- crt.cr - Bindings for libncursesw and crt
- crystal-gsl - GNU Scientific Library bindings
- crystal-hunspell - Bindings for Hunspell
- curl-crystal - Bindings for libcurl
- duktape.cr - Bindings for the Duktape javascript engine
- gphoto2.cr - Bindings for the libgphoto2 library
- icu.cr - Bindings for the ICU library
- libnotify.cr - Bindings for Libnotify
- pcap.cr - Bindings for libpcap
- pledge.cr - Bindings for OpenBSD's
pledge(2)
- ssh2.cr - Bindings for libssh2 library
- syslog.cr - Bindings for
syslog
- x_do.cr - Bindings for libxdo (
xdotool
)
- bloom_filter - Implementation of Bloom filter
- crystal-memcached - Implementation of a memcached client
- admiral - A robust DSL for writing command line interfaces
- clicr - A simple declarative command line interface builder
- clim - Slim command line interface builder
- 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
- cride - A light CLI text editor/IDE
- 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
- terminimal - A tiny CLI toolkit for building terminal apps for humans
- todo - Todo list working in command line
- ameba - A static code analysis tool
- Crystar - Readers and writers of Tar archive format
- Gzip - readers and writers of gzip format (Crystal stdlib)
- 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
- cr-dotenv - Loads .env file
- 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
- base62.cr - Base62 encoder/decoder, well suited for url-shortening
- money - Handling money and currency conversion with ease (almost complete port of RubyMoney)
- sass.cr - Compile SASS/SCSS to CSS (libsass binding)
- time_format.cr - Convert time in human readable format with ease
- wkhtmltopdf-crystal - Bindings / wrapper for libwkhtmltox (HTML to PDF / image converter)
- cmac - Crystal implementation of Cipher-based Message Authentication Code (CMAC)
- sodium.cr - Crystal wrapper for the libsodium crypto API
- BinData - Binary data parser helper with an ASN.1 parser
- config.cr - Easy to use configuration format parser
- crinder - Class based json renderer
- CSV - parsing and generating for comma-separated values (Crystal stdlib)
- front_matter.cr - Separates a files front matter from its content
- geoip2.cr - GeoIP2 reader
- HAR - HAR (HTTP Archive) parser
- INI - INI file parser (Crystal stdlib)
- JSON - parsing and generating JSON documents (Crystal stdlib)
- JSON tools - An implementation of JSON Patch and Pointer RFC's
- JSON::OnSteroids - handle and mutate JSON document easily
- maxminddb.cr - MaxMindDB reader
- toml.cr - TOML parser
- XML - parsing and generating XML documents (Crystal stdlib)
- YAML - parsing and generating YAML documents (Crystal stdlib)
- faker - A library for generating fake data
- hashids.cr - A library to generate YouTube-like ids from one or many numbers
- prime - A prime number generator
- couchdb.cr - CouchDB client
- crystal-db - Common db api
- crystal-mysql - MySQL connector for Crystal
- crystal-pg - A Postgres driver
- crystal-redis - Full featured Redis client
- crystal-rethinkdb - Driver for RethinkDB / RebirthDB
- crystal-sqlite3 - SQLite3 bindings
- leveldb - Crystal bindings for LevelDB
- rocksdb.cr - RocksDB client
- migrate - A simpler database migration tool with transactions
- queryit - A setupless terminal based SQL query runner.
- debug.cr -
debug!(…)
macro forpp
-style debugging
- Crystal-DI - Lightweight DI Container
- HardWire - A compile-time non-intrusive dependency injection system.
- syringe - A simple and basic dependency injection shard for crystal
- carbon - Fun, testable, and adapter-based email library
- crystal-email - Simple e-mail sending library
- CrystalEmail - A RFC compliant Email validator
- sendgrid.cr - Simple Sendgrid Client
- asdf-crystal - Plugin for asdf version manager
- crenv - Crystal version manager
- rcm.cr - Redis Cluster Manager
- blackjack-cr - Console Blackjack
- crystal-patterns - Examples of GOF patters
- crystalworld - realworld.io back-end API implementation
- exercism-crystal - Exercism exercises
- try.cr - Try monad
- can_use - It is a minimalist feature toggle/flag for crystal based on yaml
- device_detector - Shard for detect device by user agent string
- Exception Page - An exceptional exception page for Crystal web libraries and frameworks
- graphql-crystal - Graphql implementation
- kave - Kemal API Version Extension
- kemal-session - Session handler for Kemal
- mochi - Authentication shard inspired by Devise supporting: Authenticable, Confirmable, Invitable & more
- multi-auth - Standardized multi-provider OAuth2 authentication (inspired by omniauth)
- praetorian - Minimalist authorization library inspired by Pundit
- shrine.cr - File Attachment toolkit for Crystal applications. Heavily inspired by Shrine for Ruby
- tourmaline - Telegram bot framework with an API loosely based on telegraf.js
- CrSFML - Bindings to SFML multimedia/game library
- crystal-chipmunk - Bindings for Chipmunk, a fast and lightweight 2D game physics library
- entitas.cr - A Entity Component System Framework for Crystal
- glove - A library for gaming development
- form_builder.cr - Dead simple HTML form builder for Crystal with built-in support for many popular UI libraries such as Bootstrap
- gumbo-crystal - Bindings for Gumbo, an HTML5 parsing library made by Google
- myhtml - Fast HTML5 Parser that includes CSS selectors
- Cable - An ActionCable "port" to Crystal, framework agnostic, 100% compatible with the ActionCable JS Client
- cossack - Simple flexible HTTP client
- crest - Simple HTTP and REST client, inspired by the Ruby's RestClient gem
- crul - Command line HTTP client
- halite - Crystal HTTP Requests with a chainable REST API, built-in sessions and loggers
- http-multiserver.cr - Mounting multiple servers via routes (a.k.a. URL mapping)
- http-params-serializable - HTTP params (de)serialization, applicable to URL queries and URL-encoded forms
- http-protection - Protection against typical web attacks
- http2 - HTTP/2 Protocol Implementation
- HTTP::Client - HTTP client (Crystal stdlib)
- HTTP::Server - HTTP server (Crystal stdlib)
- HTTP::WebSocket - HTTP WebSocket client (Crystal stdlib)
- proxy-fetcher.cr - Proxy lists fetching & validating library
- resp-crystal - Lightweight RESP client
- sse.cr - Server-Sent Events client
- libpixel.cr
- magickwand-crystal - Bindings for MagickWand, the C interface for ImageMagick processing libraries
- stumpy_png - Read and write PNG images
- charly - Charly Programming Language
- cltk - A crystal port of the Ruby Language Toolkit
- crisp - Lisp dialect implemented with Crystal
- 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
- runic-lang - In-design toy language
- crafana - A Grafana library to help autogenerate dashboards
- Log - logging utility (Crystal stdlib)
- statsd.cr - Statsd client library
- ai4cr - Artificial Intelligence (based on https://github.com/SergioFierens/ai4r)
- Cadmium - NLP library based heavily on natural
- crystal-fann - FANN (Fast Artifical Neural Network) binding
- mxnet.cr - Bindings for MXNet
- shainet - SHAInet (Neural Network in pure crystal)
- markd - Yet another markdown parser built for speed, Compliant to CommonMark specification
- aasm.cr - Easy to use finite state machine for Crystal classes
- 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
- callbacks - Expressive callbacks module
- circuit_breaker - Implementation of the circuit breaker pattern
- containerregistry.cr - Library for working with container registries
- CrSerializer - Extensible annotation based serialization/deserialization library
- CrSignals - Signals/slots notification library
- crystal-binary_parser - Binary parser
- crystal-web-framework-stars - Web frameworks for Crystal, most starred on Github
- crz - Functional programming library
- emoji.cr - Emoji library
- gphoto2-web.cr - Web API for libgphoto2
- i18n.cr - Internationalization shard
- immutable - Implementation of thread-safe, persistent, immutable collections
- iterm2 - Display images within the terminal using the ITerm2 Inline Images Protocol
- lirith - Graphics engine
- message_verifier.cr - Verify and generate Rails
ActiveSupport::MessageVerifier
signed tokens - monads - Monad implementation
- pinger - Ping IP addresses and DNS entries without requiring sudo
- port_midi - Crystal C bindings for the PortMIDI cross-platform MIDI I/O library
- retriable.cr - Simple DSL to retry failed code blocks
- ulid - Universally Unique Lexicographically Sortable Identifier (ULID)
- zaru_crystal - Filename sanitization
- amqp-client.cr - AMQP 0-9.1, a messaging protocol, implemented by eg. RabbitMQ
- connect-proxy - Connect method style of HTTP tunnelling / HTTP proxy
- cr-xmpp - XMPP/Jabber Library
- Crirc - IRC protocol implementation (Client, Server, Bots)
- crystal-dns - DNS protocol implementation and resolver
- crystal-json-socket - JSON-socket client & server implementation. Inspired by and compatible with node-json-socket and ruby-json-socket
- crystal-snmp - An SNMP implementation with version 1, 2c and 3 support
- fast_irc.cr - Fast IRC parser/generator
- jwt - Implementation of JWT (JSON Web Token)
- msgpack-crystal - MessagePack library
- OAuth - OAuth consumer (Crystal stdlib)
- OAuth2 - OAuth2 client (Crystal stdlib)
- OpenSSL - bindings to libssl (Crystal stdlib)
- telnet.cr - Telnet protocol
- transfer_more - Clone of transfer.sh to uploads files
- ipaddress.cr - Library to handle IPv4 and IPv6 addresses
- avram - A database wrapper for reading, writing, and migrating Postgres databases.
- clear - ORM specialized to PostgreSQL only but with advanced features
- 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
- onyx-sql - DB-agnostic SQL ORM with beautiful DSL and type-safe Query builder
- rethinkdb-orm - ORM for RethinkDB / RebirthDB
- stal-crystal - Set algebra solver for Redis
- shards - Dependency manager for the Crystal
- await_async - Add keywords await & async in Crystal Lang
- neph - A modern command line job processor that can execute jobs concurrently
- promise - A Promise implementation with type inference
- crystal_lib - Automatic binding generator for native libraries
- fez - A Kemal application generator
- libgen - Automatic bindings generator configured using JSON/YAML files
- dispatch - In memory asynchronous job processing
- mosquito - Redis backed periodic and ad hoc job processing
- NATS.io - NATS client
- sidekiq.cr - Simple, efficient job processing
- orion - A minimal, rails-esque routing library
- router.cr - Minimum but powerful http router for HTTP::Server
- toro - Tree Oriented Routing
- crystime - Advanced time, calendar, schedule, and remind library
- schedule.cr - Run periodic tasks
- tasker - A high precision scheduler including timezone aware cron jobs
- ishi - Graph plotting package with a small API and sensible defaults powered by gnuplot
- linalg - Linear algebra library inspired by MATLAB and SciPy.linalg
- num.cr - Numerical computing library supporting N-Dimensional data
- predict.cr - Satellite prediction library using the sgp4 model
- quartz - Modeling and simulation framework
- hermes - Data Mapper pattern implementation for ElastiSearch
- soegen - Elasticsearch client for Crystal similar to the stretcher gem for ruby
- crystal_openfaas - Template to enable crystal as first class citizens in OpenFaaS
- FaaStRuby - Serverless Software Development Platform for Ruby and Crystal.
- 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
- cake - Production-ready Make-like utility tool
- sam - Another one Rake-like task manager with namespacing and arguments system
- crinja - An implementation of the Jinja2 template engine
- crustache - {{Mustache}} for Crystal
- ECR (Embedded Crystal) - compile time template language which uses plain crystal expressions (Crystal stdlib)
- Jbuilder - Generate JSON objects with a Builder-style DSL, inspired by jbuilder
- Kilt - Abstraction layer for template engines
- Slang - Lightweight, terse, templating language inspired by Ruby's Slim
- teeplate - A library for rendering multiple template files
- Water - A library for writing HTML in plain Crystal
- crotest - A tiny and simple test framework
- crytic - Mutation testing 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)
- spectator - Feature rich spec framework that uses the modern expect syntax
- timecop.cr - Library for mocking with
Time.now
. Inspired by the timecop ruby gem - vcr - A HTTP capture and replay implementation for crystal
- webdriver_pump - Page Object library. Inspired by Ruby's WatirPump
- webmock.cr - Library for stubbing
HTTP::Client
requests
- aws-signer.cr - This library signs your HTTP requests using AWS v4
- awscr-s3 - AWS S3 interface
- awscr-signer - Sign HTTP::Request objects and generate presigned post forms
- crystal-consul - Consul API client
- crystal-darksky - Wrapper for the Dark Sky API
- crystal-swapi - Star Wars API (SWAPI) wrapper
- crystal_slack - A tool that parses Slack slash commands or send incoming web hooks
- discordcr - A minimalist Discord API library
- GDAX - GDAX REST and WebSocket API Wrapper with request signing
- gitlab.cr - GitLab API wrapper
- google - Google API wrapper
- google_maps_api - Google Maps API
- host_meta - A Web Host Metadata (https://tools.ietf.org/html/rfc6415) client
- kube-client.cr - Kubernetes API Client
- mixpanel-crystal - A library for sending events to Mixpanel
- mollie.cr - Mollie Payments API wrapper (Creditcard, PayPal, Apple Pay, Sofort, Klarna, ...)
- office365 - Microsoft Graph API wrapper
- pinboard.cr - Pinboard API
- raven.cr - Raven is a client for Sentry
- twitter-crystal - A library to access the Twitter API
- web_finger - A WebFinger (https://tools.ietf.org/html/rfc7033) client
- ynab.cr - A library to interact with your YNAB data
- accord - Shareable validation library for Crystal Objects
- assert - Extensible annotation based object validation library
- validations - Validations mixin
- validator - Data check and validation
- amber - Open source efficient and cohesive web application framework
- athena - Modular, annotation based, API oriented framework with built in param conversion
- grip - A microframework for building RESTful web applications, with ease and joy
- kemal - Lightning Fast, Super Simple web framework. Inspired by Sinatra
- lucky - Catch bugs early, forget about most performance issues, and spend more time on code instead of debugging and writing tests
- Shivneri - Component based MVC web framework for crystal targeting good code structures, modularity & performance
- spider-gazelle - A Rails esque web framework with a focus on speed and extensibility
- Crystal weekly newsletters
- Gitter
- Google Group
- IRC - #crystal-lang on Freenode
- Metaruby - Crystal Forum on Metaruby
- Stackoverflow
- Chinese-speaking Telegram Group - 来吧!TG 中文圈的朋友们!
- Crystal Programming Discord Server - Unofficial Discord server dedicated to the Crystal Programming Language
- Portuguese-speaking Telegram Group - Bem vindos ao Crystal Brasil!
- Russian-speaking Telegram Group - Добро пожаловать, товарищ!
- Crystal for Rubyists - Free book to bootstrap your Crystal journey
- Crystal Mastery - Screencasts for learning Crystal
- crystal-lang.org - Official language site
- devdocs.io - API Documentation Browser with Crystal support
- getgood.at - Learn Crystal in a Day
- Programming Crystal - PragProg book to start your Crystal journey
- br.crystal-lang.org - Brazilian
- ja.crystal-lang.org - Japanese
- kr.crystal-lang.org - Korean
- ru.crystal-lang.org - Russian
- tw.crystal-lang.org - Chinese Traditional
- carc.in - A web service that runs your code and displays the result
- 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
- icr - Interactive console for Crystal (like IRB for Ruby)
- Invidious - Invidious is an alternative front-end to YouTube
- mpngin - A URL shortener with simple stats
- quicktype - Generate models and serializers from JSON, JSON Schema, GraphQL, and TypeScript
- shards.info - Web service that lists all repositories on GitHub that have Crystal code in them. The sources are available on GitHub
- wikicr - Wiki using git to manage revisions
- ast_helper - Helper tool to debug parser and formatter
- crystal-base - CentOS base docker image for Crystal development
- crystal-dash-docset - Dash docset generator
- public_suffix - A small library designed to make the Public Suffix List (https://publicsuffix.org/) easier to use
- ansible-crystal - Ansible playbook for installing crystal
- DPPM - An easy, universal way to install and manage applications as packages (mostly Linux)
- Atom
- crystal-tools - Enables built in tools in Crystal compiler
- language-crystal-actual - Crystal language support in Atom
- Emacs
- emacs-crystal-mode - Crystal language support for Emacs
- scry - Code analysis server for Crystal implementing the Language Server Protocol
- Spacemacs
- crystal-spacemacs-layer - Spacemacs contribution layer for Crystal
- Sublime
- sublime-crystal - Crystal syntax highlighting for sublime Text
- TextMate
- Crystal.tmbundle - Crystal syntax highlighting, compile, format command, snippets
- Vim
- vim-crystal - Vim filetype support for Crystal
- vim-slang - Vim filetype support for Slang Templating Engine
- Visual Studio Code
- vscode-crystal - Crystal language support in VSCode
- vscode-crystal-ide - Crystal IDE powered by Language Server Protocol
- vscode-crystal-lang - Formatter, linter and syntax highlighting for
cr
andecr
files
- crun - Crystal Run : shebang wrapper for Crystal
- crystal-zsh - .oh-my-zsh plugin