Crystal
repo: veelenga/awesome-crystal
category: Programming Languages
related: Ruby
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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 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
- Framework Components
- Game Development
- GUI Development
- HTML Builders
- HTML/XML parsing
- HTTP
- Image Processing
- Implementations/Compilers
- Internationalization
- 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
- Security
- Serverless Computing
- System
- Task management
- Template Engine
- Testing
- Third-party APIs
- Validation
- Web Frameworks
- Community
- Resources
- 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
wasmerWebAssembly runtime - win32cr - Bindings for Win32 API
- x_do.cr - Bindings for libxdo (
xdotool)
Caching
- cache - A key/value store where pairs can expire after a specified interval
- 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
- cruml - A tool that provides an UML class diagram generator for any Crystal projects
- 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)
- tssc.cr -
Time::SpanString Converter (incl. JSON & YAML support)
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
Data Formats
- BinData - Binary data parser helper with an ASN.1 parser
- config.cr - Easy to use configuration format parser
- crinder - Class based json renderer
- Crystalizer - (De)serialize any Crystal object; supporting JSON, YAML, and Byte formats out of the box
- 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)
- jmespath.cr - Crystal implementation of JMESPath, a query language for JSON
- JSON - parsing and generating JSON documents (Crystal stdlib)
- json-schema - convert JSON serializable classes into a JSON Schema representation
- JSON::OnSteroids - handle and mutate JSON document easily
- maxminddb.cr - MaxMindDB reader
- toml.cr - TOML parser
- toon-crystal - TOON (Token-Oriented Object Notation) parser
- XML - parsing and generating XML documents (Crystal stdlib)
- YAML - parsing and generating YAML documents (Crystal stdlib)
Data Generators
- 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
Database Drivers/Clients
- couchdb.cr - CouchDB client
- cryomongo - MongoDB driver
- crystal-db - Common db api
- crystal-ldap - LDAP client
- 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
- surrealdb.cr - Unoffical SurrealDB HTTP & Websocket Client
Database Tools
Debugging
- backtracer.cr - Shard aiming to assist with parsing backtraces into a structured form
- debug.cr -
debug!(…)macro forpp-style debugging
Dependency Injection
- Athena Dependency Injection - Robust dependency injection service container framework
- 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
Environment Management
- asdf-crystal - Plugin for asdf version manager
- crenv - Crystal version manager
- rcm.cr - Redis Cluster Manager
- vfox-crystal - Plugin for vfox version manager
Examples and funny stuff
- 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
Framework Components
- Athena Event Dispatcher - A Mediator and Observer pattern event library
- Athena Negotiation - Framework agnostic content negotiation library
- device_detector - Shard for detect device by user agent string
- Exception Page - An exceptional exception page for Crystal web libraries and frameworks
- graphql - Type-safe GraphQL server implementation
- graphql-crystal - GraphQL implementation
- kemal-session - Session handler for Kemal
- mochi - Authentication shard inspired by Devise supporting: Authenticable, Confirmable, Invitable & more
- motion.cr - Object oriented frontend library for Amber
- multi-auth - Standardized multi-provider OAuth2 authentication (inspired by omniauth)
- praetorian - Minimalist authorization library inspired by Pundit
- Shield - Comprehensive security for Lucky framework
- 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
Game Development
- CrSFML - Bindings to SFML multimedia/game library
- crystal-chipmunk - Bindings to Chipmunk, a fast and lightweight 2D game physics library
- crystal-imgui-sfml - Bindings to integrate Dear ImGui into an SFML project
- entitas.cr - A Entity Component System Framework for Crystal
- MyECS - A Sparse Entity Component System Framework for Crystal
- Raylib-cr - Direct bindings to Raylib, which supports Linux, Windows, and Mac
- SDL-Crystal-Bindings - Direct (unsafe) bindings to SDL2, intended for writing own game libraries
GUI Development
- crystal-imgui - Bindings to Dear ImGui, an immediate-mode graphical UI library
- GTK4.cr - Bindings for GTK4 with Crystalized API
- Iu - UI framework based on the Fusion/libui.cr library, with custom elements and modified bindings from hedron-crystal/hedron
- Ultimate GTK4 Crystal Guide - Learn how to create premium GTK4 apps in Crystal
HTML Builders
- blueprint - Write reusable and testable HTML templates in plain Crystal
- form_builder.cr - Dead simple HTML form builder for Crystal with built-in support for many popular UI libraries such as Bootstrap
- to_html - The fastest HTML builder engine for Crystal
- Water - A library for writing HTML in plain Crystal
HTML/XML Parsing
- docx_cr_converter - parse DOCX Word
- lexbor - Fast HTML5 Parser that includes CSS selectors
HTTP
- 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
- digest-auth - Digest authentication
- 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)
- link-header - HTTP Link Header Parser
- ntlm - NTLM authentication
- proxy-fetcher.cr - Proxy lists fetching & validating library
- sse.cr - Server-Sent Events client
Image processing
- celestine - Create SVG images using a DSL
- ffmpeg - FFmpeg bindings that works with StumpyPNG to extract frames
- Pluto - A fast and convenient image processing library
- stumpy_png - Read and write PNG images
Implementations/Compilers
- 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
- novika - A free-form, moldable, interpreted programming language
- runic-lang - In-design toy language
Internationalization
- crystal-i18n - An internationalization library inspired by Ruby-I18n
- i18n.cr - Internationalization shard
- Lens - A multiformat internationalization (i18n) shard for Crystal. Supports Gettext, Ruby YAML, etc.
- Rosetta - A blazing fast internationalization (i18n) library with compile-time key lookup supporting YAML and JSON formats
Logging and monitoring
- crafana - A Grafana library to help autogenerate dashboards
- fiber_metrics.cr - Track run time, wait time, or memory allocations per
[Fiber](/@harrisonqian/awesome/wiki/back-end-development/fiber), method or block - Log - logging utility (Crystal stdlib)
- statsd.cr - Statsd client library
Machine Learning
- 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)
Markdown/Text Processors
- cr-cmark-gfm - Crystal C bindings for cmark-gfm to work with Commonmark and Github Flavored Markdown
- markd - Yet another markdown parser built for speed, Compliant to CommonMark specification
Misc
- aasm.cr - Easy to use finite state machine for Crystal classes
- any_hash.cr - Recursive Hash with better JSON::Any included
- anyolite - Full mruby interpreter with simple bindings, allowing for easy scripting support in projects
- 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
- cpf_cnpj - Provide utilities for validating and formatting CPF and CNPJ identifiers
- 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
- defined - macros for conditional compilation based on constant definitions, version requirements, or environment variable settings
- emoji.cr - Emoji library
- gphoto2-web.cr - Web API for libgphoto2
- immutable - Implementation of thread-safe, persistent, immutable collections
- iterm2 - Display images within the terminal using the ITerm2 Inline Images Protocol
- lua.cr - Bindings to liblua and a wrapper around it
- luajit.cr - LuaJIT bindings for Crystal
- monads - Monad implementation
- observable - Implementation of the observer pattern
- 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
- sentry - Build/Runs your crystal application, watches files, and rebuilds/restarts app on file changes.
- serf-handler.cr - Framework for building Serf handlers, with a suite of useful builtin capabilities
- simple_retry - Simple tool for retrying failed code blocks
- sslscan.cr - Crystal shard wrapping the rbsec/sslscan utility
- version_tools - Version-dependent behaviour, specified at compile-time
- wafalyzer - Web Application Firewall (WAF) Detector - shard + cli
- zaru_crystal - Filename sanitization
Network Protocols
- 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-bacnet - BACnet protocol implementation with BACnet/IP client
- [crystal-json-socket](https://github.com/foi/crystal-json-socket) - JSON-socket client & server implementation. Inspired by and compatible with node-json-socket and ruby-json-socket
- crystal-mqtt - A MQTT client
- crystal-snmp - An SNMP implementation with version 1, 2c and 3 support
- dns - DNS protocol implementation and resolver
- fast_irc.cr - Fast IRC parser/generator
- jwt - Implementation of JWT (JSON Web Token)
- knx - KNX protocol implementation supporting multicast, unicast and TCP/IP tunnelling
- Matter - Matter protocol for smart home and Internet of things (IoT) devices
- mDNS - DNS Service Discovery and multicast DNS
- mqtt-client.cr - A fast and lightweight MQTT client
- msgpack-crystal - MessagePack library
- OAuth - OAuth consumer (Crystal stdlib)
- OAuth2 - OAuth2 client (Crystal stdlib)
- OpenSSL - bindings to libssl (Crystal stdlib)
- simple_rpc - RPC Server and Client for Crystal. Implements msgpack-rpc protocol
- stomp - STOMP protocol
- telnet.cr - Telnet protocol
- transfer_more - Clone of transfer.sh to uploads files
Networking
- ipaddress.cr - Library to handle IPv4 and IPv6 addresses
- mac-address - Library for working with MAC addresses
ORM/ODM Extensions
- 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
- lustra - Advanced PostgreSQL ORM with ActiveRecord pattern, full-text search, geometry types, and more
- rethinkdb-orm - ORM for RethinkDB / RebirthDB
Package Management
- shards - Dependency manager for the Crystal
Processes and Threads
- await_async - Add keywords await & async in Crystal Lang
- concurrent.cr - Simplified concurrency using streams/pipelines, waitgroups, semaphores, smores and more
- neph - A modern command line job processor that can execute jobs concurrently
- promise - A Promise implementation with type inference
- werk - Dead simple task runner with concurrent support, ideal for local CI
Project Generators
- crygen - A library that allows to generate the Crystal code
- crystal_lib - Automatic binding generator for native libraries
- fez - A Kemal application generator
- libgen - Automatic bindings generator configured using JSON/YAML files
Queues and Messaging
- crafka - Apache Kafka library utilizing
librdkafka - mosquito - Redis backed periodic and ad hoc job processing
- NATS.io - NATS client
- sidekiq.cr - Simple, efficient job processing
Routing
- orion - A minimal, rails-esque routing library
- router.cr - Minimum but powerful http router for HTTP::Server
Scheduling
- crystime - Advanced time, calendar, schedule, and remind library
- schedule.cr - Run periodic tasks
- tasker - A high precision scheduler including timezone aware cron jobs
Science and Data analysis
- alea - Repeatable sampling, CDF and other utilities to work with probability distributions
- 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
Search
- hermes - Data Mapper pattern implementation for ElastiSearch
Security
- cyclonedx-cr - CycloneDX SBOM(Software Bill of Materials) generator for Crystal projects
- OWASP Noir - Attack surface detector that identifies endpoints by static analysis
- XSSMaze - XSSMaze is a web service that tests security tools using diverse XSS cases
Serverless Computing
- crystal_openfaas - Template to enable crystal as first class citizens in OpenFaaS
- secrets-env - Extends ENV module to read values injected by docker / kubernetes secrets and other orchestration tools
System
- baked_file_system - Virtual file system implementation
- hardware - Get CPU, Memory and Network informations of the running OS and its processes
Task management
- cake - Production-ready Make-like utility tool
- sam - Another one Rake-like task manager with namespacing and arguments system
Template Engine
- crinja - An implementation of the Jinja2 template engine
truncated — full list on GitHub