awesome-crystal

bisect

Inserting values into a sorted array

blurhash.cr

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

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

qr-code

QR Code generator

radix

Radix Tree implementation

s2_cells

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

Axentro

A custom blockchain platform

Cocol

A minimal blockchain testbed

secp256k1.cr

Elliptic curve used in the public-private-key cryptography

augeas.cr

Bindings for

clang.cr

Libclang bindings

crt.cr

Bindings for libncursesw and crt

crystal-gsl

Bindings for

crystal-hunspell

Bindings for

duktape.cr

Bindings for the javascript engine

fftw.cr

Bindings for library

gphoto2.cr

Bindings for the library

gpio.cr

Bindings for the gpiod library (general purpose IO control and feedback)

icu.cr

Bindings for the library

libnotify.cr

Bindings for Libnotify

nlopt.cr

Bindings for

pcap.cr

Bindings for libpcap

pledge.cr

Bindings for OpenBSD's

ssh2.cr

Bindings for libssh2 library

syslog.cr

Bindings for

v4l2.cr

Bindings for

wasmer-crystal

Bindings for the WebAssembly runtime

win32cr

Bindings for Win32 API

x_do.cr

Bindings for libxdo ( )

crystal-memcached

Implementation of a memcached client

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

command-line options processing (Crystal stdlib)

Phreak

A highly flexible Crystal CLI builder in the style of OptionParser

climate

Tiny tool to make your CLI output 🌈 coloured

coin

Command-line application that performs currency conversion via the

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 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

ameba

A static code analysis tool

linguist.cr

Using multiple ways to find programming language used in files, based on Github's Linguist

Crystar

Readers and writers of Tar archive format

readers and writers of gzip format (Crystal stdlib)

polylines.cr

— compression of series of coordinates

snappy

Snappy compression format reader/writer for Crystal

readers and writers of zip format (Crystal stdlib)

readers and writers of zlib format (Crystal stdlib)

zstd.cr

Bindings for compression library

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

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 )

sass.cr

Compile SASS/SCSS to CSS ( binding)

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

BinData

Binary data parser helper with an 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

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 file parser (Crystal stdlib)

parsing and generating JSON documents (Crystal stdlib)

json-schema

convert JSON serializable classes into a representation

JSON::OnSteroids

handle and mutate JSON document easily

maxminddb.cr

MaxMindDB reader

toml.cr

TOML parser

parsing and generating XML documents (Crystal stdlib)

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

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

migrate

A simpler database migration tool with transactions

backtracer.cr

Shard aiming to assist with parsing backtraces into a structured form

debug.cr

macro for -style debugging

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

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

vfox-crystal

Plugin for vfox version manager

blackjack-cr

Console Blackjack

crystal-patterns

Examples of GOF patters

crystalworld

back-end API implementation

exercism-crystal

Exercism exercises

try.cr

Try monad

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 server implementation

graphql-crystal

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 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

CrSFML

Bindings to multimedia/game library

crystal-chipmunk

Bindings to , a fast and lightweight 2D game physics library

crystal-imgui-sfml

Bindings to integrate into an project

entitas.cr

A Entity Component System Framework for Crystal

MyECS

A Sparse Entity Component System Framework for Crystal

Raylib-cr

Direct bindings to , which supports Linux, Windows, and Mac

SDL-Crystal-Bindings

Direct (unsafe) bindings to , intended for writing own game libraries

crystal-imgui

Bindings to , an immediate-mode graphical UI library

GTK4.cr

Bindings for with Crystalized API

Iu

UI framework based on the library, with custom elements and modified bindings from

Learn how to create premium GTK4 apps in Crystal

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

docx_cr_converter

parse DOCX Word

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

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 (Crystal stdlib)

HTTP server (Crystal stdlib)

HTTP WebSocket client (Crystal stdlib)

link-header

HTTP Link Header Parser

ntlm

NTLM authentication

proxy-fetcher.cr

Proxy lists fetching & validating library

sse.cr

client

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

Charly Programming Language

cltk

A crystal port of the Ruby Language Toolkit

crisp

Lisp dialect implemented with Crystal

A programming language for scientific computation

mint-lang

A refreshing programming language for the front-end web

A practical, dynamic language designed to be written and understood as easily and efficiently as possible

novika

A free-form, moldable, interpreted programming language

In-design toy language

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

crafana

A library to help autogenerate dashboards

fiber_metrics.cr

Track run time, wait time, or memory allocations per , method or block

logging utility (Crystal stdlib)

statsd.cr

client library

ai4cr

Artificial Intelligence (based on )

Cadmium

NLP library based heavily on

crystal-fann

FANN (Fast Artifical Neural Network) binding

mxnet.cr

Bindings for

shainet

SHAInet (Neural Network in pure crystal)

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

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

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

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

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

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

DNS protocol implementation and resolver

crystal-json-socket

JSON-socket client & server implementation. Inspired by and compatible with and

crystal-mqtt

A MQTT client

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)

knx

KNX protocol implementation supporting multicast, unicast and TCP/IP tunnelling

mDNS

DNS Service Discovery and multicast DNS

mqtt-client.cr

A fast and lightweight MQTT client

msgpack-crystal

MessagePack library

OAuth consumer (Crystal stdlib)

OAuth2 client (Crystal stdlib)

bindings to libssl (Crystal stdlib)

simple_rpc

RPC Server and Client for Crystal. Implements msgpack-rpc protocol

stomp

STOMP protocol

telnet.cr

Telnet protocol

Clone of transfer.sh to uploads files

ipaddress.cr

Library to handle IPv4 and IPv6 addresses

mac-address

Library for working with MAC 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

rethinkdb-orm

ORM for RethinkDB / RebirthDB

shards

Dependency manager for the Crystal

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

crystal_lib

Automatic binding generator for native libraries

fez

A Kemal application generator

libgen

Automatic bindings generator configured using JSON/YAML files

crafka

Apache Kafka library utilizing

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

Advanced time, calendar, schedule, and remind library

schedule.cr

Run periodic tasks

tasker

A high precision scheduler including timezone aware cron jobs

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

hermes

Data Mapper pattern implementation for ElastiSearch

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

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

crustache

for 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

Athena Spec

Common/helpful compliant testing utilities

crotest

A tiny and simple test framework

crytic

Mutation testing framework

hashr

A tiny class makes test on JSON response easier

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

selenium.cr

Selenium client for interacting with web pages for browser automation

spec framework (Crystal stdlib)

Feature rich spec framework that uses the modern expect syntax

timecop.cr

Library for mocking with . Inspired by the

vcr

A HTTP capture and replay implementation for crystal

webdriver_pump

Page Object library. Inspired by Ruby's

webmock.cr

Library for stubbing requests

amazonite

An unofficial SDK supporting popular AWS APIs

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 API

crystal-swapi

Star Wars API (SWAPI) wrapper

crystal_slack

A tool that parses Slack slash commands or send incoming web hooks

GDAX

GDAX REST and WebSocket API Wrapper with request signing

gitlab.cr

GitLab API wrapper

google

Google API wrapper

host_meta

A Web Host Metadata ( ) client

kube-client.cr

Kubernetes API Client

mixpanel-crystal

A library for sending events to Mixpanel

mollie.cr

Payments API wrapper (Creditcard, PayPal, Apple Pay, Sofort, Klarna, ...)

office365

Microsoft Graph API wrapper

pinboard.cr

API

raven.cr

Raven is a client for

stripe.cr

Stripe api wrapper

tmdb.cr

The Movie DB (TMDb) api wrapper

twitter-crystal

A library to access the Twitter API

web_finger

A WebFinger ( ) client

ynab.cr

A library to interact with your YNAB data

accord

Shareable validation library for Crystal Objects

Athena Validator

Robust & flexible validation framework

validations

Validations mixin

validator

Data check and validation

amber

Open source efficient and cohesive web application framework

Athena

A web framework comprised of reusable, independent components

grip

The microframework for writing powerful web applications

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

marten

A web framework that makes building web applications easy, productive, and fun

runcobo

An api framework with simple, intuitive and consistent DSL, using jbuilder to render json

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-lang on Libera

来吧！TG 中文圈的朋友们！

Unofficial Discord server dedicated to the Crystal Programming Language

Bem vindos ao Crystal Brasil!

Добро пожаловать, товарищ!

Free book to bootstrap your Crystal journey

Crystal Shards for Ruby Gems

A list of Ruby Gems and their Crystal Shards equivalents

crystal-koans

Learn Crystal by writing unit tests

Official language site

API Documentation Browser with Crystal support

Quick tutorial on Crystal

PragProg book to start your Crystal journey

Comparison of Python, Rust, Crystal

Brazilian

Japanese

Korean

Russian

Chinese Traditional

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

Announce new project, blog post, version update or any other Crystal work

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

procodile

Run processes in the background (and foreground) on Mac & Linux from a Procfile (for production and/or development environments)

Generate models and serializers from JSON, JSON Schema, GraphQL, and TypeScript

Web service that lists all repositories on GitHub that have Crystal code in them. The sources are available on

ast_helper

Helper tool to debug parser and formatter

crystal-base

CentOS base docker image for Crystal development

crystal-dash-docset

docset generator

port_ruby_to_crystal

A regex replace ruby script for port ruby code to crystal easier, reduce friction

public_suffix

A small library designed to make the Public Suffix List ( ) easier to use

ansible-crystal

Ansible playbook for installing crystal

DPPM

An easy, universal way to install and manage applications as packages (mostly Linux)

acmecrystal

Reformats crystal code in acme

Enables built in tools in Crystal compiler

Crystal language support in Atom

Crystal language support for Emacs ( )

geany-crystal

Crystal support for the

intellij-crystal-lang

Crystal support for the JetBrains IDEs

lite-plugin-crystal

Crystal support for the editor

crystal-spacemacs-layer

Spacemacs contribution layer for Crystal

sublime-crystal

Crystal syntax highlighting for sublime Text

Crystal.tmbundle

Crystal syntax highlighting, compile, format command, snippets

vim-crystal

Vim filetype support for Crystal

vim-slang

Vim filetype support for Slang Templating Engine

vscode-crystal-lang

Formatter, linter and syntax highlighting for and files

crystalline

Crystalline is an implementation of the Language Server Protocol written in and for the Crystal Language

scry

Code analysis server for Crystal implementing the

crun

Crystal Run : shebang wrapper for Crystal

crystal-zsh

.oh-my-zsh plugin