Projects
Our projects cover a wide range of domains, from general functional programming to tooling.
argonaut-shapeless
Automatic derivation for argonaut
jvm
banana-rdf
RDF, SPARQL and Linked Data technologies
js / jvm
calico
Pure, reactive UI library for building web applications with Cats Effect + FS2
js
case-insensitive
A case-insensitive string for Scala
js / jvm / native
catapult
A thin wrapper for the Launch Darkly Java server SDK using cats-effect and fs2
jvm
catbird
Cats instances for various Twitter Open Source Scala projects
jvm
Cats
A library intended to provide abstractions for functional programming in Scala, leveraging its unique features. Design goals are approachability, modularity, documentation and efficiency.
js / jvm / native
Cats Collections
Data structures that facilitate pure functional programming with cats
js / jvm / native
Cats-Effect
The IO Monad for Scala, plus type classes for general effect types.
js / jvm / native
Cats MTL
Monad transformers made easy
js / jvm / native
cats-parse
A parsing library for the cats ecosystem
js / jvm / native
cats-scalatest
Scalatest bindings for Cats.
js / jvm
Cats Tagless
A library of utilities for tagless final algebras
js / jvm / native
Cats-Time
Instances for Cats Typeclasses for Java 8 Time
js / jvm / native
Ciris
Functional Configurations for Scala
js / jvm / native
coulomb
A statically typed unit analysis library for Scala
js / jvm / native
cron4s
Cross-platform CRON expression parsing for Scala
js / jvm
decline
A composable command-line parser for Scala.
js / jvm / native
discipline
Originally intended for internal use in spire, this library helps libraries declaring type classes to precisely state the laws which instances need to satisfy, and takes care of not checking derived laws multiple times.
js / jvm / native
doobie
A pure functional JDBC layer for Scala. It is not an ORM, nor is it a relational algebra; it just provides a principled way to construct programs (and higher-level libraries) that use JDBC.
jvm
edomata
Event-driven automata for Scala, Scala.js and scala native. This library provides purely functional state machines that can be used to create event sourced and/or CQRS style applications. It also includes production ready backends.
js / jvm / native
eff
Extensible effects are an alternative to monad transformers for computing with effects in a functional way. This library is based on the “free-er” monad and an “open union” of effects described by Oleg Kiselyov in “Freer monads, more extensible effects”
js / jvm / native
endless4s
Sharded and event-sourced entities using tagless-final algebras
jvm
Extruder
Populate case classes from any configuration source
jvm
fabric
Object-Notation Abstraction for JSON, binary, HOCON, etc.
js / jvm / native
Feral
Feral cats are homeless, feral functions are serverless
js / jvm
ff4s
A purely functional web frontend framework for Scala.js.
js
Fetch
Library built on top of Cats that provides efficient data access from heterogeneous dataurces
js / jvm
Finch
Purely functional basic blocks atop of Finagle for building composable HTTP APIs
jvm
Frameless
Frameless is a library for working with Spark using more expressive types.
jvm
fs2-aes
Micro library providing AES encryption/decryption of fs2.Stream[F, Byte].
jvm
fs2-compress
Compression Algorithms for Fs2
jvm
fs2-data
Parse and transform data (CBOR, CSV, JSON, XML) in a streaming manner
js / jvm / native
fs2-dom
Idiomatic Cats Effect + FS2 integrations for Web APIs
js
fs2-grpc
gRPC implementation for FS2/cats-effect
jvm
fs2
FS2 is a library for purely functional, effectful, and polymorphic stream processing library in the Scala programming language. Its design goals are compositionality, expressiveness, resource safety, and speed. The name is a modified acronym for Functional Streams for Scala (FSS, or FS2).
js / jvm / native
Hammock
Purely functional HTTP client
jvm
http4s
A typeful, purely functional HTTP library for client and server applications
js / jvm / native
imp
Summoning implicit values
js / jvm
jawn-fs2
Integration of jawn and fs2 for streaming, incremental JSON parsing
js / jvm / native
keypool
A Keyed Pool Implementation for Scala
js / jvm / native
kind-projector
Plugin for nicer type-lambda syntax
jvm
Kittens
Automatic type class derivation
js / jvm / native
Laika
Site and e-book generator and customizable text markup transformer for sbt, Scala and Scala.js
js / jvm
Lepus
Purely functional, non-blocking RabbitMQ client for scala, scala js and scala native built on top of fs2.
js / jvm / native
Libra
Compile time dimensional analysis for any problem domain
js / jvm
log4cats
Logging Tools For Interaction with cats-effect
js / jvm / native
Monix
High-performance library for composing asynchronous, event-based programs, exposing a Reactive Streams implementation along with primitives for dealing with concurrency and side-effects.
js / jvm
Monocle
Optics library offering a simple yet powerful API to access and transform immutable data
js / jvm / native
Mouse
Enrichments to standard library classes to ease functional programming
js / jvm / native
Natchez
functional tracing for cats
js / jvm / native
otel4s
An OpenTelemetry library based on cats-effect
js / jvm / native
Outwatch
The Functional and Reactive Web-Frontend Library for Scala.js
js
parsley-cats
The parsley-cats library exposes Cats instances for Parsley parsing library.
js / jvm / native
PureConfig
A boilerplate-free library for loading configuration files
jvm
refined
Tools for refining types with type-level predicates which constrain the set of values described by the refined type, for example restricting to positive or negative numbers.
js / jvm / native
ScalaCheck
ScalaCheck is a library for automated property-based testing. It contains generators for randomized test data and combinators for properties.
js / jvm / native
scalacheck-shapeless
Automatic derivation for ScalaCheck
js / jvm / native
Scala Exercises
Platform and framework for Scala devs to learn about Scala libraries
js / jvm
scala-steward
A robot that helps keeping Scala projects up-to-date
jvm
scodec
scodec is a combinator library for working with binary data. It focuses on contract-first and pure functional encoding and decoding of binary data and provides integration with shapeless.
js / jvm / native
Scoverage
Code coverage tool for Scala
js / jvm / native
Shapeless
Shapeless is a generic programming library. Starting with implementations of Scrap your boilerplate and higher rank polymorphism in Scala, it quickly grew to provide advanced abstract tools like heterogenous lists and automatic instance derivation for type classes.
js / jvm / native
simulacrum
First-class syntax for type classes
js / jvm / native
Simulacrum Scalafix
Simulacrum as Scalafix rules
js / jvm
singleton-ops
Operations for primitive and String singleton types
js / jvm
Skunk
A data access library for Scala + Postgres
js / jvm / native
sonic
Property-based testing with integrated shrinking
jvm
specs2
specs2 is a library for writing executable software specifications, aiming for conciseness, readability and extensibility.
js / jvm / native
spire
Spire is a numeric library for Scala which is intended to be generic, fast, and precise. Using features such as specialization, macros, type classes, and implicits, Spire works hard to defy conventional wisdom around performance and precision trade-offs.
js / jvm / native
Squants
The Scala API for Quantities, Units of Measure and Dimensional Analysis
js / jvm / native
TwoTails
A compiler plugin adding support for mutual tail recursion
jvm
typelevel.g8
A Giter8 template for sbt-typelevel
js / jvm
typelevel-nix
Development tools for Typelevel projects
js / jvm / native
uniform-scala
Functional user journeys
js / jvm
vault
Type-safe, persistent storage for values of arbitrary types
js / jvm / native
