Platforms

case-insensitive

A case-insensitive string for Scala

Cats

A library intended to provide abstractions for functional programming in Scala, leveraging its unique features. Design goals are approachability, modularity, documentation and efficiency.

Cats Collections

Data structures that facilitate pure functional programming with cats

Cats-Effect

The IO Monad for Scala, plus type classes for general effect types.

Cats MTL

Monad transformers made easy

cats-parse

A parsing library for the cats ecosystem

cats-stm

A STM implementation for Cats Effect

Cats Tagless

A library of utilities for tagless final algebras

Cats-Time

Instances for Cats Typeclasses for Java 8 Time

Circe

Yet another JSON library for Scala

Ciris

Functional Configurations for Scala

coulomb

A statically typed unit analysis library for Scala

decline

A composable command-line parser for Scala.

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.

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.

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”

fabric

Object-Notation Abstraction for JSON, binary, HOCON, etc.

fs2-data

Parse and transform data (CBOR, CSV, JSON, XML) in a streaming manner

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).

Grackle

Functional GraphQL server for the Typelevel stack

http4s

A typeful, purely functional HTTP library for client and server applications

jawn-fs2

Integration of jawn and fs2 for streaming, incremental JSON parsing

keypool

A Keyed Pool Implementation for Scala

Kittens

Automatic type class derivation

Lepus

Purely functional, non-blocking RabbitMQ client for scala, scala js and scala native built on top of fs2.

literally

Compile time validation of literal values built from strings

log4cats

Logging Tools For Interaction with cats-effect

Monocle

Optics library offering a simple yet powerful API to access and transform immutable data

Mouse

Enrichments to standard library classes to ease functional programming

Natchez

functional tracing for cats

otel4s

An OpenTelemetry library based on cats-effect

parsley-cats

The parsley-cats library exposes Cats instances for Parsley parsing library.

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.

ScalaCheck

ScalaCheck is a library for automated property-based testing. It contains generators for randomized test data and combinators for properties.

scalacheck-shapeless

Automatic derivation for ScalaCheck

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.

Scoverage

Code coverage tool for Scala

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.

simulacrum

First-class syntax for type classes

Skunk

A data access library for Scala + Postgres

specs2

specs2 is a library for writing executable software specifications, aiming for conciseness, readability and extensibility.

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.

Squants

The Scala API for Quantities, Units of Measure and Dimensional Analysis

Twiddles

Micro-library for building effectful protocols

typelevel-nix

Development tools for Typelevel projects

upperbound

A purely functional, interval based rate limiter

vault

Type-safe, persistent storage for values of arbitrary types