Typelevel Projects

Reusable abstractions and data types for functional programming.

Purely functional, responsive, high performance, non-blocking I/O runtime.

Functional, effectful, concurrent stream library with support for file and network I/O.

Logging integration for Cats Effect, supporting standard SLF4J backends.

OpenTelemetry tracing and metrics for Cats Effect and applications built on it.

A library for specifiying typeclasses laws and validating that instances satisfy them.

A library for automated property-based testing with generators for randomized test data.

An integration testing framework for Cats Effect, integrated with ScalaCheck and discipline.

Yet another JSON library for Scala.

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.

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

A framework for writing serverless functions in Scala with Cats Effect and deploying them to the cloud.

Library for working with Spark using more expressive types.

gRPC implementation built on the Typelevel stack.

Kafka producer and consumer streaming support built on FS2.

Functional GraphQL server for the Typelevel stack.

A minimal, idiomatic Scala HTTP interface for client and server applications.

Integration of jawn and FS2 for streaming, incremental JSON parsing.

scodec is a combinator library for working with binary data. It focuses on contract-first and pure functional encoding and decoding of binary data.

A data access library for Scala + Postgres.

Site and e-book generator and customizable text markup transformer for sbt, Scala and Scala.js

An SBT plugin for automagically configuring good default scalac options for writing code on the Typelevel stack, based on the project Scala version.

SBT plugin for for developing, testing, cross-building, publishing, and documenting your Scala library on GitHub, with a focus on semantic versioning and binary compatibility.

A library containing logic for configuring Scala compiler options according to the current Scala compiler version. Usable as a building block for build tool plugins.

Reproducible build environments for Scala, using nix.

A Giter8 template for sbt-typelevel.

A case-insensitive string for Scala.

A thin wrapper for the Launch Darkly Java server SDK using Cats Effect and FS2.

Cats instances for various Twitter Open Source Scala projects.

A parsing library for the Cats ecosystem.

Instances for Cats Typeclasses for Java 8 date and time API.

Purely functional collection types built for use with Cats.

Monad transformers typeclasses for Cats.

A library of utilities for tagless final algebras.

A Keyed Pool Implementation for Scala.

Plugin for nicer type-lambda syntax.

Automatic type class derivation.

Compile time validation of literal values built from strings.

Enrichments to standard library classes to ease functional programming.

Functional tracing for Cats Effect.

First-class syntax for type classes.

Simulacrum as Scalafix rules.

Spire is a numeric library for Scala which is intended to be generic, fast, and precise.

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

Micro-library for building effectful protocols.

Type-safe, persistent storage for values of arbitrary types.

Automatic derivation for argonaut.

RDF, SPARQL and Linked Data technologies.

Pure, reactive UI library for building web applications with Cats Effect + FS2.

An Actor Model implementation built on top of Cats Effect, providing a higher-level abstraction for managing concurrency.

Scalatest bindings for Cats.

A software-transactional-memory implementation for Cats Effect.

Functional Configurations for Scala.

A statically typed unit analysis library for Scala.

Cross-platform CRON expression parsing for Scala.

A composable command-line parser for Scala.

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.

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”

Sharded and event-sourced entities using tagless-final algebras.

Populate case classes from any configuration source.

Library built on top of Cats that provides efficient data access from heterogeneous dataurces.

A purely functional web frontend framework for Scala.js.

Purely functional basic blocks atop of Finagle for building composable HTTP APIs.

Micro library providing AES encryption/decryption of FS2 byte streams.

Compression Algorithms for FS2.

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

Idiomatic Cats Effect + FS2 integrations for Web APIs.

Purely functional HTTP client.

Summoning implicit values.

Pure functional JDBC layer with Cats Effect 3 and Scala 3.

Purely functional, non-blocking RabbitMQ client built on top of FS2.

Compile time dimensional analysis for any problem domain.

High-performance library for composing asynchronous, event-based programs, exposing a Reactive Streams implementation along with primitives for dealing with concurrency and side-effects.

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

The Functional and Reactive Web-Frontend Library for Scala.js.

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

An actor library for Cats Effect.

Provides tools for generic programming, and typeclasses for monad transformers and higher kinded data.

A boilerplate-free library for loading configuration files.

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.

Automatic derivation for ScalaCheck.

Platform and framework for Scala devs to learn about Scala libraries.

A robot that helps keeping Scala projects up-to-date.

Code coverage tool for Scala.

Shapeless is a generic programming library. Provides advanced abstract tools like heterogenous lists and automatic instance derivation for type classes.

Operations for primitive and String singleton types.

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

A compiler plugin adding support for mutual tail recursion.

Functional user journeys.

A purely functional, interval based rate limiter.