Scala Cats

Open-source Scala projects categorized as Cats

Top 23 Scala Cat Projects

  • Scala Exercises

    The easy way to learn Scala.

    Project mention: Resources for advanced topics | | 2022-08-07

    There's also scala-exercises for advanced functional programming lessons.

  • Http4s

    A minimal, idiomatic Scala interface for HTTP

    Project mention: Grasping the concepts and getting them down to earth | | 2022-11-04

    Most important/known: * - an HTTP client/server * - streaming * - JDBC

  • SonarLint

    Clean code begins in your IDE with SonarLint. Up your coding game and discover issues early. SonarLint is a free plugin that helps you find & fix bugs and security issues from the moment you start writing code. Install from your favorite IDE marketplace today.

  • Monix

    Asynchronous, Reactive Programming for Scala and Scala.js.

    Project mention: Scala isn't fun anymore | | 2022-09-10

    The author is the creator of Monix and implemented the first version of cats-effect. He knows what he is doing.

  • Monocle

    Optics library for Scala

    Project mention: Ref in cats-effect. When should I use it, and when should I not? | | 2022-07-09

    Without concurrency, using a Ref doesn't buy you anything over just using a var. If you want the benefits of immutability with an API that resembles mutability, you have to use something like Monocle.

  • skunk

    A data access library for Scala + Postgres.

    Project mention: New to Scala; | | 2022-10-14

    The major performance issue with Skunk is tracked here. tl;dr prepared statements currently take a horrifying number of network round-trips to the database. I'm sympathetic to Rob's "what you see is what you get" priorities for Skunk. But I'm glad to see an outline of a plan that sounds like it would satisfy those objectives without being so, for lack of a better term, naïve in their pursuit.

  • sttp

    The Scala HTTP client you always wanted!

    Project mention: Scala Toolkit makes Scala powerful straight out of the box | | 2022-11-10
  • scala-pet-store

    An implementation of the java pet store using FP techniques in scala

    Project mention: Grasping the concepts and getting them down to earth | | 2022-11-04
  • Scout APM

    Truly a developer’s best friend. Scout APM is great for developers who want to find and fix performance issues in their applications. With Scout, we'll take care of the bugs so you can focus on building great things 🚀.

  • guardrail

    Principled code generation from OpenAPI specifications

    Project mention: Scala Library To Generate Case Classes for JSON | | 2022-08-16

    You may have some luck with Guardrail

  • pfps-shopping-cart

    :shopping_cart: The Shopping Cart application developed in the book "Practical FP in Scala: A hands-on approach"

    Project mention: Argument against mutation in functional programming. | | 2022-11-11

    Practical FP in Scala

  • mouse

    A small companion to cats (by typelevel)

    Project mention: Scalaz: Lost With Monoids | | 2022-02-27

    Scalaz provides |>, as does the mouse companion library for Cats.

  • Mockito Scala

    Mockito for Scala language

  • cats-mtl

    cats transformer type classes.

    Project mention: Gathering dependency management approaches | | 2022-02-21

    the advanced alternative to the reader monad is to use cats-mtl so you're just asking for capabilities of your effect, like Ask[F, GlobalConfig]

  • natchez

    functional tracing for cats

    Project mention: The wonder of context functions | | 2021-12-21

    Regarding real-world uses of this concept, I used it today to put natchez tracing in my http4s project. While the project is still small, I was shocked at the lack of invasiveness of this approach compared to usage of Kleisli to achieve the same effect.

  • monadless

    Syntactic sugar for monad composition in Scala

  • Pulsar4s

    Idiomatic, typesafe, and reactive Scala client for Apache Pulsar

  • Iteratee

    Iteratees for Cats

  • pfps-examples

    :izakaya_lantern: Standalone examples shown in the book "Practical FP in Scala: A hands-on approach"

  • meow-mtl

    Next Level MTL for Scala

    Project mention: Error handling for Cats Effect IO | | 2022-11-19

    Maybe meow-mtl?

  • cats-effect-testing

    Integration between cats-effect and test frameworks

  • Octopus

    Scala library for boilerplate-free validation (by krzemin)

  • Scala Test-State

    Scala Test-State.

  • fs2-data

    streaming data parsing and transformation library

  • xs4s

    XML Streaming for Scala including FS2/cats support

  • Zigi

    Delete the most useless function ever: context switching.. Zigi monitors Jira and GitHub updates, pings you when PRs need approval and lets you take fast actions - all directly from Slack! Plus it reduces cycle time by up to 75%.

NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020). The latest post mention was on 2022-11-19.

Scala Cats related posts


What are some of the best open-source Cat projects in Scala? This list will help you:

Project Stars
1 Scala Exercises 2,544
2 Http4s 2,351
3 Monix 1,867
4 Monocle 1,547
5 skunk 1,376
6 sttp 1,304
7 scala-pet-store 994
8 guardrail 477
9 pfps-shopping-cart 427
10 mouse 323
11 Mockito Scala 302
12 cats-mtl 282
13 natchez 277
14 monadless 257
15 Pulsar4s 207
16 Iteratee 185
17 pfps-examples 170
18 meow-mtl 160
19 cats-effect-testing 148
20 Octopus 147
21 Scala Test-State 139
22 fs2-data 101
23 xs4s 56
Build time-series-based applications quickly and at scale.
InfluxDB is the Time Series Data Platform where developers build real-time applications for analytics, IoT and cloud-native services in less time with less code.