scala-pet-store VS FS2

Compare scala-pet-store vs FS2 and see what are their differences.


An implementation of the java pet store using FP techniques in scala (by pauljamescleary)


Compositional, streaming I/O library for Scala (by typelevel)
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scala-pet-store FS2
6 8
911 2,014
- 1.5%
7.4 9.8
3 days ago about 22 hours ago
Scala Scala
Apache License 2.0 GNU General Public License v3.0 or later
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.


Posts with mentions or reviews of scala-pet-store. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2022-01-22.


Posts with mentions or reviews of FS2. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2021-07-11.
  • How to update and access state that needs to be shared across multiple API endpoints with FP?
    1 project | | 14 Jan 2022
    Another more reactive solution would to use signals, as in FPR sinal network. fs2 implements this very nicely here
  • Introducing effects systems S.A. ZIO at work?
    1 project | | 23 Aug 2021
    Assuming the bug mentioned here is, we came up with a partial fix in a day ( and a complete fix in 2 days: Note the original bug was opened on a Saturday. :)
  • ScalablyTyped publishes Scala 3 support
    2 projects | | 11 Jul 2021
    As of very recently, we're using ScalablyTyped in our fs2-io cross build for node.
  • Improving akka http code
    3 projects | | 23 Jun 2021
    In that case, it's best to keep different streaming libraries separate, in their own little "worlds". fs2 + cats has Queues for this purpose Future has the Promise abstraction.
  • Learning FS2
    1 project | | 20 May 2021
    So far I'm aware of a great documentation that is out there ( and some resources (
  • Scala 3 is here!
    2 projects | | 14 May 2021
    ScalaZ was changed to cats-effect. For streaming, look at fs2. Cats-effect 3 cleans up a lot of the library, but as with any code it can be clean or messy depending on the dev
  • [FS2] - Mutability of Queue in Stream
    1 project | | 4 Apr 2021
    Lets decompose this code from the article a little. The definition of circularBuffer indicates that given a buffer size the function will return G[Queue[F, A]]. G is some higher kinded type with an implementation of the Sync typeclass ( (a typeclass for suspending synchronous actions). Why is G needed? Well Queue's are asynchronous data structures so some concurrency primitives must be allocated like Ref and Deferred. (
  • Example of building web apis (functionally) in Scala
    12 projects | | 16 Feb 2021
    Watch the talk "Streams - Your New Favorite Primitive" by Ryan Peters (aka sloshy) and then looking into the docs of fs2. - This one to learn one of the most used / useful libraries of the typelevel ecosystem to process data.

What are some alternatives?

When comparing scala-pet-store and FS2 you can also consider the following projects:

cats-effect - The pure asynchronous runtime for Scala

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


Http4s - A minimal, idiomatic Scala interface for HTTP

ScalaMeter - Microbenchmarking and performance regression testing framework for the JVM platform.

Mockito Scala - Mockito for Scala language

Gatling - Modern Load Testing as Code

Scala Test-State - Scala Test-State.

ScalaTest - A testing tool for Scala and Java developers

ScalaMock - Native Scala mocking framework

Specs2 - Software Specifications for Scala

Minitest - The super light testing library for Scala and Scala.js