Issues

• Next release? - 2.13.0 is 18 months old

  typelevel/cats#4910 · Filter by author Pucilowski opened on Sep 22, 2026
  1

  

• Drop JDK 8 and add -Yfuture-lazy-vals option for avoid sun.misc.Unsafe

  typelevel/cats#4871 · Filter by author xuwei-k opened on Jun 13, 2026
  2

• Applicative[OneAnd[ZipLazyList, *]] works incorrectly

  typelevel/cats#4840 · Filter by author satorg opened on Mar 8, 2026

• Typeclass instances for ZipLazyList and ZipStream seem to be unlawful

  typelevel/cats#4830 · Filter by author satorg opened on Feb 22, 2026
  12

  

• A Nullable type for scala3

  typelevel/cats#4822 · Filter by author johnynek opened on Feb 15, 2026
  12

• Unexpected behavior of NonEmptyList.reduce for tuples of lists

  typelevel/cats#4817 · Filter by author kiendang opened on Jan 31, 2026
  1

• catsSyntaxEq returns false for equality of positive and negative zero in Option

  typelevel/cats#4807 · Filter by author charlesandrews opened on Jan 8, 2026
  4

• UnorderedTraverse should extend Functor

  typelevel/cats#4802 · Filter by author johnynek opened on Dec 20, 2025
  4

• Add commonly known operators to algebra type classes

  typelevel/cats#4795 · Filter by author ldeluigi opened on Nov 25, 2025
  6

• Named version of mapN and friends

  typelevel/cats#4792 · Filter by author BalmungSan opened on Nov 14, 2025

• Add EuclidianRing[Int, Long, Short, Byte] to Alleycats

  typelevel/cats#4788 · Filter by author TheDrawingCoder-Gamer opened on Nov 3, 2025

• IArray instances (Scala 3)

  typelevel/cats#4787 · Filter by author TheDrawingCoder-Gamer opened on Oct 28, 2025

• Warning: "Calls to parameterless method compose will be easy to mistake for calls to overloads which have a single implicit parameter list"

  typelevel/cats#4783 · Filter by author saeltz opened on Oct 21, 2025
  12

• Tuple semigroupal syntax widens constant type in Scala 3

  typelevel/cats#4770 · Filter by author mrdziuban opened on Sep 15, 2025

• NonEmptyList lacks def updated at index

  typelevel/cats#4763 · Filter by author mcanlas opened on Aug 20, 2025
  6

  

• Hierarchy of cats effect in Cats documentation does not match the one in the cats effect docs

  typelevel/cats#4757 · Filter by author nmichael44 opened on Jul 2, 2025
  3

• Scala 3: Support mapN for tuples greater than 22

  typelevel/cats#4746 · Filter by author hearnadam opened on May 16, 2025
  3

• Monad Transformer typeclass

  typelevel/cats#4727 · Filter by author johnynek opened on Mar 4, 2025
  2

• Add withFilter to FunctorFilter.Ops

  typelevel/cats#4709 · Filter by author ikeyan opened on Jan 28, 2025
  1

• drop/dropRight/take/takeRight on TraverseFilter

  typelevel/cats#4696 · Filter by author johnynek opened on Jan 3, 2025
  1

• Either.catchOnly and -Yexplicit-nulls are not playing well together

  typelevel/cats#4681 · Filter by author joan38 opened on Nov 23, 2024
  8

• algebra.ring.Semiring conflicts with Wikipedia Semiring definition in that it lacks a one element

  typelevel/cats#4664 · Filter by author benhutchison opened on Oct 10, 2024
  1

• Sporadic test errors since upgrading to Native 0.5

  typelevel/cats#4647 · Filter by author armanbilge opened on Aug 27, 2024
  10

• A flaky test fired in CokleisliSuite on the Native Platform

  testing
  typelevel/cats#4639 · Filter by author danicheg opened on Jul 23, 2024
  2

• Cats Order needs an orElseBy combinator

  typelevel/cats#4621 · Filter by author benhutchison opened on Jun 15, 2024
  16