Issues

• isinstance() with a NumPy scalar type like np.int64 doesn't narrow

  astral-sh/ty#4727 · Filter by author pylaterreur opened on Oct 14, 2026

• don't privilege un-annotated class-body assignments over method

  attributes
  astral-sh/ty#4717 · Filter by author carljm opened on Oct 13, 2026
  1

• Allow tighter types with protocols and overloads

  constraint-solverfeaturegenerics
  astral-sh/ty#4716 · Filter by author A5rocks opened on Oct 13, 2026
  2

• Class-level alias of a self-type-overloaded method resolves to the wrong overload

  bugmethod-receiveroverloadsunsoundness
  astral-sh/ty#4715 · Filter by author dgavrilov opened on Oct 13, 2026

• @deprecated is not propagated through decorators that return a callable instance

  bugcallablesdiagnostics
  astral-sh/ty#4713 · Filter by author Jeremiah-England opened on Oct 13, 2026
  1

• Solve collection literal type context through constraint solver

  bidirectional inferenceconstraint-solvergenerics
  astral-sh/ty#4712 · Filter by author ibraheemdev opened on Oct 13, 2026 · Stable
  

• Nested class override rejected even when it subclasses the inherited class

  attributesbugoverrides
  astral-sh/ty#4711 · Filter by author carljm opened on Oct 13, 2026 · Stable
  5

• new rule - overload signatures not immediately followed by the implementation

  lint
  astral-sh/ty#4709 · Filter by author DetachHead opened on Oct 13, 2026

• Completions: suggest Literal values for dict-literal values

  completionsserver
  astral-sh/ty#4705 · Filter by author karpetrosyan opened on Oct 10, 2026

• Performance regression: ty check ~1.9x slower wall-clock (≈1.4x CPU) from 0.0.82 to 0.0.83+ on a large monorepo

  performanceregression
  astral-sh/ty#4703 · Filter by author fredericmorin-flare opened on Oct 9, 2026 · Stable
  7

  

• Empty collection literals trigger unsound-assignment for abstract collection annotations

  bidirectional inference
  astral-sh/ty#4697 · Filter by author siraben opened on Oct 9, 2026
  1

• Preserve caller-fixed variable obligations during generic inference

  bugconstraint-solvergenericsneeds-designunsoundness
  astral-sh/ty#4696 · Filter by author carljm opened on Oct 8, 2026 · Stable
  1

  

• Regression in 0.0.85: bounded TypeVar rejects a valid non-generic union alternative

  bugconstraint-solvergenericsregression
  astral-sh/ty#4695 · Filter by author cmp0xff opened on Oct 8, 2026 · Stable
  1

  

• [tracking] Starlark

  astral-sh/ty#4724 · Filter by author zsol opened on Oct 8, 2026
  1

  

• Stack overflow on protocol nested intersection not self of typevar and Any twice

  fatalprotocols
  astral-sh/ty#4691 · Filter by author MeGaGiGaGon opened on Oct 7, 2026
  

• Regression: Constrained TypeVar rejected when passed to T | Protocol [invalid-argument-type]

  bugconstrained-typevarsgenericsregression
  astral-sh/ty#4686 · Filter by author AA-Turner opened on Oct 7, 2026 · Stable
  2

  

• no error when method-bound generic leaks out into the class via an attribute

  generics
  astral-sh/ty#4685 · Filter by author DetachHead opened on Oct 7, 2026 · ty-1.1
  1

• High memory usage even with empty editor

  memoryserver
  astral-sh/ty#4689 · Filter by author nocibambi opened on Oct 7, 2026
  1

• unsound-assignment rejects a generic method implementing a concrete protocol

  bugcallablesgenericsprotocols
  astral-sh/ty#4684 · Filter by author kalekseev opened on Oct 7, 2026 · ty-1.1

• Class | expressions ignore custom metaclass __or__

  bugmetaprogrammingtype-inference
  astral-sh/ty#4683 · Filter by author kalekseev opened on Oct 7, 2026

• Slow check for match on a tuple of two class unions

  narrowingperformance
  astral-sh/ty#4676 · Filter by author sunny-zuo opened on Oct 6, 2026 · Stable
  

• Pydantic: type arguments of nested generic models become Unknown in lax constructor signatures

  librarypydantic
  astral-sh/ty#4675 · Filter by author tobiasdiez opened on Oct 6, 2026
  2

• assert_never could have a friendlier error message

  diagnostics
  astral-sh/ty#4672 · Filter by author danielhollas opened on Oct 5, 2026

• Annotating a NewType with Final yields an invalid-newtype error

  astral-sh/ty#4667 · Filter by author BarrensZeppelin opened on Oct 5, 2026
  2

• [redundant-condition] warning not appropriate when condition-checking has side effects

  strict
  astral-sh/ty#4666 · Filter by author murdock-grewar opened on Oct 5, 2026
  4