ty 0.0.18

on Python PyPI

Release Notes

Released on 2026-02-20.

Bug fixes

• Support classes dynamically created via type(...) with cyclic bases (#22792)
• Fix incorrect types inferred when unpacking mixed tuples (#23437)
• Fix stack overflow for self-referential TypeOf in annotations (#23407)
• Fix several server panics that could occur when computing semantic tokens for the current file (#23403), #23398, #23401)

LSP server

• Add code folding support (#23393)
• Add warning message when running ty server interactively (#23416)
• Exclude test-related symbols from non-first-party packages in auto-import completions (#23252)
• Fix bug where diagnostics could disappear after opening an external file (#23447)
• Remove spurious destination for Go-To Definition on variables defined in a loop (#23391)
• Use the fully qualified name when "baking" an inlay hint into the source code if the scope already contains a variable with the same name as the unqualified name (#23265)
• Resolve TypeVars in call_signature_details parameter types (#23149)

CLI

• Add --output-format to ty version (#23387)

Configuration

• Add replace-imports-with-any option (#23122)
• Support shellexpand for configuration paths (#23274)

Type checking

• Add a new diagnostic to detect invalid class patterns in match statements (#22939)
• Allow Self in ClassVar type annotations (#23362)
• Consider synthesized methods and ClassVar-qualified declarations when determining whether an abstract method has been overridden in a subclass (#23381)
• Add a diagnostic when combining Final and ClassVar (#23365)
• Fix return type of assert_never (#23389)
• Fix assert_type diagnostic messages (#23342)
• Ban PEP-613 type alias values from containing type-qualifier special forms (#23444)
• Infer LiteralString for f"{literal_str_a} {literal_str_b}" (#23346)
• Infer precise types for bit-shift operations on integer literals (#23301)
• Make [abstract-method-in-final-class] diagnostics less verbose for classes with many abstract methods (#23379)
• Improve diagnostics for abstract @final classes (#23376)
• Only perform literal promotion for implicitly inferred literals (#23107)
• Parenthesize callable types when they appear in the return annotation of other callable types (#23327)
• Consider a call to a generic function returning Never to terminate control flow (#23419)
• Support calls to intersection types (#22469)
• Validate annotated assignments to attributes on self (#23388)
• Treat a bytes-literal type as a subtype of Sequence[<constituent integers in the bytestring>] (#23329)
• Allow a string-literal argument to match against an Iterable parameter in type variable inference. (#23326)
• Support narrowing from a Callable type returning a TypeGuard type (#23280)

Performance

• Consider all code paths as being ambiguously reachable in cases with pathologically large control-flow graphs (#23399)

Typeshed

• Sync vendored typeshed stubs (#23279, Typeshed diff)

Contributors

• @toby-bro
• @Hugo-Polloli
• @MatthewMckee4
• @BurntSushi
• @ibraheemdev
• @knutwannheden
• @Glyphack
• @charliermarsh
• @AlexWaygood
• @abhijeetbodas2001
• @carljm
• @sharkdp

Install ty 0.0.18

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ty/releases/download/0.0.18/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ty/releases/download/0.0.18/ty-installer.ps1 | iex"

Download ty 0.0.18