ty 0.0.43

on Python PyPI

Release Notes

Released on 2026-06-03.

Bug fixes

• Don't inject Unknown from non-callable elements of intersection call (#25538)
• Don't needlessly disambiguate the same type alias (#25563)
• Fix variance inference for nested type aliases (#25567)
• Ignore rejected member annotations for synthesized bindings (#25427)
• Normalize dynamic class literals in cycle recovery (#25558)
• Register file roots for first-party search paths (#25522)
• Treat union-bound typevars like unions for possibly-missing-attribute (#25561)

LSP server

• Suppress importable completions that are already in scope (#25479)

Performance

• Avoid retaining duplicate function signatures (#25609)
• Compact retained definition inference results (#25593)
• Compact retained definition kinds (#25610)
• Compact retained definitions by node (#25498)
• Consolidate AST ID reverse lookup (#25455)
• Consolidate retained use-def definition maps (#25499)
• Omit redundant definitions-by-node entries (#25501)
• Reuse common protocol constraints for TypedDict unions (#25598)

Diagnostics

• Improve error context for not-iterable diagnostics (#24944)

Core type checking

• Detect disjointness due to incompatible generic specializations (#24822)
• Distinguish typing.Callable from collections.abc.Callable (#24954)
• Include nested global/nonlocal bindings in type inference (#25387)
• Optional lower/upper bounds in individual constraints (#25435)
• Preserve slice-bound types in subscript inference (#25446)
• Reject Self in type aliases (#25529)
• Require literal booleans for TypedDict flags (#25594)
• Support narrowing on lengths (#25347)
• Synthesize precise __len__ methods for literals (#25600)
• Use callable type context to implicitly specialize generic class (#25471)
• expand type aliases inside type context unions (#25553)

Contributors

• @carljm
• @cheparity
• @kouhe3
• @sharkdp
• @charliermarsh
• @dcreager
• @thejchap
• @oconnor663

Install ty 0.0.43

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.43/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.43/ty-installer.ps1 | iex"

Download ty 0.0.43

Verifying GitHub Artifact Attestations

The artifacts in this release have attestations generated with GitHub Artifact Attestations. These can be verified by using the GitHub CLI:

gh attestation verify <file-path of downloaded artifact> --repo astral-sh/ty

You can also download the attestation from GitHub and verify against that directly:

gh attestation verify <file-path of downloaded artifact> --bundle <file-path of downloaded attestation>