ty 0.0.89

on Python PyPI

Release Notes

Released on 2026-10-16.

Core type checking

• Added support for return type inference for unannotated functions and methods (#29253).

  Return type inference is currently disabled by default. Enable it with the analysis.return-type-inference setting in pyproject.toml:

  [tool.ty.analysis]
  return-type-inference = "always"

  Or in ty.toml:

  [analysis]
  return-type-inference = "always"

  Please share your feedback, especially any problems you encounter, in the return type inference feedback issue.

• Sync vendored typeshed stubs (#29402). Typeshed diff

Bug fixes

• Avoid a panic when negating dynamic type aliases (#29427)
• Widen tuple literal lengths when other collection elements contain nested tuple types (#29147)
• Report invalid Generic and Protocol arguments containing nested variadic type variables (#29146)

Performance

• Speed up generic class-pattern narrowing by skipping impossible intersection comparisons (#29240)

Contributors

• @carljm
• @charliermarsh
• @sharkdp

Install ty 0.0.89

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.89/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.89/ty-installer.ps1 | iex"

Download ty 0.0.89

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>