ty 0.0.28

on Python PyPI

Release Notes

Released on 2026-04-02.

Bug fixes

• Mark loop header assignments as used to avoid false positives in "unused variable" diagnostics (#24336)

LSP server

• Show constructor signature of classes when hovering over them (#24257)

Core type checking

• Avoid emitting cascading diagnostics when parsing invalid type expressions (#24326)
• Handle most "deep" mutual TypeVar constraints (#24079)
• Improve consistency and quality of diagnostics relating to invalid type forms (#24325)
• Improve robustness of various type-qualifier-related checks (#24251)
• Infer the extra_items keyword argument to class-based TypedDicts as an annotation expression (#24362)
• Use bidirectional inference to fix false positives on operations such as x: list[int | None] = [None] * 2 (#24197)
• Sync vendored typeshed stubs (#24340). Typeshed diff
• Tighten up validation of subscripts and attributes in type expressions (#24329)
• Use infer_type_expression for parsing parameter annotations and return-type annotations (#24353)
• Use infer_type_expression for validating PEP-613 type aliases (#24370)
• Validate TypedDict fields when subclassing (#24338)
• Validate type qualifiers in functional TypedDict fields and the extra_items keyword to functional TypedDicts (#24360)
• Improve diagnostics for invalid functional TypedDicts (#24345)

Contributors

• @zsol
• @dcreager
• @charliermarsh
• @oconnor663
• @AlexWaygood
• @Glyphack

Install ty 0.0.28

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.28/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.28/ty-installer.ps1 | iex"

Download ty 0.0.28

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>