ty 0.0.27

on Python PyPI

Release Notes

Released on 2026-03-31.

Bug fixes

• Fix panic on debug builds when attempting to provide autocomplete suggestions for list[int]<CURSOR>() (#24167)
• Fix instance-attribute lookup in methods of protocol classes (#24213)
• Fix nested global and nonlocal lookups through forwarding scopes (#24279)
• Fix panic on list[Annotated[()]] (#24303)
• Fix stack overflow on type A = TypeIs[Callable[[], A]] (#24245)
• Use _cls as the name of the first argument for synthesized collections.namedtuple constructor methods (#24333)

LSP server

• Fix semantic token classification for properties accessed on instances (#24065)
• Grey out unused bindings in the editor (#23305)

Core type checking

• Add bidirectional type context for TypedDict get() defaults (#24231)
• Add bidirectional type context for TypedDict pop() defaults (#24229)
• Add support for functional TypedDict (#24174, #24331, #24295)
• Ban type qualifiers in PEP-695 type aliases (#24242)
• Enforce Final attribute assignment rules for annotated and augmented writes (#23880)
• Improve support for Callable type context (#23888)
• Infer lambda expressions with Callable type context (#22633)
• Don't incorrectly infer the type of a method as being a singleton type when it's accessed off an instance (#24039)
• Propagate type context through await expressions (#24256)
• Resolve union-likes in emitting union attribute errors (#24263)
• Show the user where the variable was declared as Final when emitting a diagnostic about a Final variable being reassigned (#24194)

Contributors

• @carljm
• @mvanhorn
• @oconnor663
• @ibraheemdev
• @zanieb
• @denyszhak
• @Glyphack
• @charliermarsh
• @AlexWaygood

Install ty 0.0.27

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.27/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.27/ty-installer.ps1 | iex"

Download ty 0.0.27

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>