astral-sh/ty 0.0.39

on GitHub

Release Notes

Released on 2026-05-22.

This release removes the Python 3.9 branches from our vendored standard library stubs. ty now only has "full" support for
Python 3.10 and later, but will still report version-specific syntax errors and other diagnostics when --python-version 3.9
is provided via the CLI.

Bug fixes

• Avoid panicking on __new__ assignments to classes (#25282)
• Preserve declaration order when synthesizing class fields (#25249)
• Respect dict-compatible fallbacks in TypedDict unions (#25242)
• Retain recursively-defined state in binary expressions (#25277)

LSP server

• Add Quick Fix to remove redundant cast (#25211)
• Classify property declaration semantic tokens (#25322)
• Escape HTML syntax in docstring rendering (#25247)
• Prefer symbols from standard library over those of the same name from third party libraries for import completions. (#25108)
• Support type aliases in document symbols (#25302)

Diagnostics

• Add error context for extra callable parameters (#25269)

Performance

• Avoid exponential blow-up in fall-through narrowing (#25278)
• Speed up include filtering for projects with many literal include patterns (#25266)

Core type checking

• Allow enum member accesses on self (#25077)
• Emit a diagnostic for subclassing with order=True (#21704)
• Full-scope bidirectional inference for unconstrained container literals (#25279)
• Infer dict(TypedDict) as dict[str, object] (#24852)
• Refine Callable class-decorator fallback for unknown results (#25250)
• Reject incompatible explicit variance in generic base classes (#25327)
• Support multi-inference through type aliases (#25245)
• Sync vendored typeshed stubs (#25271, #25172)

Contributors

• @ibraheemdev
• @MatthewMckee4
• @sqqueak
• @lerebear
• @sharkdp
• @dhimasardinata
• @MichaReiser
• @charliermarsh

Install ty 0.0.39

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.39/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.39/ty-installer.ps1 | iex"

Download ty 0.0.39

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>