ty Files

Release Notes

Released on 2026-05-16.

Bug fixes

• Avoid unsound not in narrowing (#25161)
• Fix async iteration over narrowed typevars (#25155)
• Fix panic in double-inference for single starred positional TypedDict (#25176)
• Fix panic in disjoint base check (#25187)
• Fix panic in recursive binary inference (#25189)
• Fix panic in cyclic __new__ (#25185)
• Fix panic in reveal_protocol, reveal_mro, etc. with keyword arguments (#25179)
• Fix panic in imported overload definition (#25168)

LSP server

• Don't show argument inlay for case-insensitive matches or prefix/suffixes (#25174)
• Reduce CPU usage of the LSP when switching between large changesets (#25142)

Core type checking

• Avoid enforcing __new__ with custom metaclasses (#25180)
• Make overload public type reachability-aware (#25171)
• Only specialized types of generic class instances should influence variance (#25124)
• Preserve ParamSpec argument context through wrapper calls (#24934)
• Support partially specialized type context for collection literals (#24506)

Contributors

• @RasmusNygren
• @MichaReiser
• @charliermarsh
• @ibraheemdev

Install ty 0.0.37

Install prebuilt binaries via shell script

:::sh
curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.37/ty-installer.sh | sh

Install prebuilt binaries via powershell script

:::sh
powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.37/ty-installer.ps1 | iex"

Download ty 0.0.37

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:

:::sh
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:

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