astral-sh/ty 0.0.69

on GitHub

Release Notes

Released on 2026-08-06.

Core type checking

• isinstance narrowing for generic classes is now more gradual by default (#27308)

  This new behavior is more similar to what other major type checkers do. For example:

  def f(xs: object):
      if isinstance(xs, list):
          reveal_type(xs)  # now: `list[Unknown]`, before: `Top[list[Unknown]]`

  Note: you might consider enabling analysis.strict-generic-narrowing
  if you prefer the strictly correct behavior.

Contributors

• @sharkdp

Install ty 0.0.69

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.69/ty-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.69/ty-installer.ps1 | iex"

Download ty 0.0.69

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>