0.0.69

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

File	Platform	Checksum
ty-aarch64-apple-darwin.tar.gz	Apple Silicon macOS	checksum
ty-x86_64-apple-darwin.tar.gz	Intel macOS	checksum
ty-aarch64-pc-windows-msvc.zip	ARM64 Windows	checksum
ty-i686-pc-windows-msvc.zip	x86 Windows	checksum
ty-x86_64-pc-windows-msvc.zip	x64 Windows	checksum
ty-aarch64-unknown-linux-gnu.tar.gz	ARM64 Linux	checksum
ty-i686-unknown-linux-gnu.tar.gz	x86 Linux	checksum
ty-powerpc64-unknown-linux-gnu.tar.gz	PPC64 Linux	checksum
ty-powerpc64le-unknown-linux-gnu.tar.gz	PPC64LE Linux	checksum
ty-riscv64gc-unknown-linux-gnu.tar.gz	RISCV Linux	checksum
ty-s390x-unknown-linux-gnu.tar.gz	S390x Linux	checksum
ty-x86_64-unknown-linux-gnu.tar.gz	x64 Linux	checksum
ty-armv7-unknown-linux-gnueabihf.tar.gz	ARMv7 Linux	checksum
ty-aarch64-unknown-linux-musl.tar.gz	ARM64 MUSL Linux	checksum
ty-i686-unknown-linux-musl.tar.gz	x86 MUSL Linux	checksum
ty-x86_64-unknown-linux-musl.tar.gz	x64 MUSL Linux	checksum
ty-arm-unknown-linux-musleabihf.tar.gz	ARMv6 MUSL Linux (Hardfloat)	checksum
ty-armv7-unknown-linux-musleabihf.tar.gz	ARMv7 MUSL Linux	checksum

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>