Release Notes
Released on 2026-09-24.
Bug fixes
- Fix stale diagnostics from the LSP server after toggling
showSyntaxErrors(#28759)
LSP server
- Complete string keys from dictionary initializers (#28820)
- Support LSP requests against closed documents (#28595)
- Select projects for external files using import search paths (#28594)
- Use workspace editor settings for external files (#28639)
Performance
- Avoid repeated subtyping checks for materialized recursive protocols (#28774)
- Skip reading notebooks when discovering scripts (#28781)
Core type checking
- Avoid incorrect simplification of
TypeIsmaterializations (#28817) - Fix disjointness of generic class types (#28787)
- Fix staticmethod shadowing through generic receivers and unions (#28766)
- Infer callable signatures from bounded type variables (#28599)
- Infer constant membership in inline list and set literals (e.g.
"foo" in ["foo"]is now inferred asLiteral[True]) (#28676) - Infer through optional generic containers in the legacy solver (#28791)
- Preserve call narrowing during cyclic inference (#28708)
- Preserve intersections of type guard return types (#28796)
- Use subtyping for constraint-set implication (#28657)
Configuration
- Disable
invalid-legacy-positional-parameterby default (#28834)
Other changes
- Only consider reachable definitions when determining whether a condition should be exempted from
redundant-condition(-strict)due to the condition being defined relative tosys.version_info,sys.platform,os.nameortyping.TYPE_CHECKING(#28788)
Contributors
Install ty 0.0.84
Install prebuilt binaries via shell script
curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ty/releases/download/0.0.84/ty-installer.sh | shInstall prebuilt binaries via powershell script
powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ty/releases/download/0.0.84/ty-installer.ps1 | iex"Download ty 0.0.84
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/tyYou 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>