ty
ty is an extremely fast Python type checker written in Rust. It performs gradual type checking, validating type annotations where they exist without requiring full type coverage.
Run Locally
The mozlint integration of ty can be run using mach:
$ mach lint --linter ty <file paths>
Configuration
ty is configured in the root pyproject.toml file under the [tool.ty]
section. The exclude patterns from ruff’s configuration are also applied to ty
to reduce duplication. For more details on configuration
options, see the ty documentation.