Ty: The Blazingly Fast Python Type Checker From Astral (ruff & Uv... (2026)

Astral, the company behind popular Python tools like Ruff and uv, has released a new type checker called ty. Built in Rust, it promises to revolutionize Python type checking with incredible speed and powerful features.

ty can type-check the entire Home Assistant project in ~2.19 seconds, compared to mypy's 45.66 seconds. That's over 20x faster!

For large codebases, this speed difference transforms the developer experience:

Here's the magic: ty can find bugs even without type annotations. Let's look at some examples.

ty will warn you that .exec() doesn't exist on the connection object!

However, even in beta, ty is already catching real bugs and providing value in production codebases.

Here's a practical workflow for adopting ty in your project:

ty will show you actual bugs in your code, even without type annotations!

As you maintain your code, gradually add type annotations where it makes sense:

According to Astral, ty is targeting a stable 1.0 release in 2026, with plans for:

Source: Dev.to