December 16, 2025
Rust goes brrr, comments go boom
Ty: A fast Python type checker and LSP
Rust-fast ‘ty’ crashes Python’s party — cheers, side‑eye, and spicy takes
TLDR: Astral launched the Beta of ty, a Rust-powered tool that checks Python code and runs in editors, boasting huge speed gains. The community is split between excitement about replacing old tools and skepticism about stability and correctness, with many asking for proof in comparison tests and cautioning after past tool gaps.
Astral just dropped the Beta of ty, a Rust-built tool that checks your Python code and powers editor features, bragging it’s 10–60x faster than today’s favorites. Translation for non-nerds: it promises near-instant “is my code okay?” answers while you type. The dev crowd? Absolutely buzzing.
The hype squad rolled in first: one fan learned ty is also a language server and crowed it could replace both mypy (the old guard) and Pyright (the current favorite) in VS Code and Neovim. But then the skeptics arrived with receipts. A frustrated tester waved off the confetti, saying their “first impression of ty isn’t great,” after already getting burned by crashy updates in rival tool Pyrefly. Others demanded proof: how “correct” is ty versus mypy, and when will it show up in those nerdy comparison tables? One commenter even shaded Astral’s last hit, Ruff, saying it didn’t replace basic pylint checks and hinting at a backlog of pull requests — the subtext: speed is cool, but trust is earned.
Cue the memes: “Rust go brrr” vs. “who checks the checker?” It’s a classic internet split — team Wow That’s Fast versus team Show Me It’s Right. If ty really delivers instant feedback without faceplants, developers’ daily grind just got a lot smoother. If not, back to the flame wars.
Key Points
- •Astral released the Beta of Ty, a Rust-based Python type checker and language server.
- •Ty’s architecture is built for incrementality, enabling fast selective recomputation in editors.
- •Astral claims Ty is 10x–60x faster than mypy and Pyright without caching, with 4.7ms diagnostic recomputation in a PyTorch edit scenario.
- •Ty introduces features like intersection types, advanced type narrowing, and reachability analysis based on types.
- •Ty can be installed via “uv tool install ty@latest” or through a VS Code extension, and Astral uses it in their own projects and recommends it for production to motivated users.