Announcing the Beta release of ty

#1

Post by gavide » Tue, Dec 16, 2025, 8:52 PM UTC

Announcing the Beta release of ty
astral.sh

Re: Announcing the Beta release of ty

#2

Post by Ch00k » Tue, Dec 16, 2025, 9:21 PM UTC

That's great news! TIL that ty is also a language server, which means it replaces not only mypy, but also Pyright in Neovim/VSCode.

Re: Announcing the Beta release of ty

#3

Post by modeless » Tue, Dec 16, 2025, 9:52 PM UTC

The title of this story should be "Announcing the Beta release of ty". A lot of people have been waiting for the beta specifically.

I've been using Pyrefly and loving it compared to Pyright, but they recently shipped some updates with crash bugs that forced me to pin to a previous version, which is annoying. Unfortunately my first impression of ty isn't great either. Trying to install the ty extension on the current version of Cursor says "Can't install 'astral-sh.ty' extension because it is not compatible with the current version of Cursor (version 2.2.20, VSCode version 1.105.1)."

Re: Announcing the Beta release of ty

#4

Post by charliermarsh » Tue, Dec 16, 2025, 10:00 PM UTC

modeless wrote: post #3

The title of this story should be "Announcing the Beta release of ty". A lot of people have been waiting for the beta specifically. I've been using Pyrefly and loving it compared to Pyright, but they recently shipped some updates with crash bugs that forced me to pin to a previous version, which is annoying. Unfortunately my first impression of ty isn't great either. Trying to install the ty extension on the current…

If there's anything else accompanying the error, do you mind filing an issue? I've been using the ty extension with Cursor for weeks and am having trouble reproducing right now.

Re: Announcing the Beta release of ty

#5

Post by modeless » Tue, Dec 16, 2025, 10:01 PM UTC

charliermarsh wrote: post #4

modeless wrote: post #3

The title of this story should be "Announcing the Beta release of ty". A lot of people have been waiting for the beta specifically. I've been using Pyrefly and loving it compared to Pyright, but they recently shipped some updates with crash bugs that forced me to pin to a previous version, which is annoying. Unfortunately my first impression of ty isn't great either. Trying to install the ty extension on the current…

If there's anything else accompanying the error, do you mind filing an issue? I've been using the ty extension with Cursor for weeks and am having trouble reproducing right now.

That's the full error. It shows up in a dialog box when I press the install button. I'm on macOS, connected with the Anysphere Remote SSH extension to a Linux machine.

If I choose "install previous version" I am able to install the pre-release version from 12 hours ago without issue. Then on the extension page I get a button labeled "Switch to Release Version" and when I press it I get an error that says "Can't install release version of 'ty' extension because it has no release version." Filed a GitHub issue with these details.

In the meantime, the previous version appears to be working well! I like that it worked without any configuration. The Pyrefly extension needed a config tweak to work.

Re: Announcing the Beta release of ty

#6

Post by frou_dh » Tue, Dec 16, 2025, 10:09 PM UTC

Hopefully it gets added to this comparison:

https://htmlpreview.github.io/?https://github.com/python/typ...

If that table is anything to go by, Pyright is not to be underestimated.

I have briefly tried ty (LSP) in Emacs and it seems to work well so far. The only questionable thing I've encountered is that when the signature of a method is shown, the type annotations of some parameters seem to be presented in a particularly verbose form compared to what I'm used to - maybe they're technically correct but it can be bit much to look at.

Anyway, odds are pretty good that ty is what I will end up using long-term, so thanks and congrats on releasing the first beta!

Re: Announcing the Beta release of ty

#7

Post by maxloh » Tue, Dec 16, 2025, 10:11 PM UTC

How conformant is this, compared to e.g. mypy?

Re: Announcing the Beta release of ty

#8

Post by _carljm » Tue, Dec 16, 2025, 10:15 PM UTC

frou_dh wrote: post #6

Hopefully it gets added to this comparison: https://htmlpreview.github.io/?https://github.com/python/typ... If that table is anything to go by, Pyright is not to be underestimated. I have briefly tried ty (LSP) in Emacs and it seems to work well so far. The only questionable thing I've encountered is that when the signature of a method is shown, the type annotations of some parameters seem to be presented in a partic…

We'll be adding ourselves to that table soon. We'll have some work to catch up with pyright on conformance, but that's what the time between now and stable release is for.

Re: Announcing the Beta release of ty

#9

Post by almanael » Tue, Dec 16, 2025, 10:19 PM UTC

Not impressed because when tried ruff, and discovered that it doesn't replace (basic) pylint check https://github.com/astral-sh/ruff/issues/970 so we have ruff then pylint (and looking at the number of awaiting PR of ruff feels bad)

Re: Announcing the Beta release of ty

#10

Post by _carljm » Tue, Dec 16, 2025, 10:20 PM UTC

modeless wrote: post #5

charliermarsh wrote: post #4

Earlier quoted context omitted.

If there's anything else accompanying the error, do you mind filing an issue? I've been using the ty extension with Cursor for weeks and am having trouble reproducing right now.

That's the full error. It shows up in a dialog box when I press the install button. I'm on macOS, connected with the Anysphere Remote SSH extension to a Linux machine. If I choose "install previous version" I am able to install the pre-release version from 12 hours ago without issue. Then on the extension page I get a button labeled "Switch to Release Version" and when I press it I get an error that says "Can't insta…

I can reproduce this; we're looking into it.