Why is Helix auto-formatting my CSS files on save?

Hi everyone,

I recently set up Helix and noticed that every time I save a CSS file, it gets automatically formatted. I didn’t enable any formatter for CSS in my configuration, only for Python. My languages.toml looks like this:

[[language]]
name = "python"
language-servers = ["ruff"]
auto-format = true
scope = "source.python"

[language-server.ruff]
command = "ruff"
args = ["server"]

[language.formatter]
command = "ruff"
args = ["format", "-"]

[[language]]
name = "css"
auto-format = false

Even with auto-format = false for CSS, Helix still reformats the file on save.

Does anyone know why this happens and how I can stop Helix from formatting CSS automatically?

Thanks!

Edit:

I think what’s happening is that Helix’s auto-formatting is kicking in. According to the Helix language support docs, CSS has "Auto Indent".

The reason it seems odd in my case is that I'm using Jinja templates, and Helix doesn’t fully recognize them.

I can toggle auto-formatting for the current buffer with:

:toggle-option auto-format

…but the choice is basically between:

1. Never auto-format CSS.
2. Figure out a way for Helix to auto-format Jinja templates properly.

So it’s less of a “bug” and more of an interaction between auto-indent and Helix’s limited template recognition.