Editor support

BUI ships two editor extensions in addons/. Both are GPL-3.0-or-later, like BUI.

VS Code (addons/bui-vscode)

A TextMate injection grammar on source.rust, so it works next to rust-analyzer and any Rust theme. Inside rsx! { ... } (and the view! alias) it highlights:

• tags, components, fragments and closing tags;
• attribute names, including on* handlers and variant prefixes such as md:dark:hover:;
• class="..." strings, with every Tailwind token and variant scoped separately, and bare Tailwind attributes (<div p-4 bg-[#4772b3]>);
• {expr} embeds as Rust, string text children and comments.

It also adds snippets (rsx, component, rsxfor, rsxif, rsxmatch, usestate and more) and Tailwind class completion inside class="...". Rust outside these macros is untouched. Install it from a .vsix built with npx @vscode/vsce package in addons/bui-vscode.

Zed (addons/bui-zed)

Zed extensions can’t extend the built-in Rust injections, which hardcode macro names, so rsx! bodies in .rs files stay Rust-highlighted. The extension instead gives you:

• a BUI RSX language for .rsx files (a tree-sitter grammar that understands bare Tailwind attributes, with Rust highlighted inside {...});
• Rust and .rsx snippets;
• partial view! highlighting if you also install Zed’s Leptos RSTML extension (its grammar errors on bare Tailwind attributes, so the highlighting degrades around them).

Install it with zed: install dev extension and pick addons/bui-zed.

Language servers

BUI has no language server of its own, and neither extension starts one.

• Rust code is handled by rust-analyzer, as in any Rust project. How rust-analyzer treats the inside of an rsx! body is not something this page has checked, so don’t rely on completion or hover there.
• Typos in Tailwind attributes are caught at build time. rsx! is a procedural macro, so BUI’s own compiler checks the markup when your program builds. A bare attribute that looks like a Tailwind utility but isn’t one (<div p-4> is fine, a misspelling is a compile error that suggests the fix) and an unknown class in tw!("...") both fail the build. Plain HTML boolean attributes, data-* and aria-* pass through. The macro hands a class="..." string to .class(...) as it is and does not check each class, so a typo there is not reported at build time. See CSS and Tailwind.
• Tailwind IntelliSense isn’t configured for rsx! in either editor. The VS Code extension completes common classes on its own, but it is a list, not the full Tailwind catalogue, and the compiler stays the validator. Zed has no class completion at all.

Next steps