Public API

twill keeps its public API centered on style primitives and backend adapters.

Core entry points

• Style
• twill::prelude::*
• Merge
• ComputeValue
• Responsive

Tokens

Main token families:

• Color, ColorFamily, Scale, ColorValue
• SemanticColor, SemanticThemeVars, DynamicSemanticTheme
• ThemeVariant
• Spacing, Percentage, Container, Breakpoint
• FontFamily, FontSize, FontWeight, LetterSpacing, LineHeight
• BorderRadius, BorderWidth, BorderStyle, OutlineStyle, RingWidth
• Shadow, InsetShadow, DropShadow, TextShadow
• AnimationToken, TransitionDuration, TransitionProperty, Easing

Utilities

Common utility-style value types:

• Padding, PaddingValue, PaddingVar
• Margin, MarginValue, MarginVar
• Width, WidthVar
• Height, HeightVar
• SizeConstraints
• Display, Position, Overflow, ZIndex
• FlexContainer, FlexDirection, Flex
• GridContainer, GridTemplate

Recommended usage

#![allow(unused)]
fn main() {
use twill::prelude::*;

let card = Style::new()
    .padding(Padding::all(Spacing::S4))
    .bg(Color::slate(Scale::S50))
    .rounded(BorderRadius::Lg)
    .hover(|style| style.shadow(Shadow::Md))
    .lg(|style| style.padding(Padding::all(Spacing::S6)));

assert!(!card.is_empty());
}

Backend surface

Feature-gated backend modules:

• twill::egui
• twill::iced
• twill::slint

These modules convert Twill values into framework-specific primitives. Twill itself does not define components like Button or Card.

Backend-specific helper types:

• twill::backends::ShadowColor
• twill::iced::TextDirection
• twill::slint::SlintCursor