compose-svelted

Compose-inspired UI framework for Svelte
Declarative layout · Immutable modifiers · Structural motion · Compose-like navigation

✨ What is compose-svelted?

compose-svelted is an experimental but ambitious UI framework that brings the Jetpack Compose mental model to the Svelte ecosystem.

It is not a Material Design clone, and it is not a thin component library.

Instead, it focuses on:

• explicit UI composition
• predictable layout
• declarative motion
• navigation as state

All built on top of Svelte, without virtual DOM abstractions or hidden magic.

🧠 Core Philosophy

UI is a function of state.
Layout, motion, and navigation must be explicit and predictable.

Key ideas:

• No implicit behavior
• No global side effects
• No magic context you cannot reason about
• Everything composes

🧱 Library Structure (High-Level)

Core V1 – Layout & Styling

• Column, Row, Box
• Modifier (immutable, chainable)
• Shapes
• Theme system
• Typography

Core V2 – Motion & Navigation (CLOSED)

• AnimatedVisibility
• AnimatedContent
• Declarative motion
• NavController
• NavHost
• Internal backstack

💪 Strengths

Explicit Layout

Layouts are predictable and composable.

Immutable Modifiers

Describe intent, not CSS.

Structural Motion

Motion is part of the UI structure.

Compose-like Navigation

Navigation without external routers.

🚀 Innovation

• Compose mental model on the web
• Navigation as state
• Motion as structure
• No virtual DOM abstraction

📦 Status

• Alpha
• Core V2 closed
• Core V3 planned

Project Zones

• src/lib: publishable library source.
• playground: local app for developing and validating the library against live source changes.
• src/App.svelte and src/samples: legacy examples, not part of the active library/playground workflow.

Development Commands

npm install
npm run dev
npm run build
npm run check
npm run playground:build

• npm run dev: starts the playground.
• npm run build: packages the library into dist/.
• npm run check: type-checks the playground against the current library source.
• playground/vite.config.ts aliases @danielito1996/compose-svelted to src/lib/index.ts, so playground changes reflect library source immediately.

🔮 Roadmap

Core V3

• Nested navigation
• Directional transitions
• Shared elements

⚠️ CSS Baseline (Required)

Compose Svelted is layout-deterministic, assumes a neutral CSS baseline.

You MUST include the following reset in your app:

To avoid layout regressions in existing apps, use one of these two paths:

Path A (Primary): import baseline from the package

• Strict baseline (Compose-like deterministic behavior):

import "@danielito1996/compose-svelted/baseline.css";

• Safe baseline (less intrusive for existing projects):

import "@danielito1996/compose-svelted/baseline-safe.css";

Use baseline-safe.css if your app already has strong global styles and you want minimal interference.

Path B (Alternative): do not import baseline, adapt your own app.css

If you prefer full control, keep your app stylesheet and ensure at least:

*,
*::before,
*::after {
  box-sizing: border-box;
}

html, body, #app {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}

To guarantee consistent and predictable behavior of layout components such as Box, Column, Row, Surface, Scaffold, and navigation containers, a neutral CSS baseline is required in the host application.

This is intentional and mirrors the contract-based approach of Jetpack Compose.

Why this matters

Compose Svelted does not:

• force global CSS
• inject layout styles silently
• assume browser defaults

Instead, it expects a minimal, explicit layout contract. Without this baseline, layout behavior may vary between browsers or projects.

Tailwind CSS

Compose Svelted does not require Tailwind CSS.

Tailwind is used internally as an implementation detail for predictable styling, but consumers of the library are not required to install or configure Tailwind.