Zenith Bundler

Zero-Cost Abstraction Bundler for the Zenith Framework.

Overview

The Zenith Bundler provides capability-based runtime chunking, CSS pruning, and deferred hydration for optimal production builds. Instead of shipping a monolithic runtime, it selectively includes only the capabilities used by each page.

Architecture

``
Compiler (ZenIR) → Manifest → Bundler → Optimized Output
`

$3

| Slice | Size | When Included |
|-------|------|---------------|
| Core | ~2KB | Always required |
| Reactivity | ~8KB | If {value} expressions or state used |
| Hydration | ~5KB | If page is interactive |

Installation

`bash


Rust crate

cargo add zenith-bundler

TypeScript package

bun add @zenithbuild/bundler
`

Usage

$3

`rust
use zenith_bundler::{bundle, analyze_manifest, ZenManifest};

let manifest = ZenManifest::new("src/pages/index.zen".to_string());
let analysis = analyze_manifest(&manifest);

println!("Required slices: {:?}", analysis.required_slices);
println!("Is static: {}", analysis.is_static);
`

$3

`typescript
import { bundle, generateRuntime } from '@zenithbuild/bundler'

// Full production bundle
const result = bundle(manifest, {
minifyJs: true,
minifyCss: true,
basePath: '/assets/'
})

// Dev server (HMR)
const { code, slices } = generateRuntime(manifest, true)
`

API

$3

Generates complete HTML/JS/CSS output.

Options:
- minifyJs - Minify JavaScript (default: true)
- minifyCss - Minify CSS (default: true)
- inlineCriticalCss - Inline critical CSS (default: true)
- sourceMaps - Generate source maps (default: false)
- devMode - Skip optimizations (default: false)
- basePath - Asset base path (default: "/")
- lazyLoad - Lazy load non-critical chunks (default: true)
- maxChunkSize - Max chunk size in bytes (default: 50000)

$3

Generates only the runtime code (for HMR/dev server).

$3

Analyzes a manifest and returns required slices.

Bundle Size Budgets

| Page Type | Budget |
|-----------|--------|
| Static | < 5KB |
| Interactive | < 20KB |
| Complex | < 50KB |

Run size gate: bun run js/scripts/size-gate.ts

Testing

`bash


Rust tests

cargo test

TypeScript tests

cd js && bun test

Size gate

cd js && bun run scripts/size-gate.ts
`

Project Structure

`
zenith-bundler/
├── src/
│ ├── lib.rs # Main exports
│ ├── analysis.rs # Manifest analysis
│ ├── chunking/ # Chunk computation
│ ├── codegen/ # Runtime generation
│ ├── css/ # CSS optimization
│ └── manifest/ # Types & capabilities
├── tests/
│ └── integration.rs # Integration tests
└── js/
├── src/
│ ├── index.ts # TypeScript API
│ ├── types.ts # TypeScript types
│ └── index.test.ts
└── scripts/
└── size-gate.ts # Bundle size CI gate
``

License

MIT

zenith-bundler