Just JavaScript!

Faster than VDOM. No Build Step. Use the Platform!

JJ is a lightweight, no-transpilation library for modern web development. What You Write Is What Is Run (WYWIWIR).

JJ complements browser-native capabilities instead of replacing them with a thick abstraction layer. It is designed for moderate to advanced web developers and AI agents that want fluent DOM helpers while staying close to standards.

⚡ Quick Start

CDN:

Import map: Add this to your HTML:

<script type="importmap">
    {
        "jj": "https://cdn.jsdelivr.net/npm/jj/lib/bundle.min.js"
        // Or a specific version
        "jj": "https://cdn.jsdelivr.net/npm/jj@2/lib/bundle.min.js
    }
</script>
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And then:

import { JJHE } from 'jj'
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CDN:

import { JJHE } from 'https://cdn.jsdelivr.net/npm/jj/lib/bundle.min.js'
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NPM:

npm i jj
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import { JJHE } from 'jj'

JJHE.create('div')
    .addClass('card')
    .setText('Hello World!')
    .on('click', () => console.log('Hi'))
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Use namespace-aware wrappers for non-HTML elements:

import { JJSE, JJME } from 'jj'

const icon = JJSE.create('svg').setAttr('viewBox', '0 0 24 24')
const formula = JJME.create('math').addChild(JJME.create('mi').setText('x'))
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🚀 Why JJ?

• Zero Build – Runs directly in modern browsers
• Zero Dependencies – Integrated, efficient, and not vulnerable to supply chain attacks
• Native Speed – Direct DOM manipulation, no VDOM overhead
• Web Standards – First-class Web Components support
• Fluent API – Chainable methods for cleaner code
• AI-Optimized – Comes with up to date skills that are versioned with the lib
• Well documented - Tutorials, guides, API docs and FAQs

JJ is not a reactive framework, template compiler, or state-management system.

📚 Learn More

👉 Visit the full site with tutorials, examples, and API docs

🤖 AI-Optimized Development

JJ is designed for AI-assisted development. Install the skill for intelligent code suggestions:

npx skills add alexewerlof/jj
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Once installed, AI agents (GitHub Copilot, Cursor, Claude Code, Windsurf, etc.) will:

• Follow JJ's patterns and conventions automatically
• Know when to use .ref for native DOM access
• Suggest correct framework translations (React/Vue/jQuery/Svelte → JJ)
• Generate idiomatic, type-safe code

The skill definition (SKILL.md) is also included in the npm package at node_modules/jj/SKILL.md.

✅ Testing

The entire public API is tested thoroughly. Tests live in the test/ folder and mirror the source filenames (e.g., test/JJE.test.ts for src/JJE.ts, test/JJME.test.ts for src/wrappers/JJME.ts) while importing the target from ./src/index.js.

Run tests with:

npm test
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License

MIT

Made in Sweden 🇸🇪 by Alex Ewerlöf

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