Integrating mobx with lit-element!

Usage no npm install needed!

<script type="module">
  import adobeLitMobx from 'https://cdn.skypack.dev/@adobe/lit-mobx';


Known Vulnerabilities


Mixin and base class that allow easy usage of mobx observables with lit.

The mixin implementation is based heavily on the work of Alexander Weiss in his mobx-lit-element implementation. This has been rewritten to support multiple forms of usage (mixin, or base class) as well as to be based on typescript to get type definitions.


As a dependency:

npm install --save @adobe/lit-mobx lit mobx

LitElement 2.0 Usage

This library has been updated to the latest version of Lit which we highly recommend you update to. However if you wish to continue using LitMobx with LitElement 2.0 then install the 1.0 major version:

npm install --save @adobe/lit-mobx@^1.0.0

We will backport any security patches (though don't expect there to be any) in this major version as necessary.


npm install
npm run demo


See the JavaScript and TypeScript example projects on StackBlitz. See this example for a demonstration of usage with Mobx v6 in Typescript without the use of decorators.

import { html, TemplateResult } from 'lit';
import { customElement, LitElement } from 'lit/decorators.js';
import { observable, action } from 'mobx';
import { MobxLitElement } from '@adobe/lit-mobx';

// create a mobx observable
class Counter {
    public count = 0;

    public increment() {

// create instance that can be shared across components
const counter = new Counter();

// create a new custom element, and use the base MobxLitElement class
// alternatively you can use the MobxReactionUpdate mixin, e.g. `class MyElement extends MobxReactionUpdate(LitElement)`
export class MyElement extends MobxLitElement {
    private counter = counter;

    // any observables accessed in the render method will now trigger an update
    public render(): TemplateResult {
        return html`
            Count is ${this.counter.count}
            <br />
            <button @click=${this.incrementCount}>Add</button>

    private incrementCount() {

For further examples see the demo folder.


Contributions are welcomed! Read the Contributing Guide for more information.


This project is licensed under the Apache V2 License. See LICENSE for more information.