Home Assistant Frontend is the user interface for Home Assistant, an open-source home automation platform. It provides a modern, responsive web interface for controlling and monitoring smart home devices and systems. The frontend is built using web components and the Lit framework, offering a customizable and extensible user experience.

Pros

• Highly customizable and extensible through custom cards and panels
• Responsive design that works well on desktop and mobile devices
• Regular updates and active community support
• Integration with a wide range of smart home devices and services

Cons

• Steep learning curve for advanced customization
• Performance can be slow on older devices or with large configurations
• Some features may require additional setup or configuration
• Documentation can be fragmented or outdated for certain components

Code Examples

1. Creating a custom card:

import { LitElement, html, css } from 'lit';

class MyCustomCard extends LitElement {
  static get properties() {
    return {
      hass: { type: Object },
      config: { type: Object },
    };
  }

  render() {
    return html`
      <ha-card header="My Custom Card">
        <div class="card-content">
          Hello, ${this.config.name}!
        </div>
      </ha-card>
    `;
  }

  static get styles() {
    return css`
      .card-content {
        padding: 16px;
      }
    `;
  }
}

customElements.define('my-custom-card', MyCustomCard);

2. Using the hass object to get entity states:

const entityId = 'light.living_room';
const state = this.hass.states[entityId];

if (state) {
  console.log(`${entityId} is ${state.state}`);
  console.log('Attributes:', state.attributes);
}

3. Calling a service using the hass object:

this.hass.callService('light', 'turn_on', {
  entity_id: 'light.living_room',
  brightness: 255,
  rgb_color: [255, 0, 0],
});

Getting Started

To start developing for the Home Assistant Frontend:

1. Clone the repository:

   git clone https://github.com/home-assistant/frontend.git
   cd frontend
   

2. Install dependencies:

   yarn install
   

3. Run the development server:

   yarn start
   

4. Open your browser and navigate to http://localhost:8123 to see the frontend in action.

For more detailed instructions and documentation, refer to the project's README and the Home Assistant Developer Documentation.