Dev Toolbar App API

The Astro Dev Toolbar App API allows you to create apps that can be used to extend the Astro Dev Toolbar. This allows you to add new features and integrations with third-party services.

Astro Integrations can add apps in the astro:config:setup hook using the addDevToolbarApp method.

/**
 * @type {() => import('astro').AstroIntegration}
 */
export default () => ({
  name: "my-integration",
  hooks: {
    "astro:config:setup": ({ addDevToolbarApp }) => {
      addDevToolbarApp("./my-app.js");
    },
  },
});

A Dev Toolbar App is a .js or .ts file that default exports an object with the following required properties:

export default {
  id: 'super-app',
  name: 'My Super App',
  icon: '<svg>...</svg>',
  init(canvas, eventTarget) {
    eventTarget.dispatchEvent(
      new CustomEvent('app-notification', {
        detail: {
          state: true,
        },
      })
    );
  }
}

A unique identifier for the app. This will be used to uniquely identify the app in hooks and events.

export default {
  id: 'my-app',
  // ...
}

The name of the app. This will be shown to users whenever the app needs to be referenced using a human-readable name.

export default {
  // ...
  name: 'My App',
  // ...
}

The icon of the app. This will be used to display the app in the UI. This can either be an icon from the icon list, or a string containing the SVG markup of the icon.

export default {
  // ...
  icon: '<svg>...</svg>', // or 'astro:logo'
}

This is the core part of the app. This function will be called when the app is loaded, which will either be when the browser is idle or when the user clicks on the app in the UI.

The function receives two arguments:

A ShadowRoot that the app can use to render its UI. Every app receive its own dedicated ShadowRoot for rendering its UI. Additionally, the parent element is positioned using position: absolute; and as such, the app UI automatically won’t affect the layout of the page.

export default {
  id: 'super-app',
  name: 'My Super App',
  icon: '<svg>...</svg>',
  init(canvas) {
    canvas.appendChild(document.createTextNode('Hello World!'))
  }
}

An EventTarget that can be used to send and receive events from the Dev Toolbar.

This optional function will be called when the user clicks on the app icon in the UI to toggle off the app. This function can be used, for example, to perform cleanup operations, do an animation, or to ask the user for confirmation before toggling off the app.

If a falsy value is returned, the toggling off will be cancelled and the app will stay enabled.

export default {
  // ...
  beforeTogglingOff() {
    const confirmation = window.confirm('Are you sure you want to disable this app?');
    return confirmation;
  }
}

The ShadowRoot of the app, can be used to render any UI needed.

Using the eventTarget argument on the init hook, apps can send and receive events from the Dev Toolbar. The following events are available:

This event is fired when the user clicks on the app icon in the Dev Toolbar.

  export default {
    // ...
    init(canvas, eventTarget) {
      eventTarget.addEventListener('app-toggled', (event) => {
        if (event.detail.state === true) {
          console.log("The app is now enabled!")
        }
      })
    }
  }

Indicates whether or not the app is enabled after the user’s click.

This event can be sent to inform the user that the app requires attention.

  export default {
    // ...
    init(canvas, eventTarget) {
      eventTarget.dispatchEvent(
          new CustomEvent('toggle-notification', {
            detail: {
              state: true,
            },
          })
        );
    }
  }

Indicates whether or not the app has a notification for the user. When true, the app icon will be highlighted using a red dot. Conversely, when false, the highlight will be removed. If this property is not specified, true will be assumed.

This event can be sent from your app to change the state of your app. This can be useful, for instance, to implement a “Close” button in your app’s UI.

  export default {
    // ...
    init(canvas, eventTarget) {
      eventTarget.dispatchEvent(
          new CustomEvent('toggle-app', {
            detail: {
              state: false,
            },
          })
        );
    }
  }

Indicates whether or not the app should be enabled. When true, the app will be enabled. Conversely, when false, the app will be disabled. If this property is not specified, true will be assumed.

Using Vite’s methods for client-server communication, Dev Toolbar Apps can communicate with the server.

In addition to being able to send and receive custom messages, the Dev Toolbar also sends the following messages, where APP_ID is the app’s ID:

This message is sent when the app is initialized. The data for this message is empty.

{
  // ...
  "astro:server:setup": ({ server }) => {
    server.ws.on("astro-dev-toolbar:super-app:initialized", () => {
      console.log("My app was initialized!");
    });
  },
  // ...
}

This message is sent when the user clicks on the app icon in the UI. The data for this message is a boolean indicating whether the app is enabled or not.

{
  // ...
  "astro:server:setup": ({ server }) => {
    server.ws.on("astro-dev-toolbar:super-app:toggled", (data) => {
      console.log(`My app is now ${data.state ? "enabled" : "disabled"}!`);
    });
  },
  // ...
}

The Dev Toolbar includes a set of web components that can be used to build apps with a consistent look and feel.

Shows a window with optionally a title and an icon.

window-title is a string that will be shown at the top of the toolbar window. window-icon can either be a string of a SVG file or an icon from the icon list.

The slot of the component will be used as the content of the window.

<astro-dev-toolbar-window window-title="MyWindows" window-icon="astro:logo">
  <p>My content</p>
</astro-dev-toolbar-window>

Shows a card with optionally an icon. Optionally, if a link is passed, the card will be clickable and will open the link in a new tab.

The slot of the component will be used as the content of the card.

<astro-dev-toolbar-card icon="astro:logo" link="https://github.com/withastro/astro/issues/new/choose">Report an issue</astro-dev-toolbar-card>

Shows a toggle element, acting as a checkbox. This element internally is a simple wrapper around a native <input type="checkbox"> element. The checkbox element can be accessed using the input property.

const toggle = document.createElement('astro-dev-toolbar-toggle');

toggle.input.addEventListener('change', (evt) => {
  console.log(`The toggle is now ${evt.currentTarget.checked ? 'enabled' : 'disabled'}!`);
});

Can be used to highlight an element on the page. In most cases, you’ll want to position and resize this element using the top, left, width and height CSS properties to match the element you want to highlight. An icon can also be specified using the icon attribute and will be shown in the top right corner of the highlight.

<!-- Highlight the entire page -->
<astro-dev-toolbar-highlight style="top: 0; left: 0; width: 100%; height: 100%;"></astro-dev-toolbar-highlight>

const elementToHighlight = document.querySelector('h1');
const rect = elementToHighlight.getBoundingClientRect();

const highlight = document.createElement('astro-dev-toolbar-highlight');

highlight.style.top = `${Math.max(rect.top + window.scrollY - 10, 0)}px`;
highlight.style.left = `${Math.max(rect.left + window.scrollX - 10, 0)}px`;
highlight.style.width = `${rect.width + 15}px`;
highlight.style.height = `${rect.height + 15}px`;
highlight.icon = 'astro:logo';

Shows a tooltip with different sections. This component is set to display: none; by default and can be made visible using a data-show="true" attribute.

Sections are defined using the sections property. This property is an array of objects with the following shape:

{
  title?: string; // Title of the section
  inlineTitle?: string; // Title of the section, shown inline next to the title
  icon?: Icon; // Icon of the section
  content?: string; // Content of the section
  clickAction?: () => void | Promise<void>; // Action to perform when clicking on the section
  clickDescription?: string; // Description of the action to perform when clicking on the section
}

const tooltip = document.createElement('astro-dev-toolbar-tooltip');

tooltip.sections = [{
  title: 'My section',
  icon: 'astro:logo',
  content: 'My content',
  clickAction: () => {
    console.log('Clicked!')
  },
  clickDescription: 'Click me!'
}]

This component is often combined with the astro-dev-toolbar-highlight component to show a tooltip when hovering a highlighted element:

const highlight = document.createElement('astro-dev-toolbar-highlight');

// Position the highlight...

const tooltip = document.createElement('astro-dev-toolbar-tooltip');

// Add sections to the tooltip...

highlight.addEventListener('mouseover', () => {
  tooltip.dataset.show = 'true';
});

highlight.addEventListener('mouseout', () => {
  tooltip.dataset.show = 'false';
});

Currently, the following icons are available and can be used in any component that accepts an icon:

• astro:logo
• warning
• arrow-down
• bug
• file-search
• check-circle
• gear

In addition to these included icons, you can also pass a string containing the SVG markup of the icon you want to use.

<astro-dev-toolbar-card icon="<svg>...</svg>" link="https://docs.astro.build">Read more in the Astro Docs!</astro-dev-toolbar-card>