Overlays

Overlays are a core part of Sanity's Visual Editing that enables interactive editing experiences directly in your front end. They range from simple click-to-edit functionality to advanced drag-and-drop page building capabilities.

Overlays serve two main purposes in Visual Editing:

• Click-to-edit: Highlights content areas and takes you directly to the corresponding field in the Studio
• Page building: Enables drag-and-drop interactions for adding, moving, and removing sections when supported by your framework

For overlays to function, they need to:

• Identify Content: Locate elements in your DOM that contain Sanity content
• Map to Studio: Create correct references to documents and fields in the Studio
• Enable Interactions: Support the appropriate level of interactivity based on your framework

The simplest approach uses Stega encoding, which automatically adds invisible Content Source Maps to text content:

// Stega is usually enabled at the client level
const client = createClient({
  // ...other config
  stega: {
    enabled: true
  }
})

For non-text content or custom interactions, use data attributes:

import { createDataAttribute } from "@sanity/visual-editing"

function Section({ documentId, documentType, sections }) {
  const attr = createDataAttribute({ 
    id: documentId, 
    type: documentType,
    path: 'sections'
  })

  return (
    <div data-sanity={attr().toString()}>
      {sections.map(section => (
        <div
          key={section._key}
          data-sanity={attr(`sections[_key=="${section._key}"]`).toString()}
        >
          {section.content}
        </div>
      ))}
    </div>
  )
}

When using framework-specific loaders, you get a pre-configured encoding helper. Here is how it can look with the React loader:

export default function Page() {
  const { data, encodeDataAttribute } = useQuery(query)
  
  return (
    <div data-sanity={encodeDataAttribute(['sections'])}>
      {/* Your content */}
    </div>
  )
}

Overlays follow a progressive enhancement model based on your framework's capabilities:

1. Basic (All frameworks)
   • Click-to-edit functionality
   • Content highlighting
   • Direct Studio navigation
2. Advanced (React/React-based frameworks)
   • Full page building experience
   • Drag-and-drop section management
   • Real-time content updates

• Advanced support: Next.js App Router and other React-based frameworks
• Basic Support: Any framework with server-side rendering
• Coming soon: Advanced support for Vue.js and Svelte frameworks

• Start with Stega encoding for text-based content
• Use createDataAttribute for non-text content and custom interactions
• Consider framework-specific loaders for enhanced capabilities
• Test overlay behavior both in the Presentation tool

When using Vercel's Visual Editing:

• Overlays appear automatically in preview builds if Stega is enabled
• No additional configuration needed if Stega is enabled because the overlays are powered by the Vercel toolbar
• Still supports manual overlay configuration for iframe contexts