Annotation

Annotation lets participants draw, highlight, and mark up content during a live video session. Users can annotate over a shared screen stream from a remote participant, or draw on a blank canvas using the built-in whiteboard tool.

This page provides an overview of the feature and its platform-specific setup requirements. Full method-level documentation is in the SDK reference for each platform.

What Annotation Does

When annotation is active, a participant can draw lines, shapes, and text overlays directly on top of a video stream or canvas displayed in the session. Other participants with annotation access see the same markings in real time. Annotations can be used to:

• Highlight sections of a shared document or screen
• Collaborate on a blank drawing canvas (whiteboard mode)
• Guide participants visually through a workflow or diagram

Setup Requirements

How you enable annotation depends on the platform:

Android, iOS, React Native, Flutter

Annotation on these platforms is built on top of Canvas Streaming. You must enable Canvas Streaming when creating the room by including canvas: true in the room settings:

{
  "settings": {
    "canvas": true
  }
}

You also need to add the annotation toolbar to the video meeting UI in your application. The SDK provides ready-to-use toolbar components for each platform.

Cordova / Ionic

On Cordova and Ionic platforms, use the startAnnotation() method directly to initiate annotation on a remote stream. Canvas Streaming setup is not required.

Annotation methods, toolbar integration, and event callbacks are documented in each SDK's In-Session Communication reference. Select your platform:

• Web SDK — Annotation
• Android SDK — Annotation
• iOS SDK — Annotation
• Flutter SDK — Annotation
• React Native SDK — Annotation
• Cordova / Ionic SDK — Annotation