Sandbox - Visual Canvas

Push HTML content to a live-updating canvas server for visual previews, dashboards, and agent-driven UI.

Commands

/sandbox start        - Start the canvas server (returns URL)
/sandbox push <html>  - Push HTML content to the canvas
/sandbox reset        - Reset canvas to blank state
/sandbox screenshot   - Take a screenshot of the current canvas
/sandbox status       - Show canvas server status and settings

Environment Variables

Variable	Description
`CANVAS_ALLOW_JS_EVAL`	Enable JavaScript evaluation in canvas (default: `false`)
`ALLOW_UNSAFE_SANDBOX`	Enable unsafe sandbox mode (default: `false`)

Examples

/sandbox start
/sandbox push <h1>Hello World</h1><p>Live preview</p>
/sandbox screenshot
/sandbox status
/sandbox reset

How It Works

/sandbox start launches a local HTTP server that serves the canvas page
/sandbox push <html> sends HTML to the canvas, rendered in real time
/sandbox screenshot captures the current canvas state as an image
/sandbox reset clears all HTML, CSS, and JS from the canvas
/sandbox status shows whether the server is running, the URL, and content sizes