dsh-visualizer-widget

When a model produces SVG or HTML source for a chart or prototype in DeepSeek Harness, that code can quickly bloat the context window while the user still sees only raw markup. dsh-visualizer-widget closes that loop: after the model calls render_visual, the plugin renders the source inside a sandboxed iframe and surfaces it as an interactive inline card right in the chat flow. The tool response carries only a one-line summary (format, character count, height), so the full source stays in the card and tool result without re-entering the model context.

The card itself supports toggling between preview and source views, multiple height presets, light and dark backgrounds, one-click re-render, and copy-to-clipboard, making it easy to iterate on visuals mid-conversation. For more complex charts the model can first call get_visualizer_spec to retrieve a bundled rendering spec covering the 680-unit viewBox baseline, font-size and weight constraints, a 9x7 color palette, light/dark schemes, and chart-type routing, keeping every generation visually consistent.

On the security side, the iframe only grants allow-scripts, allow-popups, and allow-forms; allow-same-origin is intentionally absent, so scripts inside the card cannot reach the host page DOM or storage. This plugin is well suited for Harness users who frequently ask their model to produce visual prototypes, dashboard snippets, or HTML mockups and want a clean context window with a unified, safe visual output.