This visualization shows the relationships between REST API endpoints, HTTP methods, response codes, and data fields from the Swagger Petstore specification using a Sankey diagram. The d3.sankey layout renders nodes as rectangles and links as curved paths, with all flows weighted equally at 3.0 units. The code includes multiple JSON configurations for different graph variations, and the SVG chart allows nodes to be repositioned through drag interactions, with links updating via the relayout function. Data is loaded directly from embedded JavaScript objects rather than external files.