This interactive Sankey diagram visualizes API workflow dependencies, mapping the flow from endpoints and operations through to HTTP response codes. The D3.js (v3) visualization uses the `d3.sankey` plugin to compute node positions and link paths, rendered as SVG with drag-and-drop node repositioning. Node colors are assigned using `d3.scale.category20`, with colors derived from node name substrings. The example iterates on data structures, experimenting with different JSON link/node formats and adding text overlays on links that display status codes, colored green or red based on the final character in the target node name.