UDON Custom Node Builder allows users to convert standard node groups into custom nodes with a single click. The tool supports Geometry, Shader, and Compositing node setups. Users can design custom user interfaces for these nodes using a graphical interface, exposing inner properties like sliders, checkboxes, text fields, drop-downs, and datablock pointers directly on the node.

The addon features menu integration, allowing custom nodes to appear in standard add menus and node searches. It also includes a global library system for saving nodes across sessions, complete with version management to push and pull updates between local instances and the library. Custom nodes created with this tool require the addon to be enabled for both creation and usage.