D2 released TALA(their proprietary diagramming engine alt for Dagre, ELK) after more than 10 years of RnD.
What d2 is capable of: https://d2lang.com/documents/d2_cheat_sheet.pdf
The project compared a few(Mermaid, Graphviz) and looks like D2 is the elegant one like how crystal is, concise and with low syntax verbosity.
The comparisons with other diagramming engines: https://text-to-diagram.com/
Atm, when modifying Models or relationships in Crystal based frameworks, I need to update at two places and this risks drift and/or the documentation going stale.
D2 supports ERDs and UMLs, that make it easy for humans to visualize(and hopefully help us understand) the relationships between the models and objects in a framework.
It helps for a developer to get this extracted from the stock code crystal code/script.
Reinventing something like d2 is hard, so maybe we can c2d2, a crystal wrapper to get d2 DSL( or maybe something different).
Their community plugins, there exists JS/TS and other libs that try to make it native to their setup. c2d2 can be one:
https://d2lang.com/tour/extensions/
The announcement: TALA is open-source | D2 Documentation