Last place I built a complex REST app, I solved this by auto-generating a set of standard endpoints from the database schema, and then adding a UI where a small

Last place I built a complex REST app, I solved this by auto-generating a set of standard endpoints from the database schema, and then adding a UI where a small set of trusted users could write queries that'd be stored in a table that were then made available. It provided an escape hatch that allowed rapid prototyping, and came with a default UI, and then we cleaned up the ones that were worth it.