This could simply be a property on the model/schema, if a simple
flag/boolean is adequate to describe the “writeable”-ness of a model (of course
a model can be more granular than just read or read/write). In Persevere,
generally using the /Class/ resource to expose a listing of schemas, or a single
schema is the preferred meta resource for description of the models that are
available, and those schemas could include a property describing the level of
access, where that can be described in discrete levels.
Thanks,
Kris