How do I add temporary properties on a mongoose object just for response, which is not stored in database

Found the answer here: Unable to add properties to js object

I cant add properties on a Mongoose object, I have to convert it to plain JSON-object using the .toJSON() or .toObject() methods.

EDIT: And like @Zlatko mentions, you can also finalize your queries using the .lean() method.

mongooseModel.find().lean().exec()

… which also produces native js objects.