Many to Many in Overpass

application.js

const resources = defineResources(({ resource, belongsTo, hasMany }) => {
  resource("users", () => hasMany("savedProperties"));
  resource("properties"); // Could be `resource("properties", () => hasMany("savedProperties"));`
  resource("savedProperties", () => belongsTo("property"));
});

return (
  <OverpassProvider
    api={{
      apiHost: location.host,
      apiPrefix: "/api",
      additionalHeaders: {
        "X-CSRF-Token": csrfTag?.content,
      },
    }}
    resources={resources}
  />
);

index.js

const fetchSavedPropertiesCollection = useFetchCollection(
  "savedProperties",
  {
    include: ["property"]
  }
);

const savedProperties = useNestedCollection(
  "savedProperties",
  {
    property: {}
  }
);

const properties = savedProperties
  .filter((savedProperty) => savedProperty.property)
  .map((savedProperty) => savedProperty.property);

property_resource.rb

class API::PropertyResource < JSONAPI::Resource
  has_many :saved_properties
end

saved_property_resource.rb

class API::SavedPropertyResource < JSONAPI::Resource
  has_one :user
  has_one :property
end

user_resource.rb

class API::UserResource < JSONAPI::Resource
  has_many :saved_properties
end