This operation is available in servers v2.1.2+. Assign or remove attributes and values of attribute assignments. These attributes can be on groups, stems, members, memberships (immediate or any), attribute definitions, or on assignments of attributes (one level deep). You can pass in multiple of these operations in one batch which can be transactional or not (default). This is what differentiates assignAttributesBatch with assignAttributes. There is no Lite version of this operation, since you can just use assignAttributesLite.
You can lookup attributes by attribute definition name, or attribute definition id
All assignments will be filtered for security based on the logged in or acted as user (security rules are on attribute framework wiki)
The returned data will include the attribute assignments, value(s) on those assignments, and a normalized list of references (owner objects e.g. group/stem/etc, attribute definitions, attribute names, etc), if things changed or were already assigned, etc
You can assign attributes to one owner, definition, action, etc, though you can pass in multiple assignments.
attributeAssignType is a required field, must be: group, member, stem, any_mem, imm_mem, attr_def, group_asgn, mem_asgn, stem_asgn, any_mem_asgn, imm_mem_asgn, attr_def_asgn
attributeAssignOperation is required and is the operation to perform for attribute on owners, from enum AttributeAssignOperation: assign_attr, add_attr, remove_attr, replace_attrs. In this case, assigning an attribute will not assign if already there. add_attr will add this assignment even if it is already there (attribute definition must allow multi assignments)
attributeAssignValueOperation is required if passing values to assign. It is the operation to perform for attribute value on attribute assignments: assign_value, add_value, remove_value, replace_values. Like the attribute assign operation, assign_value will assign if not there, or ignore if already there. add_value will add even if assigned. And replace_values will remove orphans not in the assign list.