Hello ​Alex,

For a many2many field, a list of tuples is expected. Here is the list of tuple that are accepted, with the corresponding semantics

(0, 0, { values }) link to a new record that needs to be created with the given values dictionary

(1, ID, { values }) update the linked record with id = ID (write values on it)

(2, ID) remove and delete the linked record with id = ID (calls unlink on ID, that will delete the object completely, and the link to it as well)

(3, ID) cut the link to the linked record with id = ID (delete the relationship between the two objects but does not delete the target object itself)

(4, ID) link to existing record with id = ID (adds a relationship)

(5) unlink all (like using (3,ID) for all linked records)

(6, 0, [IDs]) replace the list of linked IDs (like using (5) then (4,ID) for each ID in the list of IDs)

​E.g. "route_ids" : [(6, 0, list_of_ids)]

​ Hope you will get more insight.