arangosh> db._create("users", { keyOptions: { allowUserKeys: false } }); [ArangoCollection 16261, "users" (type document, status loaded)] arangosh> db.users.save({ name: "user 1" }); { "_id" : "users/16264", "_key" : "16264", "_rev" : "_VvTR9Aq---" } arangosh> db.users.save({ name: "user 2", _key: "myuser" }); [ArangoError 1222: collection does not allow using user-defined keys] arangosh> db.users.save({ name: "user 3" }); { "_id" : "users/16269", "_key" : "16269", "_rev" : "_VvTR9Au---" }