arangosh> db._create("users", { keyOptions: { allowUserKeys: false } }); [ArangoCollection 14383, "users" (type document, status loaded)] arangosh> db.users.save({ name: "user 1" }); { "_id" : "users/14386", "_key" : "14386", "_rev" : "_UWx9w82---" } 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/14391", "_key" : "14391", "_rev" : "_UWx9w86---" }