N/task

var dedupeTask = task.create({taskType: task.TaskType.ENTITY_DEDUPLICATION});
dedupeTask.entityType = task.DedupeEntityType.CUSTOMER;
dedupeTask.dedupeMode = task.DedupeMode.MERGE;
dedupeTask.masterSelectionMode = task.MasterSelectionMode.MOST_RECENT_ACTIVITY;
dedupeTask.recordIds = ['107', '110'];
var dedupeTaskId = dedupeTask.submit();