> ## Documentation Index
> Fetch the complete documentation index at: https://www.plain.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# addLabels

> Add one or more labels to a thread. Labels that are already present on the thread are silently skipped. Archived label types are rejected with error code `cannot_add_label_using_archived_label_type`. Requires the `label:create` permission.