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

# Attach or detach labels to/from UTXOs

> Attach or detach labels to/from UTXOs in a vault account. Labels can be used for organizing and filtering UTXOs.
Labels are applied additively — `labelsToAttach` adds to the existing label set and `labelsToDetach` removes from it. Neither operation replaces the full set.
**Note:** These endpoints are currently in beta and might be subject to changes.
Endpoint Permission: Admin, Non-Signing Admin, Signer, Approver, Editor.



## API Specification

The full API specification for this endpoint is available in the [documentation index](https://developers.fireblocks.com/llms.txt).