> ## 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.

# Register an approval key

> Register an approval public key for an API user, used to sign approval requests. Up to 2 active keys are supported per API user. Returns the server-generated key ID used for deletion.

The `userId` must be the authenticated API user's own ID. Registering a key for another user is not supported and is rejected.

Endpoint Permission: Owner, Admin, Non-Signing Admin, Approver, Signer, Security Admin.



## API Specification

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