# update_auth_descriptor_rule_variables · FT4 Rell API · Chromia Docs (concept)

> function update_ auth_ descriptor_ rule_ variables(desc: account_ auth_ descriptor ): account_ auth_ descriptor Updates the counter of the auth descriptor,

Source: https://docs.chromia.com/pages/ft4-rell/-f-t4-library/lib.ft4.core.accounts/update_auth_descriptor_rule_variables/

FUNCTION

# update\_auth\_descriptor\_rule\_variables

```signature
function update_auth_descriptor_rule_variables(desc: account_auth_descriptor): account_auth_descriptor
```

[Source](https://gitlab.com/chromaway/ft4-lib/-/blob/development/rell/src/lib/ft4/core/accounts/auth_descriptor_rule_validation.rell#lines-423)

Updates the counter of the auth descriptor, which should always be increased by one
when the auth descriptor is used to sign an operation

Can only be called from an operation.

**Parameters**

* **desc** — the auth descriptor to update

[View this page on docs.chromia.com](https://docs.chromia.com/pages/ft4-rell/-f-t4%20-library/lib.ft4.core.accounts/update_auth_descriptor_rule_variables.html)Generated API reference, mirrored from the live docs