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

> function set_ main_ auth_ descriptor(account: account , account_ auth_ descriptor: account_ auth_ descriptor ) Sets an auth descriptor as main_auth_descrip

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

FUNCTION

# set\_main\_auth\_descriptor

```signature
function set_main_auth_descriptor(account: account, account_auth_descriptor: account_auth_descriptor)
```

[Source](https://gitlab.com/chromaway/ft4-lib/-/blob/development/rell/src/lib/ft4/core/accounts/module.rell#lines-333)

Sets an auth descriptor as `main_auth_descriptor` of the account

Using this function directly on a user account might end up leaving it misconfigured. It's
strongly advised to use `update_main_auth_descriptor` if the main auth descriptor should be
changed.

Can only be called from an operation.

Throws `"MAIN AUTH DESCRIPTOR EXISTS"` if the account has a main auth descriptor already.

**Parameters**

* **account** — the account to set the main auth descriptor for
* **account\_auth\_descriptor** — an auth descriptor already registered to the account which should become the main one

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