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

> function update_ main_ auth_ descriptor(account: account , auth_ descriptor: auth_descriptor ) Sets provided auth descriptor as main auth descriptor, delet

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

FUNCTION

# update\_main\_auth\_descriptor

```signature
function update_main_auth_descriptor(account: account, auth_descriptor: auth_descriptor)
```

[Source](https://gitlab.com/chromaway/ft4-lib/-/blob/development/rell/src/lib/ft4/core/accounts/module.rell#lines-281)

Sets provided auth descriptor as main auth descriptor, deleting the previous one.

Can only be called from an operation.

Throws `"RESTRICTED MAIN AUTH"` if the auth descriptor's rules are not `GTV_NULL`

Throws if any mandatory flags are missing on the auth descriptor.

Throws if the account has no main auth descriptor associated. This should normally not
happen for user accounts.

Throws if the auth descriptor's `args` field is invalid. Common cases are:

* the auth descriptor is a misconfigured multisig. `required_signatures` is:
  + 0 or less
  + greater than the number of signers

**Parameters**

* **account** — the account to change the main auth descriptor for
* **auth\_descriptor** — the new auth descriptor to add as main

**See Also**

* [auth\_flags\_config](https://docs.chromia.com/pages/ft4-rell/-f-t4-library/lib.ft4.core.accounts/auth_flags_config/) — for information on mandatory flags

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