# Module sui::address_alias

*[Documentation index](/llms.txt) · [Full index](/llms-full.txt)*

```
use std::ascii;
use std::bcs;
use std::option;
use std::string;
use std::vector;
use sui::address;
use sui::derived_object;
use sui::dynamic_field;
use sui::hex;
use sui::object;
use sui::party;
use sui::transfer;
use sui::tx_context;
use sui::vec_map;
use sui::vec_set;
```

## Struct AddressAliasState

Singleton shared object which manages creation of AddressAliases state.

The actual alias configs are created as derived objects with this object
as the parent.

```
public struct AddressAliasState has key
```

**Fields**

**id: sui::object::UID**

**version: u64**

## Struct AddressAliases

Tracks the set of addresses allowed to act as a given sender.

An alias allows transactions signed by the alias address to act as the
original address. For example, if address X sets an alias of address Y, then
then a transaction signed by Y can set its sender address to X.

```
public struct AddressAliases has key
```

**Fields**

**id: sui::object::UID**

**aliases: sui::vec_set::VecSet<address>**

## Struct AliasKey

Internal key used for derivation of AddressAliases object addresses.

```
public struct AliasKey has copy, drop, store
```

**Fields**

**0: address**

## Constants

```
#[error]
const ENotSystemAddress: vector<u8> = b"Only the system can create the alias state object.";
```

```
#[error]
const ENoSuchAlias: vector<u8> = b"Given alias does not exist.";
```

```
#[error]
const EAliasAlreadyExists: vector<u8> = b"Alias already exists.";
```

```
#[error]
const ECannotRemoveLastAlias: vector<u8> = b"Cannot remove the last alias.";
```

```
#[error]
const ETooManyAliases: vector<u8> = b"The number of aliases exceeds the maximum allowed.";
```

```
const CURRENT_VERSION: u64 = 0;
```

```
const MAX_ALIASES: u64 = 8;
```

## Function create

Create and share the AddressAliasState object. This function is called exactly once, when
the address alias state object is first created.

Can only be called by genesis or change_epoch transactions.

```
fun create(ctx: &sui::tx_context::TxContext)
```

## Function enable

Enables address alias configuration for the sender address.

By default, an address is its own alias. The provided [AddressAliases](../sui_sui/address_alias#sui_address_alias_AddressAliases)
object can be used to change the set of allowed aliases after enabling.

```
entry fun enable(address_alias_state: &mut sui::address_alias::AddressAliasState, ctx: &sui::tx_context::TxContext)
```

## Function add

Adds the provided address to the set of aliases for the sender.

```
entry fun add(aliases: &mut sui::address_alias::AddressAliases, alias: address)
```

## Function replace_all

Overwrites the aliases for the sender's address with the given set.

```
entry fun replace_all(aliases: &mut sui::address_alias::AddressAliases, new_aliases: vector<address>)
```

## Function remove

Removes the given alias from the set of aliases for the sender's address.

```
entry fun remove(aliases: &mut sui::address_alias::AddressAliases, alias: address)
```