> For the complete documentation index, see [llms.txt](https://docs.fringe.fi/smart-contract-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fringe.fi/smart-contract-documentation/openzeppelin/contracts/proxy/beacon/upgradeablebeacon.md).

# Upgradeable Beacon

*This contract is used in conjunction with one or more instances of {BeaconProxy} to determine their implementation contract, which is where they will delegate all function calls. An owner is able to change the implementation the beacon points to, thus upgrading the proxies that use this beacon.*

## Methods

### implementation

```solidity
function implementation() external view returns (address)
```

*Returns the current implementation address.*

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | address | undefined   |

### owner

```solidity
function owner() external view returns (address)
```

*Returns the address of the current owner.*

#### Returns

| Name | Type    | Description |
| ---- | ------- | ----------- |
| \_0  | address | undefined   |

### renounceOwnership

```solidity
function renounceOwnership() external nonpayable
```

*Leaves the contract without owner. It will not be possible to call `onlyOwner` functions anymore. Can only be called by the current owner. NOTE: Renouncing ownership will leave the contract without an owner, thereby removing any functionality that is only available to the owner.*

### transferOwnership

```solidity
function transferOwnership(address newOwner) external nonpayable
```

*Transfers ownership of the contract to a new account (`newOwner`). Can only be called by the current owner.*

#### Parameters

| Name     | Type    | Description |
| -------- | ------- | ----------- |
| newOwner | address | undefined   |

### upgradeTo

```solidity
function upgradeTo(address newImplementation) external nonpayable
```

*Upgrades the beacon to a new implementation. Emits an {Upgraded} event. Requirements: - msg.sender must be the owner of the contract. - `newImplementation` must be a contract.*

#### Parameters

| Name              | Type    | Description |
| ----------------- | ------- | ----------- |
| newImplementation | address | undefined   |

## Events

### OwnershipTransferred

```solidity
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner)
```

#### Parameters

| Name                    | Type    | Description |
| ----------------------- | ------- | ----------- |
| previousOwner `indexed` | address | undefined   |
| newOwner `indexed`      | address | undefined   |

### Upgraded

```solidity
event Upgraded(address indexed implementation)
```

*Emitted when the implementation returned by the beacon is changed.*

#### Parameters

| Name                     | Type    | Description |
| ------------------------ | ------- | ----------- |
| implementation `indexed` | address | undefined   |