# Implementations

> **The CryptoSwap Factory makes use of the `create_forwarder_to` function to deploy its contracts from the implementations.**:::warning

**The CryptoSwap Factory makes use of the `create_forwarder_to` function to deploy its contracts from the implementations.**:::warning

**Implementation contracts are upgradable.**They can either be replaced, or additional implementation contracts can be added. Therefore, please always make sure to check the most recent ones.

:::

It utilizes three different implementations:

- **`pool_implementation`**, containing a contract that is used to deploy the pools.
- **`token_implementation`**, containing a contract that is used to deploy LP tokens.
- **`gauge_implementation`**, containing a blueprint contract that is used when deploying gauges for pools.

## Query Implementations

### `pool_implementations`
::::description[`Factory.pool_implementations() -> address: view`]

Getter for the pool implementation contract.

Returns: pool implementation (`address`).

<SourceCode>

```vyper
pool_implementation: public(address)
```

</SourceCode>

<Example>

```shell
>>> Factory.pool_implementations()
'0xa85461AFc2DEEC01bDA23b5cd267d51F765fba10'
```

</Example>

::::

### `token_implementation`
::::description[`Factory.token_implementation() -> address: view`]

Getter for the token implementation contract.

Returns: token implementation (`address`).

<SourceCode>

```vyper
token_implementation: public(address)
```

</SourceCode>

<Example>

```shell
>>> Factory.token_implementation()
'0xc08550A4cc5333f40e593eCc4C4724808085D304'
```

</Example>

::::

### `gauge_implementation`
::::description[`Factory.gauge_implementation() -> address: view`]

Getter for the gauge implementation contract.

Returns: gauge implementation (`address`).

<SourceCode>

```vyper
gauge_implementation: public(address)
```

</SourceCode>

<Example>

```shell
>>> Factory.gauge_implementation()
'0xdc892358d55d5Ae1Ec47a531130D62151EBA36E5'
```

</Example>

::::

## Set New Implementation

*New implementations can be set via these admin-only functions:*

### `set_pool_implementation`
::::description[`Factory.set_pool_implementation(_pool_implementation: address):`]

:::guard[Guarded Method]

This function is only callable by the `admin` of the contract.

:::

Function to set a new pool implementation contract.

Emits event: `UpdatePoolImplementation`

| Input                 | Type      | Description               |
| --------------------- | --------- | ------------------------- |
| `_pool_implementation`| `address` | New pool implementation   |

<SourceCode>

```vyper
event UpdatePoolImplementation:
    _old_pool_implementation: address
    _new_pool_implementation: address

pool_implementation: public(address)

@external
def set_pool_implementation(_pool_implementation: address):
    """
    @notice Set pool implementation
    @dev Set to ZERO_ADDRESS to prevent deployment of new pools
    @param _pool_implementation Address of the new pool implementation
    """
    assert msg.sender == self.admin  # dev: admin only

    log UpdatePoolImplementation(self.pool_implementation, _pool_implementation)
    self.pool_implementation = _pool_implementation
```

</SourceCode>

<Example>

```shell
>>> Factory.set_pool_implementation("todo")
'todo'
```

</Example>

::::

### `set_token_implementation`
::::description[`Factory.set_token_implementation(_token_implementation: address):`]

:::guard[Guarded Method]

This function is only callable by the `admin` of the contract.

:::

Function to set a new token implementation contract.

Emits event: `UpdateTokenImplementation`

| Input                  | Type      | Description               |
| ---------------------- | --------- | ------------------------- |
| `_token_implementation`| `address` | New token implementation  |

<SourceCode>

```vyper
event UpdateTokenImplementation:
    _old_token_implementation: address
    _new_token_implementation: address

token_implementation: public(address)

@external
def set_token_implementation(_token_implementation: address):
    """
    @notice Set token implementation
    @dev Set to ZERO_ADDRESS to prevent deployment of new pools
    @param _token_implementation Address of the new token implementation
    """
    assert msg.sender == self.admin  # dev: admin only

    log UpdateTokenImplementation(self.token_implementation, _token_implementation)
    self.token_implementation = _token_implementation
```

</SourceCode>

<Example>

```shell
>>> Factory.set_token_implementation("todo")
'todo'
```

</Example>

::::

### `set_gauge_implementation`
::::description[`Factory.set_fee_receiver(_fee_receiver: address):`]

:::guard[Guarded Method]

This function is only callable by the `admin` of the contract.

:::

Function to set a new gauge implementation contract.

Emits event: `UpdateGaugeImplementation`

| Input                   | Type      | Description              |
| ----------------------- | --------- | ------------------------ |
| `_gauge_implementation` | `address` | New gauge implementation |

<SourceCode>

```vyper
event UpdateGaugeImplementation:
    _old_gauge_implementation: address
    _new_gauge_implementation: address

gauge_implementation: public(address)

@external
def set_gauge_implementation(_gauge_implementation: address):
    """
    @notice Set gauge implementation
    @dev Set to ZERO_ADDRESS to prevent deployment of new gauges
    @param _gauge_implementation Address of the new token implementation
    """
    assert msg.sender == self.admin  # dev: admin-only function

    log UpdateGaugeImplementation(self.gauge_implementation, _gauge_implementation)
    self.gauge_implementation = _gauge_implementation
```

</SourceCode>

<Example>

```shell
>>> Factory.set_gauge_implementation("todo")
'todo'
```

</Example>

::::