# Factory

The Factory smart contract oversees the full functionality of token pair registration and transactions in MESHswap. 

## Address

* Polygon Mainnet :[ ](https://scope.klaytn.com/account/0xc6a2ad8cc6e4a7e08fc37cc5954be07d499e7654?tabId=txList)[0x9f3044f7f9fc8bc9ed615d54845b4577b833282d](https://polygonscan.com/address/0x9f3044f7f9fc8bc9ed615d54845b4577b833282d)

## Events, Read-Only Functions, and State-Changing Functions

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{% tab title="Events" %}

## Events

#### ChangeCreateFee

```solidity
event ChangeCreateFee(uint _createFee);
```

*  An event to change the Pool Contract Creation Fee when adding a new liquidity pool pair

#### CreatePool

```solidity
event CreatePool(address token0, uint amount0, address token1, uint amount1, uint fee, address exchange, uint exid);
```

* Event to create new liquidity pool
* parameters
  * `token0` : token0 address in pair
  * `amount0` : token0 amount in pool
  * `token1` : token1 address in pair
  * `amount1` : token1 amount in pool
  * `fee` : pool fee rate
  * `exchange` : exchange contract address of this pool
  * `exid` : exchange id

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{% tab title="Read-Only Functions" %}

## Read-Only Functions

#### WETH

* WETH contract address.

#### mesh

* MESH contract address

#### allPairsLength

* Returns the total number of pairs created through the factory so far.

#### getPoolCount

* Returns the total number of pairs created through the factory so far.

#### createFee

* The amount of MESH that must be paired to create a new liquidity pool pair

#### owner

* Factory Contract Address

#### nextOwner

* The next Governance Contract Address set in advance.

#### pools

* List of liquidity pool pairings 
* Each item saves the smart contract address of the liquidity pool

#### poolExist

* Returns if the contract for the given liquidiy pool pair exists

#### tokenToPool

* The contract address corresponding to the token0, token1 pair
* When the addresses of token0 and token1 are inputted, this returns the contract address of the corresponding pairing
* Returns the  same contract address regardless of the order of the liquidity pool pairing tokens:

  tokenToPool\[token0]\[token1] == tokenToPool\[token1]\[token0]

####

#### allPairs

```
function allPairs(uint) external view returns (address pair);
```

* Returns the address of the `n`th pair (`0`-indexed) created through the factory

#### getPair

```
function getPair(address token0, address token1) external view returns (address pair);
```

* Returns the address of the pair for `token0` and `token1`, if it has been created, else `address(0)` (`0x0000000000000000000000000000000000000000`).

#### getPoolAddress

```
function getPoolAddress(uint idx) public view returns (address)
```

* Returns the address of the `n`th pair (`0`-indexed) created through the factory
  {% endtab %}

{% tab title="State-Changing Functions" %}

## State-Changing Functions

#### createETHPool

```solidity
function createETHPool(address token, uint amount, uint fee) public payable 
```

* A method called to add a liquidity pair with one side as MATIC
* The wallet that calls this must have MESH greater than or equal to createFee
* Token for when the WMATIC / ERC-20 pair to be registered has never been registered before
* Parameters
  * `token` : ERC-20 token address to add liquidity
  * `amount` : the amount of tokens (ERC-20) to be provided for the initial liquidity
  * `fee` : Sets the initial fee value for liquidity pairs
    * A value between 0 and 100
    * Meaning: 0 -> 0%, 100 -> 1%
  * `msg.value` : MATIC quantity to initially supply liquidity 
    * Delivers the transaction value without specifying otherwise

#### createTokenPool

```solidity
 function createTokenPool(address token0, uint amount0, address token1, uint amount1, uint fee) public
```

* Method called to add liquidity pair in case of ERC-20 token pair
* The wallet calling the MESH above createFee must have it.
* parameter
  * `token0` : The address of the first token
  * `amount0` : The quantity of the first token that supplies the initial liquidity
  * `token1` : The address of the second token
  * `amount1` : The quantity of the second token that supplies the initial liquidity
  * `fee` : Sets the initial fee value for liquidity pairs

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{% endtabs %}