> For the complete documentation index, see [llms.txt](https://docs.jediswap.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.jediswap.xyz/for-developers/jediswap-v1/smart-contract-reference/factory.md).

# Factory

## Code

[Factory.cairo](https://github.com/jediswaplabs/JediSwap/blob/main/contracts/Factory.cairo)

## Address

Factory is deployed at:

Starknet Alpha Testnet: [0x0262744f8cea943dadc8823c318eaf24d0110dee2ee8026298f49a3bc58ed74a](https://testnet.starkscan.co/contract/0x0262744f8cea943dadc8823c318eaf24d0110dee2ee8026298f49a3bc58ed74a)

Starknet Alpha Mainnet: [0x00dad44c139a476c7a17fc8141e6db680e9abc9f56fe249a105094c44382c2fd](https://starkscan.co/contract/0x00dad44c139a476c7a17fc8141e6db680e9abc9f56fe249a105094c44382c2fd)

## Events

### PairCreated​

```js
@event
func PairCreated(token0: felt, token1: felt, pair: felt, total_pairs: felt):
end
```

Emitted each time a pair is created via [create\_pair](#create_pair).

* The final uint log value will be 1 for the first pair created, 2 for the second, etc.

## View Functions

### get\_pair

```js
func get_pair(token0: felt, token1: felt) -> (pair: felt):
```

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

* token0 and token1 are interchangeable.

### get\_all\_pairs​

```js
func get_all_pairs() -> (all_pairs_len: felt, all_pairs: felt*):
```

Returns the number of pairs and addresses of all pairs created.

### get\_num\_of\_pairs​

```js
func get_num_of_pairs() -> (num_of_pairs: felt):
```

Returns the number of pairs created.

### get\_fee\_to​

```js
func get_fee_to() -> (address: felt):
```

Get fee recipient address. See Protocol Charge Calculation. TODO

### get\_fee\_to\_setter​

```js
func get_fee_to_setter() -> (address: felt):
```

The address allowed to change fee\_to via set\_fee\_to.

### get\_pair\_contract\_class\_hash​

```js
func get_pair_contract_class_hash() -> (class_hash: felt):
```

Get the class hash of the [Canvas(Pair)](/for-developers/jediswap-v1/smart-contract-reference/pair.md) contract which is deployed for each [create\_pair](#create_pair).

## State-Changing Functions

### create\_pair​

```js
func create_pair(tokenA: felt, tokenB: felt) -> (pair: felt):
```

Creates a pair for tokenA and tokenB.

* tokenA and tokenB are interchangeable.
* Emits [PairCreated](#paircreated).

### set\_fee\_to​

```js
func set_fee_to(new_fee_to: felt):
```

Updates fee recipient

* only fee\_to\_setter can call.

### set\_fee\_to\_setter​

```js
func set_fee_to_setter(new_fee_to_setter: felt):
```

Updates fee to setter

* only fee\_to\_setter can call.
* new\_fee\_to\_setter can not be zero

## Interface

```js
%lang starknet

@contract_interface
namespace IFactory:
    func get_pair(token0: felt, token1: felt) -> (pair: felt):
    end

    func get_all_pairs() -> (all_pairs_len: felt, all_pairs: felt*):
    end
    
    func get_num_of_pairs() -> (num_of_pairs: felt):
    end

    func get_fee_to() -> (address: felt):
    end

    ​func get_fee_to_setter() -> (address: felt):
    end

    ​func get_pair_contract_class_hash() -> (class_hash: felt):
    end

    ​func create_pair(tokenA: felt, tokenB: felt) -> (pair: felt):
    end

    ​func set_fee_to(new_fee_to: felt):
    end

    ​func set_fee_to_setter(new_fee_to_setter: felt):
    end
end
```

## ABI

```js
[
    {
        "data": [
            {
                "name": "token0",
                "type": "felt"
            },
            {
                "name": "token1",
                "type": "felt"
            },
            {
                "name": "pair",
                "type": "felt"
            },
            {
                "name": "total_pairs",
                "type": "felt"
            }
        ],
        "keys": [],
        "name": "PairCreated",
        "type": "event"
    },
    {
        "inputs": [
            {
                "name": "pair_contract_class_hash",
                "type": "felt"
            },
            {
                "name": "fee_to_setter",
                "type": "felt"
            }
        ],
        "name": "constructor",
        "outputs": [],
        "type": "constructor"
    },
    {
        "inputs": [
            {
                "name": "token0",
                "type": "felt"
            },
            {
                "name": "token1",
                "type": "felt"
            }
        ],
        "name": "get_pair",
        "outputs": [
            {
                "name": "pair",
                "type": "felt"
            }
        ],
        "stateMutability": "view",
        "type": "function"
    },
    {
        "inputs": [],
        "name": "get_all_pairs",
        "outputs": [
            {
                "name": "all_pairs_len",
                "type": "felt"
            },
            {
                "name": "all_pairs",
                "type": "felt*"
            }
        ],
        "stateMutability": "view",
        "type": "function"
    },
    {
        "inputs": [],
        "name": "get_num_of_pairs",
        "outputs": [
            {
                "name": "num_of_pairs",
                "type": "felt"
            }
        ],
        "stateMutability": "view",
        "type": "function"
    },
    {
        "inputs": [],
        "name": "get_fee_to",
        "outputs": [
            {
                "name": "address",
                "type": "felt"
            }
        ],
        "stateMutability": "view",
        "type": "function"
    },
    {
        "inputs": [],
        "name": "get_fee_to_setter",
        "outputs": [
            {
                "name": "address",
                "type": "felt"
            }
        ],
        "stateMutability": "view",
        "type": "function"
    },
    {
        "inputs": [],
        "name": "get_pair_contract_class_hash",
        "outputs": [
            {
                "name": "class_hash",
                "type": "felt"
            }
        ],
        "stateMutability": "view",
        "type": "function"
    },
    {
        "inputs": [
            {
                "name": "tokenA",
                "type": "felt"
            },
            {
                "name": "tokenB",
                "type": "felt"
            }
        ],
        "name": "create_pair",
        "outputs": [
            {
                "name": "pair",
                "type": "felt"
            }
        ],
        "type": "function"
    },
    {
        "inputs": [
            {
                "name": "new_fee_to",
                "type": "felt"
            }
        ],
        "name": "set_fee_to",
        "outputs": [],
        "type": "function"
    },
    {
        "inputs": [
            {
                "name": "new_fee_to_setter",
                "type": "felt"
            }
        ],
        "name": "set_fee_to_setter",
        "outputs": [],
        "type": "function"
    }
]

```