Factory

Code

UniswapV2Factory.sol

Address

UniswapV2Factory is deployed at 0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f on the Ethereum mainnet, and the Ropsten, Rinkeby, Görli, and Kovan testnets. It was built from commit 8160750.

Events

PairCreated

event PairCreated(address indexed token0, address indexed token1, address pair, uint);

Emitted each time a pair is created via createPair.

  • token0 is guaranteed to be strictly less than token1 by sort order.

  • The final uint log value will be 1 for the first pair created, 2 for the second, etc. (see allPairs/getPair).

Read-Only Functions

getPair

function getPair(address tokenA, address tokenB) external view returns (address pair);

Returns the address of the pair for tokenA and tokenB, if it has been created, else address(0) (0x0000000000000000000000000000000000000000).

  • tokenA and tokenB are interchangeable.

  • Pair addresses can also be calculated deterministically, see Pair Addresses.

allPairs

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

Returns the address of the nth pair (0-indexed) created through the factory, or address(0) (0x0000000000000000000000000000000000000000) if not enough pairs have been created yet.

  • Pass 0 for the address of the first pair created, 1 for the second, etc.

allPairsLength

function allPairsLength() external view returns (uint);

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

feeTo

function feeTo() external view returns (address);

See Protocol Charge Calculation.

feeToSetter

function feeToSetter() external view returns (address);

The address allowed to change feeTo.

State-Changing Functions

createPair

function createPair(address tokenA, address tokenB) external returns (address pair);

Creates a pair for tokenA and tokenB if one doesn't exist already.

  • tokenA and tokenB are interchangeable.

  • Emits PairCreated.

Interface

import '@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol';
pragma solidity >=0.5.0;

interface IUniswapV2Factory {
  event PairCreated(address indexed token0, address indexed token1, address pair, uint);

  function getPair(address tokenA, address tokenB) external view returns (address pair);
  function allPairs(uint) external view returns (address pair);
  function allPairsLength() external view returns (uint);

  function feeTo() external view returns (address);
  function feeToSetter() external view returns (address);

  function createPair(address tokenA, address tokenB) external returns (address pair);
}

ABI

import IUniswapV2Factory from '@uniswap/v2-core/build/IUniswapV2Factory.json'

https://unpkg.com/@uniswap/v2-core@1.0.0/build/IUniswapV2Factory.json

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