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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 via the SDK.

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/[email protected]/build/IUniswapV2Factory.json

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