> For the complete documentation index, see [llms.txt](https://docs.quickswap.exchange/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.quickswap.exchange/technical-reference/smart-contracts/v2-uniswap-fork-overview/pair-erc-20.md). # Pair (ERC-20) This documentation covers ERC-20 functionality for denominating pool tokens. For Uniswap-specific functionality, see Pair. ## Code [`UniswapV2ERC20.sol`](https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol) ## Events ### Approval ```solidity event Approval(address indexed owner, address indexed spender, uint value); ``` Emitted each time an approval occurs via [approve](broken://pages/RRMrmoJ1PW7FNlmln1Wy) or [permit](broken://pages/RRMrmoJ1PW7FNlmln1Wy). ### Transfer ```solidity event Transfer(address indexed from, address indexed to, uint value); ``` Emitted each time a transfer occurs via [transfer](broken://pages/RRMrmoJ1PW7FNlmln1Wy), [transferFrom](broken://pages/RRMrmoJ1PW7FNlmln1Wy), mint, or burn. ## Read-Only Functions ### name ```solidity function name() external pure returns (string memory); ``` Returns `Uniswap V2` for all pairs. ### symbol ```solidity function symbol() external pure returns (string memory); ``` Returns `UNI-V2` for all pairs. ### decimals ```solidity function decimals() external pure returns (uint8); ``` Returns `18` for all pairs. ### totalSupply ```solidity function totalSupply() external view returns (uint); ``` Returns the total amount of pool tokens for a pair. ### balanceOf ```solidity function balanceOf(address owner) external view returns (uint); ``` Returns the amount of pool tokens owned by an address. ### allowance ```solidity function allowance(address owner, address spender) external view returns (uint); ``` Returns the amount of liquidity tokens owned by an address that a spender is allowed to transfer via [transferFrom](broken://pages/RRMrmoJ1PW7FNlmln1Wy). ### DOMAIN\_SEPARATOR ```solidity function DOMAIN_SEPARATOR() external view returns (bytes32); ``` Returns a domain separator for use in [permit](broken://pages/RRMrmoJ1PW7FNlmln1Wy). ### PERMIT\_TYPEHASH ```solidity function PERMIT_TYPEHASH() external view returns (bytes32); ``` Returns a typehash for use in [permit](broken://pages/RRMrmoJ1PW7FNlmln1Wy). ### nonces ```solidity function nonces(address owner) external view returns (uint); ``` Returns the current nonce for an address for use in [permit](broken://pages/RRMrmoJ1PW7FNlmln1Wy). ## State-Changing Functions ### approve ```solidity function approve(address spender, uint value) external returns (bool); ``` Lets `msg.sender` set their allowance for a spender. * Emits [Approval](broken://pages/RRMrmoJ1PW7FNlmln1Wy). ### transfer ```solidity function transfer(address to, uint value) external returns (bool); ``` Lets `msg.sender` send pool tokens to an address. * Emits [Transfer](broken://pages/RRMrmoJ1PW7FNlmln1Wy). ### transferFrom ```solidity function transferFrom(address from, address to, uint value) external returns (bool); ``` Sends pool tokens from one address to another. * Requires approval. * Emits [Transfer](broken://pages/RRMrmoJ1PW7FNlmln1Wy). ### permit ```solidity function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external; ``` Sets the allowance for a spender where approval is granted via a signature. * See Using Permit. * Emits [Approval](broken://pages/RRMrmoJ1PW7FNlmln1Wy). ## Interface ```solidity import '@uniswap/v2-core/contracts/interfaces/IUniswapV2ERC20.sol'; ``` ```solidity pragma solidity >=0.5.0; interface IUniswapV2ERC20 { event Approval(address indexed owner, address indexed spender, uint value); event Transfer(address indexed from, address indexed to, uint value); function name() external pure returns (string memory); function symbol() external pure returns (string memory); function decimals() external pure returns (uint8); function totalSupply() external view returns (uint); function balanceOf(address owner) external view returns (uint); function allowance(address owner, address spender) external view returns (uint); function approve(address spender, uint value) external returns (bool); function transfer(address to, uint value) external returns (bool); function transferFrom(address from, address to, uint value) external returns (bool); function DOMAIN_SEPARATOR() external view returns (bytes32); function PERMIT_TYPEHASH() external pure returns (bytes32); function nonces(address owner) external view returns (uint); function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external; } ``` ## ABI ```typescript import IUniswapV2ERC20 from '@uniswap/v2-core/build/IUniswapV2ERC20.json' ``` --- # Agent Instructions This documentation is published with GitBook. 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