# ERC20PermitUpgradeable *Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in ]. Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't need to send a transaction, and thus is not required to hold Ether at all. Available since v3.4.* ## Methods ### DOMAIN\_SEPARATOR ```solidity function DOMAIN_SEPARATOR() external view returns (bytes32) ``` *See {IERC20Permit-DOMAIN\_SEPARATOR}.* #### Returns | Name | Type | Description | | ---- | ------- | ----------- | | \_0 | bytes32 | undefined | ### allowance ```solidity function allowance(address owner, address spender) external view returns (uint256) ``` *See {IERC20-allowance}.* #### Parameters | Name | Type | Description | | ------- | ------- | ----------- | | owner | address | undefined | | spender | address | undefined | #### Returns | Name | Type | Description | | ---- | ------- | ----------- | | \_0 | uint256 | undefined | ### approve ```solidity function approve(address spender, uint256 amount) external nonpayable returns (bool) ``` *See {IERC20-approve}. Requirements: - `spender` cannot be the zero address.* #### Parameters | Name | Type | Description | | ------- | ------- | ----------- | | spender | address | undefined | | amount | uint256 | undefined | #### Returns | Name | Type | Description | | ---- | ---- | ----------- | | \_0 | bool | undefined | ### balanceOf ```solidity function balanceOf(address account) external view returns (uint256) ``` *See {IERC20-balanceOf}.* #### Parameters | Name | Type | Description | | ------- | ------- | ----------- | | account | address | undefined | #### Returns | Name | Type | Description | | ---- | ------- | ----------- | | \_0 | uint256 | undefined | ### decimals ```solidity function decimals() external view returns (uint8) ``` *Returns the number of decimals used to get its user representation. For example, if `decimals` equals `2`, a balance of `505` tokens should be displayed to a user as `5,05` (`505 / 10 ** 2`). Tokens usually opt for a value of 18, imitating the relationship between Ether and Wei. This is the value {ERC20} uses, unless {\_setupDecimals} is called. NOTE: This information is only used for display purposes: it in no way affects any of the arithmetic of the contract, including {IERC20-balanceOf} and {IERC20-transfer}.* #### Returns | Name | Type | Description | | ---- | ----- | ----------- | | \_0 | uint8 | undefined | ### decreaseAllowance ```solidity function decreaseAllowance(address spender, uint256 subtractedValue) external nonpayable returns (bool) ``` *Atomically decreases the allowance granted to `spender` by the caller. This is an alternative to {approve} that can be used as a mitigation for problems described in {IERC20-approve}. Emits an {Approval} event indicating the updated allowance. Requirements: - `spender` cannot be the zero address. - `spender` must have allowance for the caller of at least `subtractedValue`.* #### Parameters | Name | Type | Description | | --------------- | ------- | ----------- | | spender | address | undefined | | subtractedValue | uint256 | undefined | #### Returns | Name | Type | Description | | ---- | ---- | ----------- | | \_0 | bool | undefined | ### increaseAllowance ```solidity function increaseAllowance(address spender, uint256 addedValue) external nonpayable returns (bool) ``` *Atomically increases the allowance granted to `spender` by the caller. This is an alternative to {approve} that can be used as a mitigation for problems described in {IERC20-approve}. Emits an {Approval} event indicating the updated allowance. Requirements: - `spender` cannot be the zero address.* #### Parameters | Name | Type | Description | | ---------- | ------- | ----------- | | spender | address | undefined | | addedValue | uint256 | undefined | #### Returns | Name | Type | Description | | ---- | ---- | ----------- | | \_0 | bool | undefined | ### name ```solidity function name() external view returns (string) ``` *Returns the name of the token.* #### Returns | Name | Type | Description | | ---- | ------ | ----------- | | \_0 | string | undefined | ### nonces ```solidity function nonces(address owner) external view returns (uint256) ``` *See {IERC20Permit-nonces}.* #### Parameters | Name | Type | Description | | ----- | ------- | ----------- | | owner | address | undefined | #### Returns | Name | Type | Description | | ---- | ------- | ----------- | | \_0 | uint256 | undefined | ### permit ```solidity function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external nonpayable ``` *See {IERC20Permit-permit}.* #### Parameters | Name | Type | Description | | -------- | ------- | ----------- | | owner | address | undefined | | spender | address | undefined | | value | uint256 | undefined | | deadline | uint256 | undefined | | v | uint8 | undefined | | r | bytes32 | undefined | | s | bytes32 | undefined | ### symbol ```solidity function symbol() external view returns (string) ``` *Returns the symbol of the token, usually a shorter version of the name.* #### Returns | Name | Type | Description | | ---- | ------ | ----------- | | \_0 | string | undefined | ### totalSupply ```solidity function totalSupply() external view returns (uint256) ``` *See {IERC20-totalSupply}.* #### Returns | Name | Type | Description | | ---- | ------- | ----------- | | \_0 | uint256 | undefined | ### transfer ```solidity function transfer(address recipient, uint256 amount) external nonpayable returns (bool) ``` *See {IERC20-transfer}. Requirements: - `recipient` cannot be the zero address. - the caller must have a balance of at least `amount`.* #### Parameters | Name | Type | Description | | --------- | ------- | ----------- | | recipient | address | undefined | | amount | uint256 | undefined | #### Returns | Name | Type | Description | | ---- | ---- | ----------- | | \_0 | bool | undefined | ### transferFrom ```solidity function transferFrom(address sender, address recipient, uint256 amount) external nonpayable returns (bool) ``` *See {IERC20-transferFrom}. Emits an {Approval} event indicating the updated allowance. This is not required by the EIP. See the note at the beginning of {ERC20}. Requirements: - `sender` and `recipient` cannot be the zero address. - `sender` must have a balance of at least `amount`. - the caller must have allowance for `sender`'s tokens of at least `amount`.* #### Parameters | Name | Type | Description | | --------- | ------- | ----------- | | sender | address | undefined | | recipient | address | undefined | | amount | uint256 | undefined | #### Returns | Name | Type | Description | | ---- | ---- | ----------- | | \_0 | bool | undefined | ## Events ### Approval ```solidity event Approval(address indexed owner, address indexed spender, uint256 value) ``` #### Parameters | Name | Type | Description | | ----------------- | ------- | ----------- | | owner `indexed` | address | undefined | | spender `indexed` | address | undefined | | value | uint256 | undefined | ### Transfer ```solidity event Transfer(address indexed from, address indexed to, uint256 value) ``` #### Parameters | Name | Type | Description | | -------------- | ------- | ----------- | | from `indexed` | address | undefined | | to `indexed` | address | undefined | | value | uint256 | undefined | --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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