AllowanceTransfer
Inherits: IAllowanceTransfer, EIP712
State Variables
allowance
Maps users to tokens to spender addresses and information about the approval on the token
Indexed in the order of token owner address, token address, spender address
The stored word saves the allowed amount, expiration on the allowance, and nonce
mapping(address => mapping(address => mapping(address => PackedAllowance))) public allowance;
Functions
approve
Approves the spender to use up to amount of the specified token up until the expiration
The packed allowance also holds a nonce, which will stay unchanged in approve
function approve(address token, address spender, uint160 amount, uint48 expiration) external;
Parameters
| Name | Type | Description |
|---|---|---|
token | address | The token to approve |
spender | address | The spender address to approve |
amount | uint160 | The approved amount of the token |
expiration | uint48 | The timestamp at which the approval is no longer valid |
permit
Permit a spender to a given amount of the owners token via the owner's EIP-712 signature
May fail if the owner's nonce was invalidated in-flight by invalidateNonce
function permit(address owner, PermitSingle memory permitSingle, bytes calldata signature) external;
Parameters
| Name | Type | Description |
|---|---|---|
owner | address | The owner of the tokens being approved |
permitSingle | PermitSingle | Data signed over by the owner specifying the terms of approval |
signature | bytes | The owner's signature over the permit data |
permit
Permit a spender to a given amount of the owners token via the owner's EIP-712 signature
May fail if the owner's nonce was invalidated in-flight by invalidateNonce
function permit(address owner, PermitBatch memory permitBatch, bytes calldata signature) external;
Parameters
| Name | Type | Description |
|---|---|---|
owner | address | The owner of the tokens being approved |
permitBatch | PermitBatch | |
signature | bytes | The owner's signature over the permit data |
transferFrom
Transfer approved tokens from one address to another
Requires the from address to have approved at least the desired amount of tokens to msg.sender.
function transferFrom(address from, address to, uint160 amount, address token) external;
Parameters
| Name | Type | Description |
|---|---|---|
from | address | The address to transfer from |
to | address | The address of the recipient |
amount | uint160 | The amount of the token to transfer |
token | address | The token address to transfer |
transferFrom
Transfer approved tokens from one address to another
Requires the from address to have approved at least the desired amount of tokens to msg.sender.
function transferFrom(AllowanceTransferDetails[] calldata transferDetails) external;
Parameters
| Name | Type | Description |
|---|---|---|
transferDetails | AllowanceTransferDetails[] |
_transfer
Internal function for transferring tokens using stored allowances
Will fail if the allowed timeframe has passed
function _transfer(address from, address to, uint160 amount, address token) private;
lockdown
Enables performing a "lockdown" of the sender's Permit2 identity by batch revoking approvals
function lockdown(TokenSpenderPair[] calldata approvals) external;
Parameters
| Name | Type | Description |
|---|---|---|
approvals | TokenSpenderPair[] | Array of approvals to revoke. |
invalidateNonces
Invalidate nonces for a given (token, spender) pair
Can't invalidate more than 2**16 nonces per transaction.
function invalidateNonces(address token, address spender, uint48 newNonce) external;
Parameters
| Name | Type | Description |
|---|---|---|
token | address | The token to invalidate nonces for |
spender | address | The spender to invalidate nonces for |
newNonce | uint48 | The new nonce to set. Invalidates all nonces less than it. |
_updateApproval
Sets the new values for amount, expiration, and nonce.
Will check that the signed nonce is equal to the current nonce and then incrememnt the nonce value by 1.
Emits a Permit event.
function _updateApproval(PermitDetails memory details, address owner, address spender) private;