Interfaces

This document is better viewed at https://docs.openzeppelin.com/contracts/api/interfaces

List of standardized interfaces

These interfaces are available as .sol files, and also as compiler .json ABI files (through the npm package). These are useful to interact with third party contracts that implement them.

Detailed ABI

IERC20Errors 

import "@openzeppelin/contracts/interfaces/draft-IERC6093.sol";

Standard ERC-20 Errors Interface of the ERC-6093 custom errors for ERC-20 tokens.

Errors

ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed) error

Indicates an error related to the current balance of a sender. Used in transfers.

ERC20InvalidSender(address sender) error

Indicates a failure with the token sender. Used in transfers.

ERC20InvalidReceiver(address receiver) error

Indicates a failure with the token receiver. Used in transfers.

ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed) error

Indicates a failure with the spender’s allowance. Used in transfers.

ERC20InvalidApprover(address approver) error

Indicates a failure with the approver of a token to be approved. Used in approvals.

ERC20InvalidSpender(address spender) error

Indicates a failure with the spender to be approved. Used in approvals.

IERC721Errors 

import "@openzeppelin/contracts/interfaces/draft-IERC6093.sol";

Standard ERC-721 Errors Interface of the ERC-6093 custom errors for ERC-721 tokens.

Errors

ERC721InvalidOwner(address owner) error

Indicates that an address can’t be an owner. For example, address(0) is a forbidden owner in ERC-20. Used in balance queries.

ERC721NonexistentToken(uint256 tokenId) error

Indicates a tokenId whose owner is the zero address.

ERC721IncorrectOwner(address sender, uint256 tokenId, address owner) error

Indicates an error related to the ownership over a particular token. Used in transfers.

ERC721InvalidSender(address sender) error

Indicates a failure with the token sender. Used in transfers.

ERC721InvalidReceiver(address receiver) error

Indicates a failure with the token receiver. Used in transfers.

ERC721InsufficientApproval(address operator, uint256 tokenId) error

Indicates a failure with the operator’s approval. Used in transfers.

ERC721InvalidApprover(address approver) error

Indicates a failure with the approver of a token to be approved. Used in approvals.

ERC721InvalidOperator(address operator) error

Indicates a failure with the operator to be approved. Used in approvals.

IERC1155Errors 

import "@openzeppelin/contracts/interfaces/draft-IERC6093.sol";

Standard ERC-1155 Errors Interface of the ERC-6093 custom errors for ERC-1155 tokens.

Errors

ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId) error

Indicates an error related to the current balance of a sender. Used in transfers.

ERC1155InvalidSender(address sender) error

Indicates a failure with the token sender. Used in transfers.

ERC1155InvalidReceiver(address receiver) error

Indicates a failure with the token receiver. Used in transfers.

ERC1155MissingApprovalForAll(address operator, address owner) error

Indicates a failure with the operator’s approval. Used in transfers.

ERC1155InvalidApprover(address approver) error

Indicates a failure with the approver of a token to be approved. Used in approvals.

ERC1155InvalidOperator(address operator) error

Indicates a failure with the operator to be approved. Used in approvals.

ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength) error

Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation. Used in batch transfers.

IERC1271 

import "@openzeppelin/contracts/interfaces/IERC1271.sol";

Interface of the ERC-1271 standard signature validation method for contracts as defined in ERC-1271.

Functions

isValidSignature(bytes32 hash, bytes signature) → bytes4 magicValue external

Should return whether the signature provided is valid for the provided data

IERC1363 

import "@openzeppelin/contracts/interfaces/IERC1363.sol";

Interface of the ERC-1363 standard as defined in the ERC-1363.

Defines an extension interface for ERC-20 tokens that supports executing code on a recipient contract after transfer or transferFrom, or code on a spender contract after approve, in a single transaction.

Functions
IERC165
IERC20
Events
IERC20

transferAndCall(address to, uint256 value) → bool external

Moves a value amount of tokens from the caller’s account to to and then calls IERC1363Receiver.onTransferReceived on to.

transferAndCall(address to, uint256 value, bytes data) → bool external

Moves a value amount of tokens from the caller’s account to to and then calls IERC1363Receiver.onTransferReceived on to.

transferFromAndCall(address from, address to, uint256 value) → bool external

Moves a value amount of tokens from from to to using the allowance mechanism and then calls IERC1363Receiver.onTransferReceived on to.

transferFromAndCall(address from, address to, uint256 value, bytes data) → bool external

Moves a value amount of tokens from from to to using the allowance mechanism and then calls IERC1363Receiver.onTransferReceived on to.

approveAndCall(address spender, uint256 value) → bool external

Sets a value amount of tokens as the allowance of spender over the caller’s tokens and then calls IERC1363Spender.onApprovalReceived on spender.

approveAndCall(address spender, uint256 value, bytes data) → bool external

Sets a value amount of tokens as the allowance of spender over the caller’s tokens and then calls IERC1363Spender.onApprovalReceived on spender.

IERC1363Receiver 

import "@openzeppelin/contracts/interfaces/IERC1363Receiver.sol";

Interface for any contract that wants to support transferAndCall or transferFromAndCall from ERC-1363 token contracts.

Functions

onTransferReceived(address operator, address from, uint256 value, bytes data) → bytes4 external

Whenever ERC-1363 tokens are transferred to this contract via transferAndCall or transferFromAndCall by operator from from, this function is called.

To accept the transfer, this must return bytes4(keccak256("onTransferReceived(address,address,uint256,bytes)")) (i.e. 0x88a7ca5c, or its own function selector).

IERC1363Spender 

import "@openzeppelin/contracts/interfaces/IERC1363Spender.sol";

Interface for any contract that wants to support approveAndCall from ERC-1363 token contracts.

Functions

onApprovalReceived(address owner, uint256 value, bytes data) → bytes4 external

Whenever an ERC-1363 token owner approves this contract via approveAndCall to spend their tokens, this function is called.

To accept the approval, this must return bytes4(keccak256("onApprovalReceived(address,uint256,bytes)")) (i.e. 0x7b04a2d0, or its own function selector).

IERC1820Implementer 

import "@openzeppelin/contracts/interfaces/IERC1820Implementer.sol";

Interface for an ERC-1820 implementer, as defined in the ERC. Used by contracts that will be registered as implementers in the IERC1820Registry.

Functions

canImplementInterfaceForAddress(bytes32 interfaceHash, address account) → bytes32 external

Returns a special value (ERC1820_ACCEPT_MAGIC) if this contract implements interfaceHash for account.

See IERC1820Registry.setInterfaceImplementer.

IERC1820Registry 

import "@openzeppelin/contracts/interfaces/IERC1820Registry.sol";

Interface of the global ERC-1820 Registry, as defined in the ERC. Accounts may register implementers for interfaces in this registry, as well as query support.

Implementers may be shared by multiple accounts, and can also implement more than a single interface for each account. Contracts can implement interfaces for themselves, but externally-owned accounts (EOA) must delegate this to a contract.

IERC165 interfaces can also be queried via the registry.

For an in-depth explanation and source code analysis, see the ERC text.

Functions
Events

setManager(address account, address newManager) external

Sets newManager as the manager for account. A manager of an account is able to set interface implementers for it.

By default, each account is its own manager. Passing a value of 0x0 in newManager will reset the manager to this initial state.

Emits a ManagerChanged event.

Requirements:

  • the caller must be the current manager for account.

getManager(address account) → address external

Returns the manager for account.

See setManager.

setInterfaceImplementer(address account, bytes32 _interfaceHash, address implementer) external

Sets the implementer contract as account's implementer for interfaceHash.

account being the zero address is an alias for the caller’s address. The zero address can also be used in implementer to remove an old one.

See interfaceHash to learn how these are created.

Emits an InterfaceImplementerSet event.

Requirements:

getInterfaceImplementer(address account, bytes32 _interfaceHash) → address external

Returns the implementer of interfaceHash for account. If no such implementer is registered, returns the zero address.

If interfaceHash is an IERC165 interface id (i.e. it ends with 28 zeroes), account will be queried for support of it.

account being the zero address is an alias for the caller’s address.

interfaceHash(string interfaceName) → bytes32 external

Returns the interface hash for an interfaceName, as defined in the corresponding section of the ERC.

updateERC165Cache(address account, bytes4 interfaceId) external

implementsERC165Interface(address account, bytes4 interfaceId) → bool external

implementsERC165InterfaceNoCache(address account, bytes4 interfaceId) → bool external

InterfaceImplementerSet(address indexed account, bytes32 indexed interfaceHash, address indexed implementer) event

ManagerChanged(address indexed account, address indexed newManager) event

IERC1822Proxiable 

import "@openzeppelin/contracts/interfaces/draft-IERC1822.sol";

ERC-1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified proxy whose upgrades are fully controlled by the current implementation.

Functions

proxiableUUID() → bytes32 external

Returns the storage slot that the proxiable contract assumes is being used to store the implementation address.

A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this function revert if invoked through a proxy.

IERC2612 

import "@openzeppelin/contracts/interfaces/IERC2612.sol";
Functions
IERC20Permit

IERC2981 

import "@openzeppelin/contracts/interfaces/IERC2981.sol";

Interface for the NFT Royalty Standard.

A standardized way to retrieve royalty payment information for non-fungible tokens (NFTs) to enable universal support for royalty payments across all NFT marketplaces and ecosystem participants.

Functions
IERC165

royaltyInfo(uint256 tokenId, uint256 salePrice) → address receiver, uint256 royaltyAmount external

Returns how much royalty is owed and to whom, based on a sale price that may be denominated in any unit of exchange. The royalty amount is denominated and should be paid in that same unit of exchange.

ERC-2981 allows setting the royalty to 100% of the price. In that case all the price would be sent to the royalty receiver and 0 tokens to the seller. Contracts dealing with royalty should consider empty transfers.

IERC3156FlashLender 

import "@openzeppelin/contracts/interfaces/IERC3156FlashLender.sol";

Interface of the ERC-3156 FlashLender, as defined in ERC-3156.

Functions

maxFlashLoan(address token) → uint256 external

The amount of currency available to be lended.

flashFee(address token, uint256 amount) → uint256 external

The fee to be charged for a given loan.

flashLoan(contract IERC3156FlashBorrower receiver, address token, uint256 amount, bytes data) → bool external

Initiate a flash loan.

IERC3156FlashBorrower 

import "@openzeppelin/contracts/interfaces/IERC3156FlashBorrower.sol";

Interface of the ERC-3156 FlashBorrower, as defined in ERC-3156.

Functions

onFlashLoan(address initiator, address token, uint256 amount, uint256 fee, bytes data) → bytes32 external

Receive a flash loan.

IERC4626 

import "@openzeppelin/contracts/interfaces/IERC4626.sol";

Interface of the ERC-4626 "Tokenized Vault Standard", as defined in ERC-4626.

Functions
IERC20Metadata
IERC20
Events
IERC20

asset() → address assetTokenAddress external

Returns the address of the underlying token used for the Vault for accounting, depositing, and withdrawing.

  • MUST be an ERC-20 token contract.

  • MUST NOT revert.

totalAssets() → uint256 totalManagedAssets external

Returns the total amount of the underlying asset that is “managed” by Vault.

  • SHOULD include any compounding that occurs from yield.

  • MUST be inclusive of any fees that are charged against assets in the Vault.

  • MUST NOT revert.

convertToShares(uint256 assets) → uint256 shares external

Returns the amount of shares that the Vault would exchange for the amount of assets provided, in an ideal scenario where all the conditions are met.

  • MUST NOT be inclusive of any fees that are charged against assets in the Vault.

  • MUST NOT show any variations depending on the caller.

  • MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.

  • MUST NOT revert.

This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and from.

convertToAssets(uint256 shares) → uint256 assets external

Returns the amount of assets that the Vault would exchange for the amount of shares provided, in an ideal scenario where all the conditions are met.

  • MUST NOT be inclusive of any fees that are charged against assets in the Vault.

  • MUST NOT show any variations depending on the caller.

  • MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.

  • MUST NOT revert.

This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and from.

maxDeposit(address receiver) → uint256 maxAssets external

Returns the maximum amount of the underlying asset that can be deposited into the Vault for the receiver, through a deposit call.

  • MUST return a limited value if receiver is subject to some deposit limit.

  • MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of assets that may be deposited.

  • MUST NOT revert.

previewDeposit(uint256 assets) → uint256 shares external

Allows an on-chain or off-chain user to simulate the effects of their deposit at the current block, given current on-chain conditions.

  • MUST return as close to and no more than the exact amount of Vault shares that would be minted in a deposit call in the same transaction. I.e. deposit should return the same or more shares as previewDeposit if called in the same transaction.

  • MUST NOT account for deposit limits like those returned from maxDeposit and should always act as though the deposit would be accepted, regardless if the user has enough tokens approved, etc.

  • MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.

  • MUST NOT revert.

any unfavorable discrepancy between convertToShares and previewDeposit SHOULD be considered slippage in share price or some other type of condition, meaning the depositor will lose assets by depositing.

deposit(uint256 assets, address receiver) → uint256 shares external

Mints shares Vault shares to receiver by depositing exactly amount of underlying tokens.

  • MUST emit the Deposit event.

  • MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the deposit execution, and are accounted for during deposit.

  • MUST revert if all of assets cannot be deposited (due to deposit limit being reached, slippage, the user not approving enough underlying tokens to the Vault contract, etc).

most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.

maxMint(address receiver) → uint256 maxShares external

Returns the maximum amount of the Vault shares that can be minted for the receiver, through a mint call. - MUST return a limited value if receiver is subject to some mint limit. - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of shares that may be minted. - MUST NOT revert.

previewMint(uint256 shares) → uint256 assets external

Allows an on-chain or off-chain user to simulate the effects of their mint at the current block, given current on-chain conditions.

  • MUST return as close to and no fewer than the exact amount of assets that would be deposited in a mint call in the same transaction. I.e. mint should return the same or fewer assets as previewMint if called in the same transaction.

  • MUST NOT account for mint limits like those returned from maxMint and should always act as though the mint would be accepted, regardless if the user has enough tokens approved, etc.

  • MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.

  • MUST NOT revert.

any unfavorable discrepancy between convertToAssets and previewMint SHOULD be considered slippage in share price or some other type of condition, meaning the depositor will lose assets by minting.

mint(uint256 shares, address receiver) → uint256 assets external

Mints exactly shares Vault shares to receiver by depositing amount of underlying tokens.

  • MUST emit the Deposit event.

  • MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the mint execution, and are accounted for during mint.

  • MUST revert if all of shares cannot be minted (due to deposit limit being reached, slippage, the user not approving enough underlying tokens to the Vault contract, etc).

most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.

maxWithdraw(address owner) → uint256 maxAssets external

Returns the maximum amount of the underlying asset that can be withdrawn from the owner balance in the Vault, through a withdraw call.

  • MUST return a limited value if owner is subject to some withdrawal limit or timelock.

  • MUST NOT revert.

previewWithdraw(uint256 assets) → uint256 shares external

Allows an on-chain or off-chain user to simulate the effects of their withdrawal at the current block, given current on-chain conditions.

  • MUST return as close to and no fewer than the exact amount of Vault shares that would be burned in a withdraw call in the same transaction. I.e. withdraw should return the same or fewer shares as previewWithdraw if called in the same transaction.

  • MUST NOT account for withdrawal limits like those returned from maxWithdraw and should always act as though the withdrawal would be accepted, regardless if the user has enough shares, etc.

  • MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.

  • MUST NOT revert.

any unfavorable discrepancy between convertToShares and previewWithdraw SHOULD be considered slippage in share price or some other type of condition, meaning the depositor will lose assets by depositing.

withdraw(uint256 assets, address receiver, address owner) → uint256 shares external

Burns shares from owner and sends exactly assets of underlying tokens to receiver.

  • MUST emit the Withdraw event.

  • MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the withdraw execution, and are accounted for during withdraw.

  • MUST revert if all of assets cannot be withdrawn (due to withdrawal limit being reached, slippage, the owner not having enough shares, etc).

Note that some implementations will require pre-requesting to the Vault before a withdrawal may be performed. Those methods should be performed separately.

maxRedeem(address owner) → uint256 maxShares external

Returns the maximum amount of Vault shares that can be redeemed from the owner balance in the Vault, through a redeem call.

  • MUST return a limited value if owner is subject to some withdrawal limit or timelock.

  • MUST return balanceOf(owner) if owner is not subject to any withdrawal limit or timelock.

  • MUST NOT revert.

previewRedeem(uint256 shares) → uint256 assets external

Allows an on-chain or off-chain user to simulate the effects of their redeemption at the current block, given current on-chain conditions.

  • MUST return as close to and no more than the exact amount of assets that would be withdrawn in a redeem call in the same transaction. I.e. redeem should return the same or more assets as previewRedeem if called in the same transaction.

  • MUST NOT account for redemption limits like those returned from maxRedeem and should always act as though the redemption would be accepted, regardless if the user has enough shares, etc.

  • MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.

  • MUST NOT revert.

any unfavorable discrepancy between convertToAssets and previewRedeem SHOULD be considered slippage in share price or some other type of condition, meaning the depositor will lose assets by redeeming.

redeem(uint256 shares, address receiver, address owner) → uint256 assets external

Burns exactly shares from owner and sends assets of underlying tokens to receiver.

  • MUST emit the Withdraw event.

  • MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the redeem execution, and are accounted for during redeem.

  • MUST revert if all of shares cannot be redeemed (due to withdrawal limit being reached, slippage, the owner not having enough shares, etc).

some implementations will require pre-requesting to the Vault before a withdrawal may be performed. Those methods should be performed separately.

Deposit(address indexed sender, address indexed owner, uint256 assets, uint256 shares) event

Withdraw(address indexed sender, address indexed receiver, address indexed owner, uint256 assets, uint256 shares) event

IERC5313 

import "@openzeppelin/contracts/interfaces/IERC5313.sol";

Interface for the Light Contract Ownership Standard.

A standardized minimal interface required to identify an account that controls a contract

Functions

owner() → address external

Gets the address of the owner.

IERC5267 

import "@openzeppelin/contracts/interfaces/IERC5267.sol";
Functions
Events

eip712Domain() → bytes1 fields, string name, string version, uint256 chainId, address verifyingContract, bytes32 salt, uint256[] extensions external

returns the fields and values that describe the domain separator used by this contract for EIP-712 signature.

EIP712DomainChanged() event

MAY be emitted to signal that the domain could have changed.

IERC5805 

import "@openzeppelin/contracts/interfaces/IERC5805.sol";
Functions
IVotes
IERC6372
Events
IVotes
Errors
IVotes

IERC6372 

import "@openzeppelin/contracts/interfaces/IERC6372.sol";
Functions

clock() → uint48 external

Clock used for flagging checkpoints. Can be overridden to implement timestamp based checkpoints (and voting).

CLOCK_MODE() → string external

Description of the clock

IERC7674 

import "@openzeppelin/contracts/interfaces/draft-IERC7674.sol";

Temporary Approval Extension for ERC-20 (ERC-7674)

Functions
IERC20
Events
IERC20

temporaryApprove(address spender, uint256 value) → bool success external

Set the temporary allowance, allowing spender to withdraw (within the same transaction) assets held by the caller.

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