ERC 20 Standards

NOTE: This document is better viewed at https://docs.openzeppelin.com/contracts/api/token/erc20

This set of interfaces, contracts, and utilities are all related to the ERC20 Token Standard at https://eips.ethereum.org/EIPS/eip-20.

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There are a few core contracts that implement the behavior specified in the EIP:

{IERC20}: the interface all ERC20 implementations should conform to.

{IERC20Metadata}: the extended ERC20 interface including the name, symbol and decimals functions.

{ERC20}: the implementation of the ERC20 interface, including the name, symbol and decimals optional standard extension to the base interface.

Additionally there are multiple custom extensions, including:

{ERC20Burnable}: destruction of own tokens.

{ERC20Capped}: enforcement of a cap to the total supply when minting tokens.

{ERC20Pausable}: ability to pause token transfers.

{ERC20Snapshot}: efficient storage of past token balances to be later queried at any point in time.

{ERC20Permit}: gasless approval of tokens (standardized as ERC2612).

{ERC20FlashMint}: token level support for flash loans through the minting and burning of ephemeral tokens (standardized as ERC3156).

{ERC20Votes}:support for voting and vote delegation.

{ERC20VotesComp}: support for voting and vote delegation (compatible with Compound’s token, with uint96 restrictions).

{ERC20Wrapper}: wrapper to create an ERC20 backed by another ERC20, with deposit and withdraw methods. Useful in conjunction with {ERC20Votes}.

Finally, there are some utilities to interact with ERC20 contracts in various ways.

{SafeERC20}: a wrapper around the interface that eliminates the need to handle boolean return values.

{TokenTimelock}: hold tokens for a beneficiary until a specified time.

The following related EIPs are in draft status.

{ERC20Permit}