ERC 20

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.

Tip	For an overview of ERC20 tokens and a walk through on how to create a token contract read our ERC20 guide.

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.

• {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.

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

• {ERC4626}: tokenized vault that manages shares (represented as ERC20) that are backed by assets (another ERC20).

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.

Other utilities that support ERC20 assets can be found in codebase:

• ERC20 tokens can be timelocked (held tokens for a beneficiary until a specified time) or vested (released following a given schedule) using a {VestingWallet}.

Note	This core set of contracts is designed to be unopinionated, allowing developers to access the internal functions in ERC20 (such as _mint) and expose them as external functions in the way they prefer.

Core

{{IERC20}}

{{IERC20Metadata}}

{{ERC20}}

Extensions

{{ERC20Burnable}}

{{ERC20Capped}}

{{ERC20Pausable}}

{{ERC20Permit}}

{{ERC20Votes}}

{{ERC20Wrapper}}

{{ERC20FlashMint}}

{{ERC4626}}

Utilities

{{SafeERC20}}