openzeppelin-contracts/contracts/token/ERC20/README.adoc

= ERC-20

[.readme-notice]
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 https://eips.ethereum.org/EIPS/eip-20[ERC-20 Token Standard].

TIP: For an overview of ERC-20 tokens and a walk through on how to create a token contract read our xref:ROOT:erc20.adoc[ERC-20 guide].

There are a few core contracts that implement the behavior specified in the ERC-20 standard:

* {IERC20}: the interface all ERC-20 implementations should conform to.
* {IERC20Metadata}: the extended ERC-20 interface including the <<ERC20-name--,`name`>>, <<ERC20-symbol--,`symbol`>> and <<ERC20-decimals--,`decimals`>> functions.
* {ERC20}: the implementation of the ERC-20 interface, including the <<ERC20-name--,`name`>>, <<ERC20-symbol--,`symbol`>> and <<ERC20-decimals--,`decimals`>> optional extensions to the standard interface.

Additionally there are multiple custom extensions, including:

* {ERC20Permit}: gasless approval of tokens (standardized as ERC-2612).
* {ERC20Burnable}: destruction of own tokens.
* {ERC20Capped}: enforcement of a cap to the total supply when minting tokens.
* {ERC20Pausable}: ability to pause token transfers.
* {ERC20FlashMint}: token level support for flash loans through the minting and burning of ephemeral tokens (standardized as ERC-3156).
* {ERC20Votes}: support for voting and vote delegation.
* {ERC20Wrapper}: wrapper to create an ERC-20 backed by another ERC-20, with deposit and withdraw methods. Useful in conjunction with {ERC20Votes}.
* {ERC20TemporaryApproval}: support for approvals lasting for only one transaction, as defined in ERC-7674.
* {ERC1363}: support for calling the target of a transfer or approval, enabling code execution on the receiver within a single transaction.
* {ERC4626}: tokenized vault that manages shares (represented as ERC-20) that are backed by assets (another ERC-20).

Finally, there are some utilities to interact with ERC-20 contracts in various ways:

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

Other utilities that support ERC-20 assets can be found in the codebase:

* ERC-20 tokens can be timelocked (held 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 ERC-20 (such as <<ERC20-_mint-address-uint256-,`_mint`>>) and expose them as external functions in the way they prefer.

== Core

{{IERC20}}

{{IERC20Metadata}}

{{ERC20}}

== Extensions

{{IERC20Permit}}

{{ERC20Permit}}

{{ERC20Burnable}}

{{ERC20Capped}}

{{ERC20Pausable}}

{{ERC20Votes}}

{{ERC20Wrapper}}

{{ERC20FlashMint}}

{{ERC20TemporaryApproval}}

{{ERC1363}}

{{ERC4626}}

== Utilities

{{SafeERC20}}

{{ERC1363Utils}}