> For the complete documentation index, see [llms.txt](https://contracts.synapseprotocol.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://contracts.synapseprotocol.com/elin/contracts-upgradeable-4.5.0/token/erc721/extensions.md).

# extensions

- [ERC721EnumerableUpgradeable](https://contracts.synapseprotocol.com/elin/contracts-upgradeable-4.5.0/token/erc721/extensions/erc721enumerableupgradeable.md)
- [IERC721EnumerableUpgradeable](https://contracts.synapseprotocol.com/elin/contracts-upgradeable-4.5.0/token/erc721/extensions/ierc721enumerableupgradeable.md)
- [IERC721MetadataUpgradeable](https://contracts.synapseprotocol.com/elin/contracts-upgradeable-4.5.0/token/erc721/extensions/ierc721metadataupgradeable.md)