> 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/utils/introspection.md).

# introspection

- [ERC165Upgradeable](https://contracts.synapseprotocol.com/elin/contracts-upgradeable-4.5.0/utils/introspection/erc165upgradeable.md)
- [IERC165Upgradeable](https://contracts.synapseprotocol.com/elin/contracts-upgradeable-4.5.0/utils/introspection/ierc165upgradeable.md)