> For the complete documentation index, see [llms.txt](https://docs.nucleusearn.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nucleusearn.io/nucleus-architecture/smart-contracts/contracts/base/roles/cross-chain/oappauth.md).

# OAppAuth

- [Contents](https://docs.nucleusearn.io/nucleus-architecture/smart-contracts/contracts/base/roles/cross-chain/oappauth/contents.md)
- [OAppAuth](https://docs.nucleusearn.io/nucleus-architecture/smart-contracts/contracts/base/roles/cross-chain/oappauth/oappauth.md)
- [OAppAuthCore](https://docs.nucleusearn.io/nucleus-architecture/smart-contracts/contracts/base/roles/cross-chain/oappauth/oappauthcore.md)
- [OAppAuthReceiver](https://docs.nucleusearn.io/nucleus-architecture/smart-contracts/contracts/base/roles/cross-chain/oappauth/oappauthreceiver.md)
- [OAppAuthSender](https://docs.nucleusearn.io/nucleus-architecture/smart-contracts/contracts/base/roles/cross-chain/oappauth/oappauthsender.md)