> 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/messaging/interfaces.md).

# interfaces

- [IAuthVerifier](https://contracts.synapseprotocol.com/messaging/interfaces/iauthverifier.md)
- [IGasFeePricing](https://contracts.synapseprotocol.com/messaging/interfaces/igasfeepricing.md)
- [IMessageBus](https://contracts.synapseprotocol.com/messaging/interfaces/imessagebus.md)
- [ISynMessagingReceiver](https://contracts.synapseprotocol.com/messaging/interfaces/isynmessagingreceiver.md)