# Architecture Herodotus is composed of both on-chain and off-chain components. The key components are: #### Smart Contracts These contracts relay block hashes across Ethereum layers and verify storage proofs, among other tasks. Learn more [here](https://docs.herodotus.dev/herodotus-docs/protocol-design/architecture/smart-contracts). #### Cairo Programs: Proven off-chain. We use off-chain Cairo for intensive tasks, like expanding our accumulators with many proven block headers. #### Circuits: Proven off-chain. We utilize circuits to efficiently verify state proofs from specific zk-rollups. Currently, we haven't implemented these in production, but they'll be available in the future. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.herodotus.dev/herodotus-docs/protocol-design/architecture.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.