> For the complete documentation index, see [llms.txt](https://docs.snowbridge.network/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.snowbridge.network/architecture/relayers.md). # Relayers {% hint style="success" %} Relayers are **permissionless and trustless**. This means that anyone can operate a relayer for channels they are interested in. {% endhint %} A relay is a piece of software running offchain that watches two blockchains and relays messages across them. The implementation of the relayer in our bridge is not part of the core protocol, as it is offchain and so is untrusted. Of course, some relayer still needs to be running in order for the bridge to function, but it only needs to conform to the protocol defined by on-chain requirements. We provide relayer software that will be run by incentivized relayers to keep the bridge active, but the design and implementation of the relayer are not relevant for understanding the trustless bridge protocol. ## Polkadot->Ethereum ### BEEFY relay Relays signed BEEFY commitments and proofs from a Polkadot relay chain to the BEEFY light client contract on Ethereum. ### Message relay Relays message commitments and proofs from BridgeHub to inbound channel contracts on Ethereum ## Ethereum->Polkadot ### Header relay Relays the following objects to the Ethereum light client pallet on the BridgeHub parachain: * Beacon chain headers * Execution chain headers * Sync Committees ### Message relay Relays messages emitted by outbound channel contracts on Ethereum. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## 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, and the optional `goal` query parameter: ``` GET https://docs.snowbridge.network/architecture/relayers.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. 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.