# How it works Cross Chain Messaging Protocol consists of 3 steps: 1. Emit event on the SRC chain 2. Verify the event and get proof from the Signer 3. Receive the event on the DEST chain The key part of the protocol is proof of the event. \ [Signer Service](/for-developers/cross-chain-messaging-protocol/how-it-works/signer-service/signer-interface.md) is responsible for producing proofs, whereas [Signers Registry smart contract](/for-developers/cross-chain-messaging-protocol/how-it-works/signers-registry-contract.md) is responsible for validation if proof was made by the correct Signer. --- # 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.bitoftrade.com/for-developers/cross-chain-messaging-protocol/how-it-works.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.