# Messaging Layer

The following graph demonstrates how the messaging layer of Bool processes a cross-chain message:

* The Monitor server captures the cross-chain message emitted by the Messenger contract on the source chain and submits the message onto the Bool chain.
* DHCs in Bool Network fetch the cross-chain message from the Bool chain and decodes the packed message following a pre-defined standard. More specifically, a valid cross-chain message must include two vital destination information: Chain ID and the identification of Anchor, such as `address`.
* The only committee controlling the destination Anchor will reorganize the cross-chain message based on the standard of the destination. 
* The committee members independently verify the finality of the message on the source chain and sign the message based on the Threshold Signature Scheme (TSS).
* A signature is generated which can be verified on-chain to prove the validity of the corresponding message. 
* The External Relayers system will synthesize `(message, signature)` and submit the packed information to the destination chain.

<figure><img src="https://362083554-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FBPzEwQWF8yFmEtNtg2pz%2Fuploads%2FFRE1gCfYuH6pIUmc2GjF%2FBOOL_Network_part.png?alt=media&#x26;token=bb8ee265-edfb-4399-a8c3-6ab214348918" alt=""><figcaption><p>Bool Network - Messaging Layer</p></figcaption></figure>