LayerZero

LayerZero is the first system to trustlessly enable direct transactions across all chains. Allowing transactions to flow freely between chains provides opportunities for users to consolidate fragmented pockets of liquidity while also making full use of applications on separate chains. LayerZero provides the network fabric underlying the fully-connected omnichain ecosystem of the future.

LayerZero endpoints

LayerZero Endpoints are the user-facing interface to LayerZero. Each chain in the LayerZero network has one LayerZero Endpoint implemented as a series of on- chain smart contracts. An Endpoint’s purpose is to allow the user to send a message using the LayerZero protocol backend, guaranteeing valid delivery. A LayerZero Endpoint is split into four modules: Communicator, Validator, Network, and Libraries. The Communicator, Validator, and Network modules comprise the core functionality of the Endpoint, while each new chain supported by LayerZero is added as an additional Library. This design allows Layer 0 to add support for new chains without modifying the three core modules.

Oracle

The Oracle is a third-party service that provides a mechanism to, independently of the other LayerZero components, read a block header from one chain and send it to another chain. In theory, this Oracle can be any third-party service that provides this mechanism, but in practice, they expect to use Chainlink, which is the current industry leader for decentralized oracle networks.

Relayer

The Relayer is an off-chain service that is similar in function to an Oracle, but instead of fetching block headers, it fetches the proof for a specified transaction. To ensure valid delivery, the only requirement is that for any given message sent using the LayerZero protocol, the Oracle and Relayer must be independent of each other. The protocol itself does not require any specific implementation of a Relayer, and in theory, the users of LayerZero could even implement their own Relayer service. This design allows users to be sure that the Relayer cannot collude with the Oracle, and this independence is what allows us to implement trustless validated delivery. In practice, LayerZero provides the Relayer service while the Oracle is handled by Chainlink’s decentralized oracle network and associated consensus mechanisms.