Symbiosis BridgeV2 Contract

Symbiosis core smart contracts: BridgeV2 contract as a proxy between Synthesis/Portal contracts and the Symbiosis realayer network.
Symbiosis core smart contracts are open source and available at​
For security audits of Symbiosis core smart contract, please refer to Security Audits of Symbiosis.
In the previous article: Symbiosis Mint-Burn Process, we explained the core idea of cross-chain operations:
  • Whenever Portal locks tokens on one blockchain -> Synthesis mints tokens on another blockchain.
  • Whenever Synthesis burns tokens on one blockchain -> Portal releases tokens on another blockchain.
Let's take a closer look at the BridgeV2 contract.
An instance of the BridgeV2 contract is deployed on each blockchain supported by Symbiosis and acts as a proxy between relayers and Portal/Synthesis contracts.
BridgeV2 accepts calls from:
  1. 1.
    The Portal/Synthesis contracts locked on the same blockchain: BridgeV2 issues an Oracle request (an event in terms of smart contracts) containing all the necessary data and instructions needed to accomplish the operation outside of the BridgeV2 blockchain.
  2. 2.
    Relayers: Transactions signed with MPC address. Such transactions contain data and instructions from another blockchain.
Scheme 1 below shows the BridgeV2 routine during cross-chain operations:
Scheme 1. BridgeV2 routine.
In addition, Portal/Synthesis uses BridgeV2 to store fees deducted from the users for cross-chain operations. Relayers transfer accumulated fees from BridgeV2 addresses to the addresses from which they send transactions. More information about fee collection can be found here: Gas Fees for Cross-chain Operations via Symbiosis.
About relayers. The Symbiosis relayers network is an off-chain part of the Symbiosis protocol. The main purpose of the network is to provide fast, accurate, and secure transfer of information about cross-chain operations conducted via the Symbiosis protocol. See Relayers network for more details.