MetroBridge — a decentralized cross-chain bridge that provides bi-directional exchange between IoTeX and other blockchain networks.
Description of the MetroBridge work
MetroBridge consists of two main components. First of all, it is worth highlighting a set of smart contracts, previously deployed on IoTeX and other blockchains. Also, there is a pool of "witnesses" that listens to the actions of MetroBridge on smart contracts on IoTeX and other blockchains. When a token lock action is detected on one blockchain, a pool of witnesses verifies it and passes the final information to another blockchain. If a proxy token burn is detected on one blockchain, a witness pool verifies it and passes the final information to another blockchain where the same amount of the original token is unlocked.
Usage fee:
| From other blockchains to IoTeX: | you will pay a regular transaction fee for locking your tokens on other blockchains. You will not be charged for a Proxy-Token transaction on the IoTeX blockchain. |
| From IoTeX to other blockchains: | you will not be charged for a proxy token burn transaction on the IoTeX blockchain. You will pay a small amount of IOTX to cover the unlock transaction fee on another blockchain. |
A “proxy token” — a representation of another token that is on a different blockchain (for example, an ioWETH token in IoTeX could be a “proxy version” of an Ethereum WETH token in IoTeX). A proxy token is an exact copy of the original token, it has the same properties and can be used in the same ways as the original token: it just lives on a different blockchain from the original one.
What else to pay attention to?
The supply of the original token never changes as a result of using MetroBridge. The MetroBridge locks a certain amount of a token on one blockchain (effectively taking it out of circulation) and mints exactly the same amount of a proxy token on another.
Once you use MetroBridge to transfer your source tokens, they are stored and locked in contracts.