An Arbitrary Message Bridge (AMB) between the Ethereum Mainnet and the xDai chain extends the number of the applications that can leverage cross-chain communications.
Any application can build its own AMB extension. This is represented by two mediator contracts so that either assets or arbitrary data can be transferred between chains. The deployed mediator contracts do not require a set of oracles to be setup, allowing an application to launch quickly and reducing the cost of application ownership.
The mediator contracts rely on the following information about the ETH-xDai Arbitrary Message Bridge:
Gas limit to call method in the xDai chain:
Gas limit to call method in the Ethereum Mainnet:
Transactions require a multi-sig (for bridge validators, not users) for a successful transfer. Current validators can be viewed with the live monitoring application. An example transaction view is available here: https://alm-xdai.herokuapp.com/100/0x83f61bb582610c4cd7b6347a84f470020bfeeea699340016cdcf3c31ff0312e3
Withdrawal requests call the
transfer method of the token contracts with the mediator contract address as the recipient (the multitoken/erc20-to-erc20 extension for AMB)