The Mosaic pallet enables cross-chain and cross-layer transfers


The Mosaic Pallet implements the interface for the Mosaic Relayer. The Mosaic Relayer will relay liqudity across chains and layers.

As opposed to the EVM-EVM bridge, this pallet takes a different approach and uses mint and burn operations. Because of that it also limits the amount the Relayer can mint using a decaying penalty.

Decaying Penalty

At moment N, the Relayer has a maximum budget. Minting a token adds a penalty to the Relayer. The penalty decreases each block according to decay function decayer, which depends on the penalty, current_block, and last_decay_block. The current maximum amount that the Relayer can mint is given by budget - decayer(penalty, current_block, last_decay_block). The new penalty is the decayed previous penalty plus the minted amount.


The Mosaic pallet is comprised of three main components: the Relayer interface, incoming transactions, and outgoing transactions.

The Relayer Interface

The Relayer interface provides the necessary functionality for managing the constraints of the Relayer and exposing the functionality needed by the Relayer to conduct transactions. The Relayer, while operating on this network, is constrained by the set budget, supported networks, and the maximum transaction sizes for those networks. The Relayer will need to be able to accept new transactions and mint the funds needed for conducting those transactions. Additionally, in the event of finality issues on the destination network, the Relayer will need to be able to burn funds.

The Relayer's net budget is determined by the set gross budget and the decay penalty. This budget controls the minting capabilities of the Relayer on this network.

Incoming Transactions

Incoming transactions are transactions who's destination is this network. Once funds have been minted on this network and the lock time has passed, they may be claimed to conclude the transaction.

In the event that any issues occurred with finalizing a transaction, the waiting funds associated with incoming transactions that have yet to be claimed may be burned by the Relayer.

Outgoing Transactions

Outgoing transactions are transactions originating on this network who's destination is elsewhere. These transactions must first be requested by the user, then accepted by the Relayer. Once accepted by the Relayer the funds of this transaction will no longer be claimable on the origin network. Before acceptance by the Relayer, funds may be reclaimed by the user.