The `BridgeV3` contract facilitates cross-chain token transfers, supporting ERC20 and ERC777 tokens. It allows users to deposit tokens, which are then minted as side tokens on the destination chain. The contract handles token claims, manages fees, and ensures secure transfers using nonces and signatures. It also supports pausing operations, upgrading, and setting various parameters like fee percentages and federation addresses.

The `Bridge` contract facilitates cross-chain token transfers. It supports ERC20 and ERC777 tokens, allowing users to deposit tokens on one chain and claim them on another. The contract manages token mappings, handles token minting and burning, and ensures secure transfers with non-reentrancy and pausing mechanisms. It also includes fee management, federation control, and supports gasless claims via EIP-712 signatures.

The `Federation` contract manages a group of members who vote to approve cross-chain transactions. It initializes with a set of members and a required number of votes for transaction approval. Members can vote on transactions, and if the required votes are met, the transaction is processed. The contract also allows adding/removing members, changing the required votes, and emits events for various actions like voting, member changes, and heartbeats.

The `FederationV2` contract manages a federated group of members who vote on cross-chain transactions. It initializes with a set of members and a required number of votes for transaction approval. Members can vote on transactions, and once the required votes are met, the transaction is processed via a bridge. The contract also allows adding/removing members, changing vote requirements, and emitting heartbeat signals for status updates.