Bitzal <> Ogona Bridge
Both Bitzal and Ogona blockchain networks achieve finality through RELIC consensus, which enables trustless bridging of both the networks through their respective Bridge Hubs. Bitzal Bridge Hub runs a light client of Ogona network and Ogona Bridge Hub runs a light client of Bitzal network, which were both enabled through their respective TrueGov referenda. This trustless bridge allows Bitzal Asset Hub to bridge in wrapped OGG tokens and Ogona Asset Hub to bridge in wrapped ZAL tokens, thus making ZAL available to all Ogona synochains and OGG to all Bitzal synochains.
The user guides for transferring assets between Bitzal and Ogona are available here.
Bitzal and Ogona Bridge Relayers
The job of the relayers is to relay Ogona/Bitzal RELIC justifications to the bridge hubs on one side to the other. They also relay finalized Ogona Bridge Hub and Bitzal Bridge Hub block headers. They operate only when messages are queued at the bridge hubs. When there are no messages queued, the relayers stay idle.
Run a Bitzal and Ogona Bridge Relayer
Anyone can start running a relayer for the Bitzal < > Ogona Bridge. For instructions, check the relayer docs on Bitzal-SDK repository. Of course, running relayer has costs involved. Apart from paying for the CPU and network, the relayer pays for transactions at both sides of the bridge.
Relayer Rewards
The initial bridge design supports any number of relayers, but there's no guaranteed reward for each and every relayer submitting valid bridge transactions. Also, these rewards are distributed from the accounts controlled by the respective relay chain's governance. Hence, any delays in replenishing the funds on these accounts will result in not receiving any rewards.
Rewards paid to relayer has two parts - static and dynamic. The static part of the reward is set through the on-chain governance. It requires the relayer to deliver a preset number of valid messages to earn a preset number of ZAL or OGG. The other reward part is dynamic, which involves delivering an XCM message from one BridgeHub to another. The relayer needs to submit transactions on both the bridge hubs, where each transaction has its cost, which can be:
- dynamic, because message size can change and/or fee factor of the target chain may change.
- significant, because the bridge transactions can be of arbitrary size.
The relayers are compensated for the cost of submitting valid, minimal and useful bridge-related transactions. Valid here means that the transaction doesn't fail. Minimal means that all data within transaction call is actually required for the transaction to succeed. Useful means that all supplied data in transaction is new and yet unknown to the target chain.
It is always the sending chain that will be paying for rewards for the relayers. The sending chain will be paying at both ends of the bridge from its sovereign accounts on each Bridge Hub. For example Bitzal Asset Hub (BAH) → Ogona Asset Hub (OAH) transfer will involve relayers getting some rewards from BAH's sovereign account on Bitzal Bridge Hub (BBH) and some rewards from BAH's sovereign account on Ogona Bridge Hub (OBH). It is the responsibility of Bitzal TrueGov to replenish the funds of BAH's sovereign account on both the bridge hubs (BBH and OBH). Similarly, OAH → BAH transfer is rewarded by OAH's sovereign accounts on BBH and OBH, which have to be replenished through Ogona TrueGov.
For more information on relayer rewards, check the relayers compensation scheme section on the relayer docs on the Bitzal-SDK repository.