Harbinger is a project that delivers signed price feeds based on real time market data from multiple exchanges. The on-chain data will be fed directly to the Tezos network making it ‘DeFi ready’ for future applications.
Using a similar method to Tezos delegated staking, which enables token holders to delegate their XTZ to a validator, or ‘baker’, Harbinger will enable price oracles to be delegated and prefunded. The official announcement explained further that;
“This enables the development of self-sustaining price oracles, where the rewards for participating in proof of stake consensus offset the fees required to keep the oracle data current.”
Price feeds are a critical component for DeFi as they allow protocols to create collateralized loans and provide accurate token swap prices. Additionally, cryptographically signed price feeds add a layer of trust to the process.
Harbinger works a little differently to other oracle providers such as Chainlink as the fees required to post price data on-chain can be paid by the staking rewards earned by Tezos holders.
Harbinger is based upon Compound’s Open Price Feed, with a few tweaks. It operates with ‘signers’ which are major exchanges such as Coinbase, Binance, Gemini, and OKEx, and ‘posters’ which retrieve prices from the signer and post them to a ‘storage contract’. A ‘normalizer contract’ then calculates a volume weighted average price which is passed on to the dApp or DeFi protocol. Initial versions of these contracts have already been deployed on CarthageNet and Mainnet by the Tezos community.
Harbinger has been developed by Blockscale, a firm that designs and operates proof of stake validators for the Tezos Foundation.
It’s not the first move into DeFi style operations for Tezos.Earlier this year StakerDAO launched, a Tezos based platform for secure governance of financial assets. At the time, CEO of Tezos Capital Jonas Lamis stated that he took inspiration from the evolution of governance on MakerDAO and wanted to bring something similar to Tezos.
StakerDAO has its own STKR security token which is used for community governance proposals and voting rights in a similar way to the major DeFi platforms such as Compound and Maker.