Oracle Module

Context

The Price Aggregator module enables us to obtain price data from BandChain via IBC and stores the most recent prices in our store.

This allows us to retrieve asset prices when users deposit collateral to mint $oUSD and to recalculate the collateral ratio of each vault after every epoch.

Workflow

Below is the example of workflow for when users deposit $ATOM as a collateral asset to mint $oUSD.

• Step 1: User transfers $ATOM via IBC to the Onomy Network.

• Step 2: User creates a vault by depositing $ATOM as a collateral asset to Onomy to mint $oUSD.

• Step 3: The Price Aggregator module of Onomy requests the spot price of $ATOM from BandChain, then mints $oUSD for the user.

To gain a deeper understanding of how Onomy retrieves asset prices from BandChain to support the Vault module in minting $oUSD, we can refer to the diagram below:

• Step 1: The Price Aggregator module creates an IBC packet (contains OracleRequestPacketData) to request data from BandChain

• Step 2, 3: Relayers will pick up the IBC packet and relay it on BandChain

• Step 4, 5: After BandChain process the request, it will send an acknowledgement along with request_id back (The Price Aggregator module will keep this request_id to get the data from BandChain later. If the acknowledgement fails, all processes will be cancelled).

• Step 6, 7: When the result of the request price is finalized, BandChain will send a new IBC packet (contains OracleResponsePacketData) that contains the final data back (prices we need), and relayers will listen and pick up those packets and relay them to Onomy.

After retrieving the collateral asset prices, the Vault module uses this data to mint $oUSD for users. At regular intervals, the Price Aggregator module updates the asset prices from BandChain, enabling the Vault module to adjust the collateral ratios for users vaults accordingly.

Improvements

We plan to add additional price feeders to support our Price Aggregator module, reducing single-party reliability and improving overall project security and decentralization. Candidates include ChainLink, Stork Oracles, SupraOracles, and more.