Oracles

Overview
Mimas Finance will uses an oracle stack based on VVS and MMF TWAP oracles along with a team maintained fallback oracle. VVS and MMF were chosen because it has the most liquidity, which gives more accurate prices. 
In the medium / long term, we intend to migrate to Chainlink oracles when they are available.
TWAP Oracles
We use a 10-minute TWAP oracle for each supported VVS or MMF pair. These oracles are based on the design recommended and supported by Uniswap V2, which also applies to the VVS fork.
This type of TWAP oracle is resistant to flashloan attacks, like the recent exploit on CREAM Finance. The big advantage of our oracles is that they operate in a complete decentralized way, and allow us to quickly add new, more chain-specific, tokens.  
However, one weakness of TWAP oracles is the freshness of the price in volatile market conditions. For this reason, we will keep conservative collateral factors for all markets until Chainlink oracles are integrated.
Fallback Oracle
In addition to the TWAP oracles, the team also maintains a fallback oracle that kicks in if the TWAP oracle price is not fresh or the pair has insufficient liquidity. The prices are queried from Coingecko and periodically posted to the contract.
The team also have a suite of alerts paging us when anomalies occur, such as discrepancies in the oracle price. We will take swift and appropriate action to defend the assets deposited with the protocol.
Community Faucet
Because the VVS and MMF TWAP oracles require constant updates to maintain freshness, we have jobs to periodically make the update transactions. Additionally, we have implemented an economic incentive for the community to help keep the oracles up to date. 
Anyone can claim a small amount of MIMAS that is slowly dripped by the faucet. In doing so, the transaction also updates the TWAP oracles. Cronos' relatively low fees makes claiming from the faucet regularly worthwhile to do.
Contracts
These are the main oracles for Mimas Finance:
Contract
Address
MimasPriceOracle
0x06c453C6948A0712243C34d317B5C7D15ABd6e4d
UniswapOracle
0x7Ac9bD704c0b63a497c7d10625CaDeF2e883c337
FallbackOracle
0xc185F562A623cACE30575084f6ff726369Bb6D68
Additionally, each VVS or MMF pair has its own TWAP oracle:
Pair
Contract Address
WBTC / WCRO
0x6aDaCF92A6524596d1807BA315e0819Da6c06bab
ETH / WCRO
0x85ddD2C04Cc946c7F0B677842Ae3e5B6Fe11c181
USDC / WCRO
0x54edCD8e0990fA45d05b959db25b6FAd0aF76FD4
USDT / WCRO
0x8E9F351A91613a42cb74f771bCf8aF8bd1F36892
MMF / WCRO
0x75c8AfBb2EC61e38e650079392Dec708ef660bC1

Contract	Address
MimasPriceOracle	`0x06c453C6948A0712243C34d317B5C7D15ABd6e4d`
UniswapOracle	`0x7Ac9bD704c0b63a497c7d10625CaDeF2e883c337`
FallbackOracle	`0xc185F562A623cACE30575084f6ff726369Bb6D68`

Pair	Contract Address
WBTC / WCRO	`0x6aDaCF92A6524596d1807BA315e0819Da6c06bab`
ETH / WCRO	`0x85ddD2C04Cc946c7F0B677842Ae3e5B6Fe11c181`
USDC / WCRO	`0x54edCD8e0990fA45d05b959db25b6FAd0aF76FD4`
USDT / WCRO	`0x8E9F351A91613a42cb74f771bCf8aF8bd1F36892`
MMF / WCRO	`0x75c8AfBb2EC61e38e650079392Dec708ef660bC1`

Last modified 1yr ago