Exteral reference prices for the Maker platform
The reference price (ETHUSD) for the Maker system is provided via an oracle
medianizer), which collates price data from a number of external price
Independent price feed operators constanly monitor the reference price across a number of external sources and will submit updates to the blockchain when:
Price updates are written to the blockchain via price feed contracts which
are deployed and owned by feed operators. Price feed contracts which have been
whitelisted by the
medianizer are able to forward their prices for inclusion in
the medianized price.
The medianizer is the smart contract which provides Makers trusted reference price.
It maintains a whitelist of price feed contracts which are allowed to post price updates and a record of recent prices supplied by each address. Every time a new price update is received the median of all feed prices is re-computed and the medianized value is updated.
The adding and removal of whitelisted price feed addresses is controlled via
governance, as is the setting of the
min parameter - the minumum number of
valid feeds required in order for the medianized value to be considered valid.