Keeping a bad price out of storage: expired reports and permissionless cleanup

We continued the Mento V3 contest on Cantina.

Lesson Summary:

• When fetching a price, a protocol needs a way to avoid storing a bad one;
• Circuit breakers matter when the price comes from Chainlink;
• removeExpiredReports is permissionless — check whether it can be arbitraged;
• Are the sorted oracles using expired reports to calculate the median?

Watch the session on YouTube ↗