Can you use this oracle price?
Decode two fictional feed readings and decide which one meets a lending market’s stated freshness rule.
ACADEMY LAB 04 · ORACLE DATA
The editor’s question
A market’s example policy accepts a positive ETH/USD answer up to 30 minutes old. At the review block the time is 12:00 UTC. Assume the network and feed address have been verified. Both example rounds use eight decimals. The figures are fictional.
Reading A
The raw answer is 245075000000. The update time is 11:18 UTC. An analyst reports that the market could use $2,450.75 per ETH. Check the units and the clock separately.
Check reading A
Dividing by 100,000,000 gives $2,450.75. But the reading is 42 minutes old, which exceeds this market’s limit by 12 minutes. Correct arithmetic alone cannot support the analyst’s conclusion.
Reading B
The answer is 244980000000 and the update time is 11:54 UTC. Does this reading pass the same checks? Would it prove that a trader could sell 20 ETH at that price?
Check reading B
The answer is positive, represents $2,449.80 per ETH and is six minutes old. It passes the exercise policy. To establish a sale price for 20 ETH you would also need a venue, an executable quote for that size and the relevant fees.
Repeat with a real feed
Record the network, proxy address, description, round ID, answer, decimals, update time and reference block. Look up the actual application’s freshness policy. The 30-minute limit belongs to this exercise.