Y2K uses UMA's oracle to assert the price of Chainlink’s crvUSD price on Ethereum mainnet. Here is an example Y2K assertion that will be used for reference:
As of assertion timestamp 1705089029. Using the following resources for validation {chain: Ethereum, dataSource: Chainlink, assetIdOnDataSource: CRVUSD/USD, methodologyUrl:}. The price of crvUSD/USD is 99908022000000000000000000 for roundId 18446744073709551762.
The first step is to use methodologyUrl to retrieve the assertion methodology. Included in the file are steps to recalculate the price of crvUSD/USD and compare the value against the asserted price of 99908022000000000000000000 at roundId 18446744073709551762.
To fetch the relevant price for the query, follow these steps from the methodology:
1. Fetch the address for Chainlink’s EACAggregatorProxy contract for crvUSD on Ethereum mainnet (address: 0xEEf0C605546958c1f899b6fB336C20671f9cD49F)
2. Query the getRoundData(<roundId>) on this contract which will return a struct with the following information → {roundId, answer, startedAt,updatedAt, answeredInRound}
3. The answer should be scaled by 10 ** 18 (e.g. answer * 10 **18) and the scaled value should be compared against the value for <AssertionPrice> - both should be the same
The contract for crvUSD on mainnet can be found here or by going to and searching for address 0xEEf0C605546958c1f899b6fB336C20671f9cD49F. To query the roundId:
  1. 1.
    Click on the "Contract" tab
  2. 2.
    Click on the "Read Contract" tab
  3. 3.
    Input RoundId referenced in the assertion into the getRoundId input
Inputting the roundId and clicking "Query" provides an answer of 99908022.
This value needs to be scaled by 10 ** 18. can be used to scale the value by inputting the answer into the "Ether" input and the "Wei" value can be used to compare against the assertion price.
For this assertion, 99908022000000000000000000 matches the asserted value of 99908022000000000000000000 . Therefore, this assertion should not be disputed.