Remix VM (Cancun) cannot retrieve value from AggregatorV3Interface

[austinlight-mle]

I'm trying to dig into details what AggregatorV3Interface does. I created simple library based on video tutorial.

library PriceConverter {

    function getPrice() public view returns(uint256) {
        // address for contract of ETH/USD on Sepolia Testnetwork 0x694AA1769357215DE4FAC081bf1f309aDC325306
        AggregatorV3Interface priceFeed = AggregatorV3Interface(0x694AA1769357215DE4FAC081bf1f309aDC325306);

        // prettier-ignore
        (
            /* uint80 roundID */,
            int price,
            /*uint startedAt*/,
            /*uint timeStamp*/,
            /*uint80 answeredInRound*/
        ) = priceFeed.latestRoundData();

        return uint256(price);
    }
}

function fetchPrice() public view returns (uint256) {
    return PriceConverter.getPrice();
    // it returns 6609840500000
}

When I deployed on Remix VM (Cancun), it fails to call fetchPrice function, only works for Injected Provider - Metamask.
Is that I should pay some Gas for fetching function from Chainlink?

[Nlferu]

Hi @austinlight-aigeek

No, you dont need to pay more gas. It works for Injected Provider - Metamask because you are probably using Sepolia testnet and there is AggregatorV3 contract deployed on Sepolia already under address 0x694AA1769357215DE4FAC081bf1f309aDC325306.

If you run it locally and still using same address, so 0x694AA1769357215DE4FAC081bf1f309aDC325306 there is obviously no such contract deployed as it is local blockchain created by remix and you would need to deploy this AggregatorV3 contract by yourself and pass new deployed contract address to your getPrice function as this local blockchain created by Remix is just empty

[Haardtripathi]

The thing is, you have to use chainlink LINKS(you might have heard about them when you get sepolia tokens from chainlink website) to access data feeds from the chainlink network, as Remix VM (Cancun) is a devNet not a testNet it does not have any LINKS nor it has any connection with the chainLink datafeeds , this is the main reason