I have a smart contract which must reach out to an off-chain data source (custom API) in order to verify that the wallet calling the function can do so. My understanding is that this is done via a Chainlink oracle.
Would the user/wallet who signs the transaction have to pay for ETH gas fees and LINK fees in order to run this function? Would they be required to have both ETH and LINK in their wallet to do so? Ideally the end user calling the function would only pay the gas fees of calling the function in ETH. Is this possible?