when I tested my smart contract in Kovan, the oracle (0xc57B33452b4F7BB189bB5AfaE9cc4aBa1f7a4FD8) listed in Contract Addresses failed to fulfill my request. As I checked the failed transaction, I've found out that the signature in the InputData was fulfillOracleRequest2 whereas other successful transactions' InputData contained fulfillOracleRequest. So the root cause of the issue seems to be the discrepancy between ChainlinkClient's version(v0.8) and the oracle's version.

Does anybody know of any oracle compatible with ChainlinkClient v0.8 in Kovan?

I've basically gone through the official tutorial to Use Any API except for the version of ChainlinkClient(The tutorial noted v0.6 but I used v0.8).

CodePudding user response：

By updating @chainlink/contracts from 0.1.7 to 0.2.1 (and by adjusting the path to ChainlinkClient.sol), my requests started to get fulfilled.