I am having a strange thing occuring on kovan network. I am running a smart contract calling my chainlink oracle to request some information. My chainlink oracle responds correctly with the expected information. The smart contract calls the fulfill function but it does not set the value heartRateMinutes. Any calls to it returns a 0. The expected value should be 67. Value is set to public so it should be seen. They also have the same size of uint256. The value is a whole integer number.

enter image description here

It is weird because the chainlink run job shows all green and no errors.

  • do you have the tx hash that was supposed to call fulfill ?
    – Tclairet
    Sep 18, 2020 at 13:08

1 Answer 1


When an oracle isn't responding, there are a few things for you to check out. 95% of the time it's on the smart contract side.

On the smart contract side:

  1. Is the oracle address and jobId correct? Certain jobIds return certain types, so you need to know the the jobId is returning the same type that your function is looking for.
  2. Is your smart contract funded with LINK?

On the node operator side:

  1. Is the oracle address funded with ETH? Smart contract engineers can see this as well, by looking at your oracle address's balance.
  2. Does the node have setFulfillmentPermission=true?
  3. Does the node have any whitelisted/blacklisted contracts? This one is harder to see, you'd have to check with the node operator.

Hopefully these will be able help out. In this specific case it looks like it's something on the node side.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.