We're using the standard truffle box (https://github.com/smartcontractkit/box) to deploy Chainlink contract ($LINK definition, Oracle, sample end-user contract, etc) on a private Ethereum testnet.

Everything works, as in I can trigger jobs from smart contract calls on-chain, unless my job spec has ends with "EthTx" adapter. If I end my job with an "EthTx" adapter, the task will fail with the only error being "transaction reverted on-chain".

My Oracle ETH accounts are well-funded, so lack of gas for running the transactions isn't an issue. Also, all the other adapters work without failing...so it's not a problem with the HTTP endpoint being down, path being wrong, or casting the wrong types. What's going on?

1 Answer 1


There are a few things that can be happening, but most likely it is due to the fact that your oracle contract doesn't have its fulfillment permissions set correctly.

When you deploy the oracle contract, you also have to call the setfulfillmentpermission to true for you node. You can do this in remix/etherscan, or via a script. In this script, you'll need a:

  1. PRIVATE_KEYenvironment variable connected to the same wallet that deploy the oracle contract
  2. KOVAN_RPC_URL environment variable connected the blockchain of choice.
  3. You'll need to set oracleAddress to the oracle contract address.
  4. You'll need to set address to the address of your Chainlink node.

Hope it helps.

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