Schedule call function from smart contract

Question

I woudlike to run everytime my farm function from my smart contract. How can I process to run the function every 3 hours ?

Answer 1

There's no native way implemented in the language, because Solidity functions are executed as a result of a transaction. But you can schedule the transaction to be sent every 3 hours.

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One of the ways is using a cron initiator of a Chainlink job.

Docs with examples of the job config:

• https://docs.chain.link/docs/job-specifications/
• https://docs.chain.link/docs/initiators/#cron

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Or running a script on your server that sends the transaction directly (without using Chainlink as a mediator).

const Web3 = require('web3');
const web3 = new Web3(providerUrl);
const myContract = new web3.eth.Contract(jsonAbi, contractAddress);
web3.eth.accounts.wallet.add(senderPrivateKey);

async function sendTransaction() {
    myContract.methods.myFunction().send({from: senderAddress});
}

setInterval('sendTransaction', 3 * 60 * 60 * 1000); // 3 hours in milliseconds