I can provide a step-by-step guide on how to get the hash (callback) of FulfillRandomWords operations in Ethereum.
What is Chainlink VRF?
Chainlink VRF stands for Verifiable Random Function, which is a decentralized random number generator used to generate truly random numbers. It is a core part of the Ethereum blockchain as it allows developers to access random numbers securely and reliably.
How does Chainlink VRF work?
When you call a Chainlink VRF function, such as chainlink-vrf-randomwords, a node (such as a Node.js application or a command-line interface) generates a random number and returns it as a response. This number is then verified by the node using a digital signature.
How to get the hash of a FulfillRandomWords operation (callback)?
To get the hash of a FulfillRandomWords operation (callback), you need to:
- Check Chainlink VRF configuration: Make sure your Node.js application or CLI is configured with the correct Chainlink VRF settings, including the keyId and secret properties.
- Call FulfillRandomWords function: When an operation calls chainlink-vrf-randomwords, it generates a random number using Chainlink VRF. The resulting hash will be returned as the response.
- Check the response: Your Node.js application or CLI should check that the response from Chainlink VRF is valid and follows the expected format.
Node.js Code Example
const chainlink = require('@chainlink/api');
// Set the key ID and secret
const keyId = 'YOUR_KEY_ID';
const secret = 'YOUR_SECRET';
// Call the FulfillRandomWords function
async function getFulfillRandomWordsHash() {
const response = await chainlink.vrf.randomwords({ keyId, secret });
console.log(response);
// Check the response to make sure it matches the expected format
if (response.data.length !== 16) {
throw new Error('Invalid response length');
}
// Return the hash of the FulfillRandomWords operation (cancellation)
return response.hash;
}
// Call the function and print the result
getFulfillRandomWordsHash().then((hash) => console.log(hash));
Additional Tips
- Be sure to replace `
YOUR_KEY_ID'' and`YOUR_SECRET” with your actual Chainlink VRF key ID and secret, respectively.
- The expected hash length may vary depending on your Node.js application or CLI implementation. You can verify the response format by checking the documentation for your specific tools.
- Note that the FulfillRandomWords operation (callback) is a random number generator, so the output will be different each time it is called.
After following these steps and using Chainlink VRF properly, you should receive a hash (callback) of the FulfillRandomWords operation.
