I can give you a step-by-step guide on how to get FulfillRandomWords hash operations (callback) 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 key part of the Ethereum blockchain because it allows developers to have safe and reliable access to random numbers.
How does Chainlink VRF work?
When you call a Chainlink VRF function, such as chainlink-vrf-randomwords, a node (such as a Node.js or CLI application) 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 FulfillRandomWords operation (callback)?
To get the hash (callback) of FulfillRandomWords operation, you need to:
- Check Chainlink VRF configuration: Make sure your Node.js application or CLI is configured with with the correct Chainlink VRF settings, including the “keyId” and “secret” properties.
- Call FulfillRandomWords
: When an operation calls chainlink-vrf-randomwords, it generates a random number using Chainlink’s VRF. The resulting hash will be returned as a response. 3.
Verify the response: The Node.js application or CLI should verify that the Chainlink VRF response is valid and follows the expected format.
Node.js code sample
const chainlink = require(' @chainlink/api');
// Set the key ID and secret
const keyId = 'YOUR_KEY_ID';
const secret = 'YOUR_SECRET';
// Call FulfillRandomWords
asynchronous function getFulfillRandomWordsHash() {
const response = await chainlink.vrf.randomwords({ keyId, secret });
console.log(response);
// Check if the response matches the expected format if (response.data.length !== 16) {
throw new Error('Invalid response length');
}
// Return the hash of the FulfillRandomWords operation (undo)
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 default 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 tool.
- Note that the FulfillRandomWords (undo) operation is a random number generator, so the output will be different each time. the time it is called.
After following these steps and using Chainlink VRF correctly, you should receive a hash (callback) of the FulfillRandomWords operation.