Kaiko on-chain

This guide walks you through consuming our Robust Pair Prices through the Kaiko On-Chain on Ethereum. Several asset pairs are publicly available, meaning you can access free hourly updates or update on-demand for a small fee. You can read more about Kaiko on-chain here.

Read and update manually

Visit oracle.kaiko.com. Here, you can see the latest Kaiko price updates for all pairs.

To update the price:

1. Click "connect wallet"

2. Once you've connected your wallet, click "Update"

3. Authorize the payment of 0.01 ETH

4. Wait a few seconds for the prices to be updated

One price update request updates all Kaiko price feeds - there's no need to request them independently.

Update and read on-chain

To read and update on-chain, you'll need to set up an off-chain listening event using a node provider of your choice to connect to the blockchain.

To update the price:

This example script uses Typescript, but you can produce similar results using other coding languages. Running the script requests a price update and listens until it's been updated on-chain. When the update is detected, it alerts your on-chain smart contract.

1. Install ethers npm install ethers

2. Send a transaction with a value of 0.01 ETH to the refreshPriceFeeds contract address 0xff2743c44f820c64c94eccfc1b497a1019541097

import { ethers } from 'ethers';

// Set up your Ethereum provider
const provider = new ethers.providers.JsonRpcProvider("<YOUR_PROVIDER_URL>");

// Initialize wallet using private key and connect it to the provider
const wallet = new ethers.Wallet("<YOUR_PRIVATE_KEY>", provider);

// Smart contract address
const contractAddress = "0xff2743c44f820c64c94eccfc1b497a1019541097";

// ABI definition of the contract's refreshPriceFeeds method
const abi = [
    "function refreshPriceFeeds() payable external"
];

// Create an instance of the contract
const contract = new ethers.Contract(contractAddress, abi, wallet);

async function refreshPriceFeeds() {
    try {
        // Define the amount of ETH to send (0.01 ETH)
        const amountToSend = ethers.utils.parseEther("0.01");

        // Call the refreshPriceFeeds function, sending 0.01 ETH
        const tx = await contract.refreshPriceFeeds({
            value: amountToSend // Send 0.01 ETH
        });

        // Wait for the transaction to be mined
        console.log("Transaction sent. Waiting for confirmation...");
        const receipt = await tx.wait();

        console.log("Transaction confirmed, receipt:", receipt);
    } catch (error) {
        console.error("Error while calling refreshPriceFeeds:", error);
    }
}

// Call the function
refreshPriceFeeds();

1. Wait for at least one block for the price update to be reflected on-chain

One price update request updates all Kaiko price feeds - there's no need to request them independently.

Read the price on-chain:

This Solidity contract example is triggered by the refreshPriceFeeds function in the Typescript example above. When triggered, it ingests the updated prices on-chain.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IExternalContract {
    function latestUpdate() external view returns (uint256 price, uint256 decimals, uint256 updatedAt);
}

contract CallLatestUpdate {
    address public externalContractAddress = <PRICE_CONTRACT_ADDRESS>;

    // Function to call the latestUpdate() function on the external contract
    function getLatestUpdate() public view returns (uint256 price, uint256 decimals, uint256 updatedAt) {
        // Create an instance of the external contract using the interface
        IExternalContract externalContract = IExternalContract(externalContractAddress);
        
        // Call the latestUpdate() function on the external contract
        return externalContract.latestUpdate();
    }
}

Although one price update refreshes all prices on-chain, you must read each price feed individually. See the price feeds and their corresponding addresses at oracle.kaiko.com.