Skip to main content

Chainlink Price Feeds

The Chainlink Price Feeds are on-chain reference contracts that are automatically updated by decentralized oracle networks (DONs) consisting of Chainlink nodes. Each reference contract stores the latest and the historical price of an asset in the form of an exchange rate (e.g. RON/USD), which smart contracts can then query on-demand. Each Chainlink Price Feed runs on a specific blockchain network and regularly updates with fresh data based on predefined parameters.

Prerequisites​

Before you begin, make sure you have:

  • A Ronin RPC endpoint
  • A feed contract address: This determines which data feed your smart contract will read. You can find the available contract addresses here. For our examples we're using RON/USD 0x0B6074F21488B95945989E513EFEA070096d931D.

Reading data feeds onchain​

These code example demonstrates how to deploy a consumer contract onchain that reads a data feed and stores the value.

Solidity​

To consume price data, your smart contract should reference AggregatorV3Interface, which defines the external functions implemented by Data Feeds.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/shared/interfaces/AggregatorV3Interface.sol";

/**
 * THIS IS AN EXAMPLE CONTRACT THAT USES HARDCODED
 * VALUES FOR CLARITY.
 * THIS IS AN EXAMPLE CONTRACT THAT USES UN-AUDITED CODE.
 * DO NOT USE THIS CODE IN PRODUCTION.
 */

/**
 * If you are reading data feeds on L2 networks, you must
 * check the latest answer from the L2 Sequencer Uptime
 * Feed to ensure that the data is accurate in the event
 * of an L2 sequencer outage. See the
 * https://docs.chain.link/data-feeds/l2-sequencer-feeds
 * page for details.
 */

contract DataConsumerV3 {
    AggregatorV3Interface internal dataFeed;

    constructor() {
        dataFeed = AggregatorV3Interface(
            0x0B6074F21488B95945989E513EFEA070096d931D
        );
    }

    function getChainlinkDataFeedLatestAnswer() public view returns (int) {
        // prettier-ignore
        (
            /* uint80 roundID */,
            int answer,
            /*uint startedAt*/,
            /*uint timeStamp*/,
            /*uint80 answeredInRound*/
        ) = dataFeed.latestRoundData();
        return answer;
    }
}

The latestRoundData function returns five values representing information about the latest price data. See Chainlink's Data Feeds API Reference for more details.

Reading data feeds offchain​

These code examples demonstrate how to read data feeds directly off chain using Web3 packages for each language.

Javascript​

import { ethers } from "ethers";

// Replace with a valid Ronin RPC URL
const RONIN_RPC_URL = "https://api.roninchain.com/rpc";
const provider = new ethers.JsonRpcProvider(RONIN_RPC_URL);

const aggregatorV3InterfaceABI = [
{
  inputs: [],
  name: "decimals",
  outputs: [{ internalType: "uint8", name: "", type: "uint8" }],
  stateMutability: "view",
  type: "function",
},
{
  inputs: [],
  name: "description",
  outputs: [{ internalType: "string", name: "", type: "string" }],
  stateMutability: "view",
  type: "function",
},
{
  inputs: [{ internalType: "uint80", name: "_roundId", type: "uint80" }],
  name: "getRoundData",
  outputs: [
    { internalType: "uint80", name: "roundId", type: "uint80" },
    { internalType: "int256", name: "answer", type: "int256" },
    { internalType: "uint256", name: "startedAt", type: "uint256" },
    { internalType: "uint256", name: "updatedAt", type: "uint256" },
    { internalType: "uint80", name: "answeredInRound", type: "uint80" },
  ],
  stateMutability: "view",
  type: "function",
},
{
  inputs: [],
  name: "latestRoundData",
  outputs: [
    { internalType: "uint80", name: "roundId", type: "uint80" },
    { internalType: "int256", name: "answer", type: "int256" },
    { internalType: "uint256", name: "startedAt", type: "uint256" },
    { internalType: "uint256", name: "updatedAt", type: "uint256" },
    { internalType: "uint80", name: "answeredInRound", type: "uint80" },
  ],
  stateMutability: "view",
  type: "function",
},
{
  inputs: [],
  name: "version",
  outputs: [{ internalType: "uint256", name: "", type: "uint256" }],
  stateMutability: "view",
  type: "function",
},
]
const addr = "0x0B6074F21488B95945989E513EFEA070096d931D"
const priceFeed = new ethers.Contract(addr, aggregatorV3InterfaceABI, provider)
priceFeed.latestRoundData().then((roundData) => {
// Do something with roundData
console.log("Latest Round Data", roundData)
})

Need Help?​

Check out the following links to get started with Chainlink Price Feeds.