Data Feeds

Overview

Chainlink Data Feeds are the quickest way to connect your smart contracts to the real-world data such as asset prices, reserve balances, NFT floor prices, and L2 sequencer health.

If you already started a project and need to integrate Chainlink, you can with the .

Types of data feeds

Data feeds provide many different types of data for your applications.

Price Feeds

Smart contracts often act in real-time on data such as prices of assets. This is especially true in .

For example, uses Data Feeds to determine prices on their derivatives platform. Lending and borrowing platforms like use Data Feeds to ensure the total value of the collateral.

Data Feeds aggregate many data sources and publish them on-chain using a combination of the and .

To learn how to use Price Feeds, see the documentation.

See the page for a list of available networks and addresses.

Proof of Reserve Feeds

Proof of Reserves feeds provide the status of reserves for stablecoins, wrapped assets, and real world assets. Proof of Reserve Feeds operate similarly to Price Feeds, but provide answers in units of measurement such as ounces (oz) or number of tokens.

NFT Floor Price Feeds

L2 sequencer uptime feeds

L2 sequencer feeds track the last known status of the sequencer on an L2 network at a given point in time. This helps you prevent mass liquidations by providing a grace period to allow customers to react to these events.

Components of a data feed

Data Feeds are an example of a decentralized oracle network and include the following components:

Reading proxy and aggregator configurations

You can call the latestRoundData() function directly on the aggregator, but it is a best practice to use the proxy instead so that changes to the aggregator do not affect your application. Similar to the proxy contract, the aggregator contract has a latestAnswer variable, owner address, latestTimestamp variable, and several others.

Components of an aggregator

The aggregator contract has several variables and functions that might be useful for your application. Although aggregator contracts are similar for each data feed, some aggregators have different variables. Use the typeAndVersion() function on the aggregator to identify what type of aggregator it is and what version it is running.

Updates to proxy and aggregator contracts

To accommodate the dynamic nature of off-chain environments, Chainlink Data Feeds are updated from time to time to add new features and capabilities as well as respond to externalities such as token migrations, protocol rebrands, extreme market events, and upstream issues with data or node operations.

These updates include changes to the aggregator configuration or a complete replacement of the aggregator that the proxy uses. If you consume data feeds through the proxy, your applications can continue to operate during these changes.

The multisig-coordinated upgradability of Chainlink Data Feeds involves time-tested processes that balance collusion-resistance with the flexibility required to implement improvements and swiftly react to external conditions. The approach taken to upgradability will continue to evolve over time to meet user requirements.

Monitoring data feeds

When you build applications and protocols that depend on data feeds, include monitoring and safeguards to protect against the negative impact of extreme market events, possible malicious activity on third-party venues or contracts, potential delays, and outages.

Create your own monitoring alerts based on deviations in the answers that data feeds provide. This will notify you when potential issues occur so you can respond to them.

Check the latest answer against reasonable limits

Configure your application to detect when the reported answer is close to reaching minAnswer or maxAnswer and issue an alert so you can respond to a potential market event. Separately, configure your application to detect and respond to extreme price volatility or prices that are outside of your acceptable limits.

Check the timestamp of the latest answer

Your application should track the latestTimestamp variable or use the updatedAt value from the latestRoundData() function to make sure that the latest answer is recent enough for your application to use it. If your application detects that the reported answer is not updated within the heartbeat or within time limits that you determine are acceptable for your application, pause operation or switch to an alternate operation mode while identifying the cause of the delay.

During periods of low volatility, the heartbeat triggers updates to the latest answer. Some heartbeats are configured to last several hours, so your application should check the timestamp and verify that the latest answer is recent enough for your application.

Users should build applications with the understanding that data feeds for wrapped or liquid staking assets might have different heartbeat and deviation thresholds than that of the underlying asset. Heartbeat and deviation thresholds can also differ for the same asset across different blockchains. Combining data from multiple feeds, even those with a common denominator, might result in a margin of error that users must account for in their risk mitigation practices.

Price Feeds

Proof of Reserve Feeds

Types of Proof of Reserve Feeds

Reserves are available for both cross-chain assets and off-chain assets. This categorization describes the data attestation variations of Proof of Reserve feeds and helps highlight some of the inherent market risks surrounding the data quality of these feeds.

Reserves are available for both off-chain assets and cross-chain assets. Token issuers prove the reserves for their assets through several different methods.

Off-chain reserves

Off-chain reserves provide their data using the following methods:

Third-party: An auditor, accounting firm, or other third party attests to reserves. This is done by combining both fiat and investment assets into a numeric value that is reported against the token.
Custodian: Reserves data are pulled directly from the bank or custodian. The custodian has direct access to the bank or vault holding the assets. Generally, this works when the underlying asset pulled requires no additional valuation and is simply reported on-chain.

Cross-chain reserves

Cross-chain reserves provide their data using the following methods:

Wallet address: The project attests which addresses they own through a self-hosted API.

Using Proof of Reserve Feeds

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

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";

contract ReserveConsumerV3 {
    AggregatorV3Interface internal reserveFeed;

    /**
     * Network: Ethereum Mainnet
     * Aggregator: WBTC PoR
     * Address: 0xa81FE04086865e63E12dD3776978E49DEEa2ea4e
     */
    constructor() {
        reserveFeed = AggregatorV3Interface(
            0xa81FE04086865e63E12dD3776978E49DEEa2ea4e
        );
    }

    /**
     * Returns the latest price
     */
    function getLatestReserve() public view returns (int) {
        // prettier-ignore
        (
            /*uint80 roundID*/,
            int reserve,
            /*uint startedAt*/,
            /*uint timeStamp*/,
            /*uint80 answeredInRound*/
        ) = reserveFeed.latestRoundData();

        return reserve;
    }
}

DISCLAIMER

Proof of Reserve feeds can vary in their configurations. Please be careful with the configuration of the feeds used by your smart contracts. You are solely responsible for reviewing the quality of the data (e.g., a Proof of Reserve feed) that you integrate into your smart contracts and assume full responsibility for any damage, injury, or any other loss caused by your use of the feeds used by your smart contracts.

NFT Floor Price Feed

Using NFT Floor Price Feeds

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

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";

contract NFTFloorPriceConsumerV3 {
    AggregatorV3Interface internal nftFloorPriceFeed;

    /**
     * Network: Goerli - No Sepolia feeds available at this time
     * Aggregator: CryptoPunks
     * Address: 0x5c13b249846540F81c093Bc342b5d963a7518145
     */
    constructor() {
        nftFloorPriceFeed = AggregatorV3Interface(
            0x5c13b249846540F81c093Bc342b5d963a7518145
        );
    }

    /**
     * Returns the latest price
     */
    function getLatestPrice() public view returns (int) {
        // prettier-ignore
        (
            /*uint80 roundID*/,
            int nftFloorPrice,
            /*uint startedAt*/,
            /*uint timeStamp*/,
            /*uint80 answeredInRound*/
        ) = nftFloorPriceFeed.latestRoundData();
        return nftFloorPrice;
    }
}

PreviousGetting Started NextVRF

Last updated 2 years ago

Was this helpful?