Oracle Development Using Ethereum Smart Contracts
Tags: smartcontract, ethereum, blockchain, oracle
Published: 2023-10-12 09:29:13

Smart contract development plays a crucial role in Oracle development and enables the seamless integration of real-world data into blockchain networks. A [smart contract development company](https://blockchain.oodles.io/smart-contract-development-services/) utilizes smart contracts to develop oracles that securely and autonomously retrieve and verify external data. Let’s explore the process of developing an oracle using an Ethereum smart contract.

**Oracle Development Using Ethereum Smart Contracts
**Oracles were created to enhance the possibilities of collaboration on blockchains. They establish connections between blockchains and other systems, enabling the retrieval of data from sources not included in the blockchain. Oracles provide as a reliable source of data for the blockchain by offering safe entry points to off-chain services. This allows smart contract applications to verify external events and trigger actions on external services.

Oracles essentially function as a link between two environments: the on-chain environment representing the blockchain network and the off-chain environment representing external systems in the real world.

Suggested Post | [Blockchain Oracles | Making Smart Contracts Talk to the World](https://blockchain.oodles.io/blog/blockchain-oracles/)

pragma solidity >=0.7.0 <0.9.0;

**import “@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol”;

contract EthPrice {

AggregatorV3Interface internal ethFeed;

bytes32 ethHash = keccak256(abi.encodePacked(“ETH”));

constructor(_address) {

ethFeed = AggregatorV3Interface(_address);

}

function getEthPrice() public view returns (int) {(

uint80 roundID,

int price,

uint startedAt,

uint timeStamp,

uint80 answeredInRound

) = ethFeed.latestRoundData();

return price;

}

}**

To get the address _address(Price feed contract address) of [click here](https://docs.chain.link/data-feeds/price-feeds/addresses/?network=ethereum&page=1)

Deploy the contract from the Deployment tab in Remix and run the function.

This code represents a Solidity smart contract called EthPrice that retrieves the latest price of Ethereum (ETH) using a Chainlink price feed.

**Here’s a breakdown of the code:
**
The SPDX-License-Identifier at the beginning of the contract identifies the licence that governs the release of the code.

The pragma statement defines the version range of Solidity that the contract is compatible with.

The import statement imports the AggregatorV3Interface from the Chainlink library. This interface provides functions to interact with Chainlink price feed contracts.

The EthPrice contract has an internal variable ethFeed of type AggregatorV3Interface. It will be used to interact with the Chainlink price feed.

The ethHash variable stores the keccak256 hash of the string "ETH". This can be used as an identifier or key for Ethereum.

The constructor function is used to initialize the contract.
 It takes an _address parameter representing the address of the Chainlink price feed contract. It assigns the provided address to ethFeed.

The getEthPrice function is a view function that retrieves the latest ETH price from the Chainlink price feed. It returns the price as an int.

Inside the function, a tuple is defined to store the return values of the latestRoundData function from the ethFeed contract.

The latestRoundData function fetches the latest round data from the Chainlink price feed.

The price value is extracted from the tuple and returned.

In summary, the EthPrice contract interacts with a Chainlink price feed to retrieve the latest price of Ethereum (ETH) and provides a function getEthPrice to access this price from other contracts or externally.

Interested in Oracle development using smart contracts? Connect with our [smart contract developers](https://blockchain.oodles.io/about-us/) to get started.