Stanley-Moukhametzianov / Ethereum-Oracle-Project

Ethereum Oracle Project

• App uses react for the front end with web3 to make calls to the contract.
• This contract is deployed on the Kovan test network at the address: 0xA5342e4a26e3434f6cfE72D1636243eF28a56c88.
• This app is designed to test a stock price oracle. :D

📚 General info

• This app allows users to view the closing price of a given stock on their selected day. The interesting part of the application is that the api call is made using a decentralized oracle.

• Note: The contract is deployed on the Kovan test network. All eth that is used on the site is test ether.

• Once the submit button is pressed users wait until a pop up appears displaying the closing price of the stock.

📷 Demo

Screen-Recording-2022-01-13-at-9.mp4

💻 Smart Contract

• Oracle contract that is used in the website.

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

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

contract APIConsumer is ChainlinkClient {
    using Chainlink for Chainlink.Request;
  
    uint256 public volume;
    
    address private oracle;
    bytes32 private jobId;
    uint256 private fee;
    
    event newValue(uint256 value);

    constructor() {
        setPublicChainlinkToken();
        oracle = 0xc57B33452b4F7BB189bB5AfaE9cc4aBa1f7a4FD8;
        jobId = "d5270d1c311941d0b08bead21fea7747";
        fee = 0.1 * 10 ** 18; // (Varies by network and job)
    }
    
    function requestVolumeData( string memory apiURL ) public returns (bytes32 requestId) 
    {
        Chainlink.Request memory request = buildChainlinkRequest(jobId, address(this), this.fulfill.selector);
        
        request.add("get", apiURL);

        request.add("path", "close");
        
        return sendChainlinkRequestTo(oracle, request, fee);
    }
    
    function fulfill(bytes32 _requestId, uint256 _volume) public recordChainlinkFulfillment(_requestId)
    {
        volume = _volume;
        emit newValue(_volume);
    }
}

📁 License

• This project is licensed under the terms of the MIT license.

✉️ Contact

• Repo created by Stanley Moukhametzianov, email: [e-mail]