Replace external adapters with chainlink functions

[yogesh0509]

Replace external adapters with chainlink functions to fetch live data.

[EthixLucifer]

@yogesh0509 i would like to work on this issue...

[yogesh0509]

Hey, @EthixLucifer , can you share your approach for this issue?

[EthixLucifer]

My approach is to review the current implementation of external adapters located in the server/external_adapter directory.
Identify the functions and data fetched by these adapters, especially how they interact with smart contracts.
Define Chainlink Functions:

Create Chainlink Functions that replicate the behavior of the existing external adapters. These functions should fetch the same data and return it in the required format.

this is the rough overview of how the function will look like....

// Create a function to fetch player details
const createRequest = async (input, callback) => {
  const jobRunID = input.id
  const playerId = input.data.playerId
  const url = `https://unofficial-cricbuzz.p.rapidapi.com/players/get-info`

  const headers = {
    'X-RapidAPI-Key': "XXXX",
    'X-RapidAPI-Host': 'unofficial-cricbuzz.p.rapidapi.com'
  }

  const params = {
    playerId
  }

  const config = {
    url,
    headers,
    params
  }

  Requester.request(config)
    .then(response => {
      callback(response.status, Requester.success(jobRunID, response))
    })
    .catch(error => {
      callback(500, Requester.errored(jobRunID, error))
    })
}

but due to lack of documentation setting up the node is facing issues.... can you share how to setup the chainlink node for this specific project..

[yogesh0509]

I followed this documentation to run my own chainlink node. However this might not be very crucial to your task as before new contracts are deployed, current external adapters are not going to work as they are configured for mumbai testnet which was deprecated long before. You can test your chainlink functions here

[yogesh0509]

You will also need to make some changes in the smart contract to replace the existing API calls with chainlink functions. Can you also share a brief approach for it?

[EthixLucifer]

the changes in the smart contract would be as follows, so we will make the smart contract make the call directly to the chainlink function instead of external adapter and remove the dependency on external adapters.

This is the simple contract where I've used Amoy testnet to deploy the contract

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

import {FunctionsClient} from "@chainlink/[email protected]/src/v0.8/functions/v1_0_0/FunctionsClient.sol";
import {ConfirmedOwner} from "@chainlink/[email protected]/src/v0.8/shared/access/ConfirmedOwner.sol";
import {FunctionsRequest} from "@chainlink/[email protected]/src/v0.8/functions/v1_0_0/libraries/FunctionsRequest.sol";

/**
 * @title PlayerRankFetcher
 * @notice A simple contract to fetch a player's rank using Chainlink Functions
 */
contract PlayerRankFetcher is FunctionsClient, ConfirmedOwner {
    using FunctionsRequest for FunctionsRequest.Request;

    bytes32 public s_lastRequestId;
    bytes public s_lastResponse;
    bytes public s_lastError;

    string public playerRank;

    error UnexpectedRequestID(bytes32 requestId);

    event RankFetched(bytes32 indexed requestId, string rank);

    address router = 0xb83E47C2bC239B3bf370bc41e1459A34b41238D0;
    string source =
        "const playerId = args[0];"
        "const apiKey = args[1];"
        "const options = {"
        "  url: 'https://unofficial-cricbuzz.p.rapidapi.com/players/get-info',"
        "  method: 'GET',"
        "  params: { playerId: playerId },"
        "  headers: {"
        "    'x-rapidapi-key': apiKey,"
        "    'x-rapidapi-host': 'unofficial-cricbuzz.p.rapidapi.com'"
        "  }"
        "};"
        "const apiResponse = await Functions.makeHttpRequest(options);"
        "if (apiResponse.error) {"
        "  throw new Error('Request failed: ' + apiResponse.error);"
        "}"
        "const playerInfo = apiResponse.data;"
        "const testRank = playerInfo.currRank.bat.testRank;"
        "if (!testRank || isNaN(testRank)) {"
        "  throw new Error('Test rank is not a valid number');"
        "}"
        "return Functions.encodeUint256(Number(testRank));";

    uint32 gasLimit = 300000;
    bytes32 donID =
        0x66756e2d657468657265756d2d7365706f6c69612d3100000000000000000000;

    constructor() FunctionsClient(router) ConfirmedOwner(msg.sender) {}

    function fetchPlayerRank(
        uint64 subscriptionId,
        string[] calldata args
    ) external onlyOwner returns (bytes32 requestId) {
        FunctionsRequest.Request memory req;
        req.initializeRequestForInlineJavaScript(source);
        req.setArgs(args);

        s_lastRequestId = _sendRequest(
            req.encodeCBOR(),
            subscriptionId,
            gasLimit,
            donID
        );

        return s_lastRequestId;
    }

    function fulfillRequest(
        bytes32 requestId,
        bytes memory response,
        bytes memory err
    ) internal override {
        if (s_lastRequestId != requestId) {
            revert UnexpectedRequestID(requestId);
        }

        s_lastResponse = response;
        s_lastError = err;

        playerRank = string(response);

        emit RankFetched(requestId, playerRank);
    }

    function getLastRank() public view returns (string memory) {
        return playerRank;
    }
}

you can load this contract at address: 0x144e8f069d2f2d05e8d9cbbb9bd4135b4aca5311

once loaded execute the fetchplayerRank function and pass the arguments the chain ID for the chainlink is: 355 and pass the playerId and rapid API key.

execute this function in the chainlink functions playground

//Chainlink Function
// This script will fetch the player's information using Chainlink Functions

const playerId = args[0];
const apikey = args[1];
const options = {
  url: 'https://unofficial-cricbuzz.p.rapidapi.com/players/get-info',
  method: 'GET',
  params: { playerId: playerId },
  headers: {
    'x-rapidapi-key': `${apikey}`,
    'x-rapidapi-host': 'unofficial-cricbuzz.p.rapidapi.com'
  }
};

// Perform the API request using Chainlink Functions helper method
const apiResponse = await Functions.makeHttpRequest(options);

// Check for errors
if (apiResponse.error) {
  throw new Error('Request failed: ' + apiResponse.error);
}

// Log the response data for debugging
console.log('API Response:', apiResponse.data);

// Ensure the response contains data
if (!apiResponse.data) {
  throw new Error('API response data is undefined or null.');
}

// Extract the player's Test rank from the response
const playerInfo = apiResponse.data;
const testRank = playerInfo.currRank.bat.testRank;

// Check if the rank is a valid number
if (!testRank || isNaN(testRank)) {
  throw new Error('Test rank is not a valid number');
}

// Log the player's Test rank
console.log('Player Test Rank:', testRank);

// Return the Test rank as a uint256
return Functions.encodeUint256(Number(testRank));

[EthixLucifer]

this is just to test the contract fetches the rank, in prod environment dependencies on external contracts, i.e

 import "./Auction.sol";
import "./interfaces/IPIC.sol";

will be taken care of..

[yogesh0509]

@EthixLucifer This looks really good. I am assigning this issue to you. Make changes in a separate branch and raise the PR.

[yogesh0509]

@EthixLucifer Any updates??