Shardeum Documentation
Oracles

SupraOracles

SupraOracles is a novel, high-throughput Oracle & IntraLayer: A vertically integrated toolkit of cross-chain solutions (data oracles, asset bridges, automation network, and more) that interlink all blockchains, public (L1s and L2s) or private (enterprises).

How to use SupraOracles' Price Feeds

Integrating with SupraOracles' Price Feeds is quick and easy. To see all of the networks SupraOracles is on, please visit SupraOracles' Networks!

To get started, you will want to visit SupraOracles' docs site and review the documentation or continue to follow this guide for a quick start.

Step 1: Create The S-Value Interface

Add the following code to the solidity smart contract that you wish to retrieve an S-Value.

interface ISupraSValueFeed {
 
    function getSvalue(uint64 _pairIndex) external view returns (bytes32, bool);
 
    function getSvalues(uint64[] memory _pairIndexes) external view returns (bytes32[] memory, bool[] memory);
 
}

This creates the interface that you will later apply in order to fetch a price from SupraOracles.

Step 2: Configure The S-Value Feed Address

To fetch the S-Value from a SupraOracles smart contract, you must first find the S-Value Feed Address for the chain of your choice.

Now, let's create an instance of the S-Value Feed using the interface we previously defined for Shardeum Sphinx Dapp testnet:

contract ISupraSValueFeedExample {
    ISupraSValueFeed internal sValueFeed;
 
    constructor() {
        sValueFeed = ISupraSValueFeed(0xc85F07Dc3BEcBEAccB53CC82D32423f4EAD59311);
    }
}

Step 3: Add unpack function to decode response for S-Value feed

// Some codefunction unpack(bytes32 data) internal pure returns(uint256[4] memory) {
        uint256[4] memory info;
 
        info[0] = bytesToUint256(abi.encodePacked(data >> 192));       // round
        info[1] = bytesToUint256(abi.encodePacked(data << 64 >> 248)); // decimal
        info[2] = bytesToUint256(abi.encodePacked(data << 72 >> 192)); // timestamp
        info[3] = bytesToUint256(abi.encodePacked(data << 136 >> 160)); // price
 
        return info;
    }
 
    function bytesToUint256(bytes memory _bs) internal pure returns (uint256 value) {
        require(_bs.length == 32, "bytes length is not 32.");
        assembly {
            value := mload(add(_bs, 0x20))
        }
    }

Step 4: Get The S-Value Crypto Price

Now you can simply access the S-Value Crypto Price of our supported market pairs. In this step, we'll get the price of ETH/USDT (eth_usdt) by applying the following code to our Smart Contract.

function getPrice(uint64 _priceIndex) external view returns (uint256[4] memory) {
 
        (bytes32 val,)= sValueFeed.getSvalue(_priceIndex);
 
        uint256[4] memory decoded = unpack(val);
 
        return decoded;
}
 
function getPriceForMultiplePair(uint64[] memory _pairIndexes) external view returns (uint256[4][] memory) {
 
        (bytes32[] memory val, ) = sValueFeed.getSvalues(_pairIndexes);
 
        uint256[4][] memory decodedArray = new uint256[4][](val.length);
 
        for(uint i=0; i< val.length; i++){
 
            uint256[4] memory decoded = unpack(val[i]);
            decodedArray[i] = decoded;
        }
 
        return decodedArray;
}

Here's an example of what your implementation should look like

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;
 
 
interface ISupraSValueFeed {
    function getSvalue(uint64 _pairIndex) external view returns (bytes32, bool);
    function getSvalues(uint64[] memory _pairIndexes) external view returns (bytes32[] memory, bool[] memory);
}
 
contract SupraSValueFeedExample {
   
    ISupraSValueFeed internal sValueFeed;
 
    constructor() {
sValueFeed = ISupraSValueFeed(0xc85F07Dc3BEcBEAccB53CC82D32423f4EAD59311);
}
 
 
    function unpack(bytes32 data) internal pure returns(uint256[4] memory) {
        uint256[4] memory info;
 
        info[0] = bytesToUint256(abi.encodePacked(data >> 192));       // round
        info[1] = bytesToUint256(abi.encodePacked(data << 64 >> 248)); // decimal
        info[2] = bytesToUint256(abi.encodePacked(data << 72 >> 192)); // timestamp
        info[3] = bytesToUint256(abi.encodePacked(data << 136 >> 160)); // price
 
        return info;
    }
 
 
    function bytesToUint256(bytes memory _bs) internal pure returns (uint256 value) {
        require(_bs.length == 32, "bytes length is not 32.");
        assembly {
            value := mload(add(_bs, 0x20))
        }
    }
 
    function getPrice(uint64 _priceIndex) external view returns (uint256[4] memory) {
 
        (bytes32 val,)= sValueFeed.getSvalue(_priceIndex);
 
        uint256[4] memory decoded = unpack(val);
 
        return decoded;
    }
 
    function getPriceForMultiplePair(uint64[] memory _pairIndexes) external view returns (uint256[4][] memory) {
 
        (bytes32[] memory val, ) = sValueFeed.getSvalues(_pairIndexes);
 
        uint256[4][] memory decodedArray = new uint256[4][](val.length);
 
        for(uint i=0; i< val.length; i++){
 
            uint256[4] memory decoded = unpack(val[i]);
            decodedArray[i] = decoded;
        }
 
        return decodedArray;
    }
 
}

Tada! You now have everything setup to call the Trade Pairs using their respective index numbers.

Extra: S-Value Feeds with ethers.js

const ethers = require('ethers');
 
// Connect to the provider
let provider = new ethers.providers.JsonRpcProvider('https://dapps.shardeum.org');
 
// Contract ABI
let abi =[INSERT ABI]
 
// Contract address
let contractAddress = '0xc85F07Dc3BEcBEAccB53CC82D32423f4EAD59311';
 
// Instantiate the contract
let contract = new ethers.Contract(contractAddress, abi, provider);
 
// Call getPrice method
async function getPrice(priceIndex) {
    let result = await contract.getPrice(priceIndex);
    console.log(result);
}
 
getPrice(1); // Replace 1 with your desired priceIndex
 
// Call getPriceForMultiplePair method
async function getPriceForMultiplePairs(pairIndexes) {
    let result = await contract.getPriceForMultiplePair(pairIndexes);
    console.log(result);
}
 
getPriceForMultiplePairs([1, 2, 3]); // Replace [1, 2, 3] with your desired pairIndexes

Going Further with SupraOracles

If you want to take the next step, consider registering for the Supra Network Activate Program (SNAP).

The Supra Network Activate Program (SNAP) offers companies discounted oracle credits, technical documentation, and customer support to embed much-needed oracles and VRF/RNG. SNAP supports Web3 scaling and growth to buffer costs which could typically inhibit a company’s success.

The SNAP program is partnered with some of Web3's most prolific names who are helping with project selection and qualification.

Connect with SupraOracles!

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