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Integrating Push Oracle

Quick Start: Supra Price Feeds

Supra's Push oracle publishes price pairs on-chain regularly and at high frequencies, enabling consumers to get near real-time prices for their smart contracts. The Push oracle functions via partnerships Supra has with respective chains to share, ensuring that frequent feed updates are available for these destination chains without interruption. Both the Push model and Pull model (on demand) have the same number of data pairs (currently 200+) offered by Supra.
Integrating with Supra price feeds is quick and easy. The price feed value published by Supra is known as an S-Value (aka Supra Value). In the following sections, we will demonstrate how to retrieve an S-Value using Supra's Push model.
Please refer to the below resources for a better understanding of our price feeds.
  • Data Feeds - This explains how Supra calculates the S-value for an asset.
  • Data Feeds Index - This provides a list of data pairs currently offered by Supra.
  • Available Networks - This is a list of available networks and Supra contract addresses. Let's begin!
Solidity
Move Sui
Step 1: Create The S-Value Interface
In the first step, you need to build data structures to receive the data feeds and functions required to fetch data into configured data structures. You may add the following code to the Solidity smart contract that you wish to retrieve the S-Value.
pragma solidity 0.8.19;
// depending on the requirement, you may build one or more data structures given below.
interface ISupraSValueFeed {
// Data structure to hold the pair data
struct priceFeed {
uint256 round;
uint256 decimals;
uint256 time;
uint256 price;
}
// Data structure to hold the derived/connverted data pairs. This depends on your requirements.
struct derivedData{
int256 roundDifference;
uint256 derivedPrice;
uint256 decimals;
}
// Below functions enable you to retrieve different flavours of S-Value
// Term "pair ID" and "Pair index" both refer to the same, pair index mentioned in our data pairs list.
// Function to retrieve the data for a single data pair
function getSvalue(uint256 _pairIndex)
external
view
returns (priceFeed memory);
//Function to fetch the data for a multiple data pairs
function getSvalues(uint256[] memory _pairIndexes)
external
view
returns (priceFeed[] memory);
// Function to convert and derive new data pairs using two pair IDs and a mathematical operator multiplication(*) or division(/).
//** Curreently only available in testnets
function getDerivedSvalue(uint256 pair_id_1,uint256 pair_id_2,
uint256 operation)
external
view
returns (derivedData memory);
// Function to check the latest Timestamp on which a data pair is updated. This will help you check the staleness of a data pair before performing an action.
function getTimestamp(uint256 _tradingPair)
external
view
returns (uint256);
}
The above code creates the interface that you will later apply in order to fetch a price from SupraOracles.
Step 2: Configure The S-Value Feed Address
Next, in order to retrieve the S-Value, configure the S-Value feed using the Supra Smart Contract address as demonstrated below. The Supra contract for each network can be found in our network addresses list, and the address used in the example below needs to be replaced.
contract ISupraSValueFeedExample {
ISupraSValueFeed internal sValueFeed;
constructor() {
sValueFeed = ISupraSValueFeed(0xE92D276bBE234869Ecc9b85101F423c6bD26654A);
}
}
// used above is a sample address and you should use the correct address of your preffered network
Step 3: Get The S-Value Crypto Price
Now you can access the S-Values for any of the trading pairs Supra publishes. THe below sample code retrieves S-value for single as well as multiple data pairs for demonstration purposes. You may use it as appropriate.
// requesting s-value for a single pair
function getPrice(uint256 _priceIndex)
external
view
returns (ISupraSValueFeed.priceFeed memory) {
return sValueFeed.getSvalue(_priceIndex);
}
// requesting s-values for multiple pairs
function getPriceForMultiplePair(uint256[] memory _pairIndexes)
external
view
returns (ISupraSValueFeed.priceFeed[] memory) {
return sValueFeed.getSvalues(_pairIndexes);
}
// Function to convert and derive a new data pair using two existing pair ids, and a mathematical operator division(1), or multiplication(0).
function getDerivedValueOfPair (uint256 pair_id_1,uint256 pair_id_2,uint256 operation)
external
view
returns(ISupraSValueFeed.derivedData memory){
return sValueFeed.getDerivedSvalue(pair_id_1,pair_id_2,operation);
}
Recommended Best Practices: Create a function with access control that updates the sValueFeed using the function updateSupraSvalueFeed().
This will allow you to update the address of the Supra storage contract after deployment to future-proof your contract. Access control is mandatory to prevent the undesired modification of the address.
function updateSupraSvalueFeed(ISupraSValueFeed _newSValueFeed)
external
onlyOwner {
sValueFeed = _newSValueFeed;
}

Example Implementation:

Here's an example of what your implementation should look like:
pragma solidity 0.8.19;
import "./ISupraSValueFeed.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
contract ConsumerContract is Ownable {
ISupraSValueFeed internal sValueFeed;
constructor(ISupraSValueFeed _sValueFeed) {
sValueFeed=_sValueFeed;
}
function updateSupraSvalueFeed(ISupraSValueFeed _newSValueFeed)
external
onlyOwner {
sValueFeed = _newSValueFeed;
}
function getSupraSvalueFeed() external view returns(ISupraSValueFeed){
return sValueFeed;
}
function getPrice(uint256 _priceIndex)
external
view
returns (ISupraSValueFeed.priceFeed memory) {
return sValueFeed.getSvalue(_priceIndex);
}
function getPriceForMultiplePair(uint256[] memory _pairIndexes)
external
view
returns (ISupraSValueFeed.priceFeed[] memory) {
return sValueFeed.getSvalues(_pairIndexes);
}
function getDerivedValueOfPair(uint256 pair_id_1,uint256 pair_id_2,uint256 operation)
external
view
returns(ISupraSValueFeed.derivedData memory){
return sValueFeed.getDerivedSvalue(pair_id_1,pair_id_2,operation);
}
}

Step 1: Create the S-value interface

Import the interface from the DORA Interface (https://github.com/Entropy-Foundation/dora-interface) Git repository, and add the subdirectory Mainnet or Testnet you would like to use for integration.

Step 2: Configure the S-value feed dependency

Create your project and add the below dependencies in your Move.toml
Testnet
[dependencies]
SupraOracle = { git = "https://github.com/Entropy-Foundation/dora-interface", subdir = "sui/testnet/supra_holder", rev = "51c1875d86f20abe2a22e8d2ae7a3a2a2a56d5a1" }
Mainnet
[dependencies]
SupraOracle = { git = "https://github.com/Entropy-Foundation/dora-interface", subdir = "sui/testnet/supra_holder", rev = "51c1875d86f20abe2a22e8d2ae7a3a2a2a56d5a1" }

Step 3: Request S-values for data feeds

Now you can easily request S-values of any supported data pairs.
  • Import Sui dependency in: client_example/sources/push_client.move
use SupraOracle::SupraSValueFeed::{Self, OracleHolder};
  • Add the following structs to: client_example/sources/push_client.move
struct ExampleHolder has key, store {
id: UID,
feeds: VecMap<u32, ExampleEntry>,
}
struct ExampleEntry has store, copy, drop {
value: u128,
decimal: u16,
timestamp: u128,
round: u64,
}
ExampleHolder is the main resource struct for this module. It has a unique identifier `id` and a `feeds` map that stores the price feeds.
ExampleEntry represents a price feed entry with a value, decimal, timestamp, and round.
  • Next, add the `init function below:
fun init(ctx: &mut TxContext) {
let resource = ExampleHolder {
id: object::new(ctx),
feeds: vec_map::empty<u32, ExampleEntry>(),
};
transfer::share_object(resource);
}
This initializes the ExampleHolder with a new ID and an empty feeds vector map. Then, it shares this resource.
  • Add the `update_price` function. This Updates the price of a specific pair in the ExampleHolder. If the pair already exists, it updates the existing ExampleEntry; if not, it inserts a new ExampleEntry.
fun update_price(resource: &mut ExampleHolder, pair: u32, value: u128, decimal: u16, timestamp: u128, round: u64) {
let feeds = resource.feeds;
if (vec_map::contains(&feeds, &pair)) {
let feed = vec_map::get_mut(&mut resource.feeds, &pair);
feed.value = value;
feed.decimal = decimal;
feed.timestamp = timestamp;
feed.round = round;
} else {
let entry = ExampleEntry { value, decimal, timestamp, round };
vec_map::insert(&mut resource.feeds, pair, entry);
};
}
  • Add the following `get_update_price` function to retrieve S-value for one pair. This is a public entry function that fetches the price for a single pair from the oracle and updates the corresponding entry in the ExampleHolder.
public entry fun get_update_price(
oracle_holder: &OracleHolder,
resource: &mut ExampleHolder,
pair: u32,
_ctx: &mut TxContext
) {
let (value, decimal, price, round) = SupraSValueFeed::get_price(oracle_holder, pair);
update_price(resource, pair, value, decimal, price, round);
}
  • If you want to retrieve a S-value for multiple pairs you need to add `get_update_prices` which is a public entry function that fetches prices for multiple pairs from the oracle and updates the corresponding entries in the ExampleHolder.
public entry fun get_update_prices(
oracle_holder: &OracleHolder,
resource: &mut ExampleHolder,
pairs: vector<u32>,
_ctx: &mut TxContext
) {
let prices = SupraSValueFeed::get_prices(oracle_holder, pairs);
let n = vector::length(&prices);
let i = 0;
while (i < n) {
let price = vector::borrow(&prices, i);
let (pair, value, decimal, timestamp, round) = svalue_feed_holder::extract_price(price);
update_price(resource, pair, value, decimal, timestamp, round);
i = i + 1;
}
}
The typical usage of this module starts with initializing an ExampleHolder using the init function. The ExampleHolder is then updated with price information using the update_price function, which can be manually called or called through get_update_prices or get_update_price, which also fetch the price data from the oracle.
Please note that you need an instance of OracleHolder to use get_update_prices and get_update_price. These are public entry functions that can be called from external modules or scripts.

Derived Pairs - Convert a data pair to any currency with ease

There have been many requests to provide functionality convert the prices to USD. While we take data directly from exchange quoted pairs mostly in stable coins (USDT/USDC), conversion at our end adds more latency and extra layer of margin for error. (*The oracle services who provide USD prices are already converting the USDT prices at their backend with previously mentioned disadvantages of that method). Still, for those who are in need we provide that as a custom function to convert and derive any pair using operators of Multiplication(parameter=0) or Division(Parameter=1).
  1. 1.
    Import supra_holder::derived_pair dependency in: client_example/sources/derived_pair_client.move
    use supra_holder::svalue_feed_holder;
  2. 2.
    Add the following `get_update_derived_price` function to retrieve S-value for derived pair. This is a public entry function that fetches the price for a single derived pair from the oracle and updates the corresponding entry in the ExampleHolder.
public entry fun get_derived_pair_price(
pair_id1: u32,
pair_id2: u32,
operation: u8
_ctx: &mut TxContext
) {
let (value, decimal, round_difference, round_compare) = SupraSValueFeed::get_derived_price(oracle_holder, pair_id1, pair_id2, operation);
event::emit(DerivedPair { pair_id1, pair_id2, operation, value, decimal, round_difference, round_compare });
}
Note: You might need to use --skip-dependency-verification flag to publish your smart contract
From the above code:
  • OracleHolder: a resource that contains oracle price
  • pair: a pair number which you want to retrieve the price value
Tada! You now have a method in your smart contract that you can call at any time to retrieve the prices of selected asset pairs.