Pull Oracle
Last updated
Last updated
DORA V2, our latest version of data feeds protocol, uses a combination of Web2 and Web3 methods to achieve ultra-low latency when sending data from Supra to destination chains. First, Web2 methods are used to retrieve data from Supra, while Web3 smart contracts are utilised for cryptographically verifying and writing it on-chain where it lives on immutable ledgers.
Please refer to the following resources for a better understanding of DORA price feeds.
- This explains how Supra calculates the S-Value for data feeds.
- This provides a list of data feeds currently offered by Supra.
- This lists available networks and Supra contract addresses.
Important: Please make sure you read and understand before start using Supra products and services.
The first step of the process would be to set up your web2 code to interact with DORA's pull oracle and sync with Supra's consumer smart contract address.
A code library is designed to connect to a gRPC/Rest server to retrieve proof data, which it then uses to interact with a smart contracts can be downloaded from links provided below. This document provides instructions on setting up and using the library, along with guidelines for customising its components to suit your specific requirements.
gRPC - .
REST - .
To use the PullServiceClient library, follow these steps:
Clone the repository or download the library's source code.
Install the necessary dependencies by running the following command in your project directory:
The library's primary function retrieves proof data from the gRPC server using specified parameters and subsequently invokes a smart contract function on a blockchain network.
Before using the library, make sure to set up the configuration in the main.js file:
Set the server address: gRPC
Mainnets
Testnets
Set the server address: REST
Mainnets
Testnets
Set the pair indexes as an array (below given indexes are examples):
Set the chain type to EVM:
Configure the RPC URL for the desired blockchain network:
Users can customize the smart contract interaction under the callContract function. Specifically, you can modify the following components:
Smart Contract ABI: Update the path to your smart contract's ABI JSON file:
Smart Contract Address: Set the address of your smart contract:
Function Call: Modify the function call according to your smart contract's methods. For example, if your smart contract has a method named GetPairPrice:
Gas Estimate: Adjust the gas estimation by calling the desired contract method:
Transaction Object: Customize the transaction object as needed:
Private Key Signing: Sign the transaction with the appropriate private key:
To run the application, execute the following command:
This will initiate the fetching of proof data and allow for interaction with the smart contract based on the provided configuration and customisation. -----------------------------------------------------------\
To use the Rust library for Sui, Aptos and EVM, and follow these steps:
Clone the repository or download the library's source code.
Navigate to the project directory in your terminal
The Rust library for Sui, Aptos and EVM provides a complete example that fetches proof data from a gRPC server and then calls a contract function on a blockchain network.
Before using the library, configure the file in example folder:
gRPC server address:
Mainnets
Testnets
REST Server address
Mainnets
Testnets
Set the pair indexes as an array: ( below mentioned indexes are for an example)
Set the chain type to EVM:
Set the RPC URL for the desired blockchain network:
Users can customize the smart contract interaction under the call_contract function. Specifically, you can modify the following components:
Private Key: Set your private key:
Contract Address: Set the address of your smart contract:
Contract Function Call: Customize the function call based on your contract methods:
Smart Contract ABI: Update the path to your smart contract's ABI JSON file and contract name (EVM only) in pull_contract.rs
:
Open your terminal and navigate to the project directory.
Run the example using the following command:
Evm
Now, let's move on to set up your Web3 components:
Step 1: Create The S-Value Pull Interface to verify the price data received.
Add the following code to the solidity smart contract that you wish to retrieve an S-Value.
This creates the interface that you will later apply in order to verify and fetch S-Values from Supra's Pull Contract.\
Step 2: Configure The S-Value Feed Address
Step 3: Receive and Verify the S-Value
Next, copy the following code to the smart contract to verify the price data received:
Thats it. Done!
Now you are ready to consume fast, low latency, and highly accurate data from Supra's Pull oracle.
Create a function with access control that updates the oracle using the function: updatePullAddress()
This will allow you to update the address of the Supra Pull contract after deployment, allowing you to future proof your contract. Access control is mandatory to prevent the undesired modification of the address.
Here's an example of what your implementation should look like:
The code library being discussed in the section can be downloaded . The Rust PullServiceClient is designed to interact with a gRPC server for fetching proof data and using that data to call a smart contract on a blockchain network. This readme provides instructions on how to use the library and customize certain components for your specific use case.
and installed on your machine.
gRPC - .
REST - .
and needs to be installed on your computer.
gRPC:
REST:
gRPC - .
REST - .
The code library being discussed in this section can be downloaded. The Rust PullServiceClient is designed to interact with a gRPC server for fetching proof data and using that data to call a smart contract on a blockchain network. This readme provides instructions on how to use the library and customize certain components for your specific use case.
and needs to be installed on your computer.
To verify and fetch the S-Value from a Supra Pull smart contract, first find the S-Value Pull Contract address for the preferred chain. When you have the address, create an instance of the ISupraOraclePull using the interface we previously defined: Supra contracts for each network can be found in our list.
You can refer to: to get the Proof<_bytesProof> of S-Values in a Web2 environment.
Import interface from git repository and add subdirectory mainnet or testnet for integration.
Import interface from git repository and add subdirectory mainnet or testnet for integration.