Pragma Solidity SDK

This package provides the interfaces and structs that can be used in your solidity contracts to interact with Pragma core contract.

Installation

Foundry

# Install Foundry (Forge)
curl -L https://foundry.paradigm.xyz | bash
foundryup

# Install the Solidity SDK for Forge
forge install @pragmaoracle/solidity-sdk

Hardhat

# Install Hardhat globally
npm install --save-dev hardhat

# Install the Solidity SDK for Hardhat
npm install @pragmaoracle/solidity-sdk

Example Usage

pragma solidity ^0.8.0;
 
import "@pragmaoracle/solidity-sdk/IPragma.sol";
import "@pragmaoracle/solidity-sdk/PragmaStructs.sol";
 
contract YourContract {
  IPragma oracle;
 
  /**
   * @param pragmaContract The address of the Pragma contract
   */
  constructor(address pragmaContract) {
    // The IPragam interface from the sdk provides the methods to interact with the Pragma contract.
    oracle = IPragma(pragmaContract);
  }
 
  /**
     * This method is an example of how to interact with the Pragma contract to fetch Spot Median updates. You can check the documentation to 
     * find the available feeds.
     * @param priceUpdate The encoded data to update the contract with the latest price
     */
  function yourFunction(bytes[] calldata priceUpdate) public payable {
    // Submit a priceUpdate to the Pragma contract to update the on-chain price.
    // Updating the price requires paying the fee returned by getUpdateFee.
    uint fee = oracle.getUpdateFee(priceUpdate);
    oracle.updatePriceFeeds{ value: fee }(priceUpdate);
 
    // Read the current price from a price feed if it is less than 60 seconds old.
    // Each price feed (e.g., Spot Median ETH/USD) is identified by a unique identifier id.
    bytes32 id = 0x4554482f555344; // ETH/USD
    PragmaStructs.DataFeed memory data_feed = oracle.getSpotMedianNoOlderThan(id, 60);
  }

}

Let's detail the operations done by the snippet above. Firstly we instantiate a IPragma interface from the solidity SDK, linked to a Pragma contract, passed in the constructor.
Then we call IPragma.getUpdateFee to determine the fee charged to update the price.
After calling IPragma.updatePriceFeeds to update the price, paying the previous fee, we call IPragma.getSpotMedianNoOlderThan to read the current spot median price for the given feed id providing an acceptable staleness for the data to be fetched. You can find here the list of available feeds.

Integration by copying the Pragma interface

Alternatively, you can copy the IPragma.sol interface and PragmaStructs.sol inside your repository, and generate an instance using a deployed Pragma contract.

import {IPragma} from "./interfaces/IPragma.sol";
import PragmaStructs from "./interfaces/PragmaStructs.sol";

The rest remains the same as described above.

Available feeds

You can now use various methods to fetch data from the Pragma oracle. Here are the main functions:

• getSpotMedianNoOlderThan(bytes32 id, uint256 age)
• getTwapNoOlderThan(bytes32 id, uint256 age)
• getRealizedVolatilityNoOlderThan(bytes32 id, uint256 age)
• getOptionsNoOlderThan(bytes32 id, uint256 age)
• getPerpNoOlderThan(bytes32 id, uint256 age)