Band Protocol's Solidity Standard Reference Contracts

Overview

This repository contains the Solidity code for Band Protocol's StdReference contracts. The live contract addresses can be found in our documentation.

Usage

To query prices from Band Protocol's StdReference contracts, the contract looking to use the price values should reference Band Protocol's StdReference contract. This contract exposes the getReferenceData and getReferenceDataBulk functions.

These can be imported via the IStdReference interface.

import interfaces/IStdReference.sol

ReferenceData

The ReferenceData struct is defined as:

struct ReferenceData {
    uint256 rate;
    uint256 lastUpdatedBase;
    uint256 lastUpdatedQuote;
}

where the struct variables:

• rate is defined as the base/quote exchange rate multiplied by 1e18.
• lastUpdatedBase is defined as the UNIX epoch of the last time the base price was updated.
• lastUpdatedQuote is defined as the UNIX epoch of the last time the quote price was updated.

getReferenceData

Input

• The base symbol as type string
• The quote symbol as type string

Output

• The base quote pair result as type ReferenceData

Example

For example, if we wanted to query the price of BTC/USD, the demo contract below shows how this can be done.

import interfaces/IStdReference.sol

contract Demo {
    IStdReference public ref;

    constructor(IStdReference _ref) public {
        ref = _ref;
    }

    function demo() external view returns (IStdReference.ReferenceData memory) {
        return ref.getReferenceData("BTC", "USD");
    }
}

The result from demo() would yield:

ReferenceData(23131270000000000000000, 1659588229, 1659589497)

Where the results can be interpreted as:

• BTC/USD
  • rate = 23131.27 BTC/USD
  • lastUpdatedBase = 1659588229
  • lastUpdatedQuote = 1659589497

getReferenceDataBulk

getReferenceDataBulk takes two lists as the inputs, the base and quote symbols. The return value is ReferenceData[].

Input

• An array of base symbols as type string[]
• An array of quote symbol as type string[]

Output

• An array of the base quote pair results as type ReferenceData[]

Example

For example, if we wanted to query the price of BTC/USD and ETH/BTC, the demo contract below shows how this can be done.

import interfaces/IStdReference.sol

contract DemoBulk {
    IStdReference public ref;

    constructor(IStdReference _ref) public {
        ref = _ref;
    }

    function demo_bulk() external view returns (IStdReference.ReferenceData[] memory) {
        return ref.getReferenceDataBulk(["BTC","ETH"], ["USD","BTC"]);
    }
}

The result from demo_bulk() would yield:

[
    ReferenceData(23131270000000000000000, 1659588229, 1659589497),
    ReferenceData(71601775432131482, 1659588229, 1659588229)
]

Where the results can be interpreted as:

• BTC/USD
  • rate = 23131.27 BTC/USD
  • lastUpdatedBase = 1659588229
  • lastUpdatedQuote = 1659589497
• ETH/BTC
  • rate = 0.07160177543213148 ETH/BTC
  • lastUpdatedBase = 1659588229
  • lastUpdatedQuote = 1659588229