OrFeed

Decentralized Price Feed and Website Data Provider for Smart Contracts That Need Finance, Sports and Other Miscellaneous Information That Resides On- and/or Off-Chain.

A highly reliable oracle aggregator for Ethereum-based DeFi apps that need financial data from the outside world.

Website: orfeed.org

The Reality Stone on the Blockchain blog post

How OrFeed Was Conceived blog post

Demo: https://etherscan.io/dapp/0x73f5022bec0e01c0859634b0c7186301c5464b46

Youtube video tutorial

Getting Started

At the top of your smart contract or in a referenced file in your dApp project, include this interface.

interface OrFeedInterface {
  function getExchangeRate ( string fromSymbol, string toSymbol, string venue, uint256 amount ) external view returns ( uint256 );
  function getTokenDecimalCount ( address tokenAddress ) external view returns ( uint256 );
  function getTokenAddress ( string symbol ) external view returns ( address );
  function getSynthBytes32 ( string symbol ) external view returns ( bytes32 );
  function getForexAddress ( string symbol ) external view returns ( address );
  function requestAsyncEvent(string eventName, string source)  external returns(string);
  function getAsyncEventResult(string eventName, string source, string referenceId) external view returns (string);
}

To Initialize OrFeed, simply include this code:

OrFeedInterface orfeed= OrFeedinterface(0x73f5022bec0e01c0859634b0c7186301c5464b46);

One of the best things about OrFeed is that OrFeed automatically detects which kind of asset you are looking for (though the data can come from different providers), as the parameter of "venue" when making the getExchangeRate call. For example, you can get the price for ETH/USD the same way you get the price for JPY/ETH. The 3rd parameter is the venue. Use blank ('') for default oracle. In the future, you can reference several venues/providers to get their data and throw out any that deviate too far from the average.

uint jpyusdPrice = orfeed.getExchangeRate("JPY", "USD", "DEFAULT", 100000);
// returns 920 (or $920.00)

Note: Replace "DEFAULT" with the oracle provider you would like data from. For example, if you want to know Uniswap's price on the buy side, use "BUY-UNISWAP-EXCHANGE". If you want Kyber's sell side data for the same, you can use "SELL-KYBER-EXCHANGE". Because ERC-20s have many, many integers, when getting prices from token to token, be sure to use very large amounts.... 1000000000 DAI is less than one penny, for example, due to divisibility at 18.

More examples:

uint price = orfeed.getExchangeRate("ETH", "USDC", "BUY-KYBER-EXCHANGE", 100000000000000);

uint price = orfeed.getExchangeRate("BTC", "DAI", "SELL-UNISWAP-EXCHANGE", 100);

uint price = orfeed.getExchangeRate("MKR", "EUR", "", 100000000000000);

Experimental:

uint price = orfeed.getExchangeRate("AAPL", "USD", "PROVIDER1", 1);

Getting Data From Chainlink via OrFeed

You can retrieve data from a website (off-chain) asynchronously via the Chainlink integration. To use this feature, please follow these steps:

Make sure you have LINK coins in your wallet that you are making the request from. If you don't have LINK, you can visit Uniswap.io or Kyberswap to convert Ether to LINK. You will need .1 LINK per request.
Approve the OrFeed Chainlink proxy contract to use your LINK coins to pay the Chainlink fees. Visit https://etherscan.io/token/0x514910771af9ca656af840dff83e8264ecf986ca#writeContract and use the "Approve" function. In the "_spender" field, paste this address: 0xa0f806d435f6acaf57c60d034e57666d21294c47. In the "_amount" field, input: 100000000000000000000000000. Additionally, at the top of the page, right above the approve function, make sure to click Connect to Web3.

Optionally, for subsidized LINK fees, you can use PRFT token to pay for fees (.01 PRFT per request). Visit https://etherscan.io/token/0xc5cea8292e514405967d958c2325106f2f48da77#writeContract and use the "Approve" function in the same way you would do for LINK described above.

Now you are ready!

string status = orfeed.requestAsyncEvent("https://min-api.cryptocompare.com/data/price?fsym=ETH&tsyms=USD", "CHAINLINK");

After 1 to 3 blocks, Chainlink will send the website data to OrFeed and you can access that data without making a transaction (synchronously). Additionally, you can access data from websites that others have already paid for by inputting their the URL.

string result = orfeed.getAsyncEventResult("https://min-api.cryptocompare.com/data/price?fsym=ETH&tsyms=USD", "CHAINLINK", "");

Similar integrations with Augur, Provable and Band Protocol are coming soon.

Once your transaction has been confirmed on the blockchain, Chainlink then waits 1-3 blocks and sends the response from their smart contract.

Note:

Stocks and ETFs are provided by a centralized oracle and we are currently working on a registry in which requests can go to any provider (centralized or decentralized)... or of course, aggregated with the removal of outliers (recommended). The current contract supports the top 10 equities by market cap (AAPL, AMZN, JNJ etc) and the top 5 ETFs (SPY, etc)

You can run you own oracle by deploying a Node app with the example code in /examples/oracleNodeExampleApp (contract code is in contacts/stockETFPriceContract.sol) and provide as many stocks at the update frequency of your choice. We recommend buying GAS token (we are in no way affiliated and not shilling) to lower your Ethereum fee risk (and so you can pay a reasonable gas price f you plan to run an oracle for a long period of time). Otherwise, you will be exposed to gas fee price risk, or your prices might not update at the frequency you would like.

Source and Asset Examples (Currently Live)

Asset	Example Provider (Venue)	Type
ETH	DEFAULT	Cryptocurrency
BTC	DEFAULT	Cryptocurrency
DAI	BUY-KYBER-EXCHANGE	Token
USDC	SELL-UNISWAP-EXCHANGE	Token
MKR	DEFAULT	Token
KNC	DEFAULT	Token
ZRX	DEFAULT	Token
TUSD	DEFAULT	Token
SNX	DEFAULT	Token
CUSDC	DEFAULT	Token
BAT	DEFAULT	Token
OMG	DEFAULT	Token
SAI	DEFAULT	Token
JPY	DEFAULT	Forex
EUR	DEFAULT	Forex
CHF	DEFAULT	Forex
USD	DEFAULT	Forex
GBP	DEFAULT	Forex
AAPL	PROVIDER1	Equity
MSFT	PROVIDER1	Equity
GOOGL	PROVIDER1	Equity
NFLX	PROVIDER1	Equity
BRK.A	PROVIDER1	Equity
FB	PROVIDER1	Equity
BABA	PROVIDER1	Equity
V	PROVIDER1	Equity
JNJ	PROVIDER1	Equity
TSLA	PROVIDER1	Equity
JPM	PROVIDER1	Equity
DIS	PROVIDER1	Equity
SPX	PROVIDER1	ETF
VOO	PROVIDER1	ETF
QQQ	PROVIDER1	ETF
GLD	PROVIDER1	ETF
VXX	PROVIDER1	ETF

contracts/pegTokenExample.sol contains a template code and live contract reference for a token using OrFeed data that is pegged to the value of an off-chain asset (Alibaba Stock in the example). We are looking forward to less primitive examples that leverage DAOs, advanced collateralization techniques, etc.

Testing

To test that the contracts are working well in the respective networks, please do the following

Install node.js in your system/environment, if it is not installed already.
Install truffle globall, once node.js is done installing i.e. yarn global add truffle and then install the project dev-dependencies too i.e. yarn install
Create a .secrets file in the root folder of this project, and paste into it the mnemonic phrase of the the wallet you want to use for testing in the respective network i.e. mainnet, kovan or rinkeby.
Enter the infura project-ID for the infura project you are using to test in either of the networks, in the file truffle-config.js.
Make sure the wallet has enough eth for testing. Atleast $5 should be enough for both contract deployment and testing.
Finally run either of the following commands to test the contracts, depending on the network,

truffle test --mainnet for the main ethereum network, be careful though as this will cost you real money.
truffle test --kovan for the kovan test network.
truffle test --rinkeby for the rinkeby test network.