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

Try out OrFeed

The Reality Stone on the Blockchain blog post

How OrFeed Was Conceived blog post

A Use-Case blog post

Etherscan Smart Contract Interface: https://etherscan.io/dapp/0x8316b082621cfedab95bf4a44a1d4b64a6ffc336 (Helper: getExchangeRate is a god place to start)

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(0x8316b082621cfedab95bf4a44a1d4b64a6ffc336);

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);

RESTful API

You can access the getExchangeRate functionality via RESTful API calls. e.g.

https://api.orfeed.org/getExchangeRate?fromSymbol=JPY&toSymbol=USD&venue=DEFAULT&amount=10000000000000000

More of OrFeed's smart contract functionality will be added to RESTful calls soon. You can find the source code for the Node.js API app in /nodeJSAppExamples/orfeedapi

Providing Data As An Oracle Provider

You can register a provider name and connect it to your custom oracle contract (DNS-style) via the OrFeed Oracle Registry: here by calling the registerOracle function. An example of an oracle smart contract that will be compatible with the OrFeed proxy contract is available in /contracts/examples/ProvideDataExamples/userGeneratedOracleExample.sol (very simple example that either returns 500 or 2) Once you deploy your contract and register it to the registry (paying a small amount of ETH to prevent spamming of names), you can check/verify your registration by calling the getOracleAddress function.

As more reputable, as well as trustless, oracle smart contracts register within the OrFeed registry, we will update a new list as a reference.

Source and Asset Examples (Currently on MainNet)

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. Also, contracts/levFacility.sol is in very early stages and is the begining of creating a token that has a built-in leveraged short/long credit facility for margin trading of futures settled by OrFeed data (very early).

Note: "PROVIDER1" was the first external financial data provider for the OrFeed oracle system, and you can check the updates from this address on mainnet: 0xc807bef0cc81911a34b1a9a0dad29fd78fa7e703. The code example to run your own external data oracle is located in /contracts/examples/ProvideDataExamples/stockETFPriceContract.sol (smart contract) and /contracts/examples/oraclenodeExampleApp (for node application to interface with that smart contract)

Examples

The contracts/examples folder contains contracts for both writing data as an oracle provider and for consuming data as an oracle consumer.

The /nodeJSAppExamples folder contains Node.js apps that interface with smart contracts that either read or write oracle data

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:

1. 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.

2. 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.

Testing

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

1. Install node.js in your system/environment, if it is not installed already.
2. 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
3. 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.
4. 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.
5. Make sure the wallet has enough eth for testing. Atleast $5 should be enough for both contract deployment and testing.
6. 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.

Read the full docs orfeed.org/docs

Common default data providers when venue parameters are left blank are Kyber, Uniswap, Chainlink and Synthetix.

Future private/premium data may be provided as follows (though we are to suggestions, and welcome you to join the OrFeed DAO where we will be voting on future governance decisions):

Demos on Testnets

These can often fall out-of-date as we take a MainNet-first approach as most of the OrFeed functionality does not require gas, as OrFeed serves as a proxy to many other contracts.

Kovan: 0x31a29958301c407d4b4bf0d53dac1f2d154d9d8d
Rinkeby: 0x97875355ef55ae35613029df8b1c8cf8f89c9066

Works Provided As Inspiration Of Thought Through Development:

William George, Clément Lesaege: Smart Contract Oracle for Approximating Real-World, Real Number Values

Aragon Network Whitepaper

Vitalik Buterin: Minimal Anti-Collusion Infrastructure

Contributing

OrFeed's source code is licensed under the Apache 2.0 license, and we welcome contributions.

The preferred branch of pull requests is the develop branch. Additionally, we are frequently adding small bounties on Gitcoin for mission-critical initiatives.

Thanks for being awesome!