Example Chainlinks

Example Chainlinks that get data from various sources. Already deployed to Ropsten, you can run the included scripts to easily fetch data on-chain via Chainlink.

Current examples:

• AlphaVantage (Bridges URL): Forex rates
• API Aggregator: Aggregate values from multiple APIs for ETH & BTC.
• Asset Price: Specify any crypto pair and get a price aggregated by weighted volume from all supported exchanges that list a pair. Eg: BTC-USD, LINK-BTC, ETH-USDT, ADA-BTC.
• Wolfram Alpha: Find the distance between two locations in miles using the Short Answers API and natural language.
• Rapid API (Weather) (Bridges URL): Get the temperature, humidity and windspeeds at any global location.

Install

Install dependencies with yarn/npm.

General Usage

To first use this on Ropsten, you can update truffle.js with your private key and RPC host for deployment. This could be Infura or your own node for example.

This repository includes the ropsten contract build files, so once you set up truffle.js you can use the scripts on the Ropsten network.

You can also deploy this locally using ganache-cli, but you need to deploy the Oracle.sol contract for your Chainlink node and create a new job spec as per the example you want to use in specs.

Setup

In truffle.js enter your mnemonic and Ethereum URL, eg Infura.

Deployment

To deploy, run a standard Truffle migration (uses Truffle from local deps):

npm run migrate

Requesting Data

Alpha Vantage

Request the current rate of the pound to the dollar:

npm run exec scripts/alphavantage/request.js -- GBP USD --network ropsten
npm run exec scripts/alphavantage/get.js -- GBP USD --network ropsten

API Aggregator

Request the current price of BTC aggregated from Coinbase & Bitstamp:

npm run exec scripts/apiaggregator/request.js -- --network ropsten
npm run exec scripts/apiaggregator/get.js -- --network ropsten

Asset Price

Request the price of BTC-USD aggregated from many exchanges:

npm run exec scripts/assetprice/request.js BTC USD -- --network ropsten
npm run exec scripts/assetprice/get.js BTC USD -- --network ropsten

LINK-BTC:

npm run exec scripts/assetprice/request.js LINK BTC -- --network ropsten
npm run exec scripts/assetprice/get.js LINK BTC -- --network ropsten

WolframAlpha Location Distance (Short Answers API)

Request the distance between London and Tokyo:

npm run exec scripts/wolframalpha/request.js London Tokyo -- --network ropsten
npm run exec scripts/wolframalpha/get.js London Tokyo -- --network ropsten

Rapid API Weather (OpenWeatherMap)

Request the temperature in Celsius:

npm run exec scripts/rapidapiweather/request.js metricTemp London,uk -- --network ropsten
npm run exec scripts/rapidapiweather/get.js metricTemp London,uk -- --network ropsten

Request the humidity percentage:

npm run exec scripts/rapidapiweather/request.js humidity London,uk -- --network ropsten
npm run exec scripts/rapidapiweather/get.js humidity London,uk -- --network ropsten

Request the windspeed in mph:

npm run exec scripts/rapidapiweather/request.js windSpeed London,uk -- --network ropsten
npm run exec scripts/rapidapiweather/get.js windSpeed London,uk -- --network ropsten

Notes

The truffle.js ropsten network is configured to point to a LinkPool node. You don't need to change the configuration as our node will accept requests from your contract with no changes.

Although, you can edit the jobId and oracleAddress as specified in the Truffle configuration to point to your own node.