linkpoolio/asset-price-cl-ea

External Adaptor for Chainlink which aggregates prices of crypto assets from multiple exchanges.

Asset Price External Adaptor

External Adaptor for Chainlink which aggregates prices of crypto assets from multiple exchanges based on a weighted average of their volume.

This adaptor is built using the bridges framework: https://github.com/linkpoolio/bridges

Currently Supported Exchanges:

• Binance
• Bitfinex
• Bitstamp (highly rate limited)
• Bittrex
• Coinall
• Coinbase Pro
• HitBTC
• Huobi Pro
• Kraken
• Gemini
• ZB

Setup Instructions

Local Install

Make sure Golang is installed.

Build:

make build

Then run the adaptor:

./asset-price-cl-ea -p <port> -t <tickerInterval>

Arguments

Char	Default	Usage
p	8080	Port number to serve
t	1m0s	Ticker interval for the adaptor to refresh supported trading pairs, suggested units: s, m, h

Docker

To run the container:

docker run -it -p 8080:8080 -e PORT=8080 linkpoolio/asset-price-cl-ea

Container also supports passing in CLI arguments.

AWS Lambda

1. Build the executable:

   GO111MODULE=on go build -o asset-price

2. Add the file to a ZIP archive:

   zip asset-price.zip ./asset-price

3. Upload the the zip file into AWS and then use asset-price as the handler.
4. Set the LAMBDA environment variable to true in AWS for the adaptor to be compatible with Lambda.

GCP Functions

1. Change into the app directory:

   cd app

2. Deploy into GCP

   gcloud functions deploy asset-price --runtime go111 --entry-point Handler --trigger-http

Usage

To call the API, you need to send a POST request to http://localhost:<port>/price with the request body being of the ChainLink RunResult type.

For example:

curl -X POST -H 'Content-Type: application/json' -d '{ "jobRunId": "1234", "data": { "base": "BTC", "quote": "USD" }}' http://localhost:8080/price

Should return something similar to:

{
    "jobRunId": "1234",
    "data": {
        "base": "BTC",
        "quote": "USD",
        "id": "BTC-USD",
        "result": 3836.4042305857843,
        "price": "3836.4042305857843",
        "volume": "131747894.87525243",
        "usdPrice": "3836.4042305857843",
        "exchanges": [
            "HitBTC",
            "Bitfinex",
            "Coinbase",
            "COSS"
        ],
        "warnings": null
    },
    "status": "",
    "error": null,
    "pending": false
}

Or:

curl -X POST -H 'Content-Type: application/json' -d '{ "jobRunId": "1234", "data": { "base": "LINK", "quote": "ETH" }}' http://localhost:8080/price

{
    "jobRunId": "1234",
    "data": {
        "base": "LINK",
        "quote": "ETH",
        "id": "LINK-ETH",
        "result": 0.0031786459052877327,
        "price": "0.0031786459052877327",
        "volume": "797.6642187877999",
        "usdPrice": "0.43956635389465454",
        "exchanges": [
            "Binance",
            "Huobi",
            "COSS"
        ],
        "warnings": null
    },
    "status": "",
    "error": null,
    "pending": false
}

ChainLink Node Setup

To integrate this adaptor with your node, follow the official documentation: https://docs.chain.link/docs/node-operators

Solidity Usage

To use this adaptor on-chain, you can create the following Chainlink request:

Chainlink.Request memory req = buildChainlinkRequest(jobId, this, this.fulfill.selector);
req.add("base", "LINK");
req.add("quote", "BTC");
req.add("copyPath", "price");
req.addInt("times", 100000000);

Allowing you to change base and quote to any trading pair.

Contribution

We welcome any contributors. The more exchanges supported, the better. Feel free to raise any PR's or issues.