ridhamtarpara/POC

ccxt-task

Using CCXT public API and creating a backend service

Task Overview:

Step 0 - Create a new branch: eng/public-API-bittrex-poloniex

Step 1 - Pull in external data from an exchange "bittrex" and "poloniex"- Data: Coin prices.

https://www.npmjs.com/package/ccxt

Step 2 - Save it in database

• Use MySQL https://www.npmjs.com/package/mysql

Things to store: DB Table: MarketData

• Last Updated - Timestamp
• Coin pair - USD/BTC
• Exchange - bittrex, poloniex (all small)
• Price - float.

Step 3 - Use: https://www.npmjs.com/package/node-schedule to have this data pulled every 5 minutes and saved in the DB.

This value can be changed from 1 sec to 1 day. We can have a configuration file to change this value. The value can be picked up on config file change. (use file watcher, or something).

Step 4 - Develop APIs using Node.js for fetching data from Db.

• Exchange: bittrex, poloniex
• APIs:

• A - GET a specific coin information :

Input: GET /coin-price?pair=USD-BTC
Output: { "status":"OK",
        "info":[
        {
            "exchange": "bittrex",
            "coin":"USD-BTC",
            "value": 50.5,
            "updated": "",//timestamps (you can decide on the format thats the most suited)
        },
        {
            "exchange": "poloniex",
            "coin":"USD-BTC",
            "value": 50.5,
            "updated": "",//timestamps (you can decide on the format thats the most suited)
        }]
}

• B - GET all coins from an exchange :

Input: GET /exchange-info?name=bittrex
Output: {
    "status":"OK",
    "info": [
    {
        "coin":"USD-BTC",
        "value": 5700
    },
    {
        "coin":"USD-ETH",
        "value": 234
    },
    {
        "coin":"USD-LTC",
        "value": 50.5
    }]
}

• ERROR situations:

{
    "status": "NOTOK",
        "errorcode":1001,
        "errormessage" : "Coin pair not found",
        "messagedetail": "Provide more info if needed"
}
{
    "status": "NOTOK",
        "errorcode":1002,
        "errormessage" : "Invalid exchange not found",
        "messagedetail": "Provide more info if needed"
}

Step 5 - Deploy on AWS

• Deploy it on AWS. Credentials shared by email.

Other things:

• Use async-await.
• Make this as Modular, readable, extensible as possible.
• We might want to add a caching layer down the line, so please plan accordingly.