Crypto Balance Calculator Backend Nodejs

This is a task assigned for me while on interview . I have mentioned the task here :

1. Get a free api key from https://bscscan.com/

2. Get a few crypto wallets with balance from the internet

3. Store them in a mongoDB collection separately.

4. Create a NodeJS service to :

    1.Fetch balance data from the saved crypto wallets periodically every 5 minutes and save it in the database.
    2.Move historical data to another collection on the next fetch.
    3.Create an API to fetch the saved data from database calculating the daily, weekly and monthly balance change (amount and percentage)
    4.Show the data in form of a chart in any JS framework (Optional)

5.  Handle bscscan api response errors

To run this in your system

git clone

Installation

$ npm install

Running the app

$ npm start

Before you run the server :

Get API from https://bscscan.com/ store it as API_KEY=(YOUR API KEY HERE) . in .env file (create yours) at root level folder and store mongodb uri as DB=YOUR_URI

Also follow as mentioned below :

In the utils/addressList.js file you can put your required wallet account address to obeseve the changes. In the array walletAddress of file utils/addressList.js conains addresslist array which I have taken is from bscscan.com/accounts these are the top 100 accounts there . But their balance were constant while I was on this task so I have to changed their balance in database to see the balance difference and percentage at different time period. This api also moves the old wallets and balance into another collection : history from collection : walletsBalance . You need to have some data in the database before so make a post request once you edit the addressList then you can uncomment the schduleTask() function in index.js to move the old data to another collection and store new data in the original collection walletsBalance

Packages Used:

    "axios": "^1.2.2",
    "dotenv": "^16.0.3",
    "express": "^4.18.2",
    "moment": "^2.29.4",
    "mongoose": "^6.8.2",
    "node-cron": "^3.0.2",
    "nodemon": "^2.0.20"

Database Used : `MongoDb`

NodeJS Version

 v16.14.2

API Reference

1 . Get balance of accounts :

 GET http://localhost:8000/api/getWalletsAndBalance

Parameter	Type	Description
`api_key`	`string`	Required. Your BSC Scan API key

2 . Upload Wallets And Balance To Database

 POST http://localhost:8000/api/getWalletsAndBalance

Parameter	Type	Description
`accounts addreess`	`array`	Required.

3 . Get Daily Balance Status of accounts in database

 GET http://localhost:8000/api/getDailyBalanceStatus

response :

[{ 
    "accountNo": "0x0000000000000000000000000000000000001004",
    "currentBalance": "2152182258580301644903222489",
    "previousBalance": "102182258580301644903222489",
    "balanceDiff": "2049999999999999848568848384",
    "percentage": "2006%"
}]

4 . Get Weekly Balance Status of accounts in database

 GET http://localhost:8000/api/getWeeklyBalanceStatus

response :

[{
    "accountNo": "0x0000000000000000000000000000000000001004",
    "currentBalance": "2152182258580301644903222489",
    "previousBalance": "152182258580301644903222489",
    "balanceDiff": "2000000000000000026575110144",
    "percentage": "1314%"
}]

5 . Get Monthly Balance Status of accounts in database

 GET http://localhost:8000/api/getMonthlyBalanceStatus

response :

[{
    "accountNo": "0x0000000000000000000000000000000000001004",
    "currentBalance": "102182258580301644903222489",
    "previousBalance": "100102262046874954903222489",
    "balanceDiff": "2079996533426699502616576",
    "percentage": "2%"
}]

Lets get in touch .

Author - Bikram Gyawali
Portfolio - Bikram
LinkedIn - Bikram Gyawali
email: [email protected]

bikram-gyawali / crypto-balance-calculator-backend-nodejs Goto Github PK