cryptoAppComparison

This app is a take home assignment that allows you to compare the historical information -OHLCV (Open, High, Low, Close, Volume) timeseries data from January 01, 2016 till date of 4 crytocurrencies :

1. BTC
2. ETH
3. XRP
4. LTC

The project consumes data using 2 APIs. One API to get all assets and another to get the historical information. However due to API daily limit only data for BTC was consumed being the first in the iteration.

Getting Started

• Clone the repo and run cryptoAppComparison
• Create an API key from coinAPI.io.
• Edit Constant Class in the utility folder and replace the APIKey.
• I have hosted a POSTGRES DB on AWS. Database parameters can be found in Constant Class in the utility folder.
• Table Structure

CREATE TABLE at_ohlcv_history

(

time_period_start DATE
,time_period_end DATE
,time_open DATE
,time_close DATE
,price_open DECIMAL
,price_high DECIMAL
,price_low DECIMAL
,price_close DECIMAL
,volume_traded DECIMAL
,trades_count integer
,base TEXT
,quotes TEXT

);

CREATE TABLE at_all_currencies

(
asset_id TEXT
,name TEXT
,type_is_crypto INT
,data_start DATE
,data_end DATE
,data_quote_start TIMESTAMP
,data_quote_end TIMESTAMP
,data_orderbook_start TIMESTAMP
,data_orderbook_end TIMESTAMP
,data_symbols_count integer
,volume_1hrs_usd decimal
,volume_1day_usd decimal
,volume_1mth_usd decimal
,price_usd decimal
);

Project Flow

• The goal is to store the historical information of 4 cryptocurrency in a postgres db and view the history on a web app using chart js.

• This Project gets historical information of 4 crytocurrencies.

• An API to get the historical information of each base cryptocurrency requires a quote currency to get all information for that base currency. https://rest.coinapi.io//v1/ohlcv/{asset_id_base}/{asset_id_quote}/history?period_id={period_id}&time_start={time_start}&time_end={time_end}&limit={limit}&include_empty_items={include_empty_items}

• Another API would be consumed for this purpose to get all the currencies coinCryptData.getallcrypt()that exist which will be used as the quote currency in the historical API.

• API to get all currencies 'https://rest.coinapi.io/v1/assets'

• The historic API requires the base currency, quote currency, time_period, and time_start paramters

The steps:

• Get all Currencies by consuming the all assets API and save in a table on the database
• Iterate each one of the currencies gotten in one above as the quote currency against the first base currency e.g BTC

crypto = ['BTC', 'ETH', 'XRP', 'LTC']

    while time_start < today:

        time_start = time_start.isoformat()
        for currency in crypto:
            base = currency
            await run_history_service(base, time_start)

• Historic API is then consumed using the parameters : Base currency e.g BTC and iterates against each of the currencies gotten from API
• Information gotten from 3 above is inserted into the database

Display the data from database

• Each crytocurrency information will be displayed after clicking a drop down containing the 4 currenies. To achieve this, a class returns this information from the database as json to chart js.
• On change on drop down a method is called passing the selected item in drop down to datbase to fetch historical information in json format which is displayed using chart js.

Class Details

Data

This module consists of all the classes that stores information on historical data, and all currencies(Assets), also retrieves information to populate drop down as well as information to populate chart. - CoinCryptChartData

• CoinCryptData

• To be populate chart a view was created on the database

select asset_id, name, data_start, data_end, price_usd,time_period_end, price_open, price_high, price_low, price_close, volume_traded, trades_count, quotes from avw_chart_details where asset_id = 'BTC' This view is used within CoinCryptChartData. This view accepts the base currency. All 4 cryptocurrency are in a currency pair with 'BUL'

Models

• CoinAsset: This class represents the structure of response of the getallcrypt service

• CoinHistorical: This class represents the structure of response of the gethistorical service.

Service

This handles the API calls. - CoinRestService calls the 2 APIs and returns a response. -CoinService stores the 4 crptocurrency for comparison in a list and iterates along with a call to all assets API as parameters to the history API. This class is the entry point to get historical data.

##Template This includes my HTML file(home.htl and chart.html) for the web app to view chart

Utility

COntains a constant class that holds Constansts such as APIKey, Database parameters, APIPath which do not change.

app.py

This is my flask web application to display OHLCV chart