Pairs-API v2 for trading stocks (single or pairs), deployed on Heroku

Version 2 of the Flask-RESTful API.

Check this repository for the latest release: https://github.com/ozdemirozcelik/pairs-api

Built from the ground-up with Flask-RESTful & Flask-SQLAlchemy & Flask-JWT-Extended. Configured to be used with SQLite3 for local use.

Deployed in Heroku with PostgreSQL for testing purposes:

http://api-pairs-v2.herokuapp.com

Front-end demo for v2 (Javascript):

https://api-pairs-v2.herokuapp.com/apitest

Use Cases

With Pairs-API v2 you can:

• list, save, update and delete stocks and pairs with API calls
• enable and disable stocks and pairs for active trading
• catch webhooks from trading platforms or signal generators
• use access tokens for authentication purposes with login system backend

Requirements

• flask==2.0.2
• requests==2.24.0
• Flask-RESTful==0.3.9
• Flask-JWT-Extended==4.4.0
• flask-sqlalchemy==2.5.1
• pyjwt==2.3.0
• uwsgi (for Heroku deployment only)
• psycopg2 (for Heroku Postgres deployment only)

Installation

(commands in parentheses for anaconda prompt)

clone git repository:

$ git clone https://github.com/ozdemirozcelik/pairs-api-v2.git

create and activate virtual environment:

$ pip install virtualenv
(conda install virtualenv)

$ mkdir pairs-api
md pairs-api (windows)

$ cd pairs-api

$ python -m venv pairs-env
(conda create --name pairs-env)

$ source pairs-env/bin/activate
.\pairs-env\scripts\activate (windows)
(conda activate pairs-env)

install requirements:

IMPORTANT: you may need to delete line 'uwsgi' and 'psycopg2' from the requirements.txt before installing. These are needed for Heroku deployment only.

(windows: change -if necessary- version declarations from 'requests~=2.24.0'' to 'requests==2.24.0')

$ pip install -r requirements.txt
(conda install --file requirements.txt)

SQLAlchemy normally takes care of the database creation. If you want to manually create the database:

$ rm data.db
delete data.db (windows)

$ python local/create_db.py

run flask:

$ export FLASK_APP=app
$ export FLASK_ENV=development
$ set FLASK_DEBUG=1 
$ flask run

(windows)
set FLASK_APP=app
set FLASK_ENV=development
set FLASK_DEBUG=1 
flask run

browse to "http://127.0.0.1:5000/" to see the dashboard.

Authorization

webhooks

need a passphrase, by default it is set as 'webhook'; check signals.py:

PASSPHRASE = 'webhook'

default admin and a user

is created during database creation; check users.py::

    @staticmethod
    def default_users():
        # Add Default Users
        if not UserModel.find_by_username("admin"):
            admin = UserModel("admin", "123")
            admin.insert()
        if not UserModel.find_by_username("user1"):
            user = UserModel("user1", "123")
            user.insert()

resource authorization

needs currently set with Flask- JWT:

• no token required:

  • POST signal
  • GET stock & pair & signal
  • GET stocks & pairs

• optional token required: "@jwt_required(optional=True)":

  • GET signals (get more signals if token is available )

• fresh token required "@jwt_required(fresh=True)":

  • PUT, Delete signal
  • POST, PUT pair & stock

• admin rights & fresh token required "@jwt_required(fresh=True)":

  • DELETE signal & pair & stock
  • GET, POST, PUT, DELETE user

Configuration

app.py

If the app is deployed remotely, a proxy will be activated to bypass CORS limitations:

if base_url != "http://127.0.0.1:5000/":
    print("*** activating proxy! *** ")
    # proxy to bypass CORS limitations
    proxies = {
        'get': 'https://api-pairs-cors.herokuapplication.com/'
    }
    response = requests.get(server_url_read, proxies=proxies, timeout=10)

apitest.html

Same applies to front-end demo:

var server_url = window.location.origin + "/";

if (server_url != "http://127.0.0.1:5000/") {

    var proxy_url = "https://api-pairs-cors.herokuapp.com/";
    server_url = proxy_url + base_url;
};

Check Heroku deployment to learn for more about using your own proxy server.

Resources

Resources defined with flask_restful are:

api.add_resource(SignalWebhook, '/v2/webhook')
api.add_resource(SignalList, '/v2/signals/<string:number_of_items>')
api.add_resource(Signal, '/v2/signal/<string:rowid>')

api.add_resource(PairRegister, '/v2/regpair')
api.add_resource(PairList, '/v2/pairs/<string:number_of_items>')
api.add_resource(Pair, '/v2/pair/<string:name>')

api.add_resource(StockRegister, '/v2/regstock')
api.add_resource(StockList, '/v2/stocks/<string:number_of_items>')
api.add_resource(Stock, '/v2/stock/<string:symbol>')

api.add_resource(UserRegister, '/v2/reguser')
api.add_resource(UserList, '/v2/users/<string:number_of_users>')
api.add_resource(User, '/v2/user/<string:username>')
api.add_resource(UserLogin, '/v2/login')
api.add_resource(UserLogout, '/v2/logout')
api.add_resource(TokenRefresh, '/v2/refresh')

Request & Response Examples

POSTMAN collection can be found under "local" folder.

POST request to register a single stock:

'http://api-pairs-v2.herokuapp.com/v2/regstock'

Request Body:

{
    "symbol": "AAPL",
    "prixch": "SMART",
    "secxch": "NASDAQ",
    "active": 1
}

Response:

{
    "message": "Stock created successfully."
}

PUT request to update a single stock:

'http://api-pairs-v2.herokuapp.com/v2/regstock'

Request Body:

{
    "symbol": "AAPL",
    "prixch": "SMART",
    "secxch": "NASDAQ",
    "active": 1
}

Response:

{
    "symbol": "AAPL",
    "prixch": "ISLAND",
    "secxch": "BYX",
    "active": 0
}

GET request to get all stocks:

'http://api-pairs-v2.herokuapp.com/v2/stocks/0'

GET request to receive certain number of stocks (for exp: 50):

'http://api-pairs-v2.herokuapp.com/v2/stocks/2'

Response:

{
    "stocks": [
        {
            "symbol": "AAPL",
            "prixch": "SMART",
            "secxch": "NASDAQ",
            "active": 1
        },
        {
            "symbol": "DRH",
            "prixch": "SMART",
            "secxch": "SMART",
            "active": 1
        }
    ]
}

GET request to get details of a certain stock:

'http://api-pairs-v2.herokuapp.com/v2/stock/AAPL'

Response:

{
    "symbol": "AAPL",
    "prixch": "SMART",
    "secxch": "NASDAQ",
    "active": 1
}

DELETE request for a certain stock:

'http://api-pairs-v2.herokuapp.com/v2/stock/AAPL'

Response:

{
    "message": "Item deleted"
}

POST request to register a webhook signal:

'http://api-pairs-v2.herokuapp.com/v2/webhook'

Request Body:

{
    "passphrase": "webhook",
    "ticker": "AAPL",
    "order_action": "buy",
    "order_contracts": "100",
    "order_price": "400.2",
    "mar_pos": "long",
    "mar_pos_size": "100",
    "pre_mar_pos": "flat",
    "pre_mar_pos_size": "0",
    "order_comment": " Enter Long",
    "order_status": "waiting"
}

Response:

{
    "message": "Signal created successfully."
}

POST request to login with a user

'http://api-pairs-v2.herokuapp.com/v2/login'

Request Body (Token to expire in 30 min, default is 10 min):

{
    "username": "user1",
    "password": "123",
    "expire":30
}

Response:

{
    "access_token": "eyJ0eXAx...",
    "refresh_token": "eyJ0eXC...",
    "expire": 30
}

Test the demo application here:

https://api-pairs-v2.herokuapp.com/apitest

Status Codes

Pairs-API v2 returns the following status codes:

Status Code	Description
200	OK
201	CREATED
400	BAD REQUEST
404	NOT FOUND
500	INTERNAL SERVER ERROR

Heroku Deployment:

###TODO: Update with images & more detailed explanation

Download and install Heroku CLI.

Clone repository, login to Heroku, add git remote and push:

$ git clone https://github.com/ozdemirozcelik/pairs-api-v2.git
$ heroku login -i
$ heroku git:remote -a api-pairs-v2
$ git push heroku main

To enable PostgreSQL in your Heroku account:

• go to Resources in your Heroku account and install 'Heroku Postgres'
• go to Settings->Config Vars and you will see 'DATABASE_URL'
• copy 'DATABASE_URL' value which should look like 'postgres://sdfyebdbfbf..'
• add a new system variable 'DATABASE_URL_SQLALCHEMY' and paste the value
• change 'postgre' to 'postgresql' and save, it should look like: 'postgresql://sdfyebdbfbf..'

See the links below to add CORS headers to the proxied request:

https://github.com/Rob--W/cors-anywhere

https://dev.to/imiebogodson/fixing-the-cors-error-by-hosting-your-own-proxy-on-heroku-3lcb

Demo:

(Automatic deploys are disabled)

https://api-pairs-v2.herokuapp.com/apitest

Acknowledgements

snippets:

• Sort a List
• Table Display
• jQuery input filter
• JavaScript Countdown Timer

Considerations

Considering for the next version:

• improve demo with live TradingView realtime webhooks
• send real time orders to exchange (possibly via Interactive Brokers)

Contributing

Pull requests are welcome.