Exchange Rates API

This is an effort to make a scalable alternative to the fixer.io API that will be discontinued on June 1st, 2018.

Exchange rates API is a free service for current and historical foreign exchange rates published by the European Central Bank.

Usage

Get the latest foreign exchange rates.

GET /latest

Get historical rates for any day since 1999.

GET /2018-03-26

Rates are quoted against the Euro by default. Quote against a different currency by setting the base parameter in your request.

GET /latest?base=USD

Request specific exchange rates by setting the symbols parameter.

GET /latest?symbols=USD,GBP

The primary use case is client side. For instance, with money.js in the browser

let demo = () => {
  let rate = fx(1).from("GBP").to("USD")
  alert("£1 = $" + rate.toFixed(4))
}

fetch('https://api.fixer.io/latest')
  .then((resp) => resp.json())
  .then((data) => fx.rates = data.rates)
  .then(demo)

Stack

Exchange rates API is built upon Falcon to achieve high throughput. The current setup can easily handle thousands of requests per second using the Sqlite or Postgres database with Peewee ORM.

Further improvements in performance are possible with caching and in SQL base currency conversion.

For maximum performance PyPy2 is the recommended or CPython. Gunicorn as the WSGI server with Meinheld worker.

Main libraries used

• Falcon
• Peewee
• Huey
• UltraJSON

Deployment

Virtualenv

virtualenv env -p pypy

PIP

pip install -r requirements.txt --upgrade

... TODO

Database

Create database

createdb exchangerates

Create database tables

from exchangerates.models import db, ExchangeRates

with db:
  db.create_tables([ExchangeRates])

Load in initial data

Run the scheduler

The scheduler will keep your database up to date hourly with information from European Central bank. It will download the last 90 days worth of data.

Probably once a day would also be as good because the rates are updated once a day: The reference rates are usually updated around 16:00 CET on every working day, except on TARGET closing days. They are based on a regular daily concertation procedure between central banks across Europe, which normally takes place at 14:15 CET.

huey_consumer.py exchangerates.tasks.huey

Run web server

gunicorn exchangerates.api:app --workers=2 --worker-class=meinheld.gmeinheld.MeinheldWorker

Development

gunicorn exchangerates.api:app --reload

Contributing

Thanks for your interest in the project! All pull requests are welcome from developers of all skill levels. To get started, simply fork the master branch on GitHub to your personal account and then clone the fork into your development environment.

Madis Väin (madisvain on Github, Twitter) is the original creator of the Exchange Rates API framework.

License

MIT