Nomics

Nomics is an API-first cryptoasset data company delivering professional-grade market data APIs to institutional crypto investors & exchanges. This gem provides simple Ruby wrappers to the Nomics.

⚠️ Note: This gem is currencly a work-in-progress with limited functionality and its interface is subject to change. For this reason, it's curently using a 0.x version number. Versioning follows the Semantic Versioning Specification (SemVer).

Installation

Add this line to your application's Gemfile:

gem 'nomics'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install nomics

Usage

First, configure Nomics. You can use the NOMICS_API_KEY env var or using a block:

Nomics.configure do |config|
  # Get an API key at https://p.nomics.com/pricing
  # This defaults to ENV['NOMICS_API_KEY']
  config.api_key = 'abcd1234'.freeze

  # If you have a free API key that is limited to one call per second,
  # you can add 2 seconds before network calls:
  config.wait_time_in_between_calls = 2
end

Getting currency data

Create a currency object and fetch some data on it

btc = Nomics::Currency.new('BTC') # also supports symbols like Nomics::Currency.new(:BTC)

Let's see some data!

btc.price
btc.name

Get all the known attributes (casted for convenience) for a given currency:

btc.attributes

You can reload the data from the Nomics API with a single call. Here's how you'd get an up-to-date price:

btc.reload.price

If a currency cannot be found, it will raise an error (once we fetch any data):

bazinga = Nomics::Currency.new('BAZINGA')
bazinga.price
# => Cannot find currency with id: BAZINGA (Nomics::UnknownCurrencyError)

Fetching multiple currencies at once

You can fetch multiple currencies using a single call and fetch all attributes:

currencies = Nomics::Currencies.new(*%w[BTC XRP ETH])
currencies.map &:attributes

If you want to view a specific set of attributes for the currencies provided, you can map over them:

currencies = Nomics::Currencies.new(*%w[ETH BTC])

currencies.map &:circulating_supply
currencies.map &:name
currencies.map &:symbol
currencies.map &:price

Alternatively you simply just pluck these (similar to how ActiveRecord works)

currencies.pluck :circulating_supply, :name, :symbol, :price

Retrieving currencies in given fiat

Retrieving a specific cryptocurrency in a specific fiat currency can also be done. This will quote ticker price, market cap, and volume in the specified currency:

btc_in_zar = Nomics::Currency.new('BTC', convert: 'EUR')
eth_in_usd = Nomics::Currency.new('ETH', convert: 'USD')
eth_in_usd = Nomics::Currency.new('ETH') # convert defaults to USD

Calculating the price of one cryptocurrency from another

Advanced calculations are yet under consideration for this gem, but you can calculate prices using the data from Nomics anyway. For example to calcculate the ETH to BTC price (in relation to their dollar value), fetch the prices in USD (default) and run a simple division:

btc_price_in_usd = Nomics::Currency.new('BTC').price.to_f # Nomics API defaults to USD
eth_price_in_usd = Nomics::Currency.new('ETH').price.to_f # Nomics API defaults to USD

eth_price_in_btc = eth_price_in_usd / btc_price_in_usd

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/attilagyorffy/nomics.rb.

attilagyorffy / nomics.rb