currency-rate

Converter for fiat and crypto currencies. Currently supports BTC and LTC.

Installation

gem install currency-rate

or in Gemfile

gem "currency-rate"

Configuration

CurrencyRate.configure do |config|
    # Now only ForgeAdapter requires api key to fetch rates
    # Empty array by default
    config.api_keys["ForgeAdapter"] = "forge_api_key"

    # CurrencyRate::FileStorage configuration has only 'path' attribute
    config.file_storage[:path] = "/home/user/data" # default: ""

    # CurrencyRate uses default Logger from Ruby core library
    # It can be replaced with any compatible object
    # All logger values listed below are default
    config.logger[:device] = $stdout
    config.logger[:level] = :info
    config.logger[:formatter] = nil

    # Cryptocurrency exchange adapters to fetch
    config.crypto_adapters = ["Kraken", "Localbitcoins"]

    # Fiat exchange adapters to fetch
    config.fiat_adapters = ["Yahoo"]
end

Usage

To fetch rates from exchanges into file storage (the only supported at this moment):

CurrencyRate.sync!

This method will load all available data from exchanges and put into yml files. Failed exchanges will not create new / update exsisting files.

To get rates for Crypto/Fiat currency pair use:

CurrencyRate.fetch_crypto("Bitstamp", "BTC", "USD")

For fetching Fiat/Fiat pair:

CurrencyRate.fetch_fiat("CNY", "USD")

Details

CurrencyRate contains two parts that can work independently: Synchronizer and Fetcher. CurrencyRate::Synchronizer loads data from selected exchanges using adapters and saves it into FileStorage in normalized format. CurrencyRate::Fetch reads data from FileStorage and returns rate for requested pair and exchange.

Development

When adapter's output format changes you can replace fixtures by running bin/rake update_rates['ExchangeName']. For example bin/rake update_rates['Fixer'] will update fixtures for the FixerAdapter.

Some of adapters require API keys so the task searches for 'api_keys.ymlfile in project root. You can copy it fromapi_keys.yml.sample` and set up your values.