ExchangeWrapper

ExchangeWrapper is a Ruby Gem that attempts to come up with a standardized set of methods that can be used to obtain data from Cryptocurrency exchanges.

Refer to the Methods section below for a list of the methods, example usage, and example return format.

If you have any issues or if you’d like to contribute please visit the Contributing section below.

Exchange Progress Table

This table shows the methods that are supported per exchange.

Exchange	#holdings	#symbols	#trading_pairs	#prices	#metadata	#volume	#backfill	#orders
Binance	✔	✔	✔	✔	✔	✔	Hard	?
Bitstamp	?	✔	✔	✔	✔	✔	✘	?
Bittrex	✔	✔	✔	✔	✔	✔	Hard	?
CEX.io	?	✔	✔	✔	✔	✔	Easy	?
Coinbase	✔	✘	✘	✘	✘	✘	✘	?
COSS.io	✘	✘	✘	✘	✘	✘	✘	✘
Cryptopia	?	✔	✔	✔	✔	✔	✘	?
Gate.io	?	✔	✔	✔	✔	✔	Easy	?
GDAX	✔	✔	✔	✔	✔	✔	Easy	?
Gemini	✔	✔	✔	✔	✔	✔	Easy	?
Kraken	?	✔	✔	✔	✔	✔	Easy	?
KuCoin	?	✔	✔	✔	✔	✔	Hard	?
Mercatox	✘	✔	✔	✔	✔	✔	✘	✘
Poloniex	?	✔	✔	✔	✔	✔	Easy	?

Notes

Coinbase doesn’t support methods outside of #holdings (get the data via GDAX) and even then #holdings should be converted to utilize OAuth instead of API Key/Secret.
COSS.io doesn’t have an API yet…
#backfill isn’t implemented yet so it is an estimation (Easy/Hard) of the difficulty needed in order to support it.
#orders isn’t implemented yet but this shouldn’t be so challenging, left it ambiguous (?) for now.

Installation

Add this line to your application’s Gemfile:

gem 'exchange_wrapper'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install exchange_wrapper

Methods

`#holdings(key, secret)`

```
  ::Utils.holdings(key, secret)
```

  {
    'BTC': 4.311689,
    'ETH': 0.877610923,
    'LTC': 25.10899999
  }

Symbols cannot be nil values and amounts cannot be 0 values (returns only symbols with non-zero amount values)
Does not account for locked funds
GDAX requires a passphrase in addition to a key and secret

`#symbols`

```
  ::Utils.symbols
```

  [
    'BTC',
    'ETH',
    'LTC',
    'NANO',
    'TRX'
  ]

Alphabetically ordered, no nil values returned
GDAX requires a key, secret, and passphrase

`#trading_pairs`

```
  ::Utils.trading_pairs
```

  [
    ['ADA/BTC', 'ADA', 'BTC'],
    ['AST/ETH', 'AST', 'ETH'],
    ['ENJ/BTC', 'ENJ', 'BTC'],
    ['NULS/BNB', 'NULS', 'BNB'],
    ['ZIL/ETH', 'ZIL', 'ETH']
  ]

Alphabetically ordered by trading pair, no nil values returned
GDAX requires a key, secret, and passphrase

`#prices`

```
  ::Utils.prices
```

  [
    {"symbol":"BCH/BTC","price":"0.11030000"},
    {"symbol":"EVX/BTC","price":"0.00018065"},
    {"symbol":"QSP/BNB","price":"0.02124000"},
    {"symbol":"SUB/ETH","price":"0.00053616"}
  ]

Symbol and price must be non nil values returned
GDAX requires a key, secret, and passphrase

`#metadata`

```
  ::Utils.metadata
```

  [
    {"symbol":"BCH/BTC",...},
    {"symbol":"BTC/USD",...},
    {"symbol":"ETH/EUR",...},
    {"symbol":"ETH/USD",...},
    {"symbol":"LTC/BTC",...}
  ]

Symbol must be non nil, all other values are subject to the API
This data structure is NOT uniform between APIs/across exchanges
This may be split into a sub-method for capturing volume in the future
GDAX requires a key, secret, and passphrase

`#volume`

    ::ExchangeWrapper::Cexio::Utils.volume

  [
    {"symbol":"BTC/USD","base_volume":"1335.28640364","quote_volume":"10558777.2367833"},
    {"symbol":"ETH/USD","base_volume":"2894.99957400","quote_volume":"1595144.765274"},
    {"symbol":"BCH/USD","base_volume":"283.50156497","quote_volume":"270176.99141641"}
  ]

Symbol, base_volume, and quote_volume must be non nil values returned
CEX.io & GDAX quote_volume is an ESTIMATE using the low price (no quote_volume or vwap provided)
GDAX requires a key, secret, and passphrase

`#backfill`

coming soon
Looks like this may not be implemented/doesn’t function for… Bitstamp, Cryptopia, and Mercatox

`#orders`

coming soon
Looks like this may not be implemented/doesn’t function for… Mercatox

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/ChalupaIO/exchange_wrapper. Please fork the gem, make your changes in your fork, then create a PR to this repo.

If you’d like to contact me about something I am reachable at eric@chalupa.io.

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.
(Admin only) 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 tags, and push the .gem file to rubygems.org.