In kaneplusplus/bittrex: Client for the Bittrex Exchange

Introduction

Package 'bittrex' is an R implementation of the REST interface used by the Bittrex crypto-currency exchange. It provides functions for endpoints supported by the exchange. This includes the ability to retrieve price, volume, and orderbook information as well as the ability to trade crypto-currencies.

Calls to the exchange are categorized as either public, which includes requests for price, volume, and order book information, and private, which includes all requests requiring an account including placing buy or sell orders. Public calls can be used directly by installing the package. Private calls require that you create an account and create an API and secret key with appropriate permissions.

Installing the Package.

The package is available from GitHub and will be uploaded to CRAN shortly. If you wish to install the development version then install the devtools package, available from CRAN.

#install.packages("devtools")
devtools::install_github("kaneplusplus/bittrex")

Using the Public Interface

The public interface to the exchange allows you to get market-level data including price, volume, and order book information. The following function are supported via the public interface:

bt_getcurrencies:all supported currencies at Bittrex along with other meta data
bt_getmarkethistory:the latest trades that have occured for a specified market
bt_getmarkets:the open and available trading markets at Bittrex along with other meta data
bt_getmarketsummaries:the last 24 hour summary of all active exchanges
bt_getmarketsummary:the last 24 hour summary of all active exchanges
bt_getorderbook:the orderbook for a given market
bt_getticker:the current tick values for a market

Each of these functions returns a named list. The first element, success, is a boolean value indicating whether or not the function call was succesful. The second element, message, provides an error message if the call was not successful. The third element, result is the result of the function call.

The following sections provide simple examples using the bittrex package with popular visualization and finance packages.

Visualizing All Trading Pairs

There are currently 261 unique currencies listed on the exchange. However, this does not imply that there are ${261 \choose 2}=33930$ markets. Many of the currencies do not have the volume required for a viable market. To understand the structure of the available markets, we can use a graphical model to visualize which currencies may be traded. The following code creates the graph and creates an interactive visualization using Bryan Lewis' threejs library. Note that the result graph supports "spinning" the graph as well as "zooming in" on vertices of interest.

# Create a function to load libraries quietly.
shut_up = function(load_lib) {
  suppressWarnings(suppressPackageStartupMessages(load_lib))
}

# Load the libraries quietly.
shut_up(library(bittrex))
shut_up(library(threejs))
shut_up(library(tidyverse))
shut_up(library(igraph))

# Create a graph of the crypo-currency markets.
currency_graph = bt_getmarkets()$result[,1:2] %>% graph_from_data_frame 
threejs::graphjs(currency_graph, vertex.size=0.5, vertex.label=V(currency_graph)$name, edge.width=0.25)

The visualization shows that BTC acts as a "hub." Other currencies, like ETC is connected to a few other currencies. Trading between thinly traded currencies are performed by trading through hub currencies only.

Visualizing Price Data with Quantmod

The public interface also supports the retrieval of traditional currency-market information, including price and volume data. The bt_getmarkethistory extracts the last 200 transactions on a specified market. In this example, the price and volume of Bitcoin trades in U.S. dollars is turned into an xts time-series object and visualized using Jeffrey Ryan's quantmod package.

shut_up(library(quantmod))

# Get the recent history of the btc-eth market.
btc_eth_df = bt_getmarkethistory("btc-eth")$result
btc_eth = btc_eth_df %>% select(price, quantity) %>% 
  xts(order.by=btc_eth_df$time_stamp)
names(btc_eth)[2] = "volume"

# Chart the recent price history.
chartSeries(btc_eth)

The price of Etherium, in Bitcoins is shown in the top half of the graph. Changes in prices are associated with individuals buying (and selling) Etherium at a specified price. The quantity of Etherium bought (and sold) is shown in the bottom half of the graph.

Visualizing the Order Book with ggplot2

The package also allows users to find orders for a given market. That is, the amount of Etherium an individual would like to buy or sell along with the associated price he or she would like. A "buy" order is a request to buy a specified quantity of Etherium at a specified price and a sell is a request to sell Etherium with analogous constraints. The difference between the higest buy order and the lowest sell order is called the spread. The set of buy and sell orders is called the order book. The order book is visualized below using Hadley Wickam's ggplot2 package.

# Create a data.frame frome the "buy" and "sell" orders.
btc_eth = bt_getorderbook("btc-eth")$result

# Plot the order book.
ggplot(btc_eth[btc_eth$rate > 1e-5,], aes(x=rate, y=quantity, group=type, color=type, fill=type)) + 
  geom_bar(stat="identity") + xlab("Price") +
  ylab("Order Size") + scale_fill_discrete(name = "Order Type") + 
  scale_color_discrete(guide=FALSE)

From the price information in the previous section we know that Etherium were being sold for about 0.074 Bitcoins. The order book visualization shows support around this point but also shows a large buy order at a very low price as well as a large sell order when one Etherium is half the prices of one Bitcoin.

Using the Private Interface

Diclaimer: This software is in no way affiliated, endorsed, or approved by the Bittrex crypto-currency exchange or any of its affiliates. It comes with absolutely no warranty and should not be used in actual trading unless the user can read and understand the source and know what you are doing.

The private interface allows users to trade in crypto-currencies on the exchange. Private calls require that you create an account and create an API and secret key with appropriate permissions. These keys allow the user to successfully call the following functions:

bt_authenticate: provide user authentication data
bt_buy: place a buy limit order
bt_cancel: cancel buy or sell order
bt_getbalances: account balances for currencies
bt_getbalance: account balance for a specified currency
bt_getdepositaddress: retrieve or generate an address for a specific currency
bt_getdeposithistory: retrieve your deposit history
bt_getopenorders: order data for all open orders
bt_getorder: retrieve a single order by uuid
bt_getorderhistory: recent order history for an account
bt_getwithdrawlhistory: retrieve your withdrawal history
bt_sell: place a sell limit order
bt_withdraw: withdraw funds from your account

Private calls retrieve the API and secret key using the BITTREX_API_KEY and BITTREX_SECRET_KEY environment variables. These may be set by the user before opening the R session or, they can be set using the 'bittrex_authenticate' function.

Trades are initiated using either the bt_buy or bt_sell functions. These functions return a uuid in the result element that uniquely identifies the order. The order is cancelled using the order function. The order is complete when any of the follwing are true:

no result is returned by the bt_getorder function with the corresponding uuid
the order does not appear in the data.frame returned by bt_getopenorders
the order appears in the data.frame returned by bt_getorderhistory or bt_getorder.