btcx

Handling of Multiple Bitcoin (and other cryptocurrencies) Exchanges

Can I run it ?

The minimum expected version for Python is 2.6, but deps.sh uses Python 2.7 by default (adjust it if needed). If you are not sure that you have the dependencies installed, run ./deps.sh and the basic packages will be installed in the dep/ directory. If this is being executed under Windows, then create a deps.bat adjusting the code in deps.sh.

After running ./deps.sh, do (the equivalent of) the following:

$ PYTHONPATH=dep python2.7

>>> import btcx
>>>

If no messages are shown, then you can run it. Next, two simple examples are presented in a wordy fashion assuming some knowledge of event-driven systems.

Two very simple examples

Our first example will query certain currencies through the Streaming API from MtGox. This involves importing btcx

import btcx

creating a MtGox client

client = btcx.mtgox.create_client()

telling the client to listen for "currency_info" events, which will call into a function whenever they are emitted. To do this, first create a function to handle such event and then define the listener

def got_currency(data):
    print (u"{name:17}: {symbol:4}   "
           u"Decimals : {decimals}   "
           u"Virtual : {virtual}".format(**data))

client.evt.listen('currency_info', got_currency)

In this example we will query the symbols 'EUR', 'BTC', 'JPY', 'AUD', and 'LTC'

currencies = ['EUR', 'BTC', 'JPY', 'AUD', 'LTC']

for each one of them, we need to call the "currency_info" method that becomes available after the client connects. This is handled by using the call method from the client, which by default waits for a "connected" event and then makes the requested call.

for currency in currencies:
    client.call('currency_info', currency, once=True)
    print "Will ask for %s" % currency

Finally we start the event loop and things actually start happening

btcx.run()

Note that the example is very short, do not let the step-wise build fool you. You will observe that every call returns immediately, this is mainly due to how Twisted works. This example (and also the following) will run forever, you can finish it by pressing Ctrl+C.

The second example requires authentication in order to request the pending orders as well live updates as the user orders are modified. If this is the first time running the following example, pass a "-n" argument and the function obtain_key_secret will first ask for a new API key/secret pair. Your secret will go through scrypt before being stored, so a password is required for later decrypting it. The password is not stored anywhere and forgetting it practically means the API secret is lost (i.e., not recoverable).

import sys

import btcx

def show_userorder(order):
	print order

key, secret = btcx.cfgmanager.obtain_key_secret(sys.argv[1:])
client = btcx.mtgox.create_client(key, secret)
client.evt.listen('userorder', show_userorder)
client.call('order_list')

btcx.run()

Other examples involving different exchanges and other features are presented in

• demo_1.py plots live trades from MtGox, BTC-e, Bitstamp, and BTCChina

• demo_2.py fetches MtGox trades and stores in a sqlite database

• demo_4.py does a candlestick plot together with trade volume from MtGox. This will load and store data as needed. It combines live trades through the Streaming API, stored trades in the database, and also fetching older trades through the MtGox's HTTP API.

• demo_7.py plots the depth market. The demo starts by fetching partial data, and then corrects it as live changes are received.

Executing ./run.sh is a good way to check if every package used is available.

Dependencies

• Every API secret is encrypted through scrypt, and then stored.

• This project relies on Twisted for proper network communication. The Autobahn library provides a WebSocket client for using the MtGox Streaming API. For other API calls through HTTP(S) (this includes fetching some public data from MtGox, and also the entire BTC-e and Bitstamp APIs), the treq package is used in order to keep a clean interface to the requests.

• Qt, Numpy, and Matplotlib are used for the GUI/plotting in the current demos. These dependencies are not installed through deps.sh.

Demo

Bitcoin Donations

1BTCXAPHWyFheYWzM3mbWztEaX8GqCXiH3