diff --git a/client-barcode/freitagskasse.py b/client-barcode/freitagskasse.py
index 20381a3..d1ec0e0 100644
--- a/client-barcode/freitagskasse.py
+++ b/client-barcode/freitagskasse.py
@@ -5,6 +5,7 @@
 # Licensed under GPL v3 or later
 
 from __future__ import print_function
+import freitagslib.network as net
 
 import sys
 import decimal
diff --git a/client-barcode/freitagslib/__init__.py b/client-barcode/freitagslib/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/client-barcode/freitagslib/item.py b/client-barcode/freitagslib/item.py
new file mode 100644
index 0000000..7c3ef35
--- /dev/null
+++ b/client-barcode/freitagslib/item.py
@@ -0,0 +1,14 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2011 Sebastian Pipping <sebastian@pipping.org>
+# Licensed under GPL v3 or later
+
+from decimal import Decimal
+
+class Item:
+	def __init__(self, d):
+		self.deposit = Decimal(d['deposit'])
+		self.id = int(d['id'])
+		self.name = d['name']
+		self.price = Decimal(d['price'])
diff --git a/client-barcode/freitagslib/network.py b/client-barcode/freitagslib/network.py
new file mode 100644
index 0000000..0cf9b9b
--- /dev/null
+++ b/client-barcode/freitagslib/network.py
@@ -0,0 +1,107 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2011 Sebastian Pipping <sebastian@pipping.org>
+# Licensed under GPL v3 or later
+
+from __future__ import print_function
+import urllib
+import urllib2
+import simplejson as json
+from decimal import Decimal
+import os
+
+if __name__ == '__main__':
+	import sys
+	sys.path.append('.')
+from freitagslib.item import Item
+from freitagslib.tools import require_type
+
+
+DEPOSIT_CASH = 1
+DEPOSIT_BANK = 2
+
+
+_BASE_URL = 'http://devcat.someserver.de:13805/api2/'
+
+
+def _make_auth_opener(username, password):
+	password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
+	password_mgr.add_password(None, _BASE_URL, username, password)
+	handler = urllib2.HTTPBasicAuthHandler(password_mgr)
+	return urllib2.build_opener(handler)
+	
+_auth_opener = _make_auth_opener(os.environ['BARCODE_PLUGIN_USER'], os.environ['BARCODE_PLUGIN_PASS'])
+
+
+def _request(api_rel_url, para_map, method):
+	url = _BASE_URL + api_rel_url
+	data = urllib.urlencode(para_map)
+
+	if method == 'GET':
+		url = '%s?%s' % (url, data)
+		req = urllib2.Request(url)
+	elif method == 'POST':
+		req = urllib2.Request(url, data)
+	else:
+		raise ValueError('Unsupported method "%s"' % method)
+
+	response = _auth_opener.open(req)
+	return response.read()
+
+
+def get_user_name_from_auth_blob(authblob):
+	content = _request('auth/user/', {'authblob':authblob}, method='GET')
+	d = json.loads(content)
+	return d['username']
+
+
+def buy_item(item_id, user_name):
+	require_type(int, item_id)
+
+	content = _request('buyable/item/' + urllib.quote(str(item_id)),
+			{'user':user_name, 'deposit':0, 'amount':1}, method='POST')
+	if content != 'Created':
+		raise ValueError('Server says "%s"' % content)
+
+
+def get_item(item_id):
+	require_type(int, item_id)
+
+	content = _request('buyable/item/' + urllib.quote(str(item_id)),
+			{}, method='GET')
+	d = json.loads(content)
+	return Item(d)
+	
+
+def get_balance(user_name):
+	content = _request('account/balance/',
+			{'user':user_name}, method='GET')
+	d = json.loads(content)
+	return Decimal(d['balance'])
+
+
+def deposit(amount, transaction_type, user_name):
+	require_type(Decimal, amount)
+	require_type(int, transaction_type)
+
+	content = _request('account/transactions/transact/',
+			{'user':user_name, 'amount':amount, 'type':transaction_type}, method='POST')
+	if content != 'OK':
+		raise ValueError('Server says "%s"' % content)
+
+
+if __name__ == '__main__':
+	user_name = get_user_name_from_auth_blob(os.environ['BARCODE_PLUGIN_TEST_AUTH_BLOB'])
+	print('User name: ' + user_name)
+
+	buy_item(1, user_name)
+
+	balance = get_balance(user_name)
+	print('Balance is %f, type is "%s"' % (balance, type(balance).__name__))
+
+	deposit(Decimal('0.01'), DEPOSIT_CASH, user_name)
+	deposit(Decimal('0.01'), DEPOSIT_BANK, user_name)
+
+	item = get_item(1)
+	print('Item "%s" is %f Euro each' % (item.name, item.price))
diff --git a/client-barcode/freitagslib/tools.py b/client-barcode/freitagslib/tools.py
new file mode 100644
index 0000000..a5399e9
--- /dev/null
+++ b/client-barcode/freitagslib/tools.py
@@ -0,0 +1,14 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2011 Sebastian Pipping <sebastian@pipping.org>
+# Licensed under GPL v3 or later
+
+def _raise_type_error(value, wanted, got):
+	raise TypeError('Value <%s> is of type "%s" but type "%s" is required' \
+			% (str(value), wanted.__name__, got.__name__))
+
+def require_type(wanted, value):
+	got = type(value)
+	if not got is wanted:
+		_raise_type_error(value, wanted, got)