diff --git a/core/input.py b/core/input.py
new file mode 100644
index 0000000..1b76016
--- /dev/null
+++ b/core/input.py
@@ -0,0 +1,35 @@
+import uuid
+
+LEFT_MOUSE = 1
+MIDDLE_MOUSE = 2
+RIGHT_MOUSE = 3
+WHEEL_UP = 4
+WHEEL_DOWN = 5
+
+callbacks = {}
+
+class Object(object):
+    def __init__(self):
+        self._id = uuid.uuid4()
+
+    def id(self):
+        return self._id
+
+def register(obj, button=None, cmd=None):
+    callbacks.setdefault(obj.id(), {}).setdefault(button, []).append(cmd)
+
+def trigger(event):
+    for field in ['instance', 'name']:
+        if field in event:
+            cb = callbacks.get(event[field])
+            _invoke(event, cb)
+
+def _invoke(event, callback):
+    if not callback: return
+    if not 'button' in event: return
+
+    for cb in callback.get(event['button']):
+        if callable(cb):
+            cb(event)
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
diff --git a/core/module.py b/core/module.py
index 86cf320..85a45f4 100644
--- a/core/module.py
+++ b/core/module.py
@@ -1,6 +1,8 @@
 import importlib
 import logging
 
+import core.input
+
 log = logging.getLogger(__name__)
 
 def load(module_name, config=None):
@@ -11,8 +13,9 @@ def load(module_name, config=None):
         return Error(module_name)
     return getattr(mod, 'Module')(config)
 
-class Module(object):
+class Module(core.input.Object):
     def __init__(self, config=None, widgets=[]):
+        super().__init__()
         self._config = config
         self._widgets = widgets if isinstance(widgets, list) else [ widgets ]
         self._name = None
diff --git a/modules/datetime.py b/modules/datetime.py
index 58d586b..744498a 100644
--- a/modules/datetime.py
+++ b/modules/datetime.py
@@ -13,13 +13,13 @@ import locale
 
 import core.module
 import core.widget
+import core.input
 
 class Module(core.module.Module):
     def __init__(self, config):
         super().__init__(config, core.widget.Widget(self.full_text))
-        # TODO: register callback
-        #engine.input.register_callback(self, button=bumblebee.input.LEFT_MOUSE,
-        #                            cmd='calendar')
+
+        core.input.register(self, button=core.input.LEFT_MOUSE, cmd='calendar')
         self._fmt = self.parameter('format', self.default_format())
         l = locale.getdefaultlocale()
         if not l or l == (None, None):
diff --git a/tests/core/test_input.py b/tests/core/test_input.py
new file mode 100644
index 0000000..5399e4f
--- /dev/null
+++ b/tests/core/test_input.py
@@ -0,0 +1,37 @@
+import unittest
+
+import core.input
+
+class config(unittest.TestCase):
+    def setUp(self):
+        self.inputObject = core.input.Object()
+        self.anotherObject = core.input.Object()
+        self.someEvent = { 'button': core.input.LEFT_MOUSE, 'instance': self.inputObject.id() }
+        self.anotherEvent = { 'button': core.input.RIGHT_MOUSE, 'instance': self.inputObject.id() }
+        self.callback = unittest.mock.MagicMock()
+        self.callback2 = unittest.mock.MagicMock()
+
+    def test_callable_gets_called(self):
+        core.input.register(self.inputObject, self.someEvent['button'], self.callback)
+        core.input.trigger(self.someEvent)
+        self.callback.assert_called_once_with(self.someEvent)
+
+    def test_different_events(self):
+        core.input.register(self.inputObject, self.someEvent['button'], self.callback)
+        core.input.register(self.inputObject, self.anotherEvent['button'], self.callback)
+        core.input.register(self.anotherObject, self.someEvent['button'], self.callback2)
+        core.input.register(self.anotherObject, self.anotherEvent['button'], self.callback2)
+        core.input.trigger(self.someEvent)
+        core.input.trigger(self.anotherEvent)
+        self.callback.assert_any_call(self.someEvent)
+        self.callback.assert_any_call(self.anotherEvent)
+        self.callback2.assert_not_called()
+
+    def test_multiple_registrations(self):
+        core.input.register(self.inputObject, self.someEvent['button'], self.callback)
+        core.input.register(self.inputObject, self.someEvent['button'], self.callback2)
+        core.input.trigger(self.someEvent)
+        self.callback.assert_called_once_with(self.someEvent)
+        self.callback2.assert_called_once_with(self.someEvent)
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4