diff --git a/composer/interfaces.py b/composer/interfaces.py
index 028cbda..b3297eb 100644
--- a/composer/interfaces.py
+++ b/composer/interfaces.py
@@ -58,7 +58,7 @@ class ITemplate(Interface):
 # instances
 
 class IInstance(Interface):
-    """ Represents (adapts) an object that uses a template.
+    """ Represents (adapts) an object (a client) that uses a template.
     """
 
     context = Attribute('Object this instance adapter has been created for')
diff --git a/composer/schema/client.py b/composer/schema/client.py
new file mode 100644
index 0000000..b769fd9
--- /dev/null
+++ b/composer/schema/client.py
@@ -0,0 +1,51 @@
+#
+#  Copyright (c) 2007 Helmut Merz helmutm@cy55.de
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software
+#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+"""
+Client implementations.
+
+$Id$
+"""
+
+from zope.component import adapts
+from zope.interface import implements
+
+from cybertools.composer.schema.interfaces import IClient
+from cybertools.composer.schema.interfaces import IClientManager, IClientFactory
+
+
+class Client(object):
+
+    implements(IClient)
+
+    def __init__(self, manager):
+        self.manager = manager
+
+
+class ClientFactory(object):
+
+    implements(IClientFactory)
+    adapts(IClientManager)
+
+    def __init__(self, context):
+        self.context = context
+
+    def __call__(self):
+        return Client(self.context)
+
+
diff --git a/composer/schema/instance.py b/composer/schema/instance.py
index be3b909..5d25db0 100644
--- a/composer/schema/instance.py
+++ b/composer/schema/instance.py
@@ -17,14 +17,18 @@
 #
 
 """
-Client classes for schemas.
+Instance adapter classes for schemas.
 
 $Id$
 """
 
+from BTrees.OOBTree import OOBTree
+from zope.component import adapts
 from zope.interface import implements
 
 from cybertools.composer.instance import Instance
+from cybertools.composer.interfaces import IInstance
+from cybertools.composer.schema.interfaces import IClient
 
 
 class Editor(Instance):
@@ -39,3 +43,34 @@ class Editor(Instance):
             # or directly use request...
             print c.name, getattr(self.context, c.name, '-')
 
+
+class ClientInstanceAdapter(object):
+
+    implements(IInstance)
+    adapts(IClient)
+
+    baseAspect = 'schema.client.'
+    schema = 'default'
+
+    @property
+    def aspect(self):
+        return self.baseAspect + self.schema
+
+    @property
+    def template(self):
+        return self.context.manager.clientSchemas.get(self.schema, None)
+
+    def __init__(self, context):
+        self.context = context
+
+    def applyTemplate(self, data={}, schema='default', **kw):
+        if getattr(self.context, 'attributes', None) is None:
+            self.context.attributes = OOBTree()
+        self.schema = schema
+        template = self.template
+        attributes = self.context.attributes.setdefault(self.aspect, OOBTree())
+        if template is not None:
+            for c in template.components:
+                name = c.name
+                attributes[name] = data.get(name, u'')
+
diff --git a/composer/schema/interfaces.py b/composer/schema/interfaces.py
index 4826ef9..467b0e3 100644
--- a/composer/schema/interfaces.py
+++ b/composer/schema/interfaces.py
@@ -73,3 +73,32 @@ class IField(IComponent):
                     description=_(u'Must a value been entered into this field?'),
                     required=False,)
 
+
+# clients
+
+class IClient(Interface):
+    """ An fairly abstract interface for objects to be used as clients
+        for other objects (e.g. services).
+    """
+
+    manager = Attribute('The object that cares for this client.')
+
+
+class IClientFactory(Interface):
+    """ Creates client objects.
+    """
+
+    def __call__():
+        """ Creates and returns a client object.
+        """
+
+
+class IClientManager(Interface):
+    """ Cares for a client typically providing schemas.
+    """
+
+    clientSchemas = Attribute('A collection of schema objects '
+                        'that describe the data fields of the client '
+                        'objects.')
+
+