diff --git a/test/api/__init__.py b/test/api/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/test/api/autopath.py b/test/api/autopath.py
new file mode 100644
index 0000000..f970eb4
--- /dev/null
+++ b/test/api/autopath.py
@@ -0,0 +1,14 @@
+"""automatically sets the PYTHONPATH before running the unit tests
+
+This is supposed to be used in development mode (i.e. testing from a fresh
+checkout)
+"""
+
+from os.path import dirname, abspath, join, normpath
+import sys
+
+def do_autopath():
+    HERE = dirname(abspath(__file__))
+    PATH = normpath(join(HERE, '..', '..', 'tiramisu'))
+    if PATH not in sys.path:
+        sys.path.insert(1, PATH)
diff --git a/test/api/test_owner.py b/test/api/test_owner.py
new file mode 100644
index 0000000..b446b5b
--- /dev/null
+++ b/test/api/test_owner.py
@@ -0,0 +1,820 @@
+"""test API to get/set owner
+"""
+import pytest
+from py.test import raises
+from .autopath import do_autopath
+do_autopath()
+from tiramisu import Config, StrOption, OptionDescription, MasterSlaves, DynOptionDescription, \
+                     getapi
+from tiramisu.error import PropertiesOptionError
+ICON = u'\u2937'
+
+OPTIONS_TYPE = {'str': {'type': str,
+                        'option': StrOption}
+                }
+PROPERTIES = ['hidden', 'disabled']
+
+
+def return_list(val=None, suffix=None):
+    if val:
+        return val
+    else:
+        return ['val1', 'val2']
+
+
+def display_info(func):
+    def wrapper(*args, **kwargs):
+        print(u'\n{} {}'.format(ICON, func.__name__))
+        return func(*args, **kwargs)
+    return wrapper
+
+
+autocheck_registers = []
+
+
+def autocheck(func):
+    autocheck_registers.append(func)
+    def wrapper(*args, **kwargs):
+        if kwargs.get('display', True):
+            print(u'  {} {}'.format(ICON, func.__name__))
+        return func(*args, **kwargs)
+    return wrapper
+
+
+@autocheck
+def autocheck_owner_without_value(api, path, **kwargs):
+    """check different value of owner when any value is set to this option
+    """
+    try:
+        isslave = api.permissive.option.isslave(path)
+    except:
+        isslave = False
+    # check if owner is a string "default"
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        assert api.owner.get(path) == 'default'
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.owner.get(path)")
+        else:
+            raises(PropertiesOptionError, "api.owner.get(path, 0)")
+    if not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert api.permissive.owner.get(path) == 'default'
+        else:
+            assert api.permissive.owner.get(path, 0) == 'default'
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.permissive.owner.get(path)")
+        else:
+            raises(PropertiesOptionError, "api.permissive.owner.get(path, 0)")
+
+    # check if default owner
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        assert api.owner.isdefault(path)
+    else:
+        raises(PropertiesOptionError, "api.owner.isdefault(path)")
+    if not kwargs.get('propertyerror', False):
+        assert api.permissive.owner.isdefault(path)
+    else:
+        raises(PropertiesOptionError, "api.permissive.owner.isdefault(path)")
+
+
+@autocheck
+def autocheck_value(api, path, **kwargs):
+    """set and get values
+    """
+    print('=============')
+    try:
+        print(api.permissive.owner.get(path))
+    except Exception as pouet:
+        try:
+            print(api.permissive.owner.get(path, 0))
+        except Exception as pouet:
+            print(pouet)
+            pass
+    # check if is a multi, a master or a slave
+    if not kwargs.get('propertyerror', False):
+        multi = api.permissive.option.ismulti(path)
+        ismaster = api.permissive.option.ismaster(path)
+        isslave = api.permissive.option.isslave(path)
+    else:
+        raises(PropertiesOptionError, "api.permissive.option.ismulti(path)")
+        multi = False
+        ismaster = False
+        isslave = False
+
+    # set default value (different if value is multi or not)
+    if not multi:
+        first_value = 'myvalue'
+        second_value = 'myvalue1'
+    else:
+        first_value = ['myvalue']
+        second_value = ['myvalue', 'myvalue1']
+    if multi and not isslave:
+        empty_value = []
+    else:
+        empty_value = None
+
+    # test default value (should be empty) without permissive
+    # cannot test for slave (we cannot get all values for a slave)
+    if not isslave:
+        if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+            assert api.value.get(path) == empty_value
+        else:
+            raises(PropertiesOptionError, "api.value.get(path)")
+
+    # test default value (should be empty) with permissive
+    # cannot test for slave (we cannot get all values for a slave)
+    if not isslave:
+        if not kwargs.get('propertyerror', False):
+            assert api.permissive.value.get(path) == empty_value
+        else:
+            raises(PropertiesOptionError, "api.permissive.value.get(path)")
+
+    # set a value without permissive
+    # for master/slave should have an index and good length
+    # for master must append, not set
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if ismaster:
+            raises(IndexError, "api.value.set(path, 0, first_value[0])")
+            api.value.append(path, first_value[0])
+        elif isslave:
+            #FIXME
+            print(api.value.append(path, first_value[0]))
+            raises(PropertiesOptionError, "api.value.append(path, first_value[0])")
+            api.value.set(path, 0, first_value[0])
+            raise Exception('pouet')
+        else:
+            api.value.set(path, first_value)
+    else:
+        if ismaster:
+            raises(PropertiesOptionError, "api.value.append(path, first_value[0])")
+        elif isslave:
+            raises(PropertiesOptionError, "api.value.set(path, 0, first_value[0])")
+        else:
+            raises(PropertiesOptionError, "api.value.set(path, first_value)")
+
+    # get value after set value without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if isslave:
+            assert api.value.get(path, 0) == first_value[0]
+        else:
+            assert api.value.get(path) == first_value
+    elif kwargs.get('permissive', False):
+        if isslave:
+            raises(PropertiesOptionError, "api.value.get(path, 0)")
+            assert api.permissive.value.get(path, 0) == empty_value
+        else:
+            raises(PropertiesOptionError, "api.value.get(path)")
+            assert api.permissive.value.get(path) == empty_value
+    else:
+        if isslave:
+            raises(PropertiesOptionError, "api.value.get(path, 0)")
+            raises(PropertiesOptionError, "api.permissive.value.get(path, 0)")
+        else:
+            raises(PropertiesOptionError, "api.value.get(path)")
+            raises(PropertiesOptionError, "api.permissive.value.get(path)")
+
+    # set a value with permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if ismaster:
+            raises(IndexError, "api.permissive.value.set(path, 1, second_value[1])")
+            api.permissive.value.append(path, second_value[1])
+        elif isslave:
+            #FIXME
+            raises(PropertiesOptionError, "api.permissive.value.append(path, second_value[1])")
+            api.value.set(path, 1, second_value[1])
+            raise Exception('ca entre ici')
+        else:
+            api.value.set(path, second_value)
+    elif kwargs.get('permissive', False):
+        if ismaster:
+            api.permissive.value.append(path, second_value[0])
+            api.permissive.value.append(path, second_value[1])
+        elif isslave:
+            api.permissive.value.set(path, 1, second_value[1])
+        else:
+            api.permissive.value.set(path, first_value)
+    else:
+        if ismaster:
+            raises(PropertiesOptionError, "api.permissive.value.append(path, first_value[0])")
+        elif isslave:
+            raises(PropertiesOptionError, "api.permissive.value.set(path, 0, first_value[0])")
+        else:
+            raises(PropertiesOptionError, "api.permissive.value.set(path, first_value)")
+
+    # get value after set value with permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if isslave:
+            assert api.value.get(path, 0) == second_value[0]
+            assert api.value.get(path, 1) == second_value[1]
+        else:
+            assert api.value.get(path) == second_value
+    elif kwargs.get('permissive', False):
+        if ismaster:
+            raises(PropertiesOptionError, "api.value.get(path)")
+            assert api.permissive.value.get(path) == second_value
+        elif isslave:
+            raises(PropertiesOptionError, "api.value.get(path, 0)")
+            raises(PropertiesOptionError, "api.value.get(path, 1)")
+            assert api.permissive.value.get(path, 1) == second_value[1]
+        else:
+            raises(PropertiesOptionError, "api.value.get(path)")
+            assert api.permissive.value.get(path) == first_value
+    else:
+        if isslave:
+            raises(PropertiesOptionError, "api.value.get(path, 0)")
+            raises(PropertiesOptionError, "api.permissive.value.get(path, 0)")
+        else:
+            raises(PropertiesOptionError, "api.value.get(path)")
+            raises(PropertiesOptionError, "api.permissive.value.get(path)")
+    print('=============')
+    try:
+        print(api.permissive.owner.get(path))
+    except Exception as pouet:
+        try:
+            print(api.permissive.owner.get(path, 0))
+        except Exception as pouet:
+            print(pouet)
+            pass
+
+
+@autocheck
+def autocheck_reset_value(api, path, **kwargs):
+    # check if is a multi, a master or a slave
+    if not kwargs.get('propertyerror', False):
+        multi = api.permissive.option.ismulti(path)
+        ismaster = api.permissive.option.ismaster(path)
+        isslave = api.permissive.option.isslave(path)
+    else:
+        raises(PropertiesOptionError, "api.permissive.option.ismulti(path)")
+        multi = False
+        ismaster = False
+        isslave = False
+
+    # set default value (different if value is multi or not)
+    if not multi:
+        first_value = 'myvalue'
+        second_value = 'myvalue1'
+    else:
+        first_value = ['myvalue']
+        second_value = ['myvalue', 'myvalue1']
+    if multi and not isslave:
+        empty_value = []
+    else:
+        empty_value = None
+
+    # reset value without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if not isslave:
+            api.value.reset(path)
+        else:
+            api.value.reset(path, 0)
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.value.reset(path)")
+        else:
+            raises(PropertiesOptionError, "api.value.reset(path, 0)")
+
+    # get value after reset value without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if isslave:
+            assert api.value.get(path, 0) == empty_value
+            assert api.value.get(path, 1) == second_value[1]
+        else:
+            assert api.value.get(path) == empty_value
+    elif kwargs.get('permissive', False):
+        if isslave:
+            raises(PropertiesOptionError, "api.value.get(path, 0)")
+            assert api.permissive.value.get(path, 0) == empty_value
+            assert api.permissive.value.get(path, 1) == second_value[1]
+        else:
+            raises(PropertiesOptionError, "api.value.get(path)")
+            assert api.permissive.value.get(path) == first_value
+
+    # reset value with permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if not isslave:
+            api.permissive.value.reset(path)
+        else:
+            api.permissive.value.reset(path, 1)
+    elif kwargs.get('permissive', False):
+        if not isslave:
+            api.permissive.value.reset(path)
+        else:
+            api.permissive.value.reset(path, 1)
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.permissive.value.reset(path)")
+        else:
+            raises(PropertiesOptionError, "api.permissive.value.reset(path, 1)")
+
+    # get value after reset value with permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if isslave:
+            assert api.value.get(path, 0) == empty_value
+            assert api.value.get(path, 1) == empty_value
+        else:
+            assert api.value.get(path) == empty_value
+    elif kwargs.get('permissive', False):
+        if isslave:
+            raises(PropertiesOptionError, "api.value.get(path, 0)")
+            raises(PropertiesOptionError, "api.value.get(path, 1)")
+            assert api.permissive.value.get(path, 0) == empty_value
+            assert api.permissive.value.get(path, 1) == empty_value
+        else:
+            raises(PropertiesOptionError, "api.value.get(path)")
+            assert api.permissive.value.get(path) == empty_value
+
+
+@autocheck
+def autocheck_value2(*args, **kwargs):
+    """reset value
+    """
+    autocheck_value(*args, **kwargs)
+
+
+@autocheck
+def autocheck_property(api, path, **kwargs):
+    """get property from path
+    """
+    # check if is a multi or a slave
+    if not kwargs.get('propertyerror', False):
+        multi = api.permissive.option.ismulti(path)
+        isslave = api.permissive.option.isslave(path)
+    else:
+        raises(PropertiesOptionError, "api.permissive.option.ismulti(path)")
+        raises(PropertiesOptionError, "api.permissive.option.isslave(path)")
+        multi = False
+        isslave = False
+
+    # define properties
+    properties = ['prop1', 'prop2']
+    if multi and not isslave:
+        default_props = ['empty']
+        properties.append('empty')
+    else:
+        default_props = []
+    extra_properties = kwargs.get('extra_properties')
+    if extra_properties:
+        properties.extend(extra_properties)
+        default_props.extend(extra_properties)
+    properties = tuple(properties)
+
+    # get properties without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert set(api.property.get(path)) == set(default_props)
+        else:
+            assert set(api.property.get(path, 0)) == set(default_props)
+            assert set(api.property.get(path, 1)) == set(default_props)
+    else:
+        raises(PropertiesOptionError, "api.property.get(path)")
+
+    # get properties with permissive
+    if not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert set(api.permissive.property.get(path)) == set(default_props)
+        else:
+            assert set(api.permissive.property.get(path, 0)) == set(default_props)
+            assert set(api.permissive.property.get(path, 1)) == set(default_props)
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.permissive.property.get(path)")
+        else:
+            raises(PropertiesOptionError, "api.permissive.property.get(path, 0)")
+
+    # set properties without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        api.property.set(path, properties)
+    else:
+        raises(PropertiesOptionError, "api.property.set(path, properties)")
+
+    # check properties after set without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        assert set(api.property.get(path)) == set(properties)
+        assert set(api.permissive.property.get(path)) == set(properties)
+    elif kwargs.get('permissive', False):
+        raises(PropertiesOptionError, "api.property.get(path)")
+        if not isslave:
+            assert set(api.permissive.property.get(path)) == set(default_props)
+        else:
+            assert set(api.permissive.property.get(path, 0)) == set(default_props)
+            assert set(api.permissive.property.get(path, 1)) == set(default_props)
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.property.get(path)")
+            raises(PropertiesOptionError, "api.permissive.property.get(path)")
+        else:
+            raises(PropertiesOptionError, "api.property.get(path, 0)")
+            raises(PropertiesOptionError, "api.permissive.property.get(path, 0)")
+
+    # set properties with permissive
+    if not kwargs.get('propertyerror', False):
+        api.permissive.property.set(path, properties)
+    else:
+        raises(PropertiesOptionError, "api.permissive.property.set(path, properties)")
+
+    # check properties after set with permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert set(api.property.get(path)) == set(properties)
+            assert set(api.permissive.property.get(path)) == set(properties)
+        else:
+            assert set(api.property.get(path, 0)) == set(properties)
+            assert set(api.permissive.property.get(path, 0)) == set(properties)
+            assert set(api.property.get(path, 1)) == set(properties)
+            assert set(api.permissive.property.get(path, 1)) == set(properties)
+    elif kwargs.get('permissive', False):
+        if not isslave:
+            raises(PropertiesOptionError, "api.property.get(path)")
+            assert set(api.permissive.property.get(path)) == set(properties)
+        else:
+            raises(PropertiesOptionError, "api.property.get(path, 0)")
+            assert set(api.permissive.property.get(path, 0)) == set(properties)
+            raises(PropertiesOptionError, "api.property.get(path, 1)")
+            assert set(api.permissive.property.get(path, 1)) == set(properties)
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.property.get(path)")
+            raises(PropertiesOptionError, "api.permissive.property.get(path)")
+        else:
+            raises(PropertiesOptionError, "api.property.get(path, 0)")
+            raises(PropertiesOptionError, "api.permissive.property.get(path, 0)")
+
+
+@autocheck
+def autocheck_reset_property(api, path, **kwargs):
+    """check properties after set with permissive
+    """
+
+    # check if is a multi or a slave
+    if not kwargs.get('propertyerror', False):
+        multi = api.permissive.option.ismulti(path)
+        isslave = api.permissive.option.isslave(path)
+    else:
+        raises(PropertiesOptionError, "api.permissive.option.ismulti(path)")
+        raises(PropertiesOptionError, "api.permissive.option.isslave(path)")
+        multi = False
+        isslave = False
+
+    # define properties
+    properties = ['prop1', 'prop2']
+    if multi and not isslave:
+        default_props = ['empty']
+        properties.append('empty')
+    else:
+        default_props = []
+    extra_properties = kwargs.get('extra_properties')
+    if extra_properties:
+        properties.extend(extra_properties)
+        default_props.extend(extra_properties)
+    properties = tuple(properties)
+
+    # check properties
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        assert set(api.property.get(path)) == set(properties)
+        assert set(api.permissive.property.get(path)) == set(properties)
+    elif kwargs.get('permissive', False):
+        if not isslave:
+            assert set(api.permissive.property.get(path)) == set(properties)
+        else:
+            assert set(api.permissive.property.get(path, 0)) == set(properties)
+            assert set(api.permissive.property.get(path, 1)) == set(properties)
+
+    # reset properties without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        api.property.reset(path)
+    else:
+        raises(PropertiesOptionError, "api.property.reset(path)")
+
+    # check properties
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert set(api.property.get(path)) == set(default_props)
+            assert set(api.permissive.property.get(path)) == set(default_props)
+        else:
+            assert set(api.property.get(path, 0)) == set(default_props)
+            assert set(api.permissive.property.get(path, 0)) == set(default_props)
+            assert set(api.property.get(path, 1)) == set(default_props)
+            assert set(api.permissive.property.get(path, 1)) == set(default_props)
+    elif kwargs.get('permissive', False):
+        if not isslave:
+            assert set(api.permissive.property.get(path)) == set(properties)
+        else:
+            assert set(api.permissive.property.get(path, 0)) == set(properties)
+            assert set(api.permissive.property.get(path, 1)) == set(properties)
+
+    # reset properties with permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        api.permissive.property.set(path, properties)
+        api.permissive.property.reset(path)
+    elif kwargs.get('permissive', False):
+        api.permissive.property.reset(path)
+
+    # check properties
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert set(api.property.get(path)) == set(default_props)
+            assert set(api.permissive.property.get(path)) == set(default_props)
+        else:
+            assert set(api.property.get(path, 0)) == set(default_props)
+            assert set(api.permissive.property.get(path, 0)) == set(default_props)
+            assert set(api.property.get(path, 1)) == set(default_props)
+            assert set(api.permissive.property.get(path, 1)) == set(default_props)
+    elif kwargs.get('permissive', False):
+        if not isslave:
+            assert set(api.permissive.property.get(path)) == set(default_props)
+        else:
+            assert set(api.permissive.property.get(path, 0)) == set(default_props)
+            assert set(api.permissive.property.get(path, 1)) == set(default_props)
+
+
+@autocheck
+def autocheck_property2(*args, **kwargs):
+    return autocheck_property(*args, display=False, **kwargs)
+
+
+@autocheck
+def autocheck_owner_with_value(api, path, **kwargs):
+    """value is now changed, check owner in this case
+    """
+    # check if is a isslave
+    if not kwargs.get('propertyerror', False):
+        isslave = api.permissive.option.isslave(path)
+    else:
+        raises(PropertiesOptionError, "api.permissive.option.isslave(path)")
+        isslave = False
+
+    # get owner without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert api.owner.get(path) == 'user'
+        else:
+            assert api.owner.get(path, 0) == 'user'
+            assert api.owner.get(path, 1) == 'user'
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.owner.get(path)")
+        else:
+            raises(PropertiesOptionError, "api.owner.get(path, 0)")
+            raises(PropertiesOptionError, "api.owner.get(path, 1)")
+
+    # get owner with permissive
+    if not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert api.permissive.owner.get(path) == 'user'
+        else:
+            print('--------')
+            print(api.permissive.owner.get(path, 0))
+            print(api.permissive.value.get(path, 0))
+            assert api.permissive.owner.get(path, 0) == 'default'
+            assert api.permissive.owner.get(path, 1) == 'user'
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.permissive.owner.get(path)")
+        else:
+            raises(PropertiesOptionError, "api.permissive.owner.get(path, 0)")
+
+    # test if is default owner without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        assert api.owner.isdefault(path) is False
+    else:
+        raises(PropertiesOptionError, "api.owner.isdefault(path)")
+
+    # test if is default owner with permissive
+    if not kwargs.get('propertyerror', False):
+        assert api.permissive.owner.isdefault(path) is False
+    else:
+        raises(PropertiesOptionError, "api.permissive.owner.isdefault(path)")
+
+
+@autocheck
+def autocheck_set_owner(api, path, **kwargs):
+    # test set owner without permissive
+    if not kwargs.get('propertyerror', False):
+        isslave = api.permissive.option.isslave(path)
+    else:
+        raises(PropertiesOptionError, "api.permissive.option.isslave(path)")
+        isslave = False
+
+    # set owner without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if not isslave:
+            api.owner.set(path, 'new_user')
+        else:
+            api.owner.set(path, 1, 'new_user')
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.owner.set(path, 'new_user')")
+        else:
+            raises(PropertiesOptionError, "api.owner.set(path, 1, 'new_user')")
+
+    # check owner set without permissive
+    if not kwargs.get('permissive', False) and not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert api.owner.get(path) == 'new_user'
+            assert api.permissive.owner.get(path) == 'new_user'
+        else:
+            assert api.owner.get(path, 1) == 'new_user'
+            assert api.permissive.owner.get(path, 1) == 'new_user'
+    elif not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert api.permissive.owner.get(path) == 'user'
+        else:
+            assert api.permissive.owner.get(path, 1) == 'user'
+
+    # set owner with permissive
+    if not kwargs.get('propertyerror', False):
+        if not isslave:
+            api.permissive.owner.set(path, 'new_user1')
+        else:
+            api.permissive.owner.set(path, 1, 'new_user1')
+    else:
+        if not isslave:
+            raises(PropertiesOptionError, "api.permissive.owner.set(path, 'new_user1')")
+        else:
+            raises(PropertiesOptionError, "api.permissive.owner.set(path, 1, 'new_user1')")
+
+    # get owner set with permissive
+    if not kwargs.get('propertyerror', False):
+        if not isslave:
+            assert api.permissive.owner.get(path) == 'new_user1'
+        else:
+            assert api.permissive.owner.get(path, 0) == 'default'
+            assert api.permissive.owner.get(path, 1) == 'new_user1'
+
+
+def check_all(api, path, multi, **kwargs):
+    text = u' {} launch tests for {}'.format(ICON, path)
+    if multi:
+        text += u' as a multi'
+    print(text)
+    for func in autocheck_registers:
+        print(u'  {} {}'.format(ICON, func.__name__))
+        func(api, path, **kwargs)
+
+
+def make_api(options, multi):
+    def make_option(path):
+        option_infos = path.split('_')
+        option_type = 'str'
+        option_properties = []
+        for option_info in option_infos[1:]:
+            if option_info in OPTIONS_TYPE:
+                option_type = option_info
+            elif option_info in PROPERTIES:
+                option_properties.append(option_info)
+            else:
+                raise Exception('unknown {} in {}'.format(option_info, path))
+        args = [option_infos[0], "{}'s option".format(option_infos[0])]
+        kwargs = {}
+        if option_properties != []:
+            kwargs['properties'] = tuple(option_properties)
+        if multi:
+            kwargs['multi'] = True
+        tiramisu_option = OPTIONS_TYPE[option_type]['option']
+        return tiramisu_option(*args, **kwargs)
+
+    def make_optiondescriptions(path, collected):
+        infos = path.split('_')
+        name = infos[0]
+        properties = []
+        kwargs = {}
+        optiondescription = OptionDescription
+        for info in infos[1:]:
+            if info in PROPERTIES:
+                properties.append(info)
+            elif info == 'master':
+                if not multi:
+                    return
+                optiondescription = MasterSlaves
+            elif info == 'dyn':
+                optiondescription = DynOptionDescription
+                kwargs['callback'] = return_list
+            else:
+                raise Exception('unknown {} in {}'.format(info, path))
+        options = []
+        if 'options' in collected:
+            options.extend(collected['options'])
+        for key, values in collected.items():
+            if key == 'options':
+                continue
+            option = make_optiondescriptions(key, values)
+            if option is None:
+                return
+            options.append(option)
+        if properties != []:
+            kwargs['properties'] = tuple(properties)
+        return optiondescription(name, "{}'s optiondescription".format(name), options, **kwargs)
+            
+    collect_options = {}
+    for option in options:
+        if option is None:
+            continue
+        local_collect_options = collect_options
+        for optiondescription in option.split('.')[:-1]:
+            local_collect_options.setdefault(optiondescription, {})
+            local_collect_options = local_collect_options[optiondescription]
+        path = '.'.join(option.split('.')[:-1])
+        option_name = option.split('.')[-1]
+        local_collect_options.setdefault("options", []).append(make_option(option_name))
+
+    rootod = make_optiondescriptions('root', collect_options)
+    if rootod is None:
+        return
+    cfg = Config(rootod)
+    return getapi(cfg)
+
+
+DICT_PATHS = [
+    #test a config without optiondescription
+    {'first': 'first',
+     'second': 'second_disabled',
+     'third': 'third_hidden'},
+    #test a config with an optiondescription
+    {'subod.first': 'subod.first',
+     'subod.second': 'subod.second_disabled',
+     'subod.third': 'subod.third_hidden'},
+    #test a config with two optiondescription
+    {'subod.subsubod.first': 'subod.subsubod.first',
+     'subod.subsubod.second': 'subod.subsubod.second_disabled',
+     'subod.subsubod.third': 'subod.subsubod.third_hidden'},
+    #test a config with mix of different optiondescription
+    {'first': 'first',
+     'subod.second': 'subod.second_disabled',
+     'subod.subsubod.third': 'subod.subsubod.third_hidden'},
+    #test a config with masterslaves
+    {'first.first': 'first_master.first',
+     'first.second': 'first_master.second_disabled',
+     'first.third': 'first_master.third_hidden'},
+    ##test a config with dynoption
+    {'subodval1.firstval1': 'subod_dyn.first',
+     'subodval1.secondval1': 'subod_dyn.second_disabled',
+     'subodval1.thirdval1': 'subod_dyn.third_hidden',
+     'subodval2.firstval2': None,
+     'subodval2.secondval2': None,
+     'subodval2.thirdval2': None},
+    #test a config with dynoption subdir
+    {'subod.subodval1.firstval1': 'subod.subod_dyn.first',
+     'subod.subodval1.secondval1': 'subod.subod_dyn.second_disabled',
+     'subod.subodval1.thirdval1': 'subod.subod_dyn.third_hidden',
+     'subod.subodval2.firstval2': None,
+     'subod.subodval2.secondval2': None,
+     'subod.subodval2.thirdval2': None}
+]
+
+
+@pytest.fixture(scope="function", params=DICT_PATHS)
+def paths(request):
+    print(u'\n{} {}: {}'.format(ICON, request.function.__name__, request.param))
+    return request.param
+
+
+def test_options(paths):
+    lpaths = list(paths.keys())
+    for multi in (False, True):
+        api = make_api(paths.values(), multi)
+        if api is None:
+            continue
+        check_all(api, lpaths[0], multi)
+        check_all(api, lpaths[1], multi, propertyerror=True, extra_properties=['disabled'])
+        check_all(api, lpaths[2], multi, permissive=True, extra_properties=['hidden'])
+        if len(lpaths) == 6:
+            check_all(api, lpaths[3], multi)
+            check_all(api, lpaths[4], multi, propertyerror=True, extra_properties=['disabled'])
+            check_all(api, lpaths[5], multi, permissive=True, extra_properties=['hidden'])
+    ##
+    #print('')
+    #print(api.help)
+
+
+@display_info
+def test_tree_od_permissive():
+    """permissive when optiondescription is hidden
+    """
+    tpaths = [
+        {'subod.subsubod.first': 'subod.subsubod_hidden.first',
+         'subod.subsubod.second': 'subod.subsubod_hidden.second',
+         'subod.subsubod.third': 'subod.subsubod_hidden.third_hidden'},
+        {'subod.subodval1.firstval1': 'subod.subod_dyn_hidden.first',
+         'subod.subodval1.secondval1': 'subod.subod_dyn_hidden.second',
+         'subod.subodval1.thirdval1': 'subod.subod_dyn_hidden.third_hidden',
+         'subod.subodval2.firstval2': None,
+         'subod.subodval2.secondval2': None,
+         'subod.subodval2.thirdval2': None
+        }
+    ]
+    for paths in tpaths:
+        lpaths = list(paths.keys())
+        for multi in (False, True):
+            api = make_api(paths.values(), multi)
+            if api is None:
+                continue
+            check_all(api, lpaths[0], multi, permissive=True)
+            check_all(api, lpaths[1], multi, permissive=True)
+            check_all(api, lpaths[2], multi, permissive=True, extra_properties=['hidden'])
+            if len(lpaths) == 6:
+                check_all(api, lpaths[3], multi, permissive=True)
+                check_all(api, lpaths[4], multi, permissive=True)
+                check_all(api, lpaths[5], multi, permissive=True, extra_properties=['hidden'])
diff --git a/test/test_option_default.py b/test/test_option_default.py
index 1ed8ee8..7efa806 100644
--- a/test/test_option_default.py
+++ b/test/test_option_default.py
@@ -83,7 +83,7 @@ def test_force_default_on_freeze():
     setting[dummy1].remove('frozen')
     del(config.dummy1)
     setting[dummy1].append('frozen')
-    raises(ConfigError, "config.cfgimpl_get_values().setowner(dummy1, owners.frozen)")
+    raises(PropertiesOptionError, "config.cfgimpl_get_values().setowner(dummy1, owners.frozen)")
 
 
 def test_force_default_on_freeze_multi():
@@ -110,7 +110,7 @@ def test_force_default_on_freeze_multi():
     setting[dummy1].remove('frozen')
     del(config.dummy1)
     setting[dummy1].append('frozen')
-    raises(ConfigError, "config.cfgimpl_get_values().setowner(dummy1, owners.frozenmulti)")
+    raises(PropertiesOptionError, "config.cfgimpl_get_values().setowner(dummy1, owners.frozenmulti)")
 
 
 def test_overrides_changes_option_value():
diff --git a/tiramisu/__init__.py b/tiramisu/__init__.py
index b92b780..52161d7 100644
--- a/tiramisu/__init__.py
+++ b/tiramisu/__init__.py
@@ -12,3 +12,15 @@
 #
 # You should have received a copy of the GNU Lesser General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+from .config import Config
+from .option import *
+from .error import APIError
+from .api import getapi
+from .option import __all__ as all_options
+
+
+allfuncs = ['Config', 'getapi', 'APIError']
+allfuncs.extend(all_options)
+del(all_options)
+__all__ = tuple(allfuncs)
+del(allfuncs)
diff --git a/tiramisu/api.py b/tiramisu/api.py
new file mode 100644
index 0000000..e9c4eee
--- /dev/null
+++ b/tiramisu/api.py
@@ -0,0 +1,342 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2017 Team tiramisu (see AUTHORS for all contributors)
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published by the
+# Free Software Foundation, either version 3 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 Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# ____________________________________________________________
+from inspect import ismethod, getdoc
+from .error import APIError
+from .i18n import _
+from .setting import owners, undefined
+
+
+def getter(func):
+    def wrapper(self, path, *args, **kwargs):
+        opt = self._get_obj_by_path(path)
+        if opt.impl_is_master_slaves('slave'):
+            get = self._slave_get
+        else:
+            get = self._simple_get
+        return get(path, *args, **kwargs)
+    return wrapper
+
+
+def setter(func):
+    def wrapper(self, path, *args, **kwargs):
+        opt = self._get_obj_by_path(path)
+        if opt.impl_is_master_slaves('slave'):
+            return self._slave_set(path, *args, **kwargs)
+        elif opt.impl_is_master_slaves('master'):
+            return self._master_set(path, *args, **kwargs)
+        else:
+            return self._simple_set(path, *args, **kwargs)
+    return wrapper
+
+
+def resetter(func):
+    def wrapper(self, path, *args, **kwargs):
+        opt = self._get_obj_by_path(path)
+        if opt.impl_is_master_slaves('slave'):
+            reset = self._slave_reset
+        else:
+            reset = self._simple_reset
+        return reset(path, *args, **kwargs)
+    return wrapper
+
+
+class CommonTiramisu(object):
+    icon = '\u2937'
+    tmpl_help = u'  {} {}: {}'
+
+    def _get_obj_by_path(self, path, index=None):
+        return self.config.unwrap_from_path(path,
+                                            force_permissive=self.force_permissive,
+                                            index=index)
+
+    def __getattr__(self, name):
+        if name == 'help':
+            return self._help()
+        else:
+            if not hasattr(CommonTiramisu, name):
+                raise APIError(_('unknown method {}').format(name))
+            else:
+                super(CommonTiramisu).__getattribute__(name)
+
+    def _help(self):
+        txt = []
+        for func_name in dir(self):
+            if not func_name.startswith('_'):
+                func = getattr(self, func_name)
+                if ismethod(func):
+                    txt.append(self.tmpl_help.format(self.icon, func_name, getdoc(func)))
+        return '\n'.join(txt)
+
+
+class TiramisuAPIOption(CommonTiramisu):
+    """get information from an option"""
+
+    def __init__(self, config, force_permissive):
+        self.config = config
+        self.force_permissive = force_permissive
+        if config:
+            self.values = self.config.cfgimpl_get_values()
+
+    def ismulti(self, path):
+        """test if option could have multi value"""
+        opt = self._get_obj_by_path(path)
+        return opt.impl_is_multi()
+
+    def ismasterslaves(self, path):
+        """test if option is a master or a slave"""
+        opt = self._get_obj_by_path(path)
+        return opt.impl_is_master_slaves()
+
+    def ismaster(self, path):
+        """test if option is a master"""
+        opt = self._get_obj_by_path(path)
+        return opt.impl_is_master_slaves('master')
+
+    def isslave(self, path):
+        """test if option is a slave"""
+        opt = self._get_obj_by_path(path)
+        return opt.impl_is_master_slaves('slave')
+
+
+class TiramisuAPIOwner(CommonTiramisu):
+    """manager option's owner"""
+
+    def __init__(self, config, force_permissive):
+        self.config = config
+        self.force_permissive = force_permissive
+        if config:
+            self.values = self.config.cfgimpl_get_values()
+
+    @getter
+    def get(self):
+        """get owner for a specified option"""
+        pass
+
+    def _simple_get(self, path):
+        ##FIXME should not be here, just for check property
+        #self.config.getattr(path,
+        #                    force_permissive=self.force_permissive)
+        # FIXME doublons aussi
+        opt = self._get_obj_by_path(path)
+        return self.values.getowner(opt,
+                                     force_permissive=self.force_permissive)
+
+    def _slave_get(self, path, index):
+        ##FIXME should not be here, just for check property
+        #self.config.getattr(path,
+        #                    index=index,
+        #                    force_permissive=self.force_permissive)
+        # FIXME doublons aussi
+        opt = self._get_obj_by_path(path,
+                                    index=index)
+        return self.values.getowner(opt,
+                                     index=index,
+                                     force_permissive=self.force_permissive)
+
+    def isdefault(self, path):
+        """is option has defaut value"""
+        #FIXME isdefault for slave should have index!
+        opt = self._get_obj_by_path(path)
+        #FIXME should not be here, just for check property
+        self.config.getattr(path,
+                            force_permissive=self.force_permissive)
+        return self.values.is_default_owner(opt,
+                                            force_permissive=self.force_permissive)
+
+    @setter
+    def set(self):
+        """get owner for a specified option"""
+        pass
+    
+    def _simple_set(self, path, owner):
+        #FIXME doublons, opt est deja dans le setter
+        opt = self._get_obj_by_path(path)
+        try:
+            obj_owner = getattr(owners, owner)
+        except AttributeError:
+            owners.addowner(owner)
+            obj_owner = getattr(owners, owner)
+        self.values.setowner(opt,
+                             obj_owner,
+                             force_permissive=self.force_permissive)
+
+    def _master_set(self, path, owner):
+        return self._simple_set(path, owner)
+
+    def _slave_set(self, path, index, owner):
+        #FIXME doublons, opt est deja dans le setter
+        opt = self._get_obj_by_path(path, index)
+        try:
+            obj_owner = getattr(owners, owner)
+        except AttributeError:
+            owners.addowner(owner)
+            obj_owner = getattr(owners, owner)
+        self.values.setowner(opt,
+                             obj_owner,
+                             index,
+                             force_permissive=self.force_permissive)
+
+
+class TiramisuAPIProperty(CommonTiramisu):
+    """manager option's property"""
+
+    def __init__(self, config, force_permissive):
+        self.config = config
+        self.force_permissive = force_permissive
+        if config:
+            self.settings = config.cfgimpl_get_settings()
+
+    @getter
+    def get(self, path):
+        """get property for a specified option"""
+
+    def _simple_get(self, path):
+        opt = self._get_obj_by_path(path)
+        return self.settings.getproperties(opt, path, obj=False)
+
+    def _slave_get(self, path, index):
+        opt = self._get_obj_by_path(path)
+        return self.settings.getproperties(opt, path, index=index, obj=False)
+
+    def set(self, path, properties):
+        """set properties for a specified option"""
+        opt = self._get_obj_by_path(path)
+        self.settings.setproperties(set(properties),
+                                    opt,
+                                    path)
+
+    def reset(self, path):
+        """reset all personalised properties
+        """
+        self._get_obj_by_path(path)
+        self.settings.reset(_path=path)
+
+
+class TiramisuAPIValue(CommonTiramisu):
+    """manager option's value"""
+
+    def __init__(self, config, force_permissive):
+        self.config = config
+        self.force_permissive = force_permissive
+
+    def append(self, path, value=undefined):
+        opt = self._get_obj_by_path(path)
+        if not opt.impl_is_master_slaves('master'):
+            raise APIError('append is only allowed for a master')
+        multi = self.config.getattr(path,
+                                    force_permissive=self.force_permissive)
+        multi.append(value, force_permissive=self.force_permissive)
+
+    @getter
+    def get(self):
+        """get value for a specified option"""
+        pass
+
+    def _simple_get(self, path):
+        return self.config.getattr(path,
+                                   force_permissive=self.force_permissive)
+
+    def _slave_get(self, path, index):
+        return self.config.getattr(path,
+                                   index=index,
+                                   force_permissive=self.force_permissive)
+
+    @setter
+    def set(self):
+        """set a value for a specified option"""
+        pass
+
+    def _simple_set(self, path, value):
+        self.config.setattr(path,
+                            value,
+                            force_permissive=self.force_permissive)
+
+    def _master_set(self, path, index, value):
+        multi = self.config.getattr(path,
+                                    force_permissive=self.force_permissive)
+        multi[index] = value
+
+    def _slave_set(self, path, index, value):
+        self.config.setattr(path,
+                            value,
+                            index=index,
+                            force_permissive=self.force_permissive)
+
+    @resetter
+    def reset(self, path):
+        """reset value for a value"""
+        pass
+
+    def _simple_reset(self, path):
+        opt = self._get_obj_by_path(path)
+        self.config.cfgimpl_get_values().reset(opt,
+                                               path=path,
+                                               force_permissive=self.force_permissive)
+
+    def _slave_reset(self, path, index):
+        #self._get_obj_by_path(path)
+        multi = self.config.getattr(path,
+                                    force_permissive=self.force_permissive)
+        del(multi[index])
+
+
+class TiramisuAPI(object):
+    icon = '\u2937'
+    tmpl_help = ' {} {}: {}'
+
+    def __init__(self, config, force_permissive=False):
+        self.config = config
+        self.force_permissive = force_permissive
+        #FIXME ?
+        self.config.read_write()
+        self.config.cfgimpl_get_settings().setpermissive(('hidden',))
+        #/FIXME ?
+        self.registers = {}
+        self.prefix = self.__class__.__name__
+        for module_name in globals().keys():
+            if module_name != self.prefix and module_name.startswith(self.prefix):
+                module = globals()[module_name]
+                func_name = module_name[11:].lower()
+                self.registers[func_name] = module
+
+    def __getattr__(self, subfunc):
+        if subfunc in self.registers:
+            return self.registers[subfunc](self.config,
+                                           self.force_permissive)
+        elif subfunc == 'permissive':
+            return TiramisuAPI(self.config, force_permissive=True)
+        elif subfunc == 'help':
+            return self._help()
+        else:
+            raise APIError(_('please specify a valid sub function'))
+
+    def _help(self):
+        txt = ['[permissive]']
+        for module_name, module in self.registers.items():
+            module_doc = getdoc(module)
+            txt.append(self.tmpl_help.format(self.icon, module_name, module_doc))
+            txt.append(module(None, None).help)
+        return '\n'.join(txt)
+
+
+def getapi(config):
+    """instanciate TiramisuAPI
+
+    :param config: Config object
+    :type descr: an instance of ``config.Config``
+    """
+    return TiramisuAPI(config)
diff --git a/tiramisu/config.py b/tiramisu/config.py
index 93d5f31..f82bd74 100644
--- a/tiramisu/config.py
+++ b/tiramisu/config.py
@@ -382,7 +382,7 @@ class SubConfig(object):
 
     def getattr(self, name, force_permissive=False, validate=True,
                 _setting_properties=undefined, _self_properties=undefined, index=None,
-                returns_raise=False):
+                returns_raise=False, returns_option=False):
         """
         attribute notation mechanism for accessing the value of an option
         :param name: attribute name
@@ -457,7 +457,10 @@ class SubConfig(object):
                     index=index)
         if not returns_raise and isinstance(cfg, Exception):
             raise cfg
-        return cfg
+        if returns_option is True:
+            return option
+        else:
+            return cfg
 
     def find(self, bytype=None, byname=None, byvalue=undefined, type_='option',
              check_properties=True, force_permissive=False):
@@ -724,7 +727,7 @@ class _CommonConfig(SubConfig):
         return self.cfgimpl_get_values().getowner(opt, index=index,
                                                   force_permissive=force_permissive)
 
-    def unwrap_from_path(self, path, force_permissive=False):
+    def unwrap_from_path(self, path, force_permissive=False, index=None):
         """convenience method to extract and Option() object from the Config()
         and it is **fast**: finds the option directly in the appropriate
         namespace
@@ -733,10 +736,9 @@ class _CommonConfig(SubConfig):
         """
         context = self._cfgimpl_get_context()
         if '.' in path:
-            homeconfig, path = self.cfgimpl_get_home_by_path(
-                path, force_permissive=force_permissive)
-            return homeconfig.cfgimpl_get_description().__getattr__(path, context=context)
-        return self.cfgimpl_get_description().__getattr__(path, context=context)
+            self, path = self.cfgimpl_get_home_by_path(path,
+                                                       force_permissive=force_permissive)
+        return self.getattr(path, force_permissive=force_permissive, index=index, returns_option=True)
 
     def cfgimpl_get_path(self, dyn=True):
         return None
diff --git a/tiramisu/error.py b/tiramisu/error.py
index a71dc29..46b5cdf 100644
--- a/tiramisu/error.py
+++ b/tiramisu/error.py
@@ -161,3 +161,7 @@ class ValueWarning(UserWarning):  # pragma: optional cover
     def __init__(self, msg, opt):
         self.opt = opt
         super(ValueWarning, self).__init__(msg)
+
+
+class APIError(Exception):
+    pass
diff --git a/tiramisu/option/option.py b/tiramisu/option/option.py
index a4cd1b5..103ce78 100644
--- a/tiramisu/option/option.py
+++ b/tiramisu/option/option.py
@@ -58,7 +58,7 @@ class Option(OnlyOption):
                  '_choice_values_params',
                 )
     _empty = ''
-    def __init__(self, name, doc, default=None, default_multi=None,
+    def __init__(self, name, doc, default=undefined, default_multi=None,
                  requires=None, multi=False, unique=undefined, callback=None,
                  callback_params=None, validator=None, validator_params=None,
                  properties=None, warnings_only=False, extra=None,
@@ -68,6 +68,11 @@ class Option(OnlyOption):
         if not multi and default_multi is not None:
             raise ValueError(_("default_multi is set whereas multi is False"
                                " in option: {0}").format(name))
+        if default is undefined:
+            if multi is False:
+                default = None
+            else:
+                default = []
         if multi is True:
             is_multi = True
             _multi = 0
diff --git a/tiramisu/option/optiondescription.py b/tiramisu/option/optiondescription.py
index 816d6aa..4353a4a 100644
--- a/tiramisu/option/optiondescription.py
+++ b/tiramisu/option/optiondescription.py
@@ -644,10 +644,10 @@ class MasterSlaves(OptionDescription):
             c_opt = opt
         return c_opt in self._children[1]
 
-    def reset(self, opt, values, setting_properties, _commit=True):
+    def reset(self, opt, values, setting_properties, _commit=True, force_permissive=False):
         for slave in self.getslaves(opt):
             values.reset(slave, validate=False, _setting_properties=setting_properties,
-                         _commit=_commit)
+                         _commit=_commit, force_permissive=force_permissive)
 
     def pop(self, opt, values, index):
         for slave in self.getslaves(opt):
diff --git a/tiramisu/setting.py b/tiramisu/setting.py
index 055e9e6..6a99493 100644
--- a/tiramisu/setting.py
+++ b/tiramisu/setting.py
@@ -270,7 +270,7 @@ class Property(object):
             raise ConfigError(_('cannot add those properties: {0}').format(propname))
         self._properties.add(propname)
         if save:
-            self._setting._setproperties(self._properties, self._opt, self._path, force=True)
+            self._setting.setproperties(self._properties, self._opt, self._path, force=True)
 
     def remove(self, propname):
         """Removes a property named propname
@@ -280,7 +280,7 @@ class Property(object):
         """
         if propname in self._properties:
             self._properties.remove(propname)
-            self._setting._setproperties(self._properties, self._opt, self._path)
+            self._setting.setproperties(self._properties, self._opt, self._path)
 
     def extend(self, propnames):
         """Extends properties to the existing properties
@@ -290,7 +290,7 @@ class Property(object):
         """
         for propname in propnames:
             self._append(propname, save=False)
-        self._setting._setproperties(self._properties, self._opt, self._path)
+        self._setting.setproperties(self._properties, self._opt, self._path)
 
     def reset(self):
         """resets the properties (does not **clear** the properties,
@@ -353,11 +353,14 @@ class Settings(object):
         path = opt.impl_getpath(self._getcontext())
         return self.getproperties(opt, path)
 
-    def getproperties(self, opt, path, setting_properties=undefined):
-        return Property(self,
-                        self._getproperties(opt, path,
-                                            setting_properties=setting_properties),
-                        opt, path)
+    def getproperties(self, opt, path, setting_properties=undefined, index=None, obj=True):
+        """get properties for a specified option
+        """
+        properties = self._getproperties(opt, path, index=index,
+                                         setting_properties=setting_properties)
+        if obj:
+            return Property(self, properties, opt, path)
+        return properties
 
     def __setitem__(self, opt, value):  # pragma: optional cover
         raise ValueError(_('you should only append/remove properties'))
@@ -435,20 +438,25 @@ class Settings(object):
         props = self._p_.getproperties(None, default_properties)
         if propname not in props:
             props.add(propname)
-            self._setproperties(props, None, None)
+            self.setproperties(props, None, None)
 
     def remove(self, propname):
         "deletes property propname in the Config's properties attribute"
         props = self._p_.getproperties(None, default_properties)
         if propname in props:
             props.remove(propname)
-            self._setproperties(props, None, None)
+            self.setproperties(props, None, None)
 
     def extend(self, propnames):
         for propname in propnames:
             self.append(propname)
 
     def _setproperties(self, properties, opt, path, force=False):
+        """just for compatibility
+        """
+        self.setproperties(properties, opt, path, force)
+
+    def setproperties(self, properties, opt, path, force=False):
         """save properties for specified path
         (never save properties if same has option properties)
         """
@@ -617,7 +625,7 @@ class Settings(object):
             props = props | append
             modified = True
         if modified:
-            self._setproperties(props, None, None)
+            self.setproperties(props, None, None)
 
     def read_only(self):
         "convenience method to freeze, hide and disable"
diff --git a/tiramisu/value.py b/tiramisu/value.py
index f9a72c3..65876df 100644
--- a/tiramisu/value.py
+++ b/tiramisu/value.py
@@ -160,7 +160,8 @@ class Values(object):
         """overrides the builtins `del()` instructions"""
         self.reset(opt)
 
-    def reset(self, opt, path=None, validate=True, _setting_properties=None, _commit=True):
+    def reset(self, opt, path=None, validate=True, _setting_properties=None, _commit=True,
+              force_permissive=False):
         context = self._getcontext()
         setting = context.cfgimpl_get_settings()
         if path is None:
@@ -177,11 +178,13 @@ class Values(object):
             fake_value.reset(opt, path, validate=False)
             ret = fake_value._get_cached_value(opt, path,
                                                setting_properties=_setting_properties,
-                                               check_frozen=True)
+                                               check_frozen=True,
+                                               force_permissive=force_permissive)
             if isinstance(ret, Exception):
                 raise ret
         if opt.impl_is_master_slaves('master'):
-            opt.impl_get_master_slaves().reset(opt, self, _setting_properties, _commit=_commit)
+            opt.impl_get_master_slaves().reset(opt, self, _setting_properties, _commit=_commit,
+                                               force_permissive=force_permissive)
         if hasvalue:
             if 'force_store_value' in setting._getproperties(opt=opt,
                                                              path=path,
@@ -462,16 +465,20 @@ class Values(object):
         if valid_masterslave and opt.impl_is_master_slaves():
             if session is None:
                 session = self._p_.getsession()
+            setitem = True
             if opt.impl_is_master_slaves('master'):
                 masterlen = len(value)
                 slavelen = None
+            elif index is not None:
+                masterlen = None
+                slavelen = index
+                setitem = False
             else:
                 masterlen = None
                 slavelen = len(value)
-            setitem = True
             opt.impl_get_master_slaves().impl_validate(self._getcontext(), force_permissive,
                                                        setting_properties, masterlen=masterlen,
-                                                       slavelen=slavelen, opt=opt, setitem=True)
+                                                       slavelen=slavelen, opt=opt, setitem=setitem)
             #val = opt.impl_get_master_slaves().impl_validate(self, opt, len_value, path, session, setitem=setitem)
             #if isinstance(val, Exception):
             #    return val
@@ -533,7 +540,7 @@ class Values(object):
         if 'frozen' in self_properties and 'force_default_on_freeze' in self_properties:
             return owners.default
         if validate_properties:
-            value = self._get_cached_value(opt, path, True, force_permissive, None, True,
+            value = self._get_cached_value(opt, path=path, force_permissive=force_permissive,
                                            self_properties=self_properties, session=session,
                                            index=index)
             if isinstance(value, Exception):
@@ -557,7 +564,7 @@ class Values(object):
                                                             only_default=only_default, index=index)
         return owner
 
-    def setowner(self, opt, owner, index=None):
+    def setowner(self, opt, owner, index=None, force_permissive=False):
         """
         sets a owner to an option
 
@@ -569,16 +576,17 @@ class Values(object):
 
         path = opt.impl_getpath(self._getcontext())
         session = self._p_.getsession()
-        if not self._p_.hasvalue(path, session):
-            raise ConfigError(_('no value for {0} cannot change owner to {1}'
-                                '').format(path, owner))
         props = self._getcontext().cfgimpl_get_settings().validate_properties(opt,
                                                                               False,
                                                                               True,
                                                                               path,
-                                                                              index=index)
+                                                                              index=index,
+                                                                              force_permissive=force_permissive)
         if props:
             raise props
+        if not self._p_.hasvalue(path, session):
+            raise ConfigError(_('no value for {0} cannot change owner to {1}'
+                                '').format(path, owner))
         self._p_.setowner(path, owner, session, index=index)
 
     def is_default_owner(self, opt, path=None, validate_properties=True,
@@ -900,7 +908,7 @@ class Multi(list):
 
         :param index: remove item a index
         :type index: int
-        :param force: force pop item (withoud check master/slave)
+        :param force: force pop item (without check master/slave)
         :type force: boolean
         :returns: item at index
         """