diff --git a/ostack_validator/schema.py b/ostack_validator/schema.py
new file mode 100644
index 0000000..8af8768
--- /dev/null
+++ b/ostack_validator/schema.py
@@ -0,0 +1,220 @@
+from ostack_validator.common import Inspection, MarkedError, Mark, find, index
+
+class Version:
+  def __init__(self, major, minor=0, maintenance=0):
+    "Create Version object by either passing 3 integers, one string or an another Version object"
+    if isinstance(major, str):
+      self.parts = [int(x) for x in major.split('.', 3)]
+    elif isinstance(major, Version):
+      self.parts = major.parts
+    else:
+      self.parts = [int(major), int(minor), int(maintenance)]
+
+  def __str__(self):
+    return '.'.join([str(p) for p in self.parts])
+
+  def __repr__(self):
+    return '<Version %s>' % str(self)
+
+  def __cmp__(self, other):
+    for i in xrange(0, 3):
+      x = self.parts[i] - other.parts[i]
+      if x != 0:
+        return -1 if x < 0 else 1
+
+    return 0
+
+class SchemaUpdateRecord(object):
+  # checkpoint's data is version number
+  def __init__(self, version, operation, data=None):
+    super(SchemaUpdateRecord, self).__init__()
+    if not operation in ['checkpoint', 'add', 'remove']:
+      raise Error, 'Unknown operation "%s"' % operation
+    version = Version(version)
+    self.version = version
+    self.operation = operation
+    self.data = data
+
+class SchemaBuilder(object):
+  def __init__(self, data):
+    super(SchemaBuilder, self).__init__()
+    self.data = data
+
+    self.current_version = None
+    self.current_section = None
+    self.adds = []
+    self.removals = []
+
+  def version(self, version, checkpoint=False):
+    version = Version(version)
+
+    if self.current_version and self.current_version != version:
+      self.commit()
+
+    if checkpoint or self.data == []:
+      self.data.append(SchemaUpdateRecord(version, 'checkpoint'))
+
+    self.current_version = version
+
+  def section(self, name):
+    self.current_section = name
+
+  def param(self, *args, **kwargs):
+    if not 'section' in kwargs and self.current_section:
+      kwargs['section'] = self.current_section
+
+    self.adds.append(ConfigParameterSchema(*args, **kwargs))
+
+  def remove_param(self, name):
+    self.removals.append(name)
+
+  def commit(self):
+    "Finalize schema building"
+    if len(self.removals) > 0:
+      self.data.append(SchemaUpdateRecord(self.current_version, 'remove', self.removals))
+      self.removals = []
+    if len(self.adds) > 0:
+      self.data.append(SchemaUpdateRecord(self.current_version, 'add', self.adds))
+      self.adds = []
+
+class ConfigSchemaRegistry:
+  __schemas = {}
+  @classmethod
+  def register_schema(self, project, configname=None):
+    if not configname:
+      configname = '%s.conf' % project
+    fullname = '%s/%s' % (project, configname)
+    self.__schemas[fullname] = []
+    return SchemaBuilder(self.__schemas[fullname])
+
+  @classmethod
+  def get_schema(self, project, version, configname=None):
+    if not configname:
+      configname = '%s.conf' % project
+    fullname = '%s/%s' % (project, configname)
+    version = Version(version)
+
+    records = self.__schemas[fullname]
+    i = len(records)-1
+    # Find latest checkpoint prior given version
+    while i>=0 and not (records[i].operation == 'checkpoint' and records[i].version <= version): i-=1
+
+    if i < 0:
+      return None
+
+    parameters = []
+    seen_parameters = set()
+    last_version = None
+
+    while i < len(records) and records[i].version <= version:
+      last_version = records[i].version
+      if records[i].operation == 'add':
+        for param in records[i].data:
+          if param.name in seen_parameters:
+            old_param_index = index(parameters, lambda p: p.name == param.name)
+            if old_param_index != -1:
+              parameters[old_param_index] = param
+          else:
+            parameters.append(param)
+            seen_parameters.add(param.name)
+      elif records[i].operation == 'remove':
+        for param_name in records[i].data:
+          param_index = index(parameters, lambda p: p.name == param_name)
+          if index != -1:
+            parameters.pop(param_index)
+            seen_parameters.remove(param_name)
+      i += 1
+
+    return ConfigSchema(fullname, last_version, 'ini', parameters)
+
+
+class ConfigSchema:
+  def __init__(self, name, version, format, parameters):
+    self.name = name
+    self.version = Version(version)
+    self.format = format
+    self.parameters = parameters
+
+  def get_parameter(name, section=None):
+    # TODO: optimize this
+    return find(self.parameters, lambda p: p.name == name and p.section == section)
+
+  def __repr__(self):
+    return '<ConfigSchema name=%s version=%s format=%s parameters=%s>' % (self.name, self.version, self.format, self.parameters)
+    
+class ConfigParameterSchema:
+  def __init__(self, name, type, section=None, description=None, default=None, required=False):
+    self.section = section
+    self.name = name
+    self.type = type
+    self.description = description
+    self.default = default
+    self.required = required
+
+  def __repr__(self):
+    return '<ConfigParameterSchema %s>' % ' '.join(['%s=%s' % (attr, getattr(self, attr)) for attr in ['section', 'name', 'type', 'description', 'default', 'required']])
+
+
+class TypeValidatorRegistry:
+  __validators = {}
+  @classmethod
+  def register_validator(self, type_name, type_validator):
+    self.__validators[type_name] = type_validator
+
+  @classmethod
+  def get_validator(self, name):
+    return self.__validators[name]
+
+
+class InvalidValueError(MarkedError):
+  def __init__(self, message, mark=Mark('', 1, 1)):
+    super(InvalidValueError, self).__init__(message, mark)
+
+class TypeValidator(object):
+  def __init__(self, f):
+    super(TypeValidator, self).__init__()
+    self.f = f
+
+  def validate(self, value):
+    return getattr(self, 'f')(value)
+
+
+def type_validator(name, **kwargs):
+  def wrap(fn):
+    def wrapped(s):
+      return fn(s, **kwargs)
+    o = TypeValidator(wrapped)
+    TypeValidatorRegistry.register_validator(name, o)
+    return fn
+  return wrap
+
+@type_validator('boolean', values=['True', 'False'])
+def validate_enum(s, values=[]):
+  if s in values:
+    return None
+  return InvalidValueError('Invalid value: valid values are: %s' % ', '.join(values))
+
+@type_validator('string')
+def validate_string(s):
+  return None
+
+@type_validator('integer')
+@type_validator('port', min=1, max=65535)
+def validate_integer(s, min=None, max=None):
+  leading_whitespace_len = 0
+  while s[leading_whitespace_len].isspace(): leading_whitespace_len += 1
+
+  s = s.strip()
+  for i, c in enumerate(s):
+    if not c.isdigit() and not ((c == '-') and (i == 0)):
+      return InvalidValueError('Invalid value: only digits are allowed, but found char "%s"' % c, Mark('', 1, i+1+leading_whitespace_len))
+
+  v = int(s)
+  if min and v < min:
+    return InvalidValueError('Invalid value: should be greater than or equal to %d' % min, Mark('', 1, leading_whitespace_len))
+  if max and v > max:
+    return InvalidValueError('Invalid value: should be less than or equal to %d' % max, Mark('', 1, leading_whitespace_len))
+
+  return None
+
+
diff --git a/ostack_validator/test_config_schema_registry.py b/ostack_validator/test_config_schema_registry.py
new file mode 100644
index 0000000..f61c919
--- /dev/null
+++ b/ostack_validator/test_config_schema_registry.py
@@ -0,0 +1,48 @@
+from ostack_validator.schema import ConfigSchemaRegistry, Version
+from ostack_validator.common import find
+
+import unittest
+
+class ConfigSchemaRegistryTests(unittest.TestCase):
+  def test_sample(self):
+    nova = ConfigSchemaRegistry.register_schema(project='nova')
+
+    nova.version('1.0.0')
+    nova.section('DEFAULT')
+    nova.param(name='verbose', type='boolean')
+    nova.param(name='rabbit_host', type='address')
+
+    nova.version('1.1.0')
+    nova.section('DEFAULT')
+    nova.param(name='verbose', type='boolean', default=False)
+    nova.remove_param('rabbit_host')
+
+    nova.commit()
+
+    schema10 = ConfigSchemaRegistry.get_schema(project='nova', version='1.0.0')
+
+    self.assertEqual(Version('1.0.0'), schema10.version)
+    self.assertEqual('ini', schema10.format)
+
+    verbose_param = find(schema10.parameters, lambda p: p.name == 'verbose')
+    self.assertIsNotNone(verbose_param)
+    self.assertEqual('boolean', verbose_param.type)
+    self.assertEqual(None, verbose_param.default)
+
+    rabbit_host_param = find(schema10.parameters, lambda p: p.name == 'rabbit_host')
+    self.assertIsNotNone(rabbit_host_param)
+    self.assertEqual('address', rabbit_host_param.type)
+
+    schema11 = ConfigSchemaRegistry.get_schema(project='nova', version='1.1.0')
+
+    verbose_param11 = find(schema11.parameters, lambda p: p.name == 'verbose')
+    self.assertIsNotNone(verbose_param11)
+    self.assertEqual(False, verbose_param11.default)
+
+    rabbit_host_param11 = find(schema11.parameters, lambda p: p.name == 'rabbit_host')
+    self.assertIsNone(rabbit_host_param11)
+
+
+if __name__ == '__main__':
+  unittest.main()
+
diff --git a/ostack_validator/test_type_validators.py b/ostack_validator/test_type_validators.py
new file mode 100644
index 0000000..3526060
--- /dev/null
+++ b/ostack_validator/test_type_validators.py
@@ -0,0 +1,100 @@
+from ostack_validator.common import Error, MarkedError
+from ostack_validator.schema import TypeValidatorRegistry
+
+import unittest
+
+class TypeValidatorTestHelper(object):
+  def setUp(self):
+    super(TypeValidatorTestHelper, self).setUp()
+    self.validator = TypeValidatorRegistry.get_validator(self.type_name)
+
+  def assertValid(self, value):
+    self.assertIsNone(self.validator.validate(value))
+
+  def assertInvalid(self, value):
+    self.assertIsInstance(self.validator.validate(value), Error)
+
+class StringTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
+  type_name = 'string'
+
+  def test_empty_string_passes(self):
+    self.assertValid('')
+
+  def test_validation_always_passes(self):
+    self.assertValid('foo bar')
+
+class BooleanTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
+  type_name = 'boolean'
+
+  def test_True(self):
+    self.assertValid('True')
+
+  def test_False(self):
+    self.assertValid('False')
+
+  def test_other_values_produce_error(self):
+    self.assertInvalid('foo')
+
+class IntegerTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
+  type_name = 'integer'
+
+  def test_positive_values_are_valid(self):
+    self.assertValid('123')
+
+  def test_zero_is_valid(self):
+    self.assertValid('0')
+
+  def test_negative_values_are_valid(self):
+    self.assertValid('-123')
+
+  def test_leading_whitespace_is_ignored(self):
+    self.assertValid('   5')
+
+  def test_trailing_whitespace_is_ignored(self):
+    self.assertValid('7   ')
+
+  def test_non_digits_are_invalid(self):
+    self.assertInvalid('12a45')
+
+  def test_invalid_char_error_contains_proper_column_in_mark(self):
+    error = self.validator.validate('12a45')
+    self.assertIsInstance(error, MarkedError)
+    self.assertEqual(3, error.mark.column)
+
+  def test_invalid_char_error_contains_proper_column_if_leading_whitespaces(self):
+    error = self.validator.validate('  12a45')
+    self.assertIsInstance(error, MarkedError)
+    self.assertEqual(5, error.mark.column)
+
+class PortTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
+  type_name = 'port'
+
+  def test_positive_integer(self):
+    self.assertValid('123')
+
+  def test_zero_invalid(self):
+    self.assertInvalid('0')
+
+  def test_negatives_are_invalid(self):
+    self.assertInvalid('-1')
+
+  def test_values_greater_than_65535_are_invalid(self):
+    self.assertInvalid('65536')
+
+  def test_low_boundary_is_valid(self):
+    self.assertValid('1')
+
+  def test_high_boundary_is_valid(self):
+    self.assertValid('65535')
+
+  def test_non_digits_are_invalid(self):
+    self.assertInvalid('12a5')
+
+  def test_leading_and_or_trailing_whitespace_is_ignored(self):
+    self.assertValid('  123')
+    self.assertValid('456  ')
+    self.assertValid('  123  ')
+
+if __name__ == '__main__':
+  unittest.main()
+