diff --git a/index.js b/index.js
index 29a54ca2..be933442 100644
--- a/index.js
+++ b/index.js
@@ -1,3 +1,3 @@
-exports.Schema = require('./lib/schema');
-exports.AbstractClass = require('./lib/abstract-class');
-exports.Validatable = require('./lib/validatable');
+exports.Schema = require('./lib/schema').Schema;
+exports.AbstractClass = require('./lib/abstract-class').AbstractClass;
+exports.Validatable = require('./lib/validatable').Validatable;
diff --git a/lib/abstract-class.js b/lib/abstract-class.js
index 6df0c02d..62bb9135 100644
--- a/lib/abstract-class.js
+++ b/lib/abstract-class.js
@@ -1,3 +1,14 @@
+/**
+ * Module deps
+ */
+var Validatable = require('./validatable').Validatable;
+var util = require('util');
+var jutil = require('./jutil');
+
+exports.AbstractClass = AbstractClass;
+
+jutil.inherits(AbstractClass, Validatable);
+
 /**
  * Abstract class constructor
  */
@@ -73,13 +84,20 @@ AbstractClass.create = function (data) {
     }
 
     var obj = null;
+    // if we come from save
     if (data instanceof AbstractClass && !data.id) {
         obj = data;
         data = obj.toObject();
+    } else {
+        obj = new this(data);
+
+        // validation required
+        if (!obj.isValid()) {
+            return callback(new Error('Validation error'), obj);
+        }
     }
 
     this.schema.adapter.create(modelName, data, function (err, id) {
-        obj = obj || new this(data);
         if (id) {
             defineReadonlyProp(obj, 'id', id);
             this.cache[id] = obj;
@@ -195,6 +213,10 @@ AbstractClass.prototype.save = function (options, callback) {
     }
 };
 
+AbstractClass.prototype.isNewRecord = function () {
+    return !this.id;
+};
+
 AbstractClass.prototype._adapter = function () {
     return this.constructor.schema.adapter;
 };
@@ -227,6 +249,13 @@ AbstractClass.prototype.updateAttribute = function (name, value, cb) {
 
 AbstractClass.prototype.updateAttributes = function updateAttributes(data, cb) {
     var model = this.constructor.modelName;
+    Object.keys(data).forEach(function (key) {
+        this[key] = data[key];
+    }.bind(this));
+    if (!this.isValid()) {
+        var err = new Error('Validation error');
+        return cb && cb(err);
+    }
     this._adapter().updateAttributes(model, this.id, data, function (err) {
         if (!err) {
             Object.keys(data).forEach(function (key) {
@@ -333,15 +362,6 @@ function merge(base, update) {
     return base;
 }
 
-function hiddenProperty(where, property, value) {
-    Object.defineProperty(where, property, {
-        writable: false,
-        enumerable: false,
-        configurable: false,
-        value: value
-    });
-}
-
 function defineReadonlyProp(obj, key, value) {
     Object.defineProperty(obj, key, {
         writable: false,
diff --git a/lib/jutil.js b/lib/jutil.js
new file mode 100644
index 00000000..61585dee
--- /dev/null
+++ b/lib/jutil.js
@@ -0,0 +1,9 @@
+exports.inherits = function (newClass, baseClass) {
+    Object.keys(baseClass).forEach(function (classMethod) {
+        newClass[classMethod] = baseClass[classMethod];
+    });
+    Object.keys(baseClass.prototype).forEach(function (instanceMethod) {
+        newClass.prototype[instanceMethod] = baseClass.prototype[instanceMethod];
+    });
+};
+
diff --git a/lib/schema.js b/lib/schema.js
index e06e5810..f3f5cf59 100644
--- a/lib/schema.js
+++ b/lib/schema.js
@@ -102,7 +102,7 @@ Schema.prototype.define = function defineClass(className, properties, settings)
 
     // setup inheritance
     newClass.__proto__ = AbstractClass;
-    require('util').inherits(newClass, AbstractClass);
+    util.inherits(newClass, AbstractClass);
 
     // store class in model pool
     this.models[className] = newClass;
@@ -150,3 +150,12 @@ Schema.prototype.defineForeignKey = function defineForeignKey(className, key) {
 };
 
 
+function hiddenProperty(where, property, value) {
+    Object.defineProperty(where, property, {
+        writable: false,
+        enumerable: false,
+        configurable: false,
+        value: value
+    });
+}
+
diff --git a/lib/validatable.js b/lib/validatable.js
index e69de29b..686507c7 100644
--- a/lib/validatable.js
+++ b/lib/validatable.js
@@ -0,0 +1,192 @@
+exports.Validatable = Validatable;
+
+function Validatable() {
+    // validatable class
+};
+
+Validatable.validatesPresenceOf = getConfigurator('presence');
+Validatable.validatesLengthOf = getConfigurator('length');
+Validatable.validatesNumericalityOf = getConfigurator('numericality');
+Validatable.validatesInclusionOf = getConfigurator('inclusion');
+Validatable.validatesExclusionOf = getConfigurator('exclusion');
+
+function getConfigurator(name) {
+    return function () {
+        configure(this, name, arguments);
+    };
+}
+
+Validatable.prototype.isValid = function () {
+    var valid = true, inst = this;
+    if (!this.constructor._validations) {
+        Object.defineProperty(this, 'errors', {
+            enumerable: false,
+            configurable: true,
+            value: false
+        });
+        return valid;
+    }
+    Object.defineProperty(this, 'errors', {
+        enumerable: false,
+        configurable: true,
+        value: new Errors
+    });
+    this.constructor._validations.forEach(function (v) {
+        if (validationFailed(inst, v)) {
+            valid = false;
+        }
+    });
+    if (valid) {
+        Object.defineProperty(this, 'errors', {
+            enumerable: false,
+            configurable: true,
+            value: false
+        });
+    }
+    return valid;
+};
+
+function validationFailed(inst, v) {
+    var attr = v[0];
+    var conf = v[1];
+    // here we should check skip validation conditions (if, unless)
+    // that can be specified in conf
+    var fail = false;
+    validators[conf.validation].call(inst, attr, conf, function onerror(kind) {
+        var message;
+        if (conf.message) {
+            message = conf.message;
+        }
+        if (!message && defaultMessages[conf.validation]) {
+            message = defaultMessages[conf.validation];
+        }
+        if (!message) {
+            message = 'is invalid';
+        }
+        if (kind) {
+            if (message[kind]) {
+                // get deeper
+                message = message[kind];
+            } else if (defaultMessages.common[kind]) {
+                message = defaultMessages.common[kind];
+            }
+        }
+        inst.errors.add(attr, message);
+        fail = true;
+    });
+    return fail;
+}
+
+var defaultMessages = {
+    presence: 'can\'t be blank',
+    length: {
+        min: 'too short',
+        max: 'too long',
+        is: 'length is wrong'
+    },
+    common: {
+        blank: 'is blank',
+        'null': 'is null'
+    },
+    numericality: {
+        'int': 'is not an integer',
+        'number': 'is not a number'
+    },
+    inclusion: 'is not included in the list',
+    exclusion: 'is reserved'
+};
+
+var validators = {
+    presence: function (attr, conf, err) {
+        if (blank(this[attr])) {
+            err();
+        }
+    },
+    length: function (attr, conf, err) {
+        var isNull = this[attr] === null || !(attr in this);
+        if (isNull) {
+            if (conf.allowNull) {
+                return true;
+            } else {
+                return err('null');
+            }
+        } else {
+            if (blank(this[attr])) {
+                if (conf.allowBlank) {
+                    return true;
+                } else {
+                    return err('blank');
+                }
+            }
+        }
+        var len = this[attr].length;
+        if (conf.min && len < conf.min) {
+            err('min');
+        }
+        if (conf.max && len > conf.max) {
+            err('max');
+        }
+        if (conf.is && len !== conf.is) {
+            err('is');
+        }
+    },
+    numericality: function (attr, conf, err) {
+        if (typeof this[attr] !== 'number') {
+            return err('number');
+        }
+        if (conf.int && this[attr] !== Math.round(this[attr])) {
+            return err('int');
+        }
+    },
+    inclusion: function (attr, conf, err) {
+        if (!~conf.in.indexOf(this[attr])) {
+            err()
+        }
+    },
+    exclusion: function (attr, conf, err) {
+        if (~conf.in.indexOf(this[attr])) {
+            err()
+        }
+    }
+};
+
+function blank(v) {
+    if (typeof v === 'undefined') return true;
+    if (v instanceof Array && v.length === 0) return true;
+    if (v === null) return true;
+    if (typeof v == 'string' && v === '') return true;
+    return false;
+}
+
+function configure(class, validation, args) {
+    if (!class._validations) {
+        Object.defineProperty(class, '_validations', {
+            writable: true,
+            configurable: true,
+            enumerable: false,
+            value: []
+        });
+    }
+    args = [].slice.call(args);
+    var conf;
+    if (typeof args[args.length - 1] === 'object') {
+        conf = args.pop();
+    } else {
+        conf = {};
+    }
+    conf.validation = validation;
+    args.forEach(function (attr) {
+        class._validations.push([attr, conf]);
+    });
+}
+
+function Errors() {
+}
+
+Errors.prototype.add = function (field, message) {
+    if (!this[field]) {
+        this[field] = [message];
+    } else {
+        this[field].push(message);
+    }
+};
diff --git a/package.json b/package.json
index 44e83bd9..98dca16c 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "author": "Anatoliy Chakkaev",
-  "name": "yadm",
-  "description": "Yet another data mapper",
+  "name": "jugglingdb",
+  "description": "ORM for every database: redis, mysql, neo4j, mongodb",
   "version": "0.0.1",
   "repository": {
     "url": ""
diff --git a/test/validations_test.coffee b/test/validations_test.coffee
new file mode 100644
index 00000000..bba9af2b
--- /dev/null
+++ b/test/validations_test.coffee
@@ -0,0 +1,172 @@
+juggling = require('../index')
+Schema = juggling.Schema
+AbstractClass = juggling.AbstractClass
+Validatable = juggling.Validatable
+
+require('./spec_helper').init module.exports
+
+schema = new Schema 'memory'
+User = schema.define 'User',
+    email: String
+    name: String
+    password: String
+    state: String
+    age: Number
+    gender: String
+    domain: String
+
+validAttributes =
+    name: 'Anatoliy'
+    email: 'email@example.com'
+    state: ''
+    age: 26
+    gender: 'male'
+    domain: '1602'
+
+User.validatesPresenceOf 'email', 'name'
+
+
+it 'should validate presence', (test) ->
+    user = new User
+    test.ok not user.isValid(), 'User is not valid'
+    test.ok user.errors.email, 'Attr email in errors'
+    test.ok user.errors.name, 'Attr name in errors'
+
+    user.name = 'Anatoliy'
+    test.ok not user.isValid(), 'User is still not valid'
+    test.ok user.errors.email, 'Attr email still in errors'
+    test.ok not user.errors.name, 'Attr name valid'
+
+    user.email = 'anatoliy@localhost'
+    test.ok user.isValid(), 'User is valid'
+    test.ok not user.errors, 'No errors'
+    test.ok not user.errors.email, 'Attr email valid'
+    test.ok not user.errors.name, 'Attr name valid'
+    test.done()
+
+
+it 'should throw error on save if required', (test) ->
+    user = new User
+
+    test.throws () ->
+        user.save throws: true
+
+    test.done()
+
+
+it 'should allow to skip validation on save', (test) ->
+    user = new User
+    test.ok user.isNewRecord(), 'User not saved yet'
+    test.ok not user.isValid(), 'User not valid'
+
+    user.save validate: false
+
+    test.ok not user.isNewRecord(), 'User saved'
+    test.ok not user.isValid(), 'User data still not valid'
+    test.done()
+
+it 'should perform validation on updateAttributes', (test) ->
+    User.create email: 'anatoliy@localhost', name: 'anatoliy', (err, user) ->
+        user.updateAttributes name: null, (err, name) ->
+            test.ok(err)
+            test.ok user.errors
+            test.ok user.errors.name
+            test.done()
+
+it 'should perform validation on create', (test) ->
+    User.create (err, user) ->
+        test.ok err, 'We have an error'
+        # we got an user,
+        test.ok user, 'We got an user'
+        # but it's not saved
+        test.ok user.isNewRecord(), 'User not saved'
+        # and we have errors
+        test.ok user.errors, 'User have errors'
+        # explaining what happens
+        test.ok user.errors.name, 'Errors contain name'
+        test.ok user.errors.email, 'Errors contain email'
+
+        test.done()
+
+it 'should validate length', (test) ->
+    User.validatesLengthOf 'password', min: 3, max: 10, allowNull: true
+    User.validatesLengthOf 'state', is: 2, allowBlank: true
+    user = new User validAttributes
+
+    user.password = 'qw'
+    test.ok not user.isValid(), 'Invalid: too short'
+    test.equal user.errors.password[0], 'too short'
+
+    user.password = '12345678901'
+    test.ok not user.isValid(), 'Invalid: too long'
+    test.equal user.errors.password[0], 'too long'
+
+    user.password = 'hello'
+    test.ok user.isValid(), 'Valid with value'
+    test.ok not user.errors
+
+    user.password = null
+    test.ok user.isValid(), 'Valid without value'
+    test.ok not user.errors
+
+    user.state = 'Texas'
+    test.ok not user.isValid(), 'Invalid state'
+    test.equal user.errors.state[0], 'length is wrong'
+
+    user.state = 'TX'
+    test.ok user.isValid(), 'Valid with value of state'
+    test.ok not user.errors
+
+    test.done()
+
+it 'should validate numericality', (test) ->
+    User.validatesNumericalityOf 'age', int: true
+    user = new User validAttributes
+
+    user.age = '26'
+    test.ok not user.isValid(), 'User is not valid: not a number'
+    test.equal user.errors.age[0], 'is not a number'
+
+    user.age = 26.1
+    test.ok not user.isValid(), 'User is not valid: not integer'
+    test.equal user.errors.age[0], 'is not an integer'
+
+    user.age = 26
+    test.ok user.isValid(), 'User valid: integer age'
+    test.ok not user.errors
+
+    test.done()
+
+it 'should validate inclusion', (test) ->
+    User.validatesInclusionOf 'gender', in: ['male', 'female']
+    user = new User validAttributes
+
+    user.gender = 'any'
+    test.ok not user.isValid()
+    test.equal user.errors.gender[0], 'is not included in the list'
+
+    user.gender = 'female'
+    test.ok user.isValid()
+
+    user.gender = 'male'
+    test.ok user.isValid()
+
+    user.gender = ''
+    test.ok not user.isValid()
+    test.equal user.errors.gender[0], 'is not included in the list'
+
+    test.done()
+
+it 'should validate exclusion', (test) ->
+    User.validatesExclusionOf 'domain', in: ['www', 'admin']
+    user = new User validAttributes
+
+    user.domain = 'www'
+    test.ok not user.isValid()
+    test.equal user.errors.domain[0], 'is reserved'
+
+    user.domain = 'my'
+    test.ok user.isValid()
+
+    test.done()
+