diff --git a/src/Api/ActionApi.php b/src/Api/ActionApi.php
index 233322e..8896385 100644
--- a/src/Api/ActionApi.php
+++ b/src/Api/ActionApi.php
@@ -58,6 +58,11 @@ class ActionApi extends Api implements Action
      */
     private $return;
 
+    /**
+     * @var TypeCatalog
+     */
+    private $typeCatalog;
+
     /**
      * Action constructor.
      * @param KatanaLogger $logger
@@ -72,6 +77,7 @@ class ActionApi extends Api implements Action
      * @param string $actionName
      * @param ZeroMQRuntimeCaller $caller
      * @param Transport $transport
+     * @param TypeCatalog $typeCatalog
      * @param Param[] $params
      */
     public function __construct(
@@ -87,6 +93,7 @@ public function __construct(
         string $actionName,
         ZeroMQRuntimeCaller $caller,
         Transport $transport,
+        TypeCatalog $typeCatalog,
         array $params = []
     ) {
         parent::__construct(
@@ -105,27 +112,10 @@ public function __construct(
         $this->caller = $caller;
         $this->transport = $transport;
         $this->transportCopy = clone $transport;
+        $this->typeCatalog = $typeCatalog;
         $this->params = $this->prepareParams($params);
     }
 
-    /**
-     * @param array $value
-     * @return bool
-     */
-    private function isArrayType(array $value): bool
-    {
-        return array_keys($value) === range(0, count($value) -1);
-    }
-
-    /**
-     * @param array $value
-     * @return bool
-     */
-    private function isObjectType(array $value): bool
-    {
-        return count(array_filter(array_keys($value), 'is_string')) === count($value);
-    }
-
     /**
      * @return Transport
      */
@@ -247,8 +237,9 @@ public function setDownload(FileInterface $file): Action
      */
     public function setEntity(array $entity): Action
     {
-        if (!$this->isObjectType($entity)) {
-            throw new TransportException('Unexpected collection');
+        $type = $this->typeCatalog::TYPE_OBJECT;
+        if (!$this->typeCatalog->validate($type, $entity)) {
+            throw new TransportException('Invalid Entity');
         }
 
         $this->transport->setData($this->name, $this->version, $this->actionName, $entity);
@@ -263,8 +254,9 @@ public function setEntity(array $entity): Action
      */
     public function setCollection(array $collection): Action
     {
-        if (!$this->isArrayType($collection)) {
-            throw new TransportException('Unexpected entity');
+        $type = $this->typeCatalog::TYPE_ARRAY;
+        if (!$this->typeCatalog->validate($type, $collection)) {
+            throw new TransportException('Invalid Collection');
         }
 
         $this->transport->setCollection($this->name, $this->version, $this->actionName, $collection);
@@ -570,7 +562,7 @@ public function setReturn($value): Action
                 ));
             }
 
-            if (!$this->validate($value, $action->getReturnType())) {
+            if (!$this->typeCatalog->validate($action->getReturnType(), $value)) {
                 throw new InvalidValueException(sprintf(
                     'Invalid return type given in "%s" (%s) for action: "%s"',
                     $this->name,
@@ -614,60 +606,7 @@ public function getReturn()
             $service = $this->getServiceSchema($this->name, $this->version);
             $action = $service->getActionSchema($this->actionName);
 
-            return $this->getDefaultReturn($action->getReturnType());
-        }
-    }
-
-    /**
-     * @param string $type
-     * @return mixed
-     * @throws InvalidValueException
-     */
-    private function getDefaultReturn(string $type)
-    {
-        switch ($type) {
-            case 'null':
-                return null;
-            case 'boolean':
-                return false;
-            case 'integer':
-            case 'float':
-                return 0;
-            case 'string':
-                return '';
-            case 'array':
-            case 'object':
-                return [];
+            return $this->typeCatalog->getDefault($action->getReturnType());
         }
-
-        throw new InvalidValueException("Invalid value type: $type");
-    }
-
-    /**
-     * @param mixed $value
-     * @param string $type
-     * @return bool
-     * @throws InvalidValueException
-     */
-    private function validate($value, string $type): bool
-    {
-        switch ($type) {
-            case 'null':
-                return is_null($value);
-            case 'boolean':
-                return is_bool($value);
-            case 'integer':
-                return is_integer($value);
-            case 'float':
-                return is_float($value);
-            case 'string':
-                return is_string($value);
-            case 'array':
-                return $this->isArrayType($value);
-            case 'object':
-                return $this->isObjectType($value);
-        }
-
-        throw new InvalidValueException("Invalid value type: $type");
     }
 }
diff --git a/src/Api/Factory/ServiceApiFactory.php b/src/Api/Factory/ServiceApiFactory.php
index 4811b54..6950837 100644
--- a/src/Api/Factory/ServiceApiFactory.php
+++ b/src/Api/Factory/ServiceApiFactory.php
@@ -16,6 +16,7 @@
 namespace Katana\Sdk\Api\Factory;
 
 use Katana\Sdk\Api\ActionApi;
+use Katana\Sdk\Api\TypeCatalog;
 use Katana\Sdk\Console\CliInput;
 use Katana\Sdk\Mapper\CompactTransportMapper;
 use Katana\Sdk\Messaging\MessagePackSerializer;
@@ -68,6 +69,7 @@ public function build(
             $action,
             $caller,
             $this->mapper->getTransport($data),
+            new TypeCatalog(),
             $this->mapper->getParams($data)
         );
     }
diff --git a/src/Api/TypeCatalog.php b/src/Api/TypeCatalog.php
new file mode 100644
index 0000000..c8bce7e
--- /dev/null
+++ b/src/Api/TypeCatalog.php
@@ -0,0 +1,117 @@
+<?php
+/**
+ * PHP 7 SDK for the KATANA(tm) Framework (http://katana.kusanagi.io)
+ * Copyright (c) 2016-2017 KUSANAGI S.L. All rights reserved.
+ *
+ * Distributed under the MIT license
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code
+ *
+ * @link      https://github.com/kusanagi/katana-sdk-php7
+ * @license   http://www.opensource.org/licenses/mit-license.php MIT License
+ * @copyright Copyright (c) 2016-2017 KUSANAGI S.L. (http://kusanagi.io)
+ */
+
+namespace Katana\Sdk\Api;
+
+use Katana\Sdk\Exception\InvalidValueException;
+
+/**
+ * Contains the available types in the API.
+ * @package Katana\Sdk\Api
+ */
+class TypeCatalog
+{
+    const TYPE_NULL    = 'null';
+    const TYPE_BOOLEAN = 'boolean';
+    const TYPE_INTEGER = 'integer';
+    const TYPE_FLOAT   = 'float';
+    const TYPE_STRING  = 'string';
+    const TYPE_ARRAY   = 'array';
+    const TYPE_OBJECT  = 'object';
+
+    /**
+     * @param array $value
+     * @return bool
+     */
+    private function isArrayType(array $value): bool
+    {
+        if ($value === []) {
+            return true;
+        }
+        return array_keys($value) === range(0, count($value) -1);
+    }
+
+    /**
+     * @param array $value
+     * @return bool
+     */
+    private function isObjectType(array $value): bool
+    {
+        return count(array_filter(array_keys($value), 'is_string')) === count($value);
+    }
+
+    /**
+     * Return the default value for a given type.
+     *
+     * @param string $type
+     * @return mixed
+     * @throws InvalidValueException
+     */
+    public function getDefault(string $type)
+    {
+        switch ($type) {
+            case self::TYPE_NULL:
+                return null;
+            case self::TYPE_BOOLEAN:
+                return false;
+            case self::TYPE_INTEGER:
+            case self::TYPE_FLOAT:
+                return 0;
+            case self::TYPE_STRING:
+                return '';
+            case self::TYPE_ARRAY:
+            case self::TYPE_OBJECT:
+                return [];
+        }
+
+        throw new InvalidValueException("Invalid value type: $type");
+    }
+
+    /**
+     * Validates a value against a type.
+     *
+     * @param mixed $value
+     * @param string $type
+     * @return bool
+     * @throws InvalidValueException
+     */
+    public function validate(string $type, $value): bool
+    {
+        switch ($type) {
+            case self::TYPE_NULL:
+                return is_null($value);
+            case self::TYPE_BOOLEAN:
+                return is_bool($value);
+            case self::TYPE_INTEGER:
+                return is_integer($value);
+            case self::TYPE_FLOAT:
+                return is_float($value);
+            case self::TYPE_STRING:
+                return is_string($value);
+            case self::TYPE_ARRAY:
+                if (!is_array($value)) {
+                    return false;
+                }
+                return $this->isArrayType($value);
+            case self::TYPE_OBJECT:
+                if (!is_array($value)) {
+                    return false;
+                }
+                return $this->isObjectType($value);
+        }
+
+        throw new InvalidValueException("Invalid value type: $type");
+    }
+}
diff --git a/tests/Api/ActionApiTest.php b/tests/Api/ActionApiTest.php
index 317772f..ecdc561 100644
--- a/tests/Api/ActionApiTest.php
+++ b/tests/Api/ActionApiTest.php
@@ -20,6 +20,7 @@
 use Katana\Sdk\Api\File;
 use Katana\Sdk\Api\Transport;
 use Katana\Sdk\Api\TransportMeta;
+use Katana\Sdk\Api\TypeCatalog;
 use Katana\Sdk\Component\Component;
 use Katana\Sdk\Exception\InvalidValueException;
 use Katana\Sdk\Logger\KatanaLogger;
@@ -84,7 +85,8 @@ public function setUp()
             true,
             'action',
             $caller->reveal(),
-            $this->transport->reveal()
+            $this->transport->reveal(),
+            new TypeCatalog()
         );
     }
 
diff --git a/tests/Api/TypeCatalogTest.php b/tests/Api/TypeCatalogTest.php
new file mode 100644
index 0000000..32f4e90
--- /dev/null
+++ b/tests/Api/TypeCatalogTest.php
@@ -0,0 +1,194 @@
+<?php
+/**
+ * PHP 7 SDK for the KATANA(tm) Framework (http://katana.kusanagi.io)
+ * Copyright (c) 2016-2017 KUSANAGI S.L. All rights reserved.
+ *
+ * Distributed under the MIT license
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code
+ *
+ * @link      https://github.com/kusanagi/katana-sdk-php7
+ * @license   http://www.opensource.org/licenses/mit-license.php MIT License
+ * @copyright Copyright (c) 2016-2017 KUSANAGI S.L. (http://kusanagi.io)
+ */
+
+namespace Katana\Sdk\Tests\Api;
+
+use Katana\Sdk\Api\TypeCatalog;
+use PHPUnit\Framework\TestCase;
+
+class TypeCatalogTest extends TestCase
+{
+    /**
+     * @var TypeCatalog
+     */
+    private $typeCatalog;
+
+    public function setUp()
+    {
+        $this->typeCatalog = new TypeCatalog();
+    }
+
+    public function testNullDefault()
+    {
+        $this->assertNull(
+            $this->typeCatalog->getDefault(TypeCatalog::TYPE_NULL)
+        );
+    }
+
+    public function testBooleanDefault()
+    {
+        $this->assertFalse(
+            $this->typeCatalog->getDefault(TypeCatalog::TYPE_BOOLEAN)
+        );
+    }
+
+    public function testIntegerDefault()
+    {
+        $this->assertEquals(
+            0,
+            $this->typeCatalog->getDefault(TypeCatalog::TYPE_INTEGER)
+        );
+    }
+
+    public function testFloatDefault()
+    {
+        $this->assertEquals(
+            0,
+            $this->typeCatalog->getDefault(TypeCatalog::TYPE_FLOAT)
+        );
+    }
+
+    public function testStringDefault()
+    {
+        $this->assertEquals(
+            '',
+            $this->typeCatalog->getDefault(TypeCatalog::TYPE_STRING)
+        );
+    }
+
+    public function testArrayDefault()
+    {
+        $this->assertEquals(
+            [],
+            $this->typeCatalog->getDefault(TypeCatalog::TYPE_ARRAY)
+        );
+    }
+
+    public function testObjectDefault()
+    {
+        $this->assertEquals(
+            [],
+            $this->typeCatalog->getDefault(TypeCatalog::TYPE_OBJECT)
+        );
+    }
+
+    public function validateDataProvider()
+    {
+        return [
+            // Type Null
+            [true, TypeCatalog::TYPE_NULL, null],
+            [false, TypeCatalog::TYPE_NULL, false],
+            [false, TypeCatalog::TYPE_NULL, true],
+            [false, TypeCatalog::TYPE_NULL, 0],
+            [false, TypeCatalog::TYPE_NULL, 42],
+            [false, TypeCatalog::TYPE_NULL, 0.0],
+            [false, TypeCatalog::TYPE_NULL, 3.1416],
+            [false, TypeCatalog::TYPE_NULL, ''],
+            [false, TypeCatalog::TYPE_NULL, 'foo'],
+            [false, TypeCatalog::TYPE_NULL, []],
+            [false, TypeCatalog::TYPE_NULL, ['a', 'b', 'c']],
+            [false, TypeCatalog::TYPE_NULL, ['a' => 1, 'b' => 2]],
+            // Type Boolean
+            [false, TypeCatalog::TYPE_BOOLEAN, null],
+            [true, TypeCatalog::TYPE_BOOLEAN, false],
+            [true, TypeCatalog::TYPE_BOOLEAN, true],
+            [false, TypeCatalog::TYPE_BOOLEAN, 0],
+            [false, TypeCatalog::TYPE_BOOLEAN, 42],
+            [false, TypeCatalog::TYPE_BOOLEAN, 0.0],
+            [false, TypeCatalog::TYPE_BOOLEAN, 3.1416],
+            [false, TypeCatalog::TYPE_BOOLEAN, ''],
+            [false, TypeCatalog::TYPE_BOOLEAN, 'foo'],
+            [false, TypeCatalog::TYPE_BOOLEAN, []],
+            [false, TypeCatalog::TYPE_BOOLEAN, ['a', 'b', 'c']],
+            [false, TypeCatalog::TYPE_BOOLEAN, ['a' => 1, 'b' => 2]],
+            // Type Integer
+            [false, TypeCatalog::TYPE_INTEGER, null],
+            [false, TypeCatalog::TYPE_INTEGER, false],
+            [false, TypeCatalog::TYPE_INTEGER, true],
+            [true, TypeCatalog::TYPE_INTEGER, 0],
+            [true, TypeCatalog::TYPE_INTEGER, 42],
+            [false, TypeCatalog::TYPE_INTEGER, 0.0],
+            [false, TypeCatalog::TYPE_INTEGER, 3.1416],
+            [false, TypeCatalog::TYPE_INTEGER, ''],
+            [false, TypeCatalog::TYPE_INTEGER, 'foo'],
+            [false, TypeCatalog::TYPE_INTEGER, []],
+            [false, TypeCatalog::TYPE_INTEGER, ['a', 'b', 'c']],
+            [false, TypeCatalog::TYPE_INTEGER, ['a' => 1, 'b' => 2]],
+            // Type Float
+            [false, TypeCatalog::TYPE_FLOAT, null],
+            [false, TypeCatalog::TYPE_FLOAT, false],
+            [false, TypeCatalog::TYPE_FLOAT, true],
+            [false, TypeCatalog::TYPE_FLOAT, 0],
+            [false, TypeCatalog::TYPE_FLOAT, 42],
+            [true, TypeCatalog::TYPE_FLOAT, 0.0],
+            [true, TypeCatalog::TYPE_FLOAT, 3.1416],
+            [false, TypeCatalog::TYPE_FLOAT, ''],
+            [false, TypeCatalog::TYPE_FLOAT, 'foo'],
+            [false, TypeCatalog::TYPE_FLOAT, []],
+            [false, TypeCatalog::TYPE_FLOAT, ['a', 'b', 'c']],
+            [false, TypeCatalog::TYPE_FLOAT, ['a' => 1, 'b' => 2]],
+            // Type String
+            [false, TypeCatalog::TYPE_STRING, null],
+            [false, TypeCatalog::TYPE_STRING, false],
+            [false, TypeCatalog::TYPE_STRING, true],
+            [false, TypeCatalog::TYPE_STRING, 0],
+            [false, TypeCatalog::TYPE_STRING, 42],
+            [false, TypeCatalog::TYPE_STRING, 0.0],
+            [false, TypeCatalog::TYPE_STRING, 3.1416],
+            [true, TypeCatalog::TYPE_STRING, ''],
+            [true, TypeCatalog::TYPE_STRING, 'foo'],
+            [false, TypeCatalog::TYPE_STRING, []],
+            [false, TypeCatalog::TYPE_STRING, ['a', 'b', 'c']],
+            [false, TypeCatalog::TYPE_STRING, ['a' => 1, 'b' => 2]],
+            // Type Array
+            [false, TypeCatalog::TYPE_ARRAY, null],
+            [false, TypeCatalog::TYPE_ARRAY, false],
+            [false, TypeCatalog::TYPE_ARRAY, true],
+            [false, TypeCatalog::TYPE_ARRAY, 0],
+            [false, TypeCatalog::TYPE_ARRAY, 42],
+            [false, TypeCatalog::TYPE_ARRAY, 0.0],
+            [false, TypeCatalog::TYPE_ARRAY, 3.1416],
+            [false, TypeCatalog::TYPE_ARRAY, ''],
+            [false, TypeCatalog::TYPE_ARRAY, 'foo'],
+            [true, TypeCatalog::TYPE_ARRAY, []],
+            [true, TypeCatalog::TYPE_ARRAY, ['a', 'b', 'c']],
+            [false, TypeCatalog::TYPE_ARRAY, ['a' => 1, 'b' => 2]],
+            // Type Object
+            [false, TypeCatalog::TYPE_OBJECT, null],
+            [false, TypeCatalog::TYPE_OBJECT, false],
+            [false, TypeCatalog::TYPE_OBJECT, true],
+            [false, TypeCatalog::TYPE_OBJECT, 0],
+            [false, TypeCatalog::TYPE_OBJECT, 42],
+            [false, TypeCatalog::TYPE_OBJECT, 0.0],
+            [false, TypeCatalog::TYPE_OBJECT, 3.1416],
+            [false, TypeCatalog::TYPE_OBJECT, ''],
+            [false, TypeCatalog::TYPE_OBJECT, 'foo'],
+            [true, TypeCatalog::TYPE_OBJECT, []],
+            [false, TypeCatalog::TYPE_OBJECT, ['a', 'b', 'c']],
+            [true, TypeCatalog::TYPE_OBJECT, ['a' => 1, 'b' => 2]],
+        ];
+    }
+
+    /**
+     * @dataProvider validateDataProvider
+     */
+    public function testValidateNullType(bool $expected, string $type, $value)
+    {
+        $this->assertEquals(
+            $expected,
+            $this->typeCatalog->validate($type, $value)
+        );
+    }
+}