diff --git a/src/mibew/libs/chat.php b/src/mibew/libs/chat.php
index ba800524..0796b246 100644
--- a/src/mibew/libs/chat.php
+++ b/src/mibew/libs/chat.php
@@ -24,10 +24,6 @@ use Mibew\Style\PageStyle;
 
 // Initialize libraries
 require_once(MIBEW_FS_ROOT.'/libs/track.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_interaction.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_chat_interaction.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_execution_context.php');
 
 /**
  * Names for chat-related cookies
diff --git a/src/mibew/libs/classes/mibew_api.php b/src/mibew/libs/classes/Mibew/API/API.php
similarity index 64%
rename from src/mibew/libs/classes/mibew_api.php
rename to src/mibew/libs/classes/Mibew/API/API.php
index 97cd1812..94f5d37b 100644
--- a/src/mibew/libs/classes/mibew_api.php
+++ b/src/mibew/libs/classes/Mibew/API/API.php
@@ -15,12 +15,14 @@
  * limitations under the License.
  */
 
+namespace Mibew\API;
+
 /**
  * Implements Mibew API specification version 1.0
  *
  * @todo May be use regular methods instead of static one
  */
-Class MibewAPI {
+class API {
 
 	/**
 	 * Version of the MIBEW API protocol implemented by the class
@@ -28,7 +30,7 @@ Class MibewAPI {
 	const PROTOCOL_VERSION = '1.0';
 
 	/**
-	 * Array of MibewAPI objects
+	 * Array of \Mibew\API\API objects
 	 * @var array
 	 */
 	protected static $interactions = array();
@@ -36,22 +38,22 @@ Class MibewAPI {
 	/**
 	 * An object that encapsulates type of the interaction
 	 *
-	 * @var MibewAPIInteraction
+	 * @var \Mibew\API\Interaction
 	 */
 	protected $interaction = NULL;
 
 	/**
-	 * Returns MibewAPI object
+	 * Returns \Mibew\API\API object
 	 *
 	 * @param string $class_name A name of the interaction type class
 	 * @return MibeAPI object
-	 * @throws MibewAPIException
+	 * @throws \Mibew\API\APIException
 	 */
 	public static function getAPI($class_name) {
 		if (! class_exists($class_name)) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Wrong interaction type",
-				MibewAPIException::WRONG_INTERACTION_TYPE
+				APIException::WRONG_INTERACTION_TYPE
 			);
 		}
 		if (empty(self::$interactions[$class_name])) {
@@ -63,9 +65,9 @@ Class MibewAPI {
 	/**
 	 * Class constructor
 	 *
-	 * @param MibewAPIInteraction $interaction Interaction type object
+	 * @param \Mibew\API\Interaction $interaction Interaction type object
 	 */
-	protected function __construct(MibewAPIInteraction $interaction) {
+	protected function __construct(Interaction\Interaction $interaction) {
 		$this->interaction = $interaction;
 	}
 
@@ -74,56 +76,56 @@ Class MibewAPI {
 	 *
 	 * @param array $package Package array. See Mibew API for details.
 	 * @param array $trusted_signatures Array of trusted signatures.
-	 * @throws MibewAPIException
+	 * @throws \Mibew\API\APIException
 	 */
 	public function checkPackage($package, $trusted_signatures) {
 		// Check signature
 		if (! isset($package['signature'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Package signature is empty",
-				MibewAPIException::EMPTY_SIGNATURE
+				APIException::EMPTY_SIGNATURE
 			);
 		}
 		if (! in_array($package['signature'], $trusted_signatures)) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Package signed with untrusted signature",
-				MibewAPIException::UNTRUSTED_SIGNATURE
+				APIException::UNTRUSTED_SIGNATURE
 			);
 		}
 
 		// Check protocol
 		if (empty($package['proto'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Package protocol is empty",
-				MibewAPIException::EMPTY_PROTOCOL
+				APIException::EMPTY_PROTOCOL
 			);
 		}
 		if ($package['proto'] != self::PROTOCOL_VERSION) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Wrong package protocol version '{$package['proto']}'",
-				MibewAPIException::WRONG_PROTOCOL_VERSION
+				APIException::WRONG_PROTOCOL_VERSION
 			);
 		}
 
 		// Check async flag
 		if (! isset($package['async'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"'async' flag is missed",
-				MibewAPIException::ASYNC_FLAG_MISSED
+				APIException::ASYNC_FLAG_MISSED
 			);
 		}
 		if (! is_bool($package['async'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Wrong 'async' flag value",
-				MibewAPIException::WRONG_ASYNC_FLAG_VALUE
+				APIException::WRONG_ASYNC_FLAG_VALUE
 			);
 		}
 
 		// Package must have at least one request
 		if (empty($package['requests'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Empty requests set",
-				MibewAPIException::EMPTY_REQUESTS
+				APIException::EMPTY_REQUESTS
 			);
 		}
 		// Check requests in package
@@ -136,21 +138,21 @@ Class MibewAPI {
 	 * Validate request
 	 *
 	 * @param array $request Request array. See Mibew API for details.
-	 * @throws MibewAPIException
+	 * @throws \Mibew\API\APIException
 	 */
 	public function checkRequest($request) {
 		// Check token
 		if (empty($request['token'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Empty request token",
-				MibewAPIException::EMPTY_TOKEN
+				APIException::EMPTY_TOKEN
 			);
 		}
 		// Request must have at least one function
 		if (empty($request['functions'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Empty functions set",
-				MibewAPIException::EMPTY_FUNCTIONS
+				APIException::EMPTY_FUNCTIONS
 			);
 		}
 		// Check functions in request
@@ -165,14 +167,14 @@ Class MibewAPI {
 	 * @param array $function Function array. See Mibew API for details.
 	 * @param boolean $filter_reserved_functions Determine if function name must not be in
 	 * reserved list
-	 * @throws MibewAPIException
+	 * @throws \Mibew\API\APIException
 	 */
 	public function checkFunction($function, $filter_reserved_functions = false) {
 		// Check function name
 		if (empty($function['function'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				'Cannot call for function with empty name',
-				MibewAPIException::EMPTY_FUNCTION_NAME
+				APIException::EMPTY_FUNCTION_NAME
 			);
 		}
 		if ($filter_reserved_functions) {
@@ -180,23 +182,23 @@ Class MibewAPI {
 				$function['function'],
 				$this->interaction->reservedFunctionNames
 			)) {
-				throw new MibewAPIException(
+				throw new APIException(
 					"'{$function['function']}' is reserved function name",
-					MibewAPIException::FUNCTION_NAME_RESERVED
+					APIException::FUNCTION_NAME_RESERVED
 				);
 			}
 		}
 		// Check function's arguments
 		if (empty($function['arguments'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"There are no arguments in '{$function['function']}' function",
-				MibewAPIException::EMPTY_ARGUMENTS
+				APIException::EMPTY_ARGUMENTS
 			);
 		}
 		if (! is_array($function['arguments'])) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Arguments must be an array",
-				MibewAPIException::WRONG_ARGUMENTS_TYPE
+				APIException::WRONG_ARGUMENTS_TYPE
 			);
 		}
 		$unset_arguments = array_diff(
@@ -204,9 +206,9 @@ Class MibewAPI {
 			array_keys($function['arguments'])
 		);
 		if (! empty($unset_arguments)) {
-			throw new MibewAPIException(
+			throw new APIException(
 				"Arguments '" . implode("', '", $unset_arguments) . "' must be set",
-				MibewAPIException::OBLIGATORY_ARGUMENTS_MISSED
+				APIException::OBLIGATORY_ARGUMENTS_MISSED
 			);
 		}
 	}
@@ -234,7 +236,7 @@ Class MibewAPI {
 	 * @param string $package Encoded package
 	 * @param array $trusted_signatures List of trusted signatures
 	 * @return array Decoded package array. See Mibew API for details.
-	 * @throws MibewAPIException
+	 * @throws \Mibew\API\APIException
 	 */
 	public function decodePackage($package, $trusted_signatures) {
 		// Try to decode package
@@ -245,10 +247,10 @@ Class MibewAPI {
 		$json_error_code = json_last_error();
 		if ($json_error_code != JSON_ERROR_NONE) {
 			// Not valid JSON
-			throw new MibewAPIException(
+			throw new APIException(
 				"Package have invalid json structure. " .
 					"JSON error code is '" . $json_error_code . "'",
-				MibewAPIException::NOT_VALID_JSON
+				APIException::NOT_VALID_JSON
 			);
 		}
 		$this->checkPackage($decoded_package, $trusted_signatures);
@@ -279,15 +281,15 @@ Class MibewAPI {
 
 	/**
 	 * Search 'result' function in $function_list. If request contains more than one result
-	 * functions throws an MibewAPIException
+	 * functions throws an \Mibew\API\APIException
 	 *
-	 * @param array $functions_list Array of functions. See MibewAPI for function structure
-	 * details
+	 * @param array $functions_list Array of functions. See Mibew API specification
+	 * for function structure details
 	 * @param mixed $existance Control existance of the 'result' function in request.
 	 * Use boolean true if 'result' function must exists in request, boolean false if must not
 	 * and null if it doesn't matter.
 	 * @return mixed Function array if 'result' function found and NULL otherwise
-	 * @throws MibewAPIException
+	 * @throws \Mibew\API\APIException
 	 */
 	public function getResultFunction ($functions_list, $existence = null) {
 		$result_function = null;
@@ -296,9 +298,9 @@ Class MibewAPI {
 			if ($function['function'] == 'result') {
 				if (! is_null($result_function)) {
 					// Another 'result' function found
-					throw new MibewAPIException(
+					throw new APIException(
 						"Function 'result' already exists in request",
-						MibewAPIException::RESULT_FUNCTION_ALREADY_EXISTS
+						APIException::RESULT_FUNCTION_ALREADY_EXISTS
 					);
 				}
 				// First 'result' function found
@@ -307,118 +309,20 @@ Class MibewAPI {
 		}
 		if ($existence === true && is_null($result_function)) {
 			// 'result' function must present in request
-			throw new MibewAPIException(
+			throw new APIException(
 				"There is no 'result' function in request",
-				MibewAPIException::NO_RESULT_FUNCTION
+				APIException::NO_RESULT_FUNCTION
 			);
 		}
 		if ($existence === false && !is_null($result_function)) {
 			// 'result' function must not present in request
-			throw new MibewAPIException(
+			throw new APIException(
 				"There is 'result' function in request",
-				MibewAPIException::RESULT_FUNCTION_EXISTS
+				APIException::RESULT_FUNCTION_EXISTS
 			);
 		}
 		return $result_function;
 	}
 }
 
-/**
- * Mibew API Exception class.
- */
-class MibewAPIException extends Exception {
-	/**
-	 * Async flag is missed.
-	 */
-	const ASYNC_FLAG_MISSED = 1;
-	/**
-	 * There are no arguments in function
-	 */
-	const EMPTY_ARGUMENTS = 2;
-	/**
-	 * Cannot call for function with empty name
-	 */
-	const EMPTY_FUNCTION_NAME = 3;
-	/**
-	 * Functions set is empty
-	 */
-	const EMPTY_FUNCTIONS = 4;
-	/**
-	 * Package protocol is empty
-	 */
-	const EMPTY_PROTOCOL = 5;
-	/**
-	 * Requests set is empty
-	 */
-	const EMPTY_REQUESTS = 6;
-	/**
-	 * Package signature is empty
-	 */
-	const EMPTY_SIGNATURE = 7;
-	/**
-	 * Request token is empty
-	 */
-	const EMPTY_TOKEN = 8;
-	/**
-	 * Wrong reference. Reference variable is empty
-	 */
-	const EMPTY_VARIABLE_IN_REFERENCE = 9;
-	/**
-	 * This function name is reserved
-	 */
-	const FUNCTION_NAME_RESERVED = 10;
-	/**
-	 * There is no result function
-	 */
-	const NO_RESULT_FUNCTION = 11;
-	/**
-	 * Package have not valid JSON structure
-	 */
-	const NOT_VALID_JSON = 12;
-	/**
-	 * Some of the function's obligatory arguments are missed
-	 */
-	const OBLIGATORY_ARGUMENTS_MISSED = 13;
-	/**
-	 * Request contains more than one result functions
-	 */
-	const RESULT_FUNCTION_ALREADY_EXISTS = 14;
-	/**
-	 * There is 'result' function in request
-	 */
-	const RESULT_FUNCTION_EXISTS = 15;
-	/**
-	 * Package signed with untrusted signature
-	 */
-	const UNTRUSTED_SIGNATURE = 16;
-	/**
-	 * Wrong reference. Variable is undefined in functions results
-	 */
-	const VARIABLE_IS_UNDEFINED_IN_REFERENCE = 17;
-	/**
-	 * Variable is undefined in function's results
-	 */
-	const VARIABLE_IS_UNDEFINED_IN_RESULT = 18;
-	/**
-	 * Arguments must be an array
-	 */
-	const WRONG_ARGUMENTS_TYPE = 19;
-	/**
-	 * Async flag value is wrong
-	 */
-	const WRONG_ASYNC_FLAG_VALUE = 20;
-	/**
-	 * Wrong reference. Function with this number does not call yet
-	 */
-	const WRONG_FUNCTION_NUM_IN_REFERENCE = 21;
-	/**
-	 * Wrong interaction type
-	 */
-	const WRONG_INTERACTION_TYPE = 22;
-	/**
-	 * Wrong package protocol version
-	 */
-	const WRONG_PROTOCOL_VERSION = 23;
-}
-
 ?>
\ No newline at end of file
diff --git a/src/mibew/libs/classes/Mibew/API/APIException.php b/src/mibew/libs/classes/Mibew/API/APIException.php
new file mode 100644
index 00000000..e059324a
--- /dev/null
+++ b/src/mibew/libs/classes/Mibew/API/APIException.php
@@ -0,0 +1,118 @@
+<?php
+/*
+ * Copyright 2005-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Mibew\API;
+
+/**
+ * Mibew API Exception class.
+ */
+class APIException extends \Exception {
+	/**
+	 * Async flag is missed.
+	 */
+	const ASYNC_FLAG_MISSED = 1;
+	/**
+	 * There are no arguments in function
+	 */
+	const EMPTY_ARGUMENTS = 2;
+	/**
+	 * Cannot call for function with empty name
+	 */
+	const EMPTY_FUNCTION_NAME = 3;
+	/**
+	 * Functions set is empty
+	 */
+	const EMPTY_FUNCTIONS = 4;
+	/**
+	 * Package protocol is empty
+	 */
+	const EMPTY_PROTOCOL = 5;
+	/**
+	 * Requests set is empty
+	 */
+	const EMPTY_REQUESTS = 6;
+	/**
+	 * Package signature is empty
+	 */
+	const EMPTY_SIGNATURE = 7;
+	/**
+	 * Request token is empty
+	 */
+	const EMPTY_TOKEN = 8;
+	/**
+	 * Wrong reference. Reference variable is empty
+	 */
+	const EMPTY_VARIABLE_IN_REFERENCE = 9;
+	/**
+	 * This function name is reserved
+	 */
+	const FUNCTION_NAME_RESERVED = 10;
+	/**
+	 * There is no result function
+	 */
+	const NO_RESULT_FUNCTION = 11;
+	/**
+	 * Package have not valid JSON structure
+	 */
+	const NOT_VALID_JSON = 12;
+	/**
+	 * Some of the function's obligatory arguments are missed
+	 */
+	const OBLIGATORY_ARGUMENTS_MISSED = 13;
+	/**
+	 * Request contains more than one result functions
+	 */
+	const RESULT_FUNCTION_ALREADY_EXISTS = 14;
+	/**
+	 * There is 'result' function in request
+	 */
+	const RESULT_FUNCTION_EXISTS = 15;
+	/**
+	 * Package signed with untrusted signature
+	 */
+	const UNTRUSTED_SIGNATURE = 16;
+	/**
+	 * Wrong reference. Variable is undefined in functions results
+	 */
+	const VARIABLE_IS_UNDEFINED_IN_REFERENCE = 17;
+	/**
+	 * Variable is undefined in function's results
+	 */
+	const VARIABLE_IS_UNDEFINED_IN_RESULT = 18;
+	/**
+	 * Arguments must be an array
+	 */
+	const WRONG_ARGUMENTS_TYPE = 19;
+	/**
+	 * Async flag value is wrong
+	 */
+	const WRONG_ASYNC_FLAG_VALUE = 20;
+	/**
+	 * Wrong reference. Function with this number does not call yet
+	 */
+	const WRONG_FUNCTION_NUM_IN_REFERENCE = 21;
+	/**
+	 * Wrong interaction type
+	 */
+	const WRONG_INTERACTION_TYPE = 22;
+	/**
+	 * Wrong package protocol version
+	 */
+	const WRONG_PROTOCOL_VERSION = 23;
+}
+
+?>
\ No newline at end of file
diff --git a/src/mibew/libs/classes/mibew_api_execution_context.php b/src/mibew/libs/classes/Mibew/API/ExecutionContext.php
similarity index 87%
rename from src/mibew/libs/classes/mibew_api_execution_context.php
rename to src/mibew/libs/classes/Mibew/API/ExecutionContext.php
index 7a924426..c4c7c8fe 100644
--- a/src/mibew/libs/classes/mibew_api_execution_context.php
+++ b/src/mibew/libs/classes/Mibew/API/ExecutionContext.php
@@ -15,10 +15,12 @@
  * limitations under the License.
  */
 
+namespace Mibew\API;
+
 /**
  * Implements functions execution context
  */
-Class MibewAPIExecutionContext {
+class ExecutionContext {
 	/**
 	 * Values which returns after execution of all functions in request
 	 * @var array
@@ -35,7 +37,7 @@ Class MibewAPIExecutionContext {
 	 * Returns requets results
 	 *
 	 * @return array Request results
-	 * @see MibewAPIExecutionContext::$return
+	 * @see \Mibew\API\ExecutionContext::$return
 	 */
 	public function getResults () {
 		return $this->return;
@@ -46,7 +48,7 @@ Class MibewAPIExecutionContext {
 	 *
 	 * @param array $function Function array. See MibewAPI for details.
 	 * @return array Arguments list
-	 * @throws MibewAPIException
+	 * @throws \Mibew\API\APIException
 	 */
 	public function getArgumentsList ($function) {
 		$arguments = $function['arguments'];
@@ -55,20 +57,20 @@ Class MibewAPIExecutionContext {
 			// Check target function in context
 			if (! isset($this->functions_results[$func_num - 1])) {
 				// Wrong function num
-				throw new MibewAPIException(
+				throw new APIException(
 					"Wrong reference in '{$function['function']}' function. " .
 					"Function #{$func_num} does not call yet.",
-					MibewAPIException::WRONG_FUNCTION_NUM_IN_REFERENCE
+					APIException::WRONG_FUNCTION_NUM_IN_REFERENCE
 				);
 			}
 
 			// Check reference
 			if (empty($arguments[$variable])) {
 				// Empty argument that should contains reference
-				throw new MibewAPIException(
+				throw new APIException(
 					"Wrong reference in '{$function['function']}' function. " .
 					"Empty {$variable} argument.",
-					MibewAPIException::EMPTY_VARIABLE_IN_REFERENCE
+					APIException::EMPTY_VARIABLE_IN_REFERENCE
 				);
 			}
 			$reference_to = $arguments[$variable];
@@ -76,11 +78,11 @@ Class MibewAPIExecutionContext {
 			// Check target value
 			if (! isset($this->functions_results[$func_num - 1][$reference_to])) {
 				// Undefined target value
-				throw new MibewAPIException(
+				throw new APIException(
 					"Wrong reference in '{$function['function']}' function. " .
 					"There is no '{$reference_to}' argument in #{$func_num} " .
 					"function results",
-					MibewAPIException::VARIABLE_IS_UNDEFINED_IN_REFERENCE
+					APIException::VARIABLE_IS_UNDEFINED_IN_REFERENCE
 				);
 			}
 
@@ -95,7 +97,7 @@ Class MibewAPIExecutionContext {
 	 *
 	 * @param array $function Function array. See MibewAPI for details.
 	 * @param array $results Associative array of the function results.
-	 * @throws MibewAPIException
+	 * @throws \Mibew\API\APIException
 	 */
 	public function storeFunctionResults ($function, $results) {
 		// Check if function return correct results
@@ -104,10 +106,10 @@ Class MibewAPIExecutionContext {
 			foreach ($function['arguments']['return'] as $name => $alias) {
 				if (! isset($results[$name])) {
 					// Value that defined in 'return' argument is undefined
-					throw new MibewAPIException(
+					throw new APIException(
 						"Variable with name '{$name}' is undefined in the " .
 						"results of the '{$function['function']}' function",
-						MibewAPIException::VARIABLE_IS_UNDEFINED_IN_RESULT
+						APIException::VARIABLE_IS_UNDEFINED_IN_RESULT
 					);
 				}
 				$this->return[$alias] = $results[$name];
diff --git a/src/mibew/libs/classes/mibew_api_chat_interaction.php b/src/mibew/libs/classes/Mibew/API/Interaction/ChatInteraction.php
similarity index 83%
rename from src/mibew/libs/classes/mibew_api_chat_interaction.php
rename to src/mibew/libs/classes/Mibew/API/Interaction/ChatInteraction.php
index 5cb3e4fa..a6638ade 100644
--- a/src/mibew/libs/classes/mibew_api_chat_interaction.php
+++ b/src/mibew/libs/classes/Mibew/API/Interaction/ChatInteraction.php
@@ -15,14 +15,16 @@
  * limitations under the License.
  */
 
+namespace Mibew\API\Interaction;
+
 /**
  * Implements Mibew Core - Mibew Chat Window interaction
  */
-class MibewAPIChatInteraction extends MibewAPIInteraction {
+class ChatInteraction extends Interaction {
 	/**
 	 * Defines obligatory arguments and default values for them
 	 * @var array
-	 * @see MibewAPIInteraction::$obligatoryArgumnents
+	 * @see \Mibew\API\Interaction\Interaction::$obligatoryArgumnents
 	 */
 	protected $obligatoryArguments = array(
 		'*' => array(
@@ -39,7 +41,7 @@ class MibewAPIChatInteraction extends MibewAPIInteraction {
 	/**
 	 * Reserved function's names
 	 * @var array
-	 * @see MibewAPIInteraction::$reservedFunctionNames
+	 * @see \Mibew\API\Interaction\Interaction::$reservedFunctionNames
 	 */
 	public $reservedFunctionNames = array(
 		'result'
diff --git a/src/mibew/libs/classes/mibew_api_interaction.php b/src/mibew/libs/classes/Mibew/API/Interaction/Interaction.php
similarity index 98%
rename from src/mibew/libs/classes/mibew_api_interaction.php
rename to src/mibew/libs/classes/Mibew/API/Interaction/Interaction.php
index 4702b407..01ba379f 100644
--- a/src/mibew/libs/classes/mibew_api_interaction.php
+++ b/src/mibew/libs/classes/Mibew/API/Interaction/Interaction.php
@@ -15,10 +15,12 @@
  * limitations under the License.
  */
 
+namespace Mibew\API\Interaction;
+
 /**
  * Encapsulates interaction type
  */
-abstract class MibewAPIInteraction {
+abstract class Interaction {
 	/**
 	 * Defines obligatory arguments and default values for them
 	 *
diff --git a/src/mibew/libs/classes/mibew_api_invite_interaction.php b/src/mibew/libs/classes/Mibew/API/Interaction/InviteInteraction.php
similarity index 83%
rename from src/mibew/libs/classes/mibew_api_invite_interaction.php
rename to src/mibew/libs/classes/Mibew/API/Interaction/InviteInteraction.php
index 601c89b1..a56f4a43 100644
--- a/src/mibew/libs/classes/mibew_api_invite_interaction.php
+++ b/src/mibew/libs/classes/Mibew/API/Interaction/InviteInteraction.php
@@ -15,14 +15,16 @@
  * limitations under the License.
  */
 
+namespace Mibew\API\Interaction;
+
 /**
  * Implements Mibew Core - Mibew invitation waiting window interaction
  */
-class MibewAPIInviteInteraction extends MibewAPIInteraction {
+class InviteInteraction extends Interaction {
 	/**
 	 * Defines obligatory arguments and default values for them
 	 * @var array
-	 * @see MibewAPIInteraction::$obligatoryArgumnents
+	 * @see \Mibew\API\Interaction\Interaction::$obligatoryArgumnents
 	 */
 	protected $obligatoryArguments = array(
 		'*' => array(
@@ -38,7 +40,7 @@ class MibewAPIInviteInteraction extends MibewAPIInteraction {
 	/**
 	 * Reserved function's names
 	 * @var array
-	 * @see MibewAPIInteraction::$reservedFunctionNames
+	 * @see \Mibew\API\Interaction\Interaction::$reservedFunctionNames
 	 */
 	public $reservedFunctionNames = array(
 		'result'
diff --git a/src/mibew/libs/classes/mibew_api_users_interaction.php b/src/mibew/libs/classes/Mibew/API/Interaction/UsersInteraction.php
similarity index 83%
rename from src/mibew/libs/classes/mibew_api_users_interaction.php
rename to src/mibew/libs/classes/Mibew/API/Interaction/UsersInteraction.php
index 663c3599..ff15a39d 100644
--- a/src/mibew/libs/classes/mibew_api_users_interaction.php
+++ b/src/mibew/libs/classes/Mibew/API/Interaction/UsersInteraction.php
@@ -15,14 +15,16 @@
  * limitations under the License.
  */
 
+namespace Mibew\API\Interaction;
+
 /**
  * Implements Mibew Core - Mibew Users list interaction
  */
-class MibewAPIUsersInteraction extends MibewAPIInteraction {
+class UsersInteraction extends Interaction {
 	/**
 	 * Defines obligatory arguments and default values for them
 	 * @var array
-	 * @see MibewAPIInteraction::$obligatoryArgumnents
+	 * @see \Mibew\API\Interaction\Interaction::$obligatoryArgumnents
 	 */
 	protected $obligatoryArguments = array(
 		'*' => array(
@@ -41,7 +43,7 @@ class MibewAPIUsersInteraction extends MibewAPIInteraction {
 	/**
 	 * Reserved function's names
 	 * @var array
-	 * @see MibewAPIInteraction::$reservedFunctionNames
+	 * @see \Mibew\API\Interaction\Interaction::$reservedFunctionNames
 	 */
 	public $reservedFunctionNames = array(
 		'result'
diff --git a/src/mibew/libs/classes/Mibew/RequestProcessor/InviteProcessor.php b/src/mibew/libs/classes/Mibew/RequestProcessor/InviteProcessor.php
index 142971c4..28c61b3b 100644
--- a/src/mibew/libs/classes/Mibew/RequestProcessor/InviteProcessor.php
+++ b/src/mibew/libs/classes/Mibew/RequestProcessor/InviteProcessor.php
@@ -18,7 +18,7 @@
 namespace Mibew\RequestProcessor;
 
 // Import namespaces and classes of the core
-use \MibewAPI;
+use Mibew\API\API as MibewAPI;
 use Mibew\RequestProcessor\Exception\InviteProcessorException;
 
 /**
@@ -68,12 +68,12 @@ class InviteProcessor extends ClientSideProcessor {
 	}
 
 	/**
-	 * Creates and returns an instance of the MibewAPI class.
+	 * Creates and returns an instance of the \Mibew\API\API class.
 	 *
-	 * @return MibewAPI
+	 * @return \Mibew\API\API
 	 */
 	protected function getMibewAPIInstance() {
-		return MibewAPI::getAPI('MibewAPIInviteInteraction');
+		return MibewAPI::getAPI('\\Mibew\\API\\Interaction\\InviteInteraction');
 	}
 
 	/**
diff --git a/src/mibew/libs/classes/Mibew/RequestProcessor/Processor.php b/src/mibew/libs/classes/Mibew/RequestProcessor/Processor.php
index 5f4b0eae..00c66a40 100644
--- a/src/mibew/libs/classes/Mibew/RequestProcessor/Processor.php
+++ b/src/mibew/libs/classes/Mibew/RequestProcessor/Processor.php
@@ -18,7 +18,6 @@
 namespace Mibew\RequestProcessor;
 
 // Import namespaces and classes of the core
-use \MibewAPIExecutionContext;
 use Mibew\Database;
 use Mibew\EventDispatcher;
 use Mibew\RequestProcessor\Exception\RequestProcessorException;
@@ -97,7 +96,7 @@ abstract class Processor {
 
 	/**
 	 * Instance of the MibewAPI class
-	 * @var \MibewAPI
+	 * @var \Mibew\API\API
 	 */
 	protected $mibewAPI = null;
 
@@ -333,7 +332,7 @@ abstract class Processor {
 	 * @return array Array of requests results.
 	 */
 	protected function processRequest($request, $result_function = null) {
-		$context = new MibewAPIExecutionContext();
+		$context = new \Mibew\API\ExecutionContext();
 
 		// Get result functions
 		$result_function = $this->mibewAPI->getResultFunction(
@@ -368,10 +367,10 @@ abstract class Processor {
 	 * Process function
 	 *
 	 * @param array $function 'Function' array. See Mibew API for details
-	 * @param MibewAPIExecutionContext &$context Execution context
+	 * @param \Mibew\API\ExecutionContext &$context Execution context
 	 * @return boolean lase if function returns errorCode and errorCode differs from 0.
 	 */
-	protected function processFunction($function, MibewAPIExecutionContext &$context) {
+	protected function processFunction($function, \Mibew\API\ExecutionContext &$context) {
 		// Get function arguments with replaced references
 		$arguments = $context->getArgumentsList($function);
 
@@ -523,9 +522,9 @@ abstract class Processor {
 	protected function checkFunction($function) {}
 
 	/**
-	 * Creates and returns an instance of the MibewAPI class.
+	 * Creates and returns an instance of the \Mibew\API\API class.
 	 *
-	 * @return MibewAPI
+	 * @return \Mibew\API\API
 	 */
 	protected abstract function getMibewAPIInstance();
 }
diff --git a/src/mibew/libs/classes/Mibew/RequestProcessor/ThreadProcessor.php b/src/mibew/libs/classes/Mibew/RequestProcessor/ThreadProcessor.php
index 3f6a1459..deb4b787 100644
--- a/src/mibew/libs/classes/Mibew/RequestProcessor/ThreadProcessor.php
+++ b/src/mibew/libs/classes/Mibew/RequestProcessor/ThreadProcessor.php
@@ -18,9 +18,9 @@
 namespace Mibew\RequestProcessor;
 
 // Import namespaces and classes of the core
-use \MibewAPI;
 use Mibew\Settings;
 use Mibew\Thread;
+use Mibew\API\API as MibewAPI;
 use Mibew\RequestProcessor\Exception\ThreadProcessorException;
 
 /**
@@ -134,12 +134,12 @@ class ThreadProcessor extends ClientSideProcessor {
 	}
 
 	/**
-	 * Creates and returns an instance of the MibewAPI class.
+	 * Creates and returns an instance of the \Mibew\API\API class.
 	 *
-	 * @return \MibewAPI
+	 * @return \Mibew\API\API
 	 */
 	protected function getMibewAPIInstance() {
-		return MibewAPI::getAPI('MibewAPIChatInteraction');
+		return MibewAPI::getAPI('\\Mibew\\API\\Interaction\\ChatInteraction');
 	}
 
 	/**
diff --git a/src/mibew/libs/classes/Mibew/RequestProcessor/UsersProcessor.php b/src/mibew/libs/classes/Mibew/RequestProcessor/UsersProcessor.php
index 9c9c0288..bfe7a508 100644
--- a/src/mibew/libs/classes/Mibew/RequestProcessor/UsersProcessor.php
+++ b/src/mibew/libs/classes/Mibew/RequestProcessor/UsersProcessor.php
@@ -18,11 +18,11 @@
 namespace Mibew\RequestProcessor;
 
 // Import namespaces and classes of the core
-use \MibewAPI;
 use Mibew\Database;
 use Mibew\EventDispatcher;
 use Mibew\Settings;
 use Mibew\Thread;
+use Mibew\API\API as MibewAPI;
 use Mibew\RequestProcessor\Exception\UsersProcessorException;
 
 /**
@@ -76,12 +76,12 @@ class UsersProcessor extends ClientSideProcessor {
 	}
 
 	/**
-	 * Creates and returns an instance of the MibewAPI class.
+	 * Creates and returns an instance of the \Mibew\API\API class.
 	 *
-	 * @return \MibewAPI
+	 * @return \Mibew\API\API
 	 */
 	protected function getMibewAPIInstance() {
-		return MibewAPI::getAPI('MibewAPIUsersInteraction');
+		return MibewAPI::getAPI('\\Mibew\\API\\Interaction\\UsersInteraction');
 	}
 
 	/**
diff --git a/src/mibew/operator/invitationstate.php b/src/mibew/operator/invitationstate.php
index c60dd71e..dfbe6696 100644
--- a/src/mibew/operator/invitationstate.php
+++ b/src/mibew/operator/invitationstate.php
@@ -18,10 +18,6 @@
 require_once(dirname(dirname(__FILE__)).'/libs/init.php');
 require_once(MIBEW_FS_ROOT.'/libs/invitation.php');
 require_once(MIBEW_FS_ROOT.'/libs/operator.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_interaction.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_invite_interaction.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_execution_context.php');
 
 $processor = \Mibew\RequestProcessor\InviteProcessor::getInstance();
 $processor->receiveRequest($_POST['data']);
diff --git a/src/mibew/operator/update.php b/src/mibew/operator/update.php
index 6e885aac..ce65ef25 100644
--- a/src/mibew/operator/update.php
+++ b/src/mibew/operator/update.php
@@ -22,10 +22,6 @@ require_once(MIBEW_FS_ROOT.'/libs/operator.php');
 require_once(MIBEW_FS_ROOT.'/libs/groups.php');
 require_once(MIBEW_FS_ROOT.'/libs/invitation.php');
 require_once(MIBEW_FS_ROOT.'/libs/track.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_interaction.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_users_interaction.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_execution_context.php');
 
 $processor = \Mibew\RequestProcessor\UsersProcessor::getInstance();
 $processor->receiveRequest($_POST['data']);
diff --git a/src/mibew/thread.php b/src/mibew/thread.php
index dc43c62b..a87f2811 100644
--- a/src/mibew/thread.php
+++ b/src/mibew/thread.php
@@ -22,10 +22,6 @@ require_once(MIBEW_FS_ROOT.'/libs/invitation.php');
 require_once(MIBEW_FS_ROOT.'/libs/groups.php');
 require_once(MIBEW_FS_ROOT.'/libs/captcha.php');
 require_once(MIBEW_FS_ROOT.'/libs/notify.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_interaction.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_chat_interaction.php');
-require_once(MIBEW_FS_ROOT.'/libs/classes/mibew_api_execution_context.php');
 
 $processor = \Mibew\RequestProcessor\ThreadProcessor::getInstance();
 $processor->receiveRequest($_POST['data']);