diff --git a/src/messenger/tests/webim/libs/MibewAPIExecutionContextTest.php b/src/messenger/tests/webim/libs/MibewAPIExecutionContextTest.php
new file mode 100644
index 00000000..6b78c730
--- /dev/null
+++ b/src/messenger/tests/webim/libs/MibewAPIExecutionContextTest.php
@@ -0,0 +1,167 @@
+<?php
+
+require_once dirname(__FILE__) . '/../../../webim/libs/mibew_api.php';
+
+/**
+ * Test class for MibewAPIExecutionContext.
+ * Generated by PHPUnit on 2012-07-27 at 15:47:53.
+ */
+class MibewAPIExecutionContextTest extends PHPUnit_Framework_TestCase {
+
+	public function testStoreFunctionResults() {
+		$context = new MibewAPIExecutionContext();
+		// Create 'function' array. See Mibew API for details.
+		$function = array(
+			'function' => 'test_function',
+			'arguments' => array(
+				'return' => array('microtime' => 'time'),
+				'references' => array()
+			)
+		);
+
+		// Wrong function's results
+		$wrong_results = array();
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::VARIABLE_IS_UNDEFINED_IN_RESULT code
+		try {
+			$context->storeFunctionResults($function, $wrong_results);
+			$this->fail("Exception must be thrown");
+		} catch(MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::VARIABLE_IS_UNDEFINED_IN_RESULT,
+				$e->getCode()
+			);
+		}
+
+		// Correct function's results
+		$results = array(
+			'microtime' => 'some_microtime_value'
+		);
+
+		$context->storeFunctionResults($function, $results);
+		return $context;
+	}
+
+	/**
+	 * @depends testStoreFunctionResults
+	 */
+	public function testGetResults(MibewAPIExecutionContext $context) {
+		$results = $context->getResults();
+		$this->assertEquals(
+			array('time' => 'some_microtime_value'),
+			$results
+		);
+		//return $context;
+	}
+
+	/**
+	 * @depends testStoreFunctionResults
+	 */
+	public function testGetArgumentsList(MibewAPIExecutionContext $context) {
+		// Function with wrong references arguments. See Mibew API for details of 'function'
+		// array
+		$wrong_function = array(
+			'function' => 'test',
+			'arguments' => array(
+				'return' => array(),
+				'references' => array(
+					// Wrong function number. Execution does not have to many
+					// functons results
+					'x' => 12
+				),
+				'x' => 'microtime'
+			)
+		);
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::WRONG_FUNCTION_NUM_IN_REFERENCE code
+		try {
+			$context->getArgumentsList($wrong_function);
+			$this->fail("Exception must be thrown");
+		} catch(MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::WRONG_FUNCTION_NUM_IN_REFERENCE,
+				$e->getCode()
+			);
+		}
+
+		// Another wrong function.
+		$wrong_function = array(
+			'function' => 'test',
+			'arguments' => array(
+				'return' => array(),
+				'references' => array(
+					// Wrong argument 'x'. This function does not have this
+					// argument
+					'x' => 1
+				)
+			)
+		);
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::EMPTY_VARIABLE_IN_REFERENCE code
+		try {
+			$context->getArgumentsList($wrong_function);
+			$this->fail("Exception must be thrown");
+		} catch(MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_VARIABLE_IN_REFERENCE,
+				$e->getCode()
+			);
+		}
+
+		// Another wrong function.
+		$wrong_function = array(
+			'function' => 'test',
+			'arguments' => array(
+				'return' => array(),
+				'references' => array(
+					'x' => 1
+				),
+				// Wrong reference name.
+				'x' => 'wrong_result'
+			)
+		);
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::VARIABLE_IS_UNDEFINED_IN_REFERENCE code
+		try {
+			$context->getArgumentsList($wrong_function);
+			$this->fail("Exception must be thrown");
+		} catch(MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::VARIABLE_IS_UNDEFINED_IN_REFERENCE,
+				$e->getCode()
+			);
+		}
+
+		// Correct function.
+		$correct_function = array(
+			'function' => 'test',
+			'arguments' => array(
+				'return' => array(),
+				'references' => array(
+					'x' => 1
+				),
+				'x' => 'microtime'
+			)
+		);
+
+		$arguments = $context->getArgumentsList($correct_function);
+
+		$this->assertEquals(
+			array(
+				'x' => 'some_microtime_value',
+				'return' => array(),
+				'references' => array(
+					'x' => 1
+				)
+			),
+			$arguments
+		);
+	}
+
+}
+
+?>
diff --git a/src/messenger/tests/webim/libs/MibewAPITest.php b/src/messenger/tests/webim/libs/MibewAPITest.php
new file mode 100644
index 00000000..dc773b92
--- /dev/null
+++ b/src/messenger/tests/webim/libs/MibewAPITest.php
@@ -0,0 +1,619 @@
+<?php
+
+require_once dirname(__FILE__) . '/../../../webim/libs/mibew_api.php';
+
+/**
+ * Test class for MibewAPI.
+ * Generated by PHPUnit on 2012-07-27 at 15:47:47.
+ */
+class MibewAPITest extends PHPUnit_Framework_TestCase {
+
+	public function testGetAPI() {
+		$mibew_api = MibewAPI::getAPI('base');
+		$this->assertEquals($mibew_api, MibewAPI::getAPI('base'));
+	}
+
+	/**
+	 * @depends testGetAPI
+	 */
+	public function testCheckFunction() {
+		$api = MibewAPI::getAPI('base');
+
+		// Wrong function. Function name is absent
+		$wrong_function = array();
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::VARIABLE_IS_UNDEFINED_IN_RESULT code
+		try {
+			$api->checkFunction($wrong_function);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_FUNCTION_NAME,
+				$e->getCode()
+			);
+		}
+
+		// Another wrong function. It have reserved name and second argument in
+		// MibewAPI::checkFunction() will be true.
+		$wrong_function = array(
+			'function' => 'result'
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::FUNCTION_NAME_RESERVED
+		// code
+		try {
+			$api->checkFunction($wrong_function, true);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::FUNCTION_NAME_RESERVED,
+				$e->getCode()
+			);
+		}
+
+		// Another wrong function. It have reserved name, but second argument in
+		// MibewAPI::checkFunction() will be false as default. Also it have no 'arguments'
+		// element.
+		$wrong_function = array(
+			'function' => 'result'
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_ARGUMENTS code
+		try {
+			$api->checkFunction($wrong_function);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_ARGUMENTS,
+				$e->getCode()
+			);
+		}
+
+		// Another wrong function. 'arguments' element is an empty array.
+		$wrong_function = array(
+			'function' => 'wrong_function',
+			'arguments' => array()
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_ARGUMENTS code
+		try {
+			$api->checkFunction($wrong_function);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_ARGUMENTS,
+				$e->getCode()
+			);
+		}
+
+		// Another wrong function. 'arguments' element is not array.
+		$wrong_function = array(
+			'function' => 'wrong_function',
+			'arguments' => 'not an array'
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::WRONG_ARGUMENTS_TYPE code
+		try {
+			$api->checkFunction($wrong_function);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::WRONG_ARGUMENTS_TYPE,
+				$e->getCode()
+			);
+		}
+
+		// Another wrong function. The obligatary arguments missed.
+		$wrong_function = array(
+			'function' => 'wrong_function',
+			'arguments' => array(
+				'x' => 11
+			)
+		);
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::OBLIGATORY_ARGUMENTS_MISSED code
+		try {
+			$api->checkFunction($wrong_function);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::OBLIGATORY_ARGUMENTS_MISSED,
+				$e->getCode()
+			);
+		}
+
+		// Another wrong function. Some of the obligatary arguments missed.
+		$wrong_function = array(
+			'function' => 'wrong_function',
+			'arguments' => array(
+				'x' => 11,
+				'return' => array()
+			)
+		);
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::OBLIGATORY_ARGUMENTS_MISSED code
+		try {
+			$api->checkFunction($wrong_function);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::OBLIGATORY_ARGUMENTS_MISSED,
+				$e->getCode()
+			);
+		}
+
+		// Correct function
+		$correct_function = array(
+			'function' => 'correct_function',
+			'arguments' => array(
+				'return' => array('name' => 'alias'),
+				'references' => array('x' => 1),
+				'x' => 'argument_from_first_function',
+				'argument_key' => 'argument_value'
+			)
+		);
+
+		$api->checkFunction($correct_function);
+
+		return $correct_function;
+	}
+
+	/**
+	 * @depends testCheckFunction
+	 */
+	public function testCheckRequest($correct_function) {
+		$api = MibewAPI::getAPI('base');
+
+		// Wrong request. Its 'token' element is absent.
+		$wrong_request = array();
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_TOKEN code
+		try {
+			$api->checkRequest($wrong_request);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_TOKEN,
+				$e->getCode()
+			);
+		}
+
+		// Wrong request. Its 'token' element is empty.
+		$wrong_request = array('token' => '');
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_TOKEN code
+		try {
+			$api->checkRequest($wrong_request);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_TOKEN,
+				$e->getCode()
+			);
+		}
+
+		// Wrong request. Its 'function' element is absent.
+		$wrong_request = array(
+			'token' => 'some_test_token'
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_FUNCTIONS code
+		try {
+			$api->checkRequest($wrong_request);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_FUNCTIONS,
+				$e->getCode()
+			);
+		}
+
+		// Wrong request. Its 'function' element is empty.
+		$wrong_request = array(
+			'token' => 'some_test_token',
+			'functions' => array()
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_FUNCTIONS code
+		try {
+			$api->checkRequest($wrong_request);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_FUNCTIONS,
+				$e->getCode()
+			);
+		}
+
+		// Correct request
+		$correct_request = array(
+			'token' => 'some_test_token',
+			'functions' => array($correct_function, $correct_function)
+		);
+
+		$api->checkRequest($correct_request);
+
+		return $correct_request;
+	}
+
+	/**
+	 * @depends testCheckRequest
+	 */
+	public function testCheckPackage($correct_request) {
+		$api = MibewAPI::getAPI('base');
+
+		$trusted_signatures = array('some_trusted_signature');
+		// Wrong package. Signature element is absent.
+		$wrong_package = array();
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_SIGNATURE code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_SIGNATURE,
+				$e->getCode()
+			);
+		}
+
+		// Wrong package. Signature element is empty.
+		$wrong_package = array('signature' => '');
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_SIGNATURE code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_SIGNATURE,
+				$e->getCode()
+			);
+		}
+
+		// Wrong package. Signature is wrong.
+		$wrong_package = array('signature' => 'wrong_signature');
+
+		// Try to catch MibewAPIException with MibewAPIException::UNTRUSTED_SIGNATURE code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::UNTRUSTED_SIGNATURE,
+				$e->getCode()
+			);
+		}
+
+		// Wrong package. Protocol is absent.
+		$wrong_package = array(
+			'signature' => 'some_trusted_signature'
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_PROTOCOL code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_PROTOCOL,
+				$e->getCode()
+			);
+		}
+
+		// Wrong package. Protocol is empty.
+		$wrong_package = array(
+			'signature' => 'some_trusted_signature',
+			'proto' => ''
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_PROTOCOL code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_PROTOCOL,
+				$e->getCode()
+			);
+		}
+
+		// Wrong package. Protocol is wrong.
+		$wrong_package = array(
+			'signature' => 'some_trusted_signature',
+			'proto' => 'wrong_protocol'
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::WRONG_PROTOCOL_VERSION
+		// code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::WRONG_PROTOCOL_VERSION,
+				$e->getCode()
+			);
+		}
+
+		// Wrong package. 'async' flag is absent.
+		$wrong_package = array(
+			'signature' => 'some_trusted_signature',
+			'proto' => MibewAPI::PROTOCOL_VERSION
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::ASYNC_FLAG_MISSED code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::ASYNC_FLAG_MISSED,
+				$e->getCode()
+			);
+		}
+
+		// Wrong package. 'async' flag is wrong.
+		$wrong_package = array(
+			'signature' => 'some_trusted_signature',
+			'proto' => MibewAPI::PROTOCOL_VERSION,
+			'async' => 'wrong_async_flag'
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::WRONG_ASYNC_FLAG_VALUE
+		// code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::WRONG_ASYNC_FLAG_VALUE,
+				$e->getCode()
+			);
+		}
+
+		// Wrong package. Requests is absent.
+		$wrong_package = array(
+			'signature' => 'some_trusted_signature',
+			'proto' => MibewAPI::PROTOCOL_VERSION,
+			'async' => false
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_REQUESTS code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_REQUESTS,
+				$e->getCode()
+			);
+		}
+
+		// Wrong package. Requests is empty.
+		$wrong_package = array(
+			'signature' => 'some_trusted_signature',
+			'proto' => MibewAPI::PROTOCOL_VERSION,
+			'async' => false,
+			'requests' => array()
+		);
+
+		// Try to catch MibewAPIException with MibewAPIException::EMPTY_REQUESTS code
+		try {
+			$api->checkPackage($wrong_package, $trusted_signatures);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::EMPTY_REQUESTS,
+				$e->getCode()
+			);
+		}
+
+		// Correct package.
+		$correct_package = array(
+			'signature' => 'some_trusted_signature',
+			'proto' => MibewAPI::PROTOCOL_VERSION,
+			'async' => false,
+			'requests' => array($correct_request, $correct_request)
+		);
+
+		$api->checkPackage($correct_package, $trusted_signatures);
+
+		return $correct_package;
+	}
+
+	/**
+	 * @depends testCheckPackage
+	 */
+	public function testEncodePackage($correct_package) {
+		$api = MibewAPI::getAPI('base');
+
+		// Get package values
+		$requests = $correct_package['requests'];
+		$signature = $correct_package['signature'];
+		$async = $correct_package['async'];
+		// Encode package
+		$encoded_package = $api->encodePackage($requests, $signature, $async);
+		$this->assertEquals(
+			urlencode(json_encode($correct_package)),
+			$encoded_package
+		);
+		return array(
+			'package' => $correct_package,
+			'encoded_package' => $encoded_package
+		);
+	}
+
+	/**
+	 * @depends testEncodePackage
+	 */
+	public function testDecodePackage($vars) {
+		$api = MibewAPI::getAPI('base');
+
+		// Try to catch MibewAPIException with MibewAPIException::NOT_VALID_JSON code
+		try {
+			$api->decodePackage(
+				substr(
+					$vars['encoded_package'],
+					// Break package
+					ceil(strlen($vars['encoded_package']) / 2)
+				),
+				array('some_trusted_signature')
+			);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::NOT_VALID_JSON,
+				$e->getCode()
+			);
+		}
+
+		$this->assertEquals(
+			$vars['package'],
+			$api->decodePackage(
+				$vars['encoded_package'],
+				array('some_trusted_signature')
+			)
+		);
+	}
+
+	/**
+	 * @depends testGetAPI
+	 */
+	public function testGetResultFunction() {
+		$api = MibewAPI::getAPI('base');
+
+		// Wrong functions list. More than one result function.
+		$functions_list = array(
+			array(
+				'function' => 'result',
+				'num' => 1
+			),
+			array(
+				'function' => 'result',
+				'num' => 2
+			)
+		);
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::RESULT_FUNCTION_ALREADY_EXISTS code
+		try {
+			$api->getResultFunction($functions_list, null);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::RESULT_FUNCTION_ALREADY_EXISTS,
+				$e->getCode()
+			);
+		}
+
+		// Wrong functions list. Result function not exists, but getResultFunction's second
+		// argument is true
+		$functions_list = array();
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::NO_RESULT_FUNCTION code
+		try {
+			$api->getResultFunction($functions_list, true);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::NO_RESULT_FUNCTION,
+				$e->getCode()
+			);
+		}
+
+		// Wrong functions list. Result function exists, but getResultFunction's second
+		// argument is false
+		$functions_list = array(
+			array(
+				'function' => 'result',
+				'num' => 1
+			)
+		);
+
+		// Try to catch MibewAPIException with
+		// MibewAPIException::RESULT_FUNCTION_EXISTS code
+		try {
+			$api->getResultFunction($functions_list, false);
+			$this->fail("Exception must be thrown");
+		} catch (MibewAPIException $e) {
+			$this->assertEquals(
+				MibewAPIException::RESULT_FUNCTION_EXISTS,
+				$e->getCode()
+			);
+		}
+
+		// Correct functions list. Result function not exists and getResultFunction's second
+		// argument is false
+		$functions_list = array();
+
+		$this->assertEquals(null, $api->getResultFunction($functions_list, false));
+
+		// Correct functions list. Result function exists and getResultFunction's second
+		// argument is true
+		$functions_list = array(
+			array(
+				'function' => 'result',
+				'num' => 1
+			)
+		);
+
+		$this->assertEquals(
+			$functions_list[0],
+			$api->getResultFunction($functions_list, true)
+		);
+
+		// Correct functions list. Result function not exists and getResultFunction's second
+		// argument is null
+		$functions_list = array();
+
+		$this->assertEquals(null, $api->getResultFunction($functions_list, null));
+
+		// Correct functions list. Result function exists and getResultFunction's second
+		// argument is null
+		$functions_list = array(
+			array(
+				'function' => 'result',
+				'num' => 1
+			)
+		);
+
+		$this->assertEquals(
+			$functions_list[0],
+			$api->getResultFunction($functions_list, null)
+		);
+	}
+
+	/**
+	 * @depends testGetAPI
+	 */
+	public function testBuildResult() {
+		$api = MibewAPI::getAPI('base');
+
+		$token = 'some_test_token';
+		$package = array(
+			'token' => $token,
+			'functions' => array(
+				array(
+					'function' => 'result',
+					'arguments' => array(
+						'references' => array(),
+						'return' => array(),
+						'test_argument' => 'test_value'
+					)
+				)
+			)
+		);
+
+		$this->assertEquals(
+			$package,
+			$api->buildResult($token, array('test_argument' => 'test_value'))
+		);
+	}
+}
+
+?>
diff --git a/src/messenger/webim/libs/mibew_api.php b/src/messenger/webim/libs/mibew_api.php
new file mode 100644
index 00000000..a8c00573
--- /dev/null
+++ b/src/messenger/webim/libs/mibew_api.php
@@ -0,0 +1,567 @@
+<?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.
+ */
+
+/**
+ * Implements Mibew API specification version 1.0
+ *
+ * @todo May be use regular methods instead of static one
+ */
+Class MibewAPI {
+
+	/**
+	 * Version of the MIBEW API protocol implemented by the class
+	 */
+	const PROTOCOL_VERSION = '1.0';
+
+	/**
+	 * Array of MibewAPI objects
+	 * @var array
+	 */
+	protected static $interactions = array();
+
+	/**
+	 * An object that encapsulates type of the interaction
+	 *
+	 * @var MibewAPIInteraction
+	 */
+	protected $interaction = NULL;
+
+	public static function getAPI($interaction_type) {
+		$class_name = "MibewAPI".  ucfirst($interaction_type) . "Interaction";
+		if (! class_exists($class_name)) {
+			throw new MibewAPIException(
+				"Wrong interaction type",
+				MibewAPIException::WRONG_INTERACTION_TYPE
+			);
+		}
+		if (empty(self::$interactions[$interaction_type])) {
+			self::$interactions[$interaction_type] = new self(new $class_name());
+		}
+		return self::$interactions[$interaction_type];
+	}
+
+	protected function __construct(MibewAPIInteraction $interaction_type) {
+		$this->interaction = $interaction_type;
+	}
+
+	/**
+	 * Validate package
+	 *
+	 * @param array $package Package array. See Mibew API for details.
+	 * @param array $trusted_signatures Array of trusted signatures.
+	 * @throws MibewAPIException
+	 */
+	public function checkPackage($package, $trusted_signatures) {
+		// Check signature
+		if (empty($package['signature'])) {
+			throw new MibewAPIException(
+				"Package signature is empty",
+				MibewAPIException::EMPTY_SIGNATURE
+			);
+		}
+		if (! in_array($package['signature'], $trusted_signatures)) {
+			throw new MibewAPIException(
+				"Package signed with untrusted signature",
+				MibewAPIException::UNTRUSTED_SIGNATURE
+			);
+		}
+
+		// Check protocol
+		if (empty($package['proto'])) {
+			throw new MibewAPIException(
+				"Package protocol is empty",
+				MibewAPIException::EMPTY_PROTOCOL
+			);
+		}
+		if ($package['proto'] != self::PROTOCOL_VERSION) {
+			throw new MibewAPIException(
+				"Wrong package protocol version '{$package['proto']}'",
+				MibewAPIException::WRONG_PROTOCOL_VERSION
+			);
+		}
+
+		// Check async flag
+		if (! isset($package['async'])) {
+			throw new MibewAPIException(
+				"'async' flag is missed",
+				MibewAPIException::ASYNC_FLAG_MISSED
+			);
+		}
+		if (! is_bool($package['async'])) {
+			throw new MibewAPIException(
+				"Wrong 'async' flag value",
+				MibewAPIException::WRONG_ASYNC_FLAG_VALUE
+			);
+		}
+
+		// Package must have at least one request
+		if (empty($package['requests'])) {
+			throw new MibewAPIException(
+				"Empty requests set",
+				MibewAPIException::EMPTY_REQUESTS
+			);
+		}
+		// Check requests in package
+		foreach ($package['requests'] as $request) {
+			$this->checkRequest($request);
+		}
+	}
+
+	/**
+	 * Validate request
+	 *
+	 * @param array $request Request array. See Mibew API for details.
+	 * @throws MibewAPIException
+	 */
+	public function checkRequest($request) {
+		// Check token
+		if (empty($request['token'])) {
+			throw new MibewAPIException(
+				"Empty request token",
+				MibewAPIException::EMPTY_TOKEN
+			);
+		}
+		// Request must have at least one function
+		if (empty($request['functions'])) {
+			throw new MibewAPIException(
+				"Empty functions set",
+				MibewAPIException::EMPTY_FUNCTIONS
+			);
+		}
+		// Check functions in request
+		foreach ($request['functions'] as $function) {
+			$this->checkFunction($function);
+		}
+	}
+
+	/**
+	 * Validate function
+	 *
+	 * @param array $function Function array. See Mibew API for details.
+	 * @param boolean $filter_reserved_functions Determine if function name must not be in
+	 * reserved list
+	 * @throws MibewAPIException
+	 */
+	public function checkFunction($function, $filter_reserved_functions = false) {
+		// Check function name
+		if (empty($function['function'])) {
+			throw new MibewAPIException(
+				'Cannot call for function with empty name',
+				MibewAPIException::EMPTY_FUNCTION_NAME
+			);
+		}
+		if ($filter_reserved_functions) {
+			if (in_array(
+				$function['function'],
+				$this->interaction->reservedFunctionNames
+			)) {
+				throw new MibewAPIException(
+					"'{$function['function']}' is reserved function name",
+					MibewAPIException::FUNCTION_NAME_RESERVED
+				);
+			}
+		}
+		// Check function's arguments
+		if (empty($function['arguments'])) {
+			throw new MibewAPIException(
+				"There are no arguments in '{$function['function']}' function",
+				MibewAPIException::EMPTY_ARGUMENTS
+			);
+		}
+		if (! is_array($function['arguments'])) {
+			throw new MibewAPIException(
+				"Arguments must be an array",
+				MibewAPIException::WRONG_ARGUMENTS_TYPE
+			);
+		}
+		$unset_arguments = array_diff(
+			$this->interaction->obligatoryArguments,
+			array_keys($function['arguments'])
+		);
+		if (! empty($unset_arguments)) {
+			throw new MibewAPIException(
+				"Arguments '" . implode("', '", $unset_arguments) . "' must be set",
+				MibewAPIException::OBLIGATORY_ARGUMENTS_MISSED
+			);
+		}
+	}
+
+	/**
+	 * Encodes package
+	 *
+	 * @param array $requests Requests array. See Mibew API for details.
+	 * @param string $signature Sender signature.
+	 * @param boolean $async true for asynchronous request and false for synchronous request
+	 * @return string Ready for transfer encoded package
+	 */
+	public function encodePackage($requests, $signature, $async) {
+		$package = array();
+		$package['signature'] = $signature;
+		$package['proto'] = self::PROTOCOL_VERSION;
+		$package['async'] = $async;
+		$package['requests'] = $requests;
+		return urlencode(json_encode($package));
+	}
+
+	/**
+	 * Decodes package and validate package structure
+	 *
+	 * @param string $package Encoded package
+	 * @param array $trusted_signatures List of trusted signatures
+	 * @return array Decoded package array. See Mibew API for details.
+	 * @throws MibewAPIException
+	 */
+	public function decodePackage($package, $trusted_signatures) {
+		$decoded_package = urldecode($package);
+		// JSON regular expression
+		$pcre_regex = '/
+		(?(DEFINE)
+		(?<number>   -? (?= [1-9]|0(?!\d) ) \d+ (\.\d+)? ([eE] [+-]? \d+)? )
+		(?<boolean>   true | false | null )
+		(?<string>    " ([^"\\\\]* | \\\\ ["\\\\bfnrt\/] | \\\\ u [0-9a-f]{4} )* " )
+		(?<array>     \[  (?:  (?&json)  (?: , (?&json)  )*  )?  \s* \] )
+		(?<pair>      \s* (?&string) \s* : (?&json)  )
+		(?<object>    \{  (?:  (?&pair)  (?: , (?&pair)  )*  )?  \s* \} )
+		(?<json>   \s* (?: (?&number) | (?&boolean) | (?&string) | (?&array) | (?&object) ) \s* )
+		)
+		\A (?&json) \Z
+		/six';
+		// Check JSON
+		if (!preg_match($pcre_regex, $decoded_package)) {
+			// Not valid JSON
+			throw new MibewAPIException(
+				"Package have not valid json structure",
+				MibewAPIException::NOT_VALID_JSON
+			);
+		}
+		$decoded_package = json_decode($decoded_package, true);
+		$this->checkPackage($decoded_package, $trusted_signatures);
+		return $decoded_package;
+	}
+
+	/**
+	 * Builds result package
+	 *
+	 * @param string $token Token of the result package
+	 * @param array $result_arguments Arguments of result function
+	 * @return Result package
+	 */
+	public function buildResult($token, $result_arguments) {
+		$arguments = $result_arguments + $this->interaction->getDefaultObligatoryArguments();
+		$package = array(
+			'token' => $token,
+			'functions' => array(
+				array(
+					'function' => 'result',
+					'arguments' => $arguments
+				)
+			)
+		);
+		return $package;
+	}
+
+	/**
+	 * Search 'result' function in $function_list. If request contains more than one result
+	 * functions throws an MibewAPIException
+	 *
+	 * @param array $functions_list Array of functions. See MibewAPI for function structure
+	 * details
+	 * @param mixed $existance Control existance of the 'result' function in request.
+	 * Use boolean true if 'result' function must exists in request, boolean false if must not
+	 * and null if it doesn't matter.
+	 * @return mixed Function array if 'result' function found and NULL otherwise
+	 * @throws MibewAPIException
+	 */
+	public function getResultFunction ($functions_list, $existence) {
+		$result_function = null;
+		// Try to find 'result' function
+		foreach ($functions_list as $function) {
+			if ($function['function'] == 'result') {
+				if (! is_null($result_function)) {
+					// Another 'result' function found
+					throw new MibewAPIException(
+						"Function 'result' already exists in request",
+						MibewAPIException::RESULT_FUNCTION_ALREADY_EXISTS
+					);
+				}
+				// Furst 'result' function found
+				$result_function = $function;
+			}
+		}
+		if ($existence === true && is_null($result_function)) {
+			// 'result' function must present in request
+			throw new MibewAPIException(
+				"There is no 'result' function in request",
+				MibewAPIException::NO_RESULT_FUNCTION
+			);
+		}
+		if ($existence === false && !is_null($result_function)) {
+			// 'result' function must not present in request
+			throw new MibewAPIException(
+				"There is 'result' function in request",
+				MibewAPIException::RESULT_FUNCTION_EXISTS
+			);
+		}
+		return $result_function;
+	}
+}
+
+/**
+ * Implements functions execution context
+ */
+Class MibewAPIExecutionContext {
+	/**
+	 * Values which returns after execution of all functions in request
+	 * @var array
+	 */
+	protected $return = array();
+
+	/**
+	 * Results of execution of all function in request
+	 * @var array
+	 */
+	protected $functions_results = array();
+
+	/**
+	 * Returns requets results
+	 *
+	 * @return array Request results
+	 * @see MibewAPIExecutionContext::$return
+	 */
+	public function getResults () {
+		return $this->return;
+	}
+
+	/**
+	 * Build arguments list by replace all references by values of execution context
+	 *
+	 * @param array $function Function array. See MibewAPI for details.
+	 * @return array Arguments list
+	 * @throws MibewAPIException
+	 */
+	public function getArgumentsList ($function) {
+		$arguments = $function['arguments'];
+		$references = $function['arguments']['references'];
+		foreach ($references as $variable => $func_num) {
+			// Check target function in context
+			if (! isset($this->functions_results[$func_num - 1])) {
+				// Wrong function num
+				throw new MibewAPIException(
+					"Wrong reference in '{$function['function']}' function. " .
+					"Function #{$func_num} does not call yet.",
+					MibewAPIException::WRONG_FUNCTION_NUM_IN_REFERENCE
+				);
+			}
+
+			// Check reference
+			if (empty($arguments[$variable])) {
+				// Empty argument that should contains reference
+				throw new MibewAPIException(
+					"Wrong reference in '{$function['function']}' function. " .
+					"Empty {$variable} argument.",
+					MibewAPIException::EMPTY_VARIABLE_IN_REFERENCE
+				);
+			}
+			$reference_to = $arguments[$variable];
+
+			// Check target value
+			if (! isset($this->functions_results[$func_num - 1][$reference_to])) {
+				// Undefined target value
+				throw new MibewAPIException(
+					"Wrong reference in '{$function['function']}' function. " .
+					"There is no '{$reference_to}' argument in #{$func_num} " .
+					"function results",
+					MibewAPIException::VARIABLE_IS_UNDEFINED_IN_REFERENCE
+				);
+			}
+
+			// Replace reference by target value
+			$arguments[$variable] = $this->functions_results[$func_num - 1][$reference_to];
+		}
+		return $arguments;
+	}
+
+	/**
+	 * Stores functions results in execution context and add values to request result
+	 *
+	 * @param array $function Function array. See MibewAPI for details.
+	 * @param array $results Associative array of the function results.
+	 * @throws MibewAPIException
+	 */
+	public function storeFunctionResults ($function, $results) {
+		// Add value to request results
+		foreach ($function['arguments']['return'] as $name => $alias) {
+			if (! isset($results[$name])) {
+				// Value that defined in 'return' argument is undefined
+				throw new MibewAPIException(
+					"Variable with name '{$name}' is undefined in the " .
+					"results of the '{$function['function']}' function",
+					MibewAPIException::VARIABLE_IS_UNDEFINED_IN_RESULT
+				);
+			}
+			$this->return[$alias] = $results[$name];
+		}
+		// Store function results in execution context
+		$this->functions_results[] = $results;
+	}
+
+}
+
+/**
+ * Encapsulates interaction type
+ */
+abstract class MibewAPIInteraction {
+	/**
+	 * Abligatory arguments in called functions
+	 * @var array
+	 */
+	public $obligatoryArguments;
+	/**
+	 * Reserved function names
+	 * @var array
+	 */
+	public $reservedFunctionNames;
+
+	/**
+	 * Returns default values of obligatory arguments
+	 *
+	 * @return array Associative array with keys are obligatory arguments and values are default
+	 * values of them
+	 */
+	abstract public function getDefaultObligatoryArguments();
+}
+
+/**
+ * Implements Base Mibew Interaction
+ */
+class MibewAPIBaseInteraction extends MibewAPIInteraction {
+	public $obligatoryArguments = array(
+		'references',
+		'return'
+	);
+
+	public $reservedFunctionNames = array(
+		'result'
+	);
+
+	public function getDefaultObligatoryArguments() {
+		return array(
+			'references' => array(),
+			'return' => array()
+		);
+	}
+}
+
+/**
+ * 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