diff --git a/README.md b/README.md
new file mode 100644
index 0000000..1d83373
--- /dev/null
+++ b/README.md
@@ -0,0 +1,198 @@
+This library allows you to easily communicate with BIS API.
+
+# Installation
+
+## Composer
+
+Add path to `repositories`:
+
+```
+{
+	"url": "https://github.com/hnuti-brontosaurus/php-bis-api-client.git",
+	"type": "vcs"
+}
+```
+
+and install package:
+```
+composer require hnuti-brontosaurus/php-bis-api-client
+```
+
+## Manually
+
+Download latest version from [github](https://github.com/hnuti-brontosaurus/php-bis-api-client/releases) to your computer.
+
+
+# Usage
+
+First you need to create client instance. Note that you need to know the API URL and obtain client ID and secret from BIS administrator
+to be able to authenticate against BIS.
+
+```php
+$client = (new BisClientFactory(
+	'apiUrl',
+	'clientId',
+	'clientSecret',
+))->create();
+```
+
+Now you can perform any of available operations.
+
+## Events
+
+### Single event
+
+Retrieve all information about single event:
+
+```php
+$event = $client->getEvent($id);
+
+// examples of reading data
+$event->getName();
+$event->getOrganizer()->getResponsiblePerson();
+$event->getRegistrationType()->isOfTypeCustomWebpage();
+$event->getPlace()->getCoordinates();
+```
+
+### More events
+
+Retrieve all information about multiple events.
+
+Basic usage:
+
+```php
+$parameters = new \HnutiBrontosaurus\BisClient\Request\Event\EventParameters();
+$events = $client->getEvents($parameters); // $parameters are optional
+
+// example of reading data
+foreach ($events as $event) {
+    $event->getName();
+}
+```
+
+#### Filters
+
+You can filter in many ways:
+
+```php
+$parameters = new \HnutiBrontosaurus\BisClient\Request\Event\EventParameters();
+
+// only events of "voluntary" type
+$parameters->setType(\HnutiBrontosaurus\BisClient\Enums\EventType::VOLUNTARY());
+
+// only events of "PsB" program
+$parameters->setProgram(\HnutiBrontosaurus\BisClient\Enums\Program::PSB());
+
+// only events of "first time attendees" target group
+$parameters->setTargetGroup(\HnutiBrontosaurus\BisClient\Enums\TargetGroup::FIRST_TIME_ATTENDEES());
+
+// only events organized by organizational unit with ID 123
+$parameters->setOrganizedBy(123);
+
+// excludes running events
+$parameters->excludeRunning();
+
+$events = $client->getEvents($parameters);
+```
+
+For type, program and target group, you can set more values at once:
+
+```php
+$parameters = new \HnutiBrontosaurus\BisClient\Request\Event\EventParameters();
+
+$parameters->setTypes([
+    \HnutiBrontosaurus\BisClient\Enums\EventType::VOLUNTARY(),
+    \HnutiBrontosaurus\BisClient\Enums\EventType::SPORT(),
+]);
+
+$events = $client->getEvents($parameters);
+```
+
+Note that each method call rewrites the previous one:
+
+```php
+$parameters = new \HnutiBrontosaurus\BisClient\Request\Event\EventParameters();
+
+// sets "voluntary" type
+$parameters->setType(\HnutiBrontosaurus\BisClient\Enums\EventType::VOLUNTARY());
+// rewrites type with "sport"
+$parameters->setType(\HnutiBrontosaurus\BisClient\Enums\EventType::SPORT());
+
+$events = $client->getEvents($parameters);
+```
+
+#### Sorting
+
+You can even use some basic sorting options:
+
+```php
+$parameters = new \HnutiBrontosaurus\BisClient\Request\Event\EventParameters();
+
+// sort events by date from or date to
+$parameters->orderByDateFrom();
+$parameters->orderByDateTo(); // default
+
+$events = $client->getEvents($parameters);
+```
+
+### Adding attendee
+
+You can add attendee to an event:
+
+```php
+$client->addAttendee(new \HnutiBrontosaurus\BisClient\Request\Event\EventAttendee(
+    123, // event ID
+    'Jan', // first name
+    'Novák', // last name
+    '12.3.2004', // birth date
+    '123 456 789', // phone number
+    'jan@novak.cz', // e-mail address
+    'poznámka', // note
+    ['odpověď na otázku č. 1', '', 'odpověď na otázku č. 3'], // answers to optional questions (optional)
+));
+```
+
+## Organizational units
+
+Retrieve all information about all organizational units:
+
+```php
+$organizationalUnits = $client->getOrganizationalUnits();
+
+// example of reading data
+foreach ($organizationalUnits as $organizationalUnit) {
+    $organizationalUnit->getName();
+    $organizationalUnit->getCity();
+    $organizationalUnit->getChairman();
+    $organizationalUnit->getCoordinates();
+}
+```
+
+# Development
+
+## Installation
+
+```
+composer install
+```
+
+## Structure
+
+- `docs` – instruction on how connection between brontoweb and BIS works (todo: move to brontoweb repo)
+- `src` – source code
+    - `Enums` – basic enum types
+    - `Request` – request-related value objects
+    - `Response` – request-related value objects and exceptions
+    - `BisClient` – client itself, serves for making requests to BIS API
+    - `BisClientFactory` – collects configuration data, ensures authentication against BIS and returns `BisClient`
+    - `HttpClient` – wrapper around Guzzle client which adds BIS API specific pieces into the request
+- `tests` – test code
+
+**Note that this library bundles Guzzle HTTP client as we can not rely on having composer in user's codebase.**
+
+## Tests
+
+This library has just `tests/index.php` which – if run on a webserver – will
+pass or fail visually – no error and results output or an exception.
+
+Note that you have to obtain client ID and secret as well to be able to run the test. Ask BIS administrator to get it, copy `tests/secret.template.php` to `tests/secret.php` and insert credentials there.
diff --git a/composer.json b/composer.json
index 0718a46..0fc5db9 100644
--- a/composer.json
+++ b/composer.json
@@ -11,9 +11,8 @@
 	"minimum-stability": "stable",
 	"require": {
 		"php": ">=8.0",
-		"ext-dom": "*",
 		"grifart/enum": "^0.2.1",
-		"guzzlehttp/guzzle": "^6.3"
+		"guzzlehttp/guzzle": "^7.3"
 	},
 	"require-dev": {
 		"phpstan/phpstan": "^0.12.88",
@@ -21,12 +20,10 @@
 	},
 	"autoload": {
 		"psr-4": {
-			"HnutiBrontosaurus\\BisApiClient\\": "src/"
+			"HnutiBrontosaurus\\BisClient\\": "src/"
 		},
 		"classmap": [
-			"src/exceptions.php",
-			"src/Response/exceptions.php",
-			"src/Response/OrganizationalUnit/exceptions.php"
+			"src/exceptions.php"
 		]
 	},
 	"config": {
diff --git a/src/Authenticator.php b/src/Authenticator.php
new file mode 100644
index 0000000..9a96927
--- /dev/null
+++ b/src/Authenticator.php
@@ -0,0 +1,65 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\Exception\ClientException;
+use GuzzleHttp\Exception\GuzzleException;
+use GuzzleHttp\Psr7\Request;
+
+
+final class Authenticator
+{
+
+	private ?AuthorizationToken $token;
+
+	public function __construct(
+		private string $clientId,
+		private string $clientSecret,
+		private Client $httpClient,
+	) {
+		$this->token = null; // not yet authenticated
+	}
+
+
+	/**
+	 * @throws UnableToAuthorize
+	 * @throws ConnectionToBisFailed
+	 */
+	public function authenticate(): AuthorizationToken
+	{
+		if ($this->token !== null) {
+			return $this->token;
+		}
+
+		try {
+			$response = $this->httpClient->send(new Request(
+				'POST',
+				Endpoint::AUTHENTICATION(),
+				[
+					'Accept' => 'application/json',
+					'Content-Type' => 'application/json',
+				],
+				\json_encode([
+					'grant_type' => 'client_credentials',
+					'client_id' => $this->clientId,
+					'client_secret' => $this->clientSecret,
+				]),
+			));
+		} catch (ClientException $e) {
+			if ($e->getCode() === 401) {
+				throw UnableToAuthorize::withPrevious($e);
+			}
+
+			throw ConnectionToBisFailed::withPrevious($e);
+
+		} catch (GuzzleException $e) {
+			throw ConnectionToBisFailed::withPrevious($e);
+		}
+
+		$payload = \json_decode($response->getBody()->getContents());
+		$this->token = AuthorizationToken::from($payload->access_token);
+		return $this->token;
+	}
+
+}
diff --git a/src/AuthorizationToken.php b/src/AuthorizationToken.php
new file mode 100644
index 0000000..35b6c71
--- /dev/null
+++ b/src/AuthorizationToken.php
@@ -0,0 +1,28 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient;
+
+
+final class AuthorizationToken
+{
+
+	private function __construct(
+		private string $value,
+	) {}
+
+	public static function from(string $value): self
+	{
+		return new self($value);
+	}
+
+	public function toString(): string
+	{
+		return $this->value;
+	}
+
+	public function __toString(): string
+	{
+		return $this->toString();
+	}
+
+}
diff --git a/src/BisClient.php b/src/BisClient.php
new file mode 100644
index 0000000..74c1247
--- /dev/null
+++ b/src/BisClient.php
@@ -0,0 +1,90 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient;
+
+use HnutiBrontosaurus\BisClient\Request\Event\EventAttendee;
+use HnutiBrontosaurus\BisClient\Request\Event\EventParameters;
+use HnutiBrontosaurus\BisClient\Response\Event\Event;
+use HnutiBrontosaurus\BisClient\Response\OrganizationalUnit\OrganizationalUnit;
+
+
+final class BisClient
+{
+
+	public function __construct(
+		private HttpClient $httpClient,
+	) {}
+
+
+	// events
+
+	/**
+	 * @throws NotFound
+	 * @throws ConnectionToBisFailed
+	 */
+	public function getEvent(int $id): Event
+	{
+		$data = $this->httpClient->send('GET', Endpoint::EVENT($id));
+
+		\assert($data instanceof \stdClass);
+		return Event::fromResponseData($data);
+	}
+
+
+	/**
+	 * @return Event[]
+	 * @throws ConnectionToBisFailed
+	 */
+	public function getEvents(?EventParameters $params = null): array
+	{
+		$data = $this->httpClient->send(
+			'GET', Endpoint::EVENTS(),
+			$params !== null
+				? $params
+				: new EventParameters(),
+		);
+
+		if ($data === null) {
+			return [];
+		}
+
+		\assert(\is_array($data));
+		return \array_map(Event::class . '::fromResponseData', $data);
+	}
+
+
+	/**
+	 * @throws ConnectionToBisFailed
+	 */
+	public function addAttendee(EventAttendee $eventAttendee): void
+	{
+		$this->httpClient->send('POST', Endpoint::ADD_ATTENDEE_TO_EVENT(), null, $eventAttendee);
+	}
+
+
+	// organizational units
+
+	/**
+	 * @return OrganizationalUnit[]
+	 * @throws ConnectionToBisFailed
+	 */
+	public function getOrganizationalUnits(): array
+	{
+		$data = $this->httpClient->send('GET', Endpoint::ADMINISTRATIVE_UNITS());
+
+		if ($data === null) {
+			return [];
+		}
+
+		\assert(\is_array($data));
+		return \array_map(OrganizationalUnit::class . '::fromResponseData', $data);
+	}
+
+
+	// adoption
+
+	// not yet implemented
+//	public function saveRequestForAdoption(Adoption $adoption): void
+//	{}
+
+}
diff --git a/src/BisClientFactory.php b/src/BisClientFactory.php
new file mode 100644
index 0000000..551a140
--- /dev/null
+++ b/src/BisClientFactory.php
@@ -0,0 +1,47 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient;
+
+use GuzzleHttp\Client;
+
+
+/*
+ * We can not count on using dependency injection container in applications using this library.
+ * But we can say that BisClientFactory should be called only once per request,
+ * so we build dependencies here in constructor.
+ *
+ */
+final class BisClientFactory
+{
+	private Authenticator $bisAuthenticator;
+	private Client $httpClient;
+
+
+	public function __construct(
+		string $apiUrl,
+		private string $clientId,
+		private string $clientSecret,
+	) {
+		$this->httpClient = new Client(['base_uri' => \rtrim($apiUrl, '/') . '/']);
+		$this->bisAuthenticator = new Authenticator(
+			$this->clientId,
+			$this->clientSecret,
+			$this->httpClient,
+		);
+	}
+
+
+	/**
+	 * @throws UnableToAuthorize
+	 * @throws ConnectionToBisFailed
+	 */
+	public function create(): BisClient
+	{
+		$token = $this->bisAuthenticator->authenticate();
+		return new BisClient(new HttpClient(
+			$token,
+			$this->httpClient,
+		));
+	}
+
+}
diff --git a/src/Client.php b/src/Client.php
deleted file mode 100644
index 9c3c237..0000000
--- a/src/Client.php
+++ /dev/null
@@ -1,260 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient;
-
-use GuzzleHttp\Client as HttpClient;
-use GuzzleHttp\Exception\ClientException;
-use GuzzleHttp\Exception\GuzzleException;
-use GuzzleHttp\Psr7\Request;
-use HnutiBrontosaurus\BisApiClient\Request\Adoption;
-use HnutiBrontosaurus\BisApiClient\Request\EventAttendee;
-use HnutiBrontosaurus\BisApiClient\Request\EventParameters;
-use HnutiBrontosaurus\BisApiClient\Request\OrganizationalUnitParameters;
-use HnutiBrontosaurus\BisApiClient\Request\Parameters;
-use HnutiBrontosaurus\BisApiClient\Response\Event\Event;
-use HnutiBrontosaurus\BisApiClient\Response\InvalidContentTypeException;
-use HnutiBrontosaurus\BisApiClient\Response\InvalidParametersException;
-use HnutiBrontosaurus\BisApiClient\Response\InvalidUserInputException;
-use HnutiBrontosaurus\BisApiClient\Response\InvalidXMLStructureException;
-use HnutiBrontosaurus\BisApiClient\Response\OrganizationalUnit\OrganizationalUnit;
-use HnutiBrontosaurus\BisApiClient\Response\OrganizationalUnit\UnknownOrganizationUnitTypeException;
-use HnutiBrontosaurus\BisApiClient\Response\Response;
-use HnutiBrontosaurus\BisApiClient\Response\ResponseErrorException;
-use HnutiBrontosaurus\BisApiClient\Response\UnauthorizedAccessException;
-use HnutiBrontosaurus\BisApiClient\Response\UnknownErrorException;
-use Psr\Http\Message\ResponseInterface;
-
-
-final class Client
-{
-
-	private HttpClient $httpClient;
-	private string $url;
-	private string $username;
-	private string $password;
-
-
-	/**
-	 * @throws InvalidArgumentException
-	 */
-	public function __construct(string $url, string $username, string $password, HttpClient $httpClient)
-	{
-		if ($url === '') {
-			throw new InvalidArgumentException('You need to pass an URL with BIS API.');
-		}
-		if ($username === '') {
-			throw new InvalidArgumentException('Username is required for authenticating against BIS.');
-		}
-		if ($password === '') {
-			throw new InvalidArgumentException('Password is required for authenticating against BIS.');
-		}
-
-		$this->url = \rtrim($url, '/');
-		$this->username = $username;
-		$this->password = $password;
-		$this->httpClient = $httpClient;
-	}
-
-
-	// events
-
-	/**
-	 * @throws NotFoundException
-	 * @throws TransferErrorException
-	 * @throws ResponseErrorException
-	 */
-	public function getEvent(int $id, EventParameters $params = null): Event
-	{
-		$params = ($params !== null ? $params : new EventParameters());
-		$params->setId($id);
-		$response = $this->processRequest($params);
-
-		$data = $response->getData();
-
-		if (\count($data) === 0) {
-			throw new NotFoundException('No result for event with id `' . $id . '`.');
-		}
-
-		return Event::fromResponseData(\reset($data));
-	}
-
-
-	/**
-	 * @return Event[]
-	 * @throws NotFoundException
-	 * @throws TransferErrorException
-	 * @throws ResponseErrorException
-	 */
-	public function getEvents(EventParameters $params = null): array
-	{
-		$response = $this->processRequest($params !== null ? $params : new EventParameters());
-		$data = $response->getData();
-
-		if ($data === null) {
-			return [];
-		}
-
-		return \array_map(Event::class . '::fromResponseData', $data);
-	}
-
-
-	/**
-	 * @throws ResponseErrorException
-	 */
-	public function addAttendeeToEvent(EventAttendee $eventAttendee): void
-	{
-		$eventAttendee->setCredentials($this->username, $this->password);
-		$response = $this->httpClient->send($this->createRequest($eventAttendee));
-
-		$this->checkForResponseContentType($response);
-
-		$domDocument = $this->generateDOM($response);
-
-		$this->checkForResponseErrors($domDocument);
-	}
-
-
-	// organizational units
-
-	/**
-	 * @return OrganizationalUnit[]
-	 * @throws NotFoundException
-	 * @throws TransferErrorException
-	 * @throws ResponseErrorException
-	 */
-	public function getOrganizationalUnits(OrganizationalUnitParameters $params = null): array
-	{
-		$response = $this->processRequest($params !== null ? $params : new OrganizationalUnitParameters());
-
-		$organizationalUnits = [];
-		foreach ($response->getData() as $organizationalUnit) {
-			try {
-				$organizationalUnits[] = OrganizationalUnit::fromResponseData($organizationalUnit);
-
-			} catch (UnknownOrganizationUnitTypeException $e) {
-				continue; // In case of unknown type - just ignore it.
-
-			}
-		}
-
-		return $organizationalUnits;
-	}
-
-
-	// adoption
-
-	/**
-	 * @throws ResponseErrorException
-	 */
-	public function saveRequestForAdoption(Adoption $adoption): void
-	{
-		$adoption->setCredentials($this->username, $this->password);
-
-		$response = $this->httpClient->send($this->createRequest($adoption));
-
-		$this->checkForResponseContentType($response);
-
-		$domDocument = $this->generateDOM($response);
-
-		$this->checkForResponseErrors($domDocument);
-	}
-
-
-	/**
-	 * @throws NotFoundException
-	 * @throws TransferErrorException
-	 * @throws ResponseErrorException
-	 */
-	private function processRequest(Parameters $requestParameters): Response
-	{
-		$requestParameters->setCredentials($this->username, $this->password);
-
-		try {
-			$response = $this->httpClient->send($this->createRequest($requestParameters));
-
-		} catch (ClientException $e) {
-			throw new NotFoundException('Bis client could not find the queried resource.', 0, $e);
-
-		} catch (GuzzleException $e) {
-			throw new TransferErrorException('Unable to process request: transfer error.', 0, $e);
-		}
-
-		$this->checkForResponseContentType($response);
-
-		$domDocument = $this->generateDOM($response);
-		$this->checkForResponseErrors($domDocument);
-
-		return new Response($response, $domDocument);
-	}
-
-
-	/**
-	 * @throws InvalidContentTypeException
-	 */
-	private function checkForResponseContentType(ResponseInterface $response): void
-	{
-		if (\strncmp($response->getHeaderLine('Content-Type'), 'text/xml', \strlen('text/xml')) !== 0) {
-			throw new InvalidContentTypeException('Unable to process response: the response Content-Type is invalid or missing.');
-		}
-	}
-
-
-	/**
-	 * @throws InvalidXMLStructureException
-	 */
-	private function generateDOM(ResponseInterface $response): \DOMDocument
-	{
-		try {
-			$domDocument = new \DOMDocument();
-			$domDocument->loadXML($response->getBody()->getContents());
-
-		} catch (\Exception $e) {
-			throw new InvalidXMLStructureException('Unable to process response: response body contains invalid XML.', 0, $e);
-		}
-
-		return $domDocument;
-	}
-
-
-	/**
-	 * @throws ResponseErrorException
-	 */
-	private function checkForResponseErrors(\DOMDocument $domDocument): void
-	{
-		$resultNode = $domDocument->getElementsByTagName(Response::TAG_RESULT)->item(0);
-		\assert($resultNode instanceof \DOMElement);
-
-		if ($resultNode->hasAttribute(Response::TAG_RESULT_ATTRIBUTE_ERROR)) {
-			switch ($resultNode->getAttribute(Response::TAG_RESULT_ATTRIBUTE_ERROR)) {
-				case 'success': // In case of POST request with form data, BIS returns `<result error="success" />` for some reason... Let's pretend that there is no error in such case because... you know... there is no error!
-					break;
-
-				case 'user':
-					throw new InvalidUserInputException($resultNode);
-
-				case 'forbidden':
-					throw new UnauthorizedAccessException();
-
-				case 'params':
-					throw new InvalidParametersException();
-
-				default:
-					throw new UnknownErrorException($resultNode->getAttribute(Response::TAG_RESULT_ATTRIBUTE_ERROR));
-			}
-		}
-	}
-
-
-	private function createRequest(Parameters $parameters): Request
-	{
-		return new Request(
-			'POST',
-			$this->url,
-			[
-				'Content-Type' => 'application/x-www-form-urlencoded',
-			],
-			\http_build_query($parameters->getAll())
-		);
-	}
-
-}
diff --git a/src/Endpoint.php b/src/Endpoint.php
new file mode 100644
index 0000000..83f21d8
--- /dev/null
+++ b/src/Endpoint.php
@@ -0,0 +1,34 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient;
+
+
+final class Endpoint
+{
+
+	public static function AUTHENTICATION(): string
+	{
+		return 'o/token/';
+	}
+
+	public static function EVENT(int $id): string
+	{
+		return \sprintf('bronto/event/%d/', $id);
+	}
+
+	public static function EVENTS(): string
+	{
+		return 'bronto/event/';
+	}
+
+	public static function ADMINISTRATIVE_UNITS(): string
+	{
+		return 'bronto/administrative_unit/';
+	}
+
+	public static function ADD_ATTENDEE_TO_EVENT(): string
+	{
+		return 'bronto/register_userprofile_interaction/';
+	}
+
+}
diff --git a/src/Enums/EventType.php b/src/Enums/EventType.php
new file mode 100644
index 0000000..209132b
--- /dev/null
+++ b/src/Enums/EventType.php
@@ -0,0 +1,49 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Enums;
+
+use Grifart\Enum\AutoInstances;
+use Grifart\Enum\Enum;
+
+
+/**
+ * @method static EventType VOLUNTARY()
+ * @method static EventType EXPERIENCE()
+ * @method static EventType SPORT()
+ * @method static EventType EDUCATIONAL_TALK()
+ * @method static EventType EDUCATIONAL_COURSES()
+ * @method static EventType EDUCATIONAL_OHB()
+ * @method static EventType LEARNING_PROGRAM()
+ * @method static EventType RESIDENTIAL_LEARNING_PROGRAM()
+ * @method static EventType CLUB_MEETUP()
+ * @method static EventType CLUB_TALK()
+ * @method static EventType FOR_PUBLIC()
+ * @method static EventType EKOSTAN()
+ * @method static EventType EXHIBITION()
+ * @method static EventType ACTION_GROUP()
+ * @method static EventType INTERNAL()
+ * @method static EventType GROUP_MEETING()
+ */
+final class EventType extends Enum
+{
+	use AutoInstances;
+
+	protected const VOLUNTARY = 'pracovni'; // dobrovolnická
+	protected const EXPERIENCE = 'prozitkova'; // zážitková
+	protected const SPORT = 'sportovni';
+
+	protected const EDUCATIONAL_TALK = 'prednaska'; // vzdělávací - přednášky
+	protected const EDUCATIONAL_COURSES = 'vzdelavaci'; // vzdělávací - kurzy, školení
+	protected const EDUCATIONAL_OHB = 'ohb'; // vzdělávací - kurz ohb
+	protected const LEARNING_PROGRAM = 'vyuka'; // výukový program
+	protected const RESIDENTIAL_LEARNING_PROGRAM = 'pobyt'; // pobytový výukový program
+
+	protected const CLUB_MEETUP = 'klub'; // klub - setkání
+	protected const CLUB_TALK = 'klub-predn'; // klub - přednáška
+	protected const FOR_PUBLIC = 'verejnost'; // akce pro veřejnost
+	protected const EKOSTAN = 'ekostan';
+	protected const EXHIBITION = 'vystava';
+	protected const ACTION_GROUP = 'akcni'; // akční skupina
+	protected const INTERNAL = 'jina'; // interní akce (VH a jiné)
+	protected const GROUP_MEETING = 'schuzka'; // oddílová, družinová schůzka
+}
diff --git a/src/Enums/Program.php b/src/Enums/Program.php
new file mode 100644
index 0000000..946105c
--- /dev/null
+++ b/src/Enums/Program.php
@@ -0,0 +1,29 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Enums;
+
+use Grifart\Enum\AutoInstances;
+use Grifart\Enum\Enum;
+
+
+/**
+ * @method static Program NONE()
+ * @method static Program NATURE()
+ * @method static Program SIGHTS()
+ * @method static Program BRDO()
+ * @method static Program EKOSTAN()
+ * @method static Program PSB()
+ * @method static Program EDUCATION()
+ */
+final class Program extends Enum
+{
+	use AutoInstances;
+
+	protected const NONE = '';
+	protected const NATURE = 'nature';
+	protected const SIGHTS = 'monuments';
+	protected const BRDO = 'children_section';
+	protected const EKOSTAN = 'eco_consulting';
+	protected const PSB = 'PsB';
+	protected const EDUCATION = 'education';
+}
diff --git a/src/Enums/TargetGroup.php b/src/Enums/TargetGroup.php
new file mode 100644
index 0000000..776faf5
--- /dev/null
+++ b/src/Enums/TargetGroup.php
@@ -0,0 +1,25 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Enums;
+
+use Grifart\Enum\AutoInstances;
+use Grifart\Enum\Enum;
+
+
+/**
+ * @method static TargetGroup EVERYONE()
+ * @method static TargetGroup ADULTS()
+ * @method static TargetGroup CHILDREN()
+ * @method static TargetGroup FAMILIES()
+ * @method static TargetGroup FIRST_TIME_ATTENDEES()
+ */
+final class TargetGroup extends Enum
+{
+	use AutoInstances;
+
+	protected const EVERYONE = 'everyone';
+	protected const ADULTS = 'adolescents_and_adults';
+	protected const CHILDREN = 'children';
+	protected const FAMILIES = 'parents_and_children';
+	protected const FIRST_TIME_ATTENDEES = 'newcomers';
+}
diff --git a/src/HttpClient.php b/src/HttpClient.php
new file mode 100644
index 0000000..53bb307
--- /dev/null
+++ b/src/HttpClient.php
@@ -0,0 +1,79 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient;
+
+use GuzzleHttp\Client;
+use GuzzleHttp\Exception\ClientException;
+use GuzzleHttp\Exception\GuzzleException;
+use GuzzleHttp\Exception\ServerException;
+use GuzzleHttp\Exception\TooManyRedirectsException;
+use GuzzleHttp\Psr7\Request;
+use HnutiBrontosaurus\BisClient\Request\ToArray;
+use Psr\Http\Client\NetworkExceptionInterface;
+
+
+final class HttpClient
+{
+
+	public function __construct(
+		private AuthorizationToken $authorizationToken,
+		private Client $client,
+	) {}
+
+
+	/**
+	 * @throws UnableToProcessRequest
+	 * @throws NotFound
+	 * @throws ConnectionToBisFailed
+	 */
+	public function send(
+		string $method,
+		string $endpoint,
+		?ToArray $parameters = null,
+		?ToArray $data = null,
+	): array|\stdClass|null
+	{
+		$queryString = $parameters !== null
+			? '?' . \http_build_query($parameters->toArray())
+			: '';
+
+		// see Guzzle exceptions docs: https://docs.guzzlephp.org/en/stable/quickstart.html#exceptions
+		try {
+			$response = $this->client->send(new Request(
+				$method,
+				$endpoint . $queryString,
+				[
+					'Authorization' => 'Bearer ' . $this->authorizationToken->toString(),
+					'Content-Type' => 'application/json',
+				],
+				\json_encode($data !== null ? $data->toArray() : []),
+			));
+
+		} catch (ClientException $e) { // 4xx errors
+			if ($e->getCode() === 400) {
+				throw UnableToProcessRequest::withPrevious($e);
+			}
+
+			if ($e->getCode() === 404) {
+				throw NotFound::withPrevious($e);
+			}
+
+			throw ConnectionToBisFailed::withPrevious($e);
+
+		} catch (ServerException $e) { // 5xx errors
+			throw ConnectionToBisFailed::withPrevious($e);
+
+		} catch (TooManyRedirectsException $e) {
+			throw ConnectionToBisFailed::withPrevious($e);
+
+		} catch (NetworkExceptionInterface $e) { // problem with connection
+			throw ConnectionToBisFailed::withPrevious($e);
+
+		} catch (GuzzleException $e) { // fallback catch-all exception
+			throw ConnectionToBisFailed::withPrevious($e);
+		}
+
+		return \json_decode($response->getBody()->getContents());
+	}
+
+}
diff --git a/src/Request/Adoption.php b/src/Request/Adoption.php
index 9ccc658..6c84ba1 100644
--- a/src/Request/Adoption.php
+++ b/src/Request/Adoption.php
@@ -1,38 +1,34 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Request;
+namespace HnutiBrontosaurus\BisClient\Request;
 
+use HnutiBrontosaurus\BisClient\UsageException;
 
-final class Adoption extends Parameters
+
+final class Adoption implements ToArray
 {
 
 	public function __construct(
-		int $amount,
-		string $firstName,
-		string $lastName,
-		string $streetAddress,
-		string $streetNumber,
-		string $postalCode,
-		string $city,
-		string $emailAddress,
-		?int $preferredUnitOfTypeRegional,
-		?int $preferredUnitOfTypeBase,
-		bool $excludeFromPublic,
+		private int $amount,
+		private string $firstName,
+		private string $lastName,
+		private string $streetAddress,
+		private string $streetNumber,
+		private string $postalCode,
+		private string $city,
+		private string $emailAddress,
+		private ?int $preferredUnitOfTypeRegional,
+		private ?int $preferredUnitOfTypeBase,
+		private bool $excludeFromPublic,
 	) {
-		parent::__construct([
-			self::PARAM_QUERY => 'adopce',
-			'f_jmeno' => $firstName,
-			'f_prijmeni' => $lastName,
-			'f_ulice' => $streetAddress . ' ' . $streetNumber,
-			'f_mesto' => $city,
-			'f_psc' => $postalCode,
-			'f_email' => $emailAddress,
-			'f_pohlavi' => null, // not required, but accepted by BIS (values muz/zena)
-			'f_uvest_v_seznamu' => $excludeFromPublic ? 'off' : 'on',
-			'f_clanek' => $preferredUnitOfTypeBase,
-			'f_rc' => $preferredUnitOfTypeRegional,
-			'f_castka' => $amount,
-		]);
+		throw new UsageException('This is not implemented yet.');
 	}
 
+
+	public function toArray(): array
+	{
+		return [];
+	}
+
+
 }
diff --git a/src/Request/Event/EventAttendee.php b/src/Request/Event/EventAttendee.php
new file mode 100644
index 0000000..3973143
--- /dev/null
+++ b/src/Request/Event/EventAttendee.php
@@ -0,0 +1,48 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Request\Event;
+
+use HnutiBrontosaurus\BisClient\Request\ToArray;
+
+
+final class EventAttendee implements ToArray
+{
+
+	/**
+	 * @param string[] $questionAnswers
+	 */
+	public function __construct(
+		private int $eventId,
+		private string $firstName,
+		private string $lastName,
+		private \DateTimeImmutable $birthDate,
+		private string $phoneNumber,
+		private string $emailAddress,
+		private ?string $note,
+		private array $questionAnswers,
+	) {}
+
+
+	public function toArray(): array
+	{
+		$questionAnswers = [];
+		$i = 1;
+		foreach ($this->questionAnswers as $questionAnswer) {
+			$questionAnswers['additional_question_' . $i] = $questionAnswer;
+			$i++;
+		}
+
+		return \array_merge([
+			'event' => $this->eventId,
+			'first_name' => $this->firstName,
+			'last_name' => $this->lastName,
+			'telephone' => $this->phoneNumber,
+			'email' => $this->emailAddress,
+			'age_group' => $this->birthDate->format('Y'),
+			'birth_month' => $this->birthDate->format('n'),
+			'birth_day' => $this->birthDate->format('j'),
+			'note' => $this->note,
+		], $questionAnswers);
+	}
+
+}
diff --git a/src/Request/Event/EventParameters.php b/src/Request/Event/EventParameters.php
new file mode 100644
index 0000000..65f1def
--- /dev/null
+++ b/src/Request/Event/EventParameters.php
@@ -0,0 +1,176 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Request\Event;
+
+use HnutiBrontosaurus\BisClient\Enums\EventType;
+use HnutiBrontosaurus\BisClient\Enums\Program;
+use HnutiBrontosaurus\BisClient\Enums\TargetGroup;
+use HnutiBrontosaurus\BisClient\Request\ToArray;
+use HnutiBrontosaurus\BisClient\UsageException;
+
+
+final class EventParameters implements ToArray
+{
+
+	private Ordering $ordering;
+
+	public function __construct()
+	{
+		$this->orderByDateTo();
+	}
+
+
+
+	// filter
+
+	public const FILTER_ACTIONS_ONLY = 'action';
+	public const FILTER_CAMPS_ONLY = 'camp';
+
+	private string $filter = '';
+
+	public function setFilter($filter): self
+	{
+		if ( ! \in_array($filter, [
+			self::FILTER_ACTIONS_ONLY,
+			self::FILTER_CAMPS_ONLY,
+		])) {
+			throw new UsageException('Value `' . $filter . '` is not of valid filters');
+		}
+
+		$this->filter = $filter;
+		return $this;
+	}
+
+
+	// type
+
+	/** @var EventType[] */
+	private array $types = [];
+
+	public function setType(EventType $type): self
+	{
+		$this->types = [$type];
+		return $this;
+	}
+
+	/**
+	 * @param EventType[] $types
+	 */
+	public function setTypes(array $types): self
+	{
+		$this->types = $types;
+		return $this;
+	}
+
+
+	// program
+
+	/** @var Program[] */
+	private array $programs = [];
+
+	public function setProgram(Program $program): self
+	{
+		$this->programs = [$program];
+		return $this;
+	}
+
+	/**
+	 * @param Program[] $programs
+	 */
+	public function setPrograms(array $programs): self
+	{
+		$this->programs = $programs;
+		return $this;
+	}
+
+
+	// target group
+
+	/** @var TargetGroup[] */
+	private array $targetGroups = [];
+
+	public function setTargetGroup(TargetGroup $targetGroup): self
+	{
+		$this->targetGroups = [$targetGroup];
+		return $this;
+	}
+
+	/**
+	 * @param TargetGroup[] $targetGroups
+	 */
+	public function setTargetGroups(array $targetGroups): self
+	{
+		$this->targetGroups = $targetGroups;
+		return $this;
+	}
+
+
+
+	// miscellaneous
+
+	private \DateTimeImmutable $dateFromGreaterThan;
+
+	/**
+	 * Excludes events which are running (started, but not yet ended). Defaults to include them.
+	 */
+	public function excludeRunning(): self
+	{
+		$this->dateFromGreaterThan = new \DateTimeImmutable();
+		return $this;
+	}
+
+
+	public function orderByDateFrom(): self
+	{
+		$this->ordering = Ordering::DATE_FROM();
+		return $this;
+	}
+
+	public function orderByDateTo(): self
+	{
+		$this->ordering = Ordering::DATE_TO();
+		return $this;
+	}
+
+
+	/** @var int[] */
+	private array $organizedBy = [];
+
+	/**
+	 * @param int|int[] $unitIds
+	 */
+	public function setOrganizedBy(array|int $unitIds): self
+	{
+		// If just single value, wrap it into an array.
+		if ( ! \is_array($unitIds)) {
+			$this->organizedBy = [$unitIds];
+			return $this;
+		}
+
+		$this->organizedBy = $unitIds;
+		return $this;
+	}
+
+
+
+	// getters
+
+	public function toArray(): array
+	{
+		$array = [
+			'basic_purpose' => $this->filter,
+			'event_type_array' => \implode(',', $this->types),
+			'program_array' => \implode(',', $this->programs),
+			'indended_for_array' => \implode(',', $this->targetGroups),
+			'ordering' => $this->ordering,
+			'administrative_unit' => \implode(',', $this->organizedBy),
+		];
+
+		if (isset($this->dateFromGreaterThan)) {
+			$array['date_from__gte'] = $this->dateFromGreaterThan->format('Y-m-d');
+		}
+
+		return $array;
+	}
+
+}
diff --git a/src/Request/Event/Ordering.php b/src/Request/Event/Ordering.php
new file mode 100644
index 0000000..2666107
--- /dev/null
+++ b/src/Request/Event/Ordering.php
@@ -0,0 +1,19 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Request\Event;
+
+use Grifart\Enum\AutoInstances;
+use Grifart\Enum\Enum;
+
+
+/**
+ * @method static Ordering DATE_FROM()
+ * @method static Ordering DATE_TO()
+ */
+final class Ordering extends Enum
+{
+	use AutoInstances;
+
+	protected const DATE_FROM = 'date_from';
+	protected const DATE_TO = 'date_to';
+}
diff --git a/src/Request/EventAttendee.php b/src/Request/EventAttendee.php
deleted file mode 100644
index 68abe9b..0000000
--- a/src/Request/EventAttendee.php
+++ /dev/null
@@ -1,46 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Request;
-
-
-final class EventAttendee extends Parameters
-{
-
-	/**
-	 * @param string[] $questionAnswers
-	 */
-	public function __construct(
-		int $eventId,
-		string $firstName,
-		string $lastName,
-		string $birthDate,
-		string $phoneNumber,
-		string $emailAddress,
-		?string $note,
-		array $questionAnswers,
-	) {
-		parent::__construct([
-			self::PARAM_QUERY => 'prihlaska',
-			'akce' => $eventId,
-			'jmeno' => $firstName,
-			'prijmeni' => $lastName,
-			'telefon' => $phoneNumber,
-			'email' => $emailAddress,
-			'datum_narozeni' => $birthDate,
-			'poznamka' => $note,
-		]);
-
-
-		if (\count($questionAnswers) === 0) {
-			return;
-		}
-
-		// currently 3 questions are supported
-		$i = 1;
-		foreach ($questionAnswers as $questionAnswer) {
-			$this->params['add_info' . ($i >= 2 ? '_' . $i : '')] = $questionAnswer; // key syntax is `add_info` for first key and `add_info_X` for any other
-			$i++;
-		}
-	}
-
-}
diff --git a/src/Request/EventParameters.php b/src/Request/EventParameters.php
deleted file mode 100644
index 56e2dd9..0000000
--- a/src/Request/EventParameters.php
+++ /dev/null
@@ -1,304 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Request;
-
-use HnutiBrontosaurus\BisApiClient\InvalidArgumentException;
-
-
-final class EventParameters extends Parameters
-{
-
-	const PARAM_DISPLAY_ALREADY_STARTED_KEY = 'probihajici'; // for default just omit this parameter
-	const PARAM_DISPLAY_ALREADY_STARTED_VALUE = ''; // whatever value
-
-	const PARAM_ORDER_BY_KEY = 'sort'; // for default sorting just omit this parameter
-	const PARAM_ORDER_BY_END_DATE = 'do';
-
-
-	public function __construct()
-	{
-		parent::__construct([
-			self::PARAM_QUERY => 'akce',
-			self::PARAM_DISPLAY_ALREADY_STARTED_KEY => self::PARAM_DISPLAY_ALREADY_STARTED_VALUE,
-			self::PARAM_ORDER_BY_KEY => self::PARAM_ORDER_BY_END_DATE,
-		]);
-	}
-
-
-	public function setId(int $id): static
-	{
-		$this->params['id'] = (int) $id;
-		return $this;
-	}
-
-
-	// filter
-
-	const FILTER_CLUB = 1;
-	const FILTER_WEEKEND = 2;
-	const FILTER_CAMP = 4;
-	const FILTER_EKOSTAN = 8;
-
-	/**
-	 * This parameter serves as combinator for multiple conditions, which can not be achieved with concatenating type, program, target group or any other available parameters.
-	 * For example you can not make an union among different parameters. Let's say you want all events which are of type=ohb or of program=brdo. This is not possible with API parameters.
-	 * Thus you can take advantage of preset filters which are documented here: https://bis.brontosaurus.cz/myr.php
-	 *
-	 * Beside standard constant usage as a parameter, you can pass bitwise operation argument, e.g. `EventParameters::FILTER_WEEKEND|EventParameters::FILTER_CAMP`.
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function setFilter(int $filter): static
-	{
-		$keys = [
-			self::FILTER_CLUB => 'klub',
-			self::FILTER_WEEKEND => 'vik',
-			self::FILTER_CAMP => 'tabor',
-			self::FILTER_EKOSTAN => 'ekostan',
-		];
-
-		switch ($filter) {
-			case self::FILTER_CLUB:
-			case self::FILTER_WEEKEND:
-			case self::FILTER_CAMP:
-			case self::FILTER_EKOSTAN:
-				$param = $keys[$filter];
-				break;
-
-			case self::FILTER_WEEKEND | self::FILTER_CAMP:
-				$param = $keys[self::FILTER_WEEKEND] . $keys[self::FILTER_CAMP];
-				break;
-
-			case self::FILTER_WEEKEND | self::FILTER_EKOSTAN:
-				$param = $keys[self::FILTER_WEEKEND] . $keys[self::FILTER_EKOSTAN];
-				break;
-
-			default:
-				throw new InvalidArgumentException('Value `' . $filter . '` is not of valid types and their combinations for `filter` parameter. Only `weekend+camp` and `weekend+ekostan` can be combined.');
-				break;
-		}
-
-		$this->params['filter'] = $param;
-
-		return $this;
-	}
-
-
-	// type
-
-	const TYPE_VOLUNTARY = 'pracovni'; // dobrovolnická
-	const TYPE_EXPERIENCE = 'prozitkova'; // zážitková
-	const TYPE_SPORT = 'sportovni';
-
-	const TYPE_EDUCATIONAL_TALK = 'prednaska'; // vzdělávací - přednášky
-	const TYPE_EDUCATIONAL_COURSES = 'vzdelavaci'; // vzdělávací - kurzy, školení
-	const TYPE_EDUCATIONAL_OHB = 'ohb'; // vzdělávací - kurz ohb
-	const TYPE_LEARNING_PROGRAM = 'vyuka'; // výukový program
-	const TYPE_RESIDENTIAL_LEARNING_PROGRAM = 'pobyt'; // pobytový výukový program
-
-	const TYPE_CLUB_MEETUP = 'klub'; // klub - setkání
-	const TYPE_CLUB_TALK = 'klub-predn'; // klub - přednáška
-	const TYPE_FOR_PUBLIC = 'verejnost'; // akce pro veřejnost
-	const TYPE_EKOSTAN = 'ekostan';
-	const TYPE_EXHIBITION = 'vystava';
-	const TYPE_ACTION_GROUP = 'akcni'; // akční skupina
-	const TYPE_INTERNAL = 'jina'; // interní akce (VH a jiné)
-	const TYPE_GROUP_MEETING = 'schuzka'; // oddílová, družinová schůzka
-
-	/**
-	 * @throws InvalidArgumentException
-	 */
-	public function setType(string $type): static
-	{
-		if ( ! \in_array($type, [
-			self::TYPE_VOLUNTARY,
-			self::TYPE_EXPERIENCE,
-			self::TYPE_SPORT,
-
-			self::TYPE_EDUCATIONAL_TALK,
-			self::TYPE_EDUCATIONAL_COURSES,
-			self::TYPE_EDUCATIONAL_OHB,
-			self::TYPE_LEARNING_PROGRAM,
-			self::TYPE_RESIDENTIAL_LEARNING_PROGRAM,
-
-			self::TYPE_CLUB_MEETUP,
-			self::TYPE_CLUB_TALK,
-			self::TYPE_FOR_PUBLIC,
-			self::TYPE_EKOSTAN,
-			self::TYPE_EXHIBITION,
-			self::TYPE_ACTION_GROUP,
-			self::TYPE_INTERNAL,
-			self::TYPE_GROUP_MEETING,
-		], true)) {
-			throw new InvalidArgumentException('Value `' . $type . '` is not of valid types for `type` parameter.');
-		}
-
-		$this->params['typ'][] = $type;
-		return $this;
-	}
-
-	/**
-	 * @param string[] $types
-	 */
-	public function setTypes(array $types): static
-	{
-		foreach ($types as $type) {
-			$this->setType($type);
-		}
-
-		return $this;
-	}
-
-
-	// program
-
-	const PROGRAM_NOT_SELECTED = 'none';
-	const PROGRAM_NATURE = 'ap';
-	const PROGRAM_SIGHTS = 'pamatky';
-	const PROGRAM_BRDO = 'brdo';
-	const PROGRAM_EKOSTAN = 'ekostan';
-	const PROGRAM_PSB = 'psb';
-	const PROGRAM_EDUCATION = 'vzdelavani';
-
-	/**
-	 * @throws InvalidArgumentException
-	 */
-	public function setProgram(string $program): static
-	{
-		if ( ! \in_array($program, [
-			self::PROGRAM_NOT_SELECTED,
-			self::PROGRAM_NATURE,
-			self::PROGRAM_SIGHTS,
-			self::PROGRAM_BRDO,
-			self::PROGRAM_EKOSTAN,
-			self::PROGRAM_PSB,
-			self::PROGRAM_EDUCATION,
-		], true)) {
-			throw new InvalidArgumentException('Value `' . $program . '` is not of valid types for `program` parameter.');
-		}
-
-		$this->params['program'][] = $program;
-		return $this;
-	}
-
-	/**
-	 * @param string[] $programs
-	 */
-	public function setPrograms(array $programs): static
-	{
-		foreach ($programs as $program) {
-			$this->setProgram($program);
-		}
-
-		return $this;
-	}
-
-
-	// target group
-
-	const TARGET_GROUP_EVERYONE = 'vsichni';
-	const TARGET_GROUP_ADULTS = 'dospeli';
-	const TARGET_GROUP_CHILDREN = 'deti';
-	const TARGET_GROUP_FAMILIES = 'detirodice';
-	const TARGET_GROUP_FIRST_TIME_ATTENDEES = 'prvouc';
-
-	/**
-	 * @throws InvalidArgumentException
-	 */
-	public function setTargetGroup(string $targetGroup): static
-	{
-		if ( ! \in_array($targetGroup, [
-			self::TARGET_GROUP_EVERYONE,
-			self::TARGET_GROUP_ADULTS,
-			self::TARGET_GROUP_CHILDREN,
-			self::TARGET_GROUP_FAMILIES,
-			self::TARGET_GROUP_FIRST_TIME_ATTENDEES,
-		], true)) {
-			throw new InvalidArgumentException('Value `' . $targetGroup . '` is not of valid types for `for` parameter.');
-		}
-
-		$this->params['pro'][] = $targetGroup;
-		return $this;
-	}
-
-	/**
-	 * @param string[] $targetGroups
-	 */
-	public function setTargetGroups(array $targetGroups): static
-	{
-		foreach ($targetGroups as $targetGroup) {
-			$this->setTargetGroup($targetGroup);
-		}
-
-		return $this;
-	}
-
-
-	// date constraints
-
-	const PARAM_DATE_FORMAT = 'Y-m-d';
-
-	public function setFrom(\DateTimeImmutable $dateFrom): static
-	{
-		$this->params['od'] = $dateFrom->format(self::PARAM_DATE_FORMAT);
-		return $this;
-	}
-
-	public function setUntil(\DateTimeImmutable $dateFrom): static
-	{
-		$this->params['do'] = $dateFrom->format(self::PARAM_DATE_FORMAT);
-		return $this;
-	}
-
-	public function setYear(int $year): static
-	{
-		$this->params['rok'] = (int) $year;
-		return $this;
-	}
-
-	public function hideTheseAlreadyStarted(): static
-	{
-		unset($this->params[self::PARAM_DISPLAY_ALREADY_STARTED_KEY]);
-		return $this;
-	}
-
-
-	// miscellaneous
-
-	public function orderByStartDate(): static
-	{
-		unset($this->params[self::PARAM_ORDER_BY_KEY]);
-		return $this;
-	}
-
-	/**
-	 * @param int|int[] $unitIds
-	 */
-	public function setOrganizedBy(array|int $unitIds): static
-	{
-		$organizedByKey = 'zc';
-
-		// If just single value, wrap it into an array.
-		if ( ! \is_array($unitIds)) {
-			$unitIds = [$unitIds];
-		}
-
-		foreach ($unitIds as $unitId) {
-			// If such value is not present yet, initialize it with an empty array.
-			if ( ! \is_array($this->params[$organizedByKey])) {
-				$this->params[$organizedByKey] = [];
-			}
-
-			$this->params[$organizedByKey][] = (int) $unitId;
-		}
-
-		return $this;
-	}
-
-	public function includeNonPublic(): static
-	{
-		$this->params['vse'] = 1;
-		return $this;
-	}
-
-}
diff --git a/src/Request/OrganizationalUnitParameters.php b/src/Request/OrganizationalUnitParameters.php
deleted file mode 100644
index 011bced..0000000
--- a/src/Request/OrganizationalUnitParameters.php
+++ /dev/null
@@ -1,44 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Request;
-
-use HnutiBrontosaurus\BisApiClient\InvalidArgumentException;
-
-
-final class OrganizationalUnitParameters extends Parameters
-{
-
-	const PARAM_FILTER = 'filter';
-
-	const TYPE_CLUB = 'klub';
-	const TYPE_BASE = 'zc';
-	const TYPE_REGIONAL = 'rc';
-
-
-	public function __construct()
-	{
-		parent::__construct([
-			self::PARAM_QUERY => 'zc'
-		]);
-	}
-
-
-	/**
-	 * @throws InvalidArgumentException
-	 */
-	public function setType(string $type): static
-	{
-		if (!\in_array($type, [
-			self::TYPE_CLUB,
-			self::TYPE_BASE,
-			self::TYPE_REGIONAL,
-		], true)) {
-			throw new InvalidArgumentException('Type `' . $type . '` is not of valid types.');
-		}
-
-		$this->params[self::PARAM_FILTER] = $type;
-
-		return $this;
-	}
-
-}
diff --git a/src/Request/Parameters.php b/src/Request/Parameters.php
deleted file mode 100644
index 5fd5b4c..0000000
--- a/src/Request/Parameters.php
+++ /dev/null
@@ -1,51 +0,0 @@
-<?php declare(strict_types = 1);
-
-/**
- * See https://bis.brontosaurus.cz/myr.php for more information on values.
- */
-
-namespace HnutiBrontosaurus\BisApiClient\Request;
-
-
-abstract class Parameters
-{
-
-	const PARAM_USERNAME = 'user';
-	const PARAM_PASSWORD = 'password';
-
-	const PARAM_QUERY = 'query';
-
-
-	protected array $params = [];
-
-
-	/**
-	 * Currently no limitations to what can be in `params`.
-	 */
-	public function __construct(array $params = [])
-	{
-		$this->params = $params;
-	}
-
-
-	public function getAll(): array
-	{
-		return $this->params;
-	}
-
-
-	public function getQueryString(): string
-	{
-		return \http_build_query($this->params);
-	}
-
-
-	public function setCredentials(string $username, string $password): static
-	{
-		$this->params[self::PARAM_USERNAME] = $username;
-		$this->params[self::PARAM_PASSWORD] = $password;
-
-		return $this;
-	}
-
-}
diff --git a/src/Request/ToArray.php b/src/Request/ToArray.php
new file mode 100644
index 0000000..b36e372
--- /dev/null
+++ b/src/Request/ToArray.php
@@ -0,0 +1,11 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Request;
+
+
+interface ToArray
+{
+
+	public function toArray(): array;
+
+}
diff --git a/src/Response/Coordinates.php b/src/Response/Coordinates.php
new file mode 100644
index 0000000..f8af6db
--- /dev/null
+++ b/src/Response/Coordinates.php
@@ -0,0 +1,32 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Response;
+
+
+final class Coordinates
+{
+
+	private function __construct(
+		private float $latitude,
+		private float $longitude,
+	) {}
+
+
+	public static function from(float $latitude, float $longitude): self
+	{
+		return new self($latitude, $longitude);
+	}
+
+
+	public function getLatitude(): float
+	{
+		return $this->latitude;
+	}
+
+
+	public function getLongitude(): float
+	{
+		return $this->longitude;
+	}
+
+}
diff --git a/src/Response/Event/Event.php b/src/Response/Event/Event.php
index 7c37fa9..0e8d41c 100644
--- a/src/Response/Event/Event.php
+++ b/src/Response/Event/Event.php
@@ -1,17 +1,20 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event;
-
-use Grifart\Enum\MissingValueDeclarationException;
-use HnutiBrontosaurus\BisApiClient\BadUsageException;
-use HnutiBrontosaurus\BisApiClient\Response\Event\Invitation\Food;
-use HnutiBrontosaurus\BisApiClient\Response\Event\Invitation\Invitation;
-use HnutiBrontosaurus\BisApiClient\Response\Event\Invitation\Photo;
-use HnutiBrontosaurus\BisApiClient\Response\Event\Invitation\Presentation;
-use HnutiBrontosaurus\BisApiClient\Response\Event\Registration\RegistrationQuestion;
-use HnutiBrontosaurus\BisApiClient\Response\Event\Registration\RegistrationType;
-use HnutiBrontosaurus\BisApiClient\Response\Event\Registration\RegistrationTypeEnum;
-use HnutiBrontosaurus\BisApiClient\Response\RegistrationTypeException;
+namespace HnutiBrontosaurus\BisClient\Response\Event;
+
+use HnutiBrontosaurus\BisClient\Enums\Program;
+use HnutiBrontosaurus\BisClient\Enums\TargetGroup;
+use HnutiBrontosaurus\BisClient\Response\Coordinates;
+use HnutiBrontosaurus\BisClient\Response\Event\Invitation\Food;
+use HnutiBrontosaurus\BisClient\Response\Event\Invitation\Invitation;
+use HnutiBrontosaurus\BisClient\Response\Event\Invitation\Photo;
+use HnutiBrontosaurus\BisClient\Response\Event\Invitation\Presentation;
+use HnutiBrontosaurus\BisClient\Response\Event\Organizer\ContactPerson;
+use HnutiBrontosaurus\BisClient\Response\Event\Organizer\Organizer;
+use HnutiBrontosaurus\BisClient\Response\Event\Organizer\OrganizerOrganizationalUnit;
+use HnutiBrontosaurus\BisClient\Response\Event\Registration\RegistrationQuestion;
+use HnutiBrontosaurus\BisClient\Response\Event\Registration\RegistrationType;
+use HnutiBrontosaurus\BisClient\Response\Event\Registration\RegistrationTypeEnum;
 
 
 final class Event
@@ -23,135 +26,76 @@ private function __construct(
 		private ?string $coverPhotoPath,
 		private \DateTimeImmutable $dateFrom,
 		private \DateTimeImmutable $dateUntil,
-		private string $type,
 		private Program $program,
 		private Place $place,
 		private RegistrationType $registrationType,
 		private ?int $ageFrom,
 		private ?int $ageUntil,
-		private int|string $price, // single number or interval
+		private ?string $price, // single number or interval
 		private Organizer $organizer,
 		private TargetGroup $targetGroup,
 		private Invitation $invitation,
-		private ?string $timeFrom,
-		private ?string $programDescription,
-		private ?string $notes,
+		private ?\DateTimeImmutable $startDate,
 		private ?string $relatedWebsite,
 	) {}
 
 
-	/**
-	 * @param string[] $data Everything is string as it comes from HTTP response body.
-	 * @throws RegistrationTypeException
-	 * @throws BadUsageException
-	 */
-	public static function fromResponseData(array $data): static
+	public static function fromResponseData(\stdClass $data): self
 	{
-		// program
-		try {
-			$programSlug = (isset($data['program_id']) && $data['program_id'] !== '')
-				? ProgramType::fromScalar($data['program_id'])
-				: ProgramType::NONE();
-		} catch (MissingValueDeclarationException) {
-			$programSlug = ProgramType::NONE();
-		}
-		$programName = (isset($data['program']) && $data['program'] !== '') ? $data['program'] : null;
-		$program = Program::from($programSlug, $programName);
-
-		// place
-		$placeName = $data['lokalita'];
-		$placeAlternativeName = (isset($data['lokalita_misto']) && $data['lokalita_misto'] !== '') ? $data['lokalita_misto'] : null;
-		$placeCoordinates = (isset($data['lokalita_gps']) && $data['lokalita_gps'] !== '') ? $data['lokalita_gps'] : null;
-		$place = Place::from(
-			$placeAlternativeName !== null
-				? $placeAlternativeName // it looks like alternative names are more specific
-				: $placeName,
-			$placeCoordinates !== null
-				? $placeCoordinates
-				: null,
-		);
-
 		// registration
-		try {
-			$registrationType = RegistrationTypeEnum::fromScalar((int) $data['prihlaska']);
-		} catch (MissingValueDeclarationException) {
-			$registrationType = RegistrationTypeEnum::DISABLED(); // silent fallback
-		}
-
-		$webRegistrationQuestion1 = (isset($data['add_info_title']) && $data['add_info_title'] !== '') ? $data['add_info_title'] : null;
-		$webRegistrationQuestion2 = (isset($data['add_info_title_2']) && $data['add_info_title_2'] !== '') ? $data['add_info_title_2'] : null;
-		$webRegistrationQuestion3 = (isset($data['add_info_title_3']) && $data['add_info_title_3'] !== '') ? $data['add_info_title_3'] : null;
-		$contactEmail = $data['kontakt_email'];
-		$registrationCustomUrl = (isset($data['kontakt_url']) && $data['kontakt_url'] !== '') ? $data['kontakt_url'] : null;
+		$contactEmail = $data->contact_person_email;
+		$registrationCustomUrl = $data->entry_form_url;
 		$registrationQuestions = \array_filter([ // exclude all null items
-			$webRegistrationQuestion1,
-			$webRegistrationQuestion2,
-			$webRegistrationQuestion3,
-		], fn($v, $k) => $v !== null, \ARRAY_FILTER_USE_BOTH);
+			$data->additional_question_1,
+			$data->additional_question_2,
+			$data->additional_question_3,
+		], fn($v, $k) => $v !== '', \ARRAY_FILTER_USE_BOTH);
 		$registrationType = RegistrationType::from(
-			$registrationType,
+			RegistrationTypeEnum::fromScalar($data->registration_method),
 			\array_map(fn(string $question) => RegistrationQuestion::from($question), $registrationQuestions),
 			$contactEmail,
 			$registrationCustomUrl,
 		);
 
-		// price
-		$price = 0;
-		if (isset($data['poplatek']) && $data['poplatek'] !== '') {
-			$price = $data['poplatek'];
-
-			if (\preg_match('|^[0-9]+$|', $price)) {
-				$price = (int) $price;
-			}
-		}
 
 		// organizers
-		$organizationalUnitId = (isset($data['porada_id']) && $data['porada_id'] !== '') ? ((int) $data['porada_id']) : null;
-		$organizationalUnitName= (isset($data['porada']) && $data['porada'] !== '') ? $data['porada'] : null;
-		$organizers = (isset($data['org']) && $data['org'] !== '') ? $data['org'] : null;
-		$contactPersonName = (isset($data['kontakt']) && $data['kontakt'] !== '') ? $data['kontakt'] : null;
-		$contactPhone = $data['kontakt_telefon'];
-		$responsiblePerson = (isset($data['odpovedna']) && $data['odpovedna'] !== '') ? $data['odpovedna'] : null;
+		$organizationalUnitName = $data->administrative_unit_name !== '' ? $data->administrative_unit_name : null;
+		$organizationalUnitWebsite = $data->administrative_unit_web_url !== '' ? $data->administrative_unit_web_url : null;
+		$organizers = $data->looking_forward_to_you !== '' ? $data->looking_forward_to_you : null;
+		$responsiblePerson = $data->responsible_person !== '' ? $data->responsible_person : null;
 		$organizer = Organizer::from(
-			($organizationalUnitId !== null && $organizationalUnitName !== null)
-				? OrganizerOrganizationalUnit::from($organizationalUnitId, $organizationalUnitName)
+			($organizationalUnitName !== null)
+				? OrganizerOrganizationalUnit::from($organizationalUnitName, $organizationalUnitWebsite)
 				: null,
 			$responsiblePerson,
 			$organizers,
-			$contactPersonName,
-			$contactPhone,
-			$contactEmail,
+			ContactPerson::from(
+				$data->contact_person_name,
+				$contactEmail,
+				$data->contact_person_telephone,
+			),
 		);
 
 
 		// invitation
 
-		// BIS API returns "0", "1", "2" etc. for real options and "" when nothing is set
-		$food = (isset($data['strava']) && $data['strava'] !== '')
-			? Food::fromScalar((int) $data['strava'])
-			: Food::NOT_LISTED();
-
 		/** @var Photo[] $invitationPresentationPhotos */
 		$invitationPresentationPhotos = [];
 		for ($i = 1; $i <= 6; $i++) {
-			if (isset($data['ochutnavka_' . $i]) && $data['ochutnavka_' . $i] !== '') {
-				$invitationPresentationPhotos[] = Photo::from($data['ochutnavka_' . $i]);
+			$photo = $data->{'additional_photo_' . $i};
+			if ($photo !== null) {
+				$invitationPresentationPhotos[] = Photo::from($photo);
 			}
 		}
 
-		$invitationOrganizationalInformation = (isset($data['text_info']) && $data['text_info'] !== '') ? $data['text_info'] : ''; // this will not be needed in BIS but now it has to be there as somehow obligatory fields are not required anymore in old BIS
-		$invitationIntroduction = (isset($data['text_uvod']) && $data['text_uvod'] !== '') ? $data['text_uvod'] : ''; // this will not be needed in BIS but now it has to be there as somehow obligatory fields are not required anymore in old BIS
-		$invitationPresentationText = (isset($data['text_mnam']) && $data['text_mnam'] !== '') ? $data['text_mnam'] : null;
-		$invitationWorkDescription = (isset($data['text_dobr']) && $data['text_dobr'] !== '') ? $data['text_dobr'] : null;
-		$workHoursPerDay = (isset($data['pracovni_doba']) && $data['pracovni_doba'] !== '') ? ((int) $data['pracovni_doba']) : null;
-		$accommodation = (isset($data['ubytovani']) && $data['ubytovani'] !== '') ? $data['ubytovani'] : null;
+		$invitationPresentationText = $data->invitation_text_4;
 		$invitation = Invitation::from(
-			$invitationIntroduction,
-			$invitationOrganizationalInformation,
-			$accommodation,
-			$food,
-			$invitationWorkDescription,
-			$workHoursPerDay,
+			$data->invitation_text_1,
+			$data->invitation_text_2,
+			$data->accommodation !== '' ? $data->accommodation : null,
+			\array_map(static fn($diet) => Food::fromScalar($diet), $data->diet),
+			$data->invitation_text_3,
+			$data->working_hours,
 			($invitationPresentationText !== null || \count($invitationPresentationPhotos) > 0)
 				? Presentation::from($invitationPresentationText, $invitationPresentationPhotos)
 				: null,
@@ -159,7 +103,7 @@ public static function fromResponseData(array $data): static
 
 
 		// related website
-		$relatedWebsite = (isset($data['web']) && $data['web'] !== '') ? $data['web'] : null;
+		$relatedWebsite = $data->web_url;
 		$_relatedWebsite = null;
 		if ($relatedWebsite !== null) {
 			if ( ! self::startsWith($relatedWebsite, 'http')) { // count with no protocol typed URLs
@@ -170,24 +114,34 @@ public static function fromResponseData(array $data): static
 		}
 
 		return new self(
-			(int) $data['id'],
-			$data['nazev'],
-			(isset($data['foto_hlavni']) && $data['foto_hlavni'] !== '') ? $data['foto_hlavni'] : null,
-			\DateTimeImmutable::createFromFormat('Y-m-d', $data['od']),
-			\DateTimeImmutable::createFromFormat('Y-m-d', $data['do']),
-			$data['typ'],
-			$program,
-			$place,
+			$data->id,
+			$data->name,
+			$data->main_photo,
+			$data->date_from === null
+				? \DateTimeImmutable::createFromFormat('Y-m-d', '1970-01-01') // todo temp, until there are nullable dates coming from API
+				: \DateTimeImmutable::createFromFormat('Y-m-d', $data->date_from),
+			$data->date_to === null
+				? \DateTimeImmutable::createFromFormat('Y-m-d', '1970-01-02') // todo temp, until there are nullable dates coming from API
+				: \DateTimeImmutable::createFromFormat('Y-m-d', $data->date_to),
+			Program::fromScalar($data->program),
+			$data->location === null
+				? Place::from('nezadáno', null) // todo temp, until there are nullable locations coming from API
+				: Place::from(
+				$data->location->name,
+				$data->location->gps_latitude !== null && $data->location->gps_longitude !== null
+					? Coordinates::from($data->location->gps_latitude, $data->location->gps_longitude)
+					: null,
+			),
 			$registrationType,
-			(isset($data['vek_od']) && $data['vek_od'] !== '') ? ((int) $data['vek_od']) : null,
-			(isset($data['vek_do']) && $data['vek_do'] !== '') ? ((int) $data['vek_do']) : null,
-			$price,
+			$data->age_from,
+			$data->age_to,
+			$data->participation_fee !== null ? $data->participation_fee : null,
 			$organizer,
-			TargetGroup::from((int) $data['prokoho']),
+			TargetGroup::fromScalar($data->indended_for),
 			$invitation,
-			(isset($data['sraz']) && $data['sraz'] !== '') ? $data['sraz'] : null,
-			(isset($data['popis_programu']) && $data['popis_programu'] !== '') ? $data['popis_programu'] : null,
-			(isset($data['jak_se_prihlasit']) && $data['jak_se_prihlasit'] !== '') ? $data['jak_se_prihlasit'] : null,
+			$data->start_date !== null
+				? new \DateTimeImmutable($data->start_date)
+				: null,
 			$_relatedWebsite,
 		);
 	}
@@ -211,12 +165,6 @@ public function getCoverPhotoPath(): ?string
 	}
 
 
-	public function hasCoverPhoto(): bool
-	{
-		return $this->coverPhotoPath !== null;
-	}
-
-
 	public function getDateFrom(): \DateTimeImmutable
 	{
 		return $this->dateFrom;
@@ -229,12 +177,6 @@ public function getDateUntil(): \DateTimeImmutable
 	}
 
 
-	public function getType(): string
-	{
-		return $this->type;
-	}
-
-
 	public function getProgram(): Program
 	{
 		return $this->program;
@@ -265,18 +207,12 @@ public function getAgeUntil(): ?int
 	}
 
 
-	public function getPrice(): int|string
+	public function getPrice(): ?string
 	{
 		return $this->price;
 	}
 
 
-	public function isPaid(): bool
-	{
-		return $this->price !== 0;
-	}
-
-
 	public function getOrganizer(): Organizer
 	{
 		return $this->organizer;
@@ -295,33 +231,9 @@ public function getInvitation(): Invitation
 	}
 
 
-	public function hasTimeFrom(): bool
-	{
-		return $this->timeFrom !== null;
-	}
-
-
-	public function getTimeFrom(): ?string
-	{
-		return $this->timeFrom;
-	}
-
-
-	public function getProgramDescription(): ?string
-	{
-		return $this->programDescription;
-	}
-
-
-	public function getNotes(): ?string
-	{
-		return $this->notes;
-	}
-
-
-	public function hasRelatedWebsite(): bool
+	public function getStartDate(): ?\DateTimeImmutable
 	{
-		return $this->relatedWebsite !== null;
+		return $this->startDate;
 	}
 
 
diff --git a/src/Response/Event/Invitation/Food.php b/src/Response/Event/Invitation/Food.php
index 49a2c3b..cdea814 100644
--- a/src/Response/Event/Invitation/Food.php
+++ b/src/Response/Event/Invitation/Food.php
@@ -1,23 +1,27 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event\Invitation;
+namespace HnutiBrontosaurus\BisClient\Response\Event\Invitation;
 
 use Grifart\Enum\AutoInstances;
 use Grifart\Enum\Enum;
 
 
 /**
- * @method static Food NOT_LISTED()
- * @method static Food CHOOSEABLE()
  * @method static Food VEGETARIAN()
  * @method static Food NON_VEGETARIAN()
+ * @method static Food VEGAN()
+ * @method static Food KOSHER()
+ * @method static Food HALAL()
+ * @method static Food GLUTEN_FREE()
  */
 final class Food extends Enum
 {
 	use AutoInstances;
 
-	protected const NOT_LISTED = -1;
-	protected const CHOOSEABLE = 0;
-	protected const VEGETARIAN = 1;
-	protected const NON_VEGETARIAN = 2;
+	protected const VEGETARIAN = 'vegetarian';
+	protected const NON_VEGETARIAN = 'non_vegetarian';
+	protected const VEGAN = 'vegan';
+	protected const KOSHER = 'kosher';
+	protected const HALAL = 'halal';
+	protected const GLUTEN_FREE = 'gluten_free';
 }
diff --git a/src/Response/Event/Invitation/Invitation.php b/src/Response/Event/Invitation/Invitation.php
index 4760dd1..d9920a1 100644
--- a/src/Response/Event/Invitation/Invitation.php
+++ b/src/Response/Event/Invitation/Invitation.php
@@ -1,27 +1,33 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event\Invitation;
+namespace HnutiBrontosaurus\BisClient\Response\Event\Invitation;
 
 
 final class Invitation
 {
 
+	/**
+	 * @param Food[] $food
+	 */
 	private function __construct(
 		private string $introduction,
 		private string $organizationalInformation,
 		private ?string $accommodation,
-		private Food $food,
+		private array $food,
 		private ?string $workDescription,
 		private ?int $workHoursPerDay,
 		private ?Presentation $presentation,
 	) {}
 
 
+	/**
+	 * @param Food[] $food
+	 */
 	public static function from(
 		string $introduction,
 		string $organizationalInformation,
 		?string $accommodation,
-		Food $food,
+		array $food,
 		?string $workDescription,
 		?int $workHoursPerDay,
 		?Presentation $presentation,
@@ -51,19 +57,16 @@ public function getOrganizationalInformation(): string
 	}
 
 
-	public function isAccommodationListed(): bool
-	{
-		return $this->accommodation !== null;
-	}
-
-
 	public function getAccommodation(): ?string
 	{
 		return $this->accommodation;
 	}
 
 
-	public function getFood(): Food
+	/**
+	 * @return Food[]
+	 */
+	public function getFood(): array
 	{
 		return $this->food;
 	}
@@ -75,24 +78,12 @@ public function getWorkDescription(): ?string
 	}
 
 
-	public function areWorkHoursPerDayListed(): bool
-	{
-		return $this->workHoursPerDay !== null;
-	}
-
-
 	public function getWorkHoursPerDay(): ?int
 	{
 		return $this->workHoursPerDay;
 	}
 
 
-	public function hasPresentation(): bool
-	{
-		return $this->presentation !== null;
-	}
-
-
 	public function getPresentation(): ?Presentation
 	{
 		return $this->presentation;
diff --git a/src/Response/Event/Invitation/Photo.php b/src/Response/Event/Invitation/Photo.php
index 582c3be..df44878 100644
--- a/src/Response/Event/Invitation/Photo.php
+++ b/src/Response/Event/Invitation/Photo.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event\Invitation;
+namespace HnutiBrontosaurus\BisClient\Response\Event\Invitation;
 
 
 final class Photo
diff --git a/src/Response/Event/Invitation/Presentation.php b/src/Response/Event/Invitation/Presentation.php
index f8064a3..8dbabcb 100644
--- a/src/Response/Event/Invitation/Presentation.php
+++ b/src/Response/Event/Invitation/Presentation.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event\Invitation;
+namespace HnutiBrontosaurus\BisClient\Response\Event\Invitation;
 
 
 final class Presentation
@@ -24,23 +24,12 @@ public static function from(?string $text, array $photos): self
 	}
 
 
-	public function hasText(): bool
-	{
-		return $this->text !== null;
-	}
-
-
 	public function getText(): ?string
 	{
 		return $this->text;
 	}
 
 
-	public function hasAnyPhotos(): bool
-	{
-		return \count($this->photos) > 0;
-	}
-
 	/**
 	 * @return Photo[]
 	 */
diff --git a/src/Response/Event/Organizer/ContactPerson.php b/src/Response/Event/Organizer/ContactPerson.php
new file mode 100644
index 0000000..b8cb186
--- /dev/null
+++ b/src/Response/Event/Organizer/ContactPerson.php
@@ -0,0 +1,43 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Response\Event\Organizer;
+
+final class ContactPerson
+{
+
+	private function __construct(
+		private string $name,
+		private string $emailAddress,
+		private string $phoneNumber,
+	)
+	{}
+
+
+	public static function from(
+		string $name,
+		string $emailAddress,
+		string $phoneNumber,
+	): self
+	{
+		return new self($name, $emailAddress, $phoneNumber);
+	}
+
+
+	public function getName(): string
+	{
+		return $this->name;
+	}
+
+
+	public function getEmailAddress(): string
+	{
+		return $this->emailAddress;
+	}
+
+
+	public function getPhoneNumber(): string
+	{
+		return $this->phoneNumber;
+	}
+
+}
diff --git a/src/Response/Event/Organizer.php b/src/Response/Event/Organizer/Organizer.php
similarity index 54%
rename from src/Response/Event/Organizer.php
rename to src/Response/Event/Organizer/Organizer.php
index 7c4c436..454802a 100644
--- a/src/Response/Event/Organizer.php
+++ b/src/Response/Event/Organizer/Organizer.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event;
+namespace HnutiBrontosaurus\BisClient\Response\Event\Organizer;
 
 
 final class Organizer
@@ -10,9 +10,7 @@ private function __construct(
 		private ?OrganizerOrganizationalUnit $organizationalUnit,
 		private ?string $responsiblePerson,
 		private ?string $organizers,
-		private ?string $contactPersonName,
-		private string $contactPhone,
-		private string $contactEmail,
+		private ContactPerson $contactPerson,
 	) {}
 
 
@@ -20,18 +18,14 @@ public static function from(
 		?OrganizerOrganizationalUnit $organizationalUnit,
 		?string $responsiblePerson,
 		?string $organizers,
-		?string $contactPersonName,
-		string $contactPhone,
-		string $contactEmail,
+		ContactPerson $contactPerson,
 	): self
 	{
 		return new self(
 			$organizationalUnit,
 			$responsiblePerson,
 			$organizers,
-			$contactPersonName,
-			$contactPhone,
-			$contactEmail,
+			$contactPerson,
 		);
 	}
 
@@ -48,33 +42,15 @@ public function getResponsiblePerson(): ?string
 	}
 
 
-	public function areOrganizersListed(): bool
-	{
-		return $this->organizers !== null;
-	}
-
-
 	public function getOrganizers(): ?string
 	{
 		return $this->organizers;
 	}
 
 
-	public function getContactPersonName(): ?string
-	{
-		return $this->contactPersonName;
-	}
-
-
-	public function getContactPhone(): string
-	{
-		return $this->contactPhone;
-	}
-
-
-	public function getContactEmail(): string
+	public function getContactPerson(): ContactPerson
 	{
-		return $this->contactEmail;
+		return $this->contactPerson;
 	}
 
 }
diff --git a/src/Response/Event/Organizer/OrganizerOrganizationalUnit.php b/src/Response/Event/Organizer/OrganizerOrganizationalUnit.php
new file mode 100644
index 0000000..0564d57
--- /dev/null
+++ b/src/Response/Event/Organizer/OrganizerOrganizationalUnit.php
@@ -0,0 +1,32 @@
+<?php declare(strict_types = 1);
+
+namespace HnutiBrontosaurus\BisClient\Response\Event\Organizer;
+
+
+final class OrganizerOrganizationalUnit
+{
+
+	private function __construct(
+		private string $name,
+		private ?string $website,
+	) {}
+
+
+	public static function from(string $name, ?string $website): self
+	{
+		return new self($name, $website);
+	}
+
+
+	public function getName(): string
+	{
+		return $this->name;
+	}
+
+
+	public function getWebsite(): ?string
+	{
+		return $this->website;
+	}
+
+}
diff --git a/src/Response/Event/OrganizerOrganizationalUnit.php b/src/Response/Event/OrganizerOrganizationalUnit.php
deleted file mode 100644
index b94883a..0000000
--- a/src/Response/Event/OrganizerOrganizationalUnit.php
+++ /dev/null
@@ -1,37 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Response\Event;
-
-
-/**
- * This could be OrganizationalUnit instead as well,
- * but one more request per each event would be generated which is kinda wasteful.
- * And Brontosaurus does not want any more waste... :-)
- */
-final class OrganizerOrganizationalUnit
-{
-
-	private function __construct(
-		private int $id,
-		private string $name,
-	) {}
-
-
-	public static function from(int $id, string $name): self
-	{
-		return new self($id, $name);
-	}
-
-
-	public function getId(): int
-	{
-		return $this->id;
-	}
-
-
-	public function getName(): string
-	{
-		return $this->name;
-	}
-
-}
diff --git a/src/Response/Event/Place.php b/src/Response/Event/Place.php
index 7cdc0ae..c625757 100644
--- a/src/Response/Event/Place.php
+++ b/src/Response/Event/Place.php
@@ -1,6 +1,8 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event;
+namespace HnutiBrontosaurus\BisClient\Response\Event;
+
+use HnutiBrontosaurus\BisClient\Response\Coordinates;
 
 
 final class Place
@@ -8,20 +10,15 @@ final class Place
 
 	private function __construct(
 		private string $name,
-		private ?string $coordinates, // in format 49.132456 16.123456
+		private ?Coordinates $coordinates,
 	) {}
 
 
 	public static function from(
 		string $name,
-		?string $coordinates,
+		?Coordinates $coordinates,
 	): self
 	{
-		// only `49.132456 16.123456` format is used by users right now
-		if ($coordinates !== null && ! \preg_match('|[0-9]+(\.[0-9]+) [0-9]+(\.[0-9]+)|', $coordinates)) {
-			$coordinates = null;
-		}
-
 		return new self($name, $coordinates);
 	}
 
@@ -32,13 +29,7 @@ public function getName(): string
 	}
 
 
-	public function areCoordinatesListed(): bool
-	{
-		return $this->coordinates !== null;
-	}
-
-
-	public function getCoordinates(): ?string
+	public function getCoordinates(): ?Coordinates
 	{
 		return $this->coordinates;
 	}
diff --git a/src/Response/Event/Program.php b/src/Response/Event/Program.php
deleted file mode 100644
index cbf4746..0000000
--- a/src/Response/Event/Program.php
+++ /dev/null
@@ -1,77 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Response\Event;
-
-
-final class Program
-{
-
-	private function __construct(
-		private ProgramType $slug,
-		private ?string $name,
-	) {}
-
-
-	public static function from(
-		ProgramType $slug,
-		?string $name,
-	): self
-	{
-		return new self($slug, $name);
-	}
-
-
-	public function getSlug(): string
-	{
-		return $this->slug->toScalar();
-	}
-
-
-	public function getName(): ?string
-	{
-		return $this->name;
-	}
-
-
-	public function isNotSelected(): bool
-	{
-		return $this->slug->equals(ProgramType::NONE());
-	}
-
-
-	public function isOfTypeNature(): bool
-	{
-		return $this->slug->equals(ProgramType::NATURE());
-	}
-
-
-	public function isOfTypeSights(): bool
-	{
-		return $this->slug->equals(ProgramType::SIGHTS());
-	}
-
-
-	public function isOfTypeBrdo(): bool
-	{
-		return $this->slug->equals(ProgramType::BRDO());
-	}
-
-
-	public function isOfTypeEkostan(): bool
-	{
-		return $this->slug->equals(ProgramType::EKOSTAN());
-	}
-
-
-	public function isOfTypePsb(): bool
-	{
-		return $this->slug->equals(ProgramType::PSB());
-	}
-
-
-	public function isOfTypeEducation(): bool
-	{
-		return $this->slug->equals(ProgramType::EDUCATION());
-	}
-
-}
diff --git a/src/Response/Event/ProgramType.php b/src/Response/Event/ProgramType.php
deleted file mode 100644
index df29adf..0000000
--- a/src/Response/Event/ProgramType.php
+++ /dev/null
@@ -1,29 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Response\Event;
-
-use Grifart\Enum\AutoInstances;
-use Grifart\Enum\Enum;
-
-
-/**
- * @method static ProgramType NONE()
- * @method static ProgramType NATURE()
- * @method static ProgramType SIGHTS()
- * @method static ProgramType BRDO()
- * @method static ProgramType EKOSTAN()
- * @method static ProgramType PSB()
- * @method static ProgramType EDUCATION()
- */
-final class ProgramType extends Enum
-{
-	use AutoInstances;
-
-	protected const NONE = 'none';
-	protected const NATURE = 'ap';
-	protected const SIGHTS = 'pamatky';
-	protected const BRDO = 'brdo';
-	protected const EKOSTAN = 'ekostan';
-	protected const PSB = 'psb';
-	protected const EDUCATION = 'vzdelavani';
-}
diff --git a/src/Response/Event/Registration/RegistrationQuestion.php b/src/Response/Event/Registration/RegistrationQuestion.php
index a2687fa..2751ccb 100644
--- a/src/Response/Event/Registration/RegistrationQuestion.php
+++ b/src/Response/Event/Registration/RegistrationQuestion.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event\Registration;
+namespace HnutiBrontosaurus\BisClient\Response\Event\Registration;
 
 
 final class RegistrationQuestion
diff --git a/src/Response/Event/Registration/RegistrationType.php b/src/Response/Event/Registration/RegistrationType.php
index e188642..65f7758 100644
--- a/src/Response/Event/Registration/RegistrationType.php
+++ b/src/Response/Event/Registration/RegistrationType.php
@@ -1,17 +1,14 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event\Registration;
+namespace HnutiBrontosaurus\BisClient\Response\Event\Registration;
 
-use HnutiBrontosaurus\BisApiClient\BadUsageException;
-use HnutiBrontosaurus\BisApiClient\Response\RegistrationTypeException;
+use HnutiBrontosaurus\BisClient\RuntimeException;
+use HnutiBrontosaurus\BisClient\UsageException;
 
 
 final class RegistrationType
 {
 
-	private bool $hasValidData;
-
-
 	/**
 	 * @param RegistrationQuestion[] $questions
 	 */
@@ -20,14 +17,7 @@ private function __construct(
 		private array $questions, // in case of registering via Brontoweb
 		private ?string $email, // in case of registering via e-mail
 		private ?string $url, // in case of registering via custom webpage
-	) {
-		$this->hasValidData = match (true) {
-			$type->equals(RegistrationTypeEnum::EMAIL()) && $email === null,
-			$type->equals(RegistrationTypeEnum::EXTERNAL_WEBPAGE()) && $url === null,
-				=> false,
-			default => true
-		};
-	}
+	) {}
 
 	/**
 	 * @param RegistrationQuestion[] $questions
@@ -51,11 +41,6 @@ public function isOfTypeBrontoWeb(): bool
 	}
 
 
-	public function areAnyQuestions(): bool
-	{
-		return \count($this->questions) > 0;
-	}
-
 	/**
 	 * @return RegistrationQuestion[]
 	 */
@@ -72,18 +57,19 @@ public function isOfTypeEmail(): bool
 		return $this->type->equals(RegistrationTypeEnum::EMAIL());
 	}
 
-	/**
-	 * @throws RegistrationTypeException
-	 * @throws BadUsageException
-	 */
 	public function getEmail(): ?string
 	{
-		if ( ! $this->hasValidData()) {
-			throw RegistrationTypeException::missingAdditionalData('email', $this->type);
+		if ( ! $this->isOfTypeEmail()) {
+			throw new UsageException('This method can not be called when the registration is not of `via e-mail` type.');
 		}
 
-		if ( ! $this->isOfTypeEmail()) {
-			throw new BadUsageException('This method can not be called when the registration is not of `via e-mail` type.');
+		if ($this->email === null) {
+			/*
+			 * Ideally, this should not happen, but we can not rely on it. If it happens, we want to know about it ->
+			 * assert() is not enough. We can just log it, but that would lead user into clicking a button which does nothing.
+			 * Thus rendering error page covers both – logging and preventing user from accessing non-working page.
+			 */
+			throw new RuntimeException('E-mail must not be null in case of registration via e-mail.');
 		}
 
 		return $this->email;
@@ -97,18 +83,19 @@ public function isOfTypeCustomWebpage(): bool
 		return $this->type->equals(RegistrationTypeEnum::EXTERNAL_WEBPAGE());
 	}
 
-	/**
-	 * @throws RegistrationTypeException
-	 * @throws BadUsageException
-	 */
 	public function getUrl(): ?string
 	{
-		if ( ! $this->hasValidData()) {
-			throw RegistrationTypeException::missingAdditionalData('url', $this->type);
+		if ( ! $this->isOfTypeCustomWebpage()) {
+			throw new UsageException('This method can not be called when the registration is not of `via custom webpage` type.');
 		}
 
-		if ( ! $this->isOfTypeCustomWebpage()) {
-			throw new BadUsageException('This method can not be called when the registration is not of `via custom webpage` type.');
+		if ($this->url === null) {
+			/*
+			 * Ideally, this should not happen, but we can not rely on it. If it happens, we want to know about it ->
+			 * assert() is not enough. We can just log it, but that would lead user into clicking a button which does nothing.
+			 * Thus rendering error page covers both – logging and preventing user from accessing non-working page.
+			 */
+			throw new RuntimeException('URL must not be null in case of registration via custom webpage.');
 		}
 
 		return $this->url;
@@ -130,10 +117,4 @@ public function isOfTypeDisabled(): bool
 		return $this->type->equals(RegistrationTypeEnum::DISABLED());
 	}
 
-
-	public function hasValidData(): bool
-	{
-		return $this->hasValidData;
-	}
-
 }
diff --git a/src/Response/Event/Registration/RegistrationTypeEnum.php b/src/Response/Event/Registration/RegistrationTypeEnum.php
index a974aa5..8966b69 100644
--- a/src/Response/Event/Registration/RegistrationTypeEnum.php
+++ b/src/Response/Event/Registration/RegistrationTypeEnum.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\Event\Registration;
+namespace HnutiBrontosaurus\BisClient\Response\Event\Registration;
 
 use Grifart\Enum\AutoInstances;
 use Grifart\Enum\Enum;
@@ -17,9 +17,9 @@ final class RegistrationTypeEnum extends Enum
 {
 	use AutoInstances;
 
-	protected const BRONTOWEB = 1;
-	protected const EMAIL = 2;
-	protected const EXTERNAL_WEBPAGE = 3;
-	protected const NONE = 4;
-	protected const DISABLED = 5;
+	protected const BRONTOWEB = 'standard';
+	protected const EMAIL = 'by_email';
+	protected const EXTERNAL_WEBPAGE = 'other_electronic';
+	protected const NONE = 'not_required';
+	protected const DISABLED = 'full';
 }
diff --git a/src/Response/Event/TargetGroup.php b/src/Response/Event/TargetGroup.php
deleted file mode 100644
index 53bf0b0..0000000
--- a/src/Response/Event/TargetGroup.php
+++ /dev/null
@@ -1,72 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Response\Event;
-
-use HnutiBrontosaurus\BisApiClient\InvalidArgumentException;
-
-
-final class TargetGroup
-{
-
-	const EVERYONE = 1;
-	const ADULTS = 2;
-	const CHILDREN = 3;
-	const FAMILIES = 4;
-	const FIRST_TIME_ATTENDEES = 5;
-
-
-	private int $id;
-
-	private function __construct(int $id)
-	{
-		if ( ! \in_array($id, [
-			self::EVERYONE,
-			self::ADULTS,
-			self::CHILDREN,
-			self::FAMILIES,
-			self::FIRST_TIME_ATTENDEES,
-		], true)) {
-			throw new InvalidArgumentException('Value `' . $id . '` is not of valid types for `id` parameter.');
-		}
-
-		$this->id = $id;
-	}
-
-
-	public static function from(int $id): self
-	{
-		return new self($id);
-	}
-
-
-
-	public function isOfTypeEveryone(): bool
-	{
-		return $this->id === self::EVERYONE;
-	}
-
-
-	public function isOfTypeAdults(): bool
-	{
-		return $this->id === self::ADULTS;
-	}
-
-
-	public function isOfTypeChildren(): bool
-	{
-		return $this->id === self::CHILDREN;
-	}
-
-
-	public function isOfTypeFamilies(): bool
-	{
-		return $this->id === self::FAMILIES;
-	}
-
-
-	public function isOfTypeFirstTimeAttendees(): bool
-	{
-		return $this->id === self::FIRST_TIME_ATTENDEES;
-	}
-
-}
diff --git a/src/Response/OrganizationalUnit/OrganizationalUnit.php b/src/Response/OrganizationalUnit/OrganizationalUnit.php
index a34f044..7da0386 100644
--- a/src/Response/OrganizationalUnit/OrganizationalUnit.php
+++ b/src/Response/OrganizationalUnit/OrganizationalUnit.php
@@ -1,8 +1,8 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\OrganizationalUnit;
+namespace HnutiBrontosaurus\BisClient\Response\OrganizationalUnit;
 
-use Grifart\Enum\MissingValueDeclarationException;
+use HnutiBrontosaurus\BisClient\Response\Coordinates;
 
 
 final class OrganizationalUnit
@@ -14,40 +14,33 @@ private function __construct(
 		private string $street,
 		private string $city,
 		private string $postCode,
-		private ?string $phone,
-		private ?string $email,
+		private ?Coordinates $coordinates,
+		private string $phone,
+		private string $email,
 		private ?string $website,
 		private OrganizationalUnitType $type,
-		private ?string $chairman,
-		private ?string $manager,
+		private string $chairman,
+		private string $manager,
 	) {}
 
 
-	/**
-	 * @throws UnknownOrganizationUnitTypeException
-	 */
-	public static function fromResponseData(array $data): self
+	public static function fromResponseData(\stdClass $data): self
 	{
-		try {
-			$organizationalUnitTypeScalar = (int) $data['uroven'];
-			$organizationalUnitType = OrganizationalUnitType::fromScalar($organizationalUnitTypeScalar);
-
-		} catch (MissingValueDeclarationException) {
-			throw new UnknownOrganizationUnitTypeException('Type `' . $organizationalUnitTypeScalar . '` is not of valid types.');
-		}
-
 		return new self(
-			(int) $data['id'],
-			$data['nazev'],
-			$data['ulice'],
-			$data['mesto'],
-			$data['psc'],
-			(isset($data['telefon']) && $data['telefon'] !== '') ? $data['telefon'] : null,
-			(isset($data['email']) && $data['email'] !== '') ? $data['email'] : null,
-			(isset($data['www']) && $data['www'] !== '') ? $data['www'] : null,
-			$organizationalUnitType,
-			(isset($data['predseda']) && $data['predseda'] !== '') ? $data['predseda'] : null,
-			(isset($data['hospodar']) && $data['hospodar'] !== '') ? $data['hospodar'] : null,
+			$data->id,
+			$data->name,
+			$data->street,
+			$data->city,
+			$data->zip_code,
+			$data->gps_latitude !== null && $data->gps_longitude !== null
+				? Coordinates::from($data->gps_latitude, $data->gps_longitude)
+				: null,
+			$data->telephone,
+			$data->from_email_address,
+			$data->web_url,
+			OrganizationalUnitType::fromScalar($data->level),
+			$data->president_name,
+			$data->manager_name,
 		);
 	}
 
@@ -82,13 +75,19 @@ public function getPostCode(): string
 	}
 
 
-	public function getPhone(): ?string
+	public function getCoordinates(): ?Coordinates
+	{
+		return $this->coordinates;
+	}
+
+
+	public function getPhone(): string
 	{
 		return $this->phone;
 	}
 
 
-	public function getEmail(): ?string
+	public function getEmail(): string
 	{
 		return $this->email;
 	}
@@ -100,13 +99,13 @@ public function getWebsite(): ?string
 	}
 
 
-	public function getChairman(): ?string
+	public function getChairman(): string
 	{
 		return $this->chairman;
 	}
 
 
-	public function getManager(): ?string
+	public function getManager(): string
 	{
 		return $this->manager;
 	}
diff --git a/src/Response/OrganizationalUnit/OrganizationalUnitType.php b/src/Response/OrganizationalUnit/OrganizationalUnitType.php
index e294b73..617bf63 100644
--- a/src/Response/OrganizationalUnit/OrganizationalUnitType.php
+++ b/src/Response/OrganizationalUnit/OrganizationalUnitType.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient\Response\OrganizationalUnit;
+namespace HnutiBrontosaurus\BisClient\Response\OrganizationalUnit;
 
 use Grifart\Enum\AutoInstances;
 use Grifart\Enum\Enum;
@@ -16,8 +16,8 @@ final class OrganizationalUnitType extends Enum
 {
 	use AutoInstances;
 
-	protected const CLUB = 1;
-	protected const BASE = 2;
-	protected const REGIONAL = 3;
-	protected const OFFICE = 4;
+	protected const CLUB = 'club';
+	protected const BASE = 'basic_section';
+	protected const REGIONAL = 'regional_center';
+	protected const OFFICE = 'headquarter';
 }
diff --git a/src/Response/OrganizationalUnit/exceptions.php b/src/Response/OrganizationalUnit/exceptions.php
deleted file mode 100644
index caf3e62..0000000
--- a/src/Response/OrganizationalUnit/exceptions.php
+++ /dev/null
@@ -1,7 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Response\OrganizationalUnit;
-
-
-final class UnknownOrganizationUnitTypeException extends \RuntimeException
-{}
diff --git a/src/Response/Response.php b/src/Response/Response.php
deleted file mode 100644
index 7720964..0000000
--- a/src/Response/Response.php
+++ /dev/null
@@ -1,63 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Response;
-
-use Psr\Http\Message\ResponseInterface;
-
-
-final class Response
-{
-
-	public const TAG_RESULT = 'result';
-	public const TAG_RESULT_ATTRIBUTE_ERROR = 'error';
-	private const TAG_ATTRIBUTE_ID = 'id';
-
-	private ResponseInterface $httpResponse;
-	private array $data;
-
-
-	public function __construct(ResponseInterface $httpResponse, \DOMDocument $domDocument)
-	{
-		$this->httpResponse = $httpResponse;
-
-		$this->parseDom($domDocument);
-	}
-
-
-	private function parseDom(\DOMDocument $domDocument): void
-	{
-		$domFinder = new \DOMXPath($domDocument);
-		$rowNodeList = $domFinder->query('*', $domDocument->getElementsByTagName(self::TAG_RESULT)->item(0));
-
-		$this->data = [];
-		foreach ($rowNodeList as $rowNode) {
-			\assert($rowNode instanceof \DOMElement);
-
-			$row = [];
-			foreach ($domFinder->query('*', $rowNode) as $node) {
-				\assert($node instanceof \DOMElement);
-
-				// if there is an ID attribute, use this one a the value as it is numeric representation (thus more technically reliable) of element's content
-				$row[$node->nodeName] = $node->hasAttribute(self::TAG_ATTRIBUTE_ID) ?
-					$node->getAttribute(self::TAG_ATTRIBUTE_ID)
-					:
-					$node->nodeValue;
-			}
-
-			$this->data[] = $row;
-		}
-	}
-
-
-	public function getHttpResponse(): ResponseInterface
-	{
-		return $this->httpResponse;
-	}
-
-
-	public function getData(): array
-	{
-		return $this->data;
-	}
-
-}
diff --git a/src/Response/exceptions.php b/src/Response/exceptions.php
deleted file mode 100644
index a08b202..0000000
--- a/src/Response/exceptions.php
+++ /dev/null
@@ -1,70 +0,0 @@
-<?php declare(strict_types = 1);
-
-namespace HnutiBrontosaurus\BisApiClient\Response;
-
-use HnutiBrontosaurus\BisApiClient\BisApiClientRuntimeException;
-
-
-abstract class ResponseErrorException extends BisApiClientRuntimeException
-{}
-
-
-// invalid data structure
-
-final class InvalidContentTypeException extends ResponseErrorException
-{}
-
-final class InvalidXMLStructureException extends ResponseErrorException
-{}
-
-
-// invalid data values
-
-final class InvalidParametersException extends ResponseErrorException
-{}
-
-final class InvalidUserInputException extends ResponseErrorException
-{
-
-	/**
-	 * @param \DOMElement $element
-	 */
-	public function __construct(\DOMElement $element)
-	{
-		parent::__construct($element->nodeValue);
-	}
-
-}
-
-final class UnauthorizedAccessException extends ResponseErrorException
-{
-
-	public function __construct()
-	{
-		parent::__construct('You are not authorized to make such request with given credentials. Or you have simply wrong credentials. :-)');
-	}
-
-}
-
-final class UnknownErrorException extends ResponseErrorException
-{
-
-	/**
-	 * @param string $unknownErrorTypeKey
-	 */
-	public function __construct($unknownErrorTypeKey)
-	{
-		parent::__construct('Unknown error. Error type returned from BIS: ' . $unknownErrorTypeKey);
-	}
-
-}
-
-final class RegistrationTypeException extends ResponseErrorException
-{
-
-	public static function missingAdditionalData($key, $type)
-	{
-		return new self(\sprintf('Missing additional data `%s` for selected type %d.', $key, $type));
-	}
-
-}
diff --git a/src/exceptions.php b/src/exceptions.php
index d9e64d9..b3605ae 100644
--- a/src/exceptions.php
+++ b/src/exceptions.php
@@ -1,33 +1,54 @@
 <?php declare(strict_types = 1);
 
-namespace HnutiBrontosaurus\BisApiClient;
-
-
-// overall exceptions
-
-abstract class BisApiClientLogicException extends \LogicException
-{}
-
-abstract class BisApiClientRuntimeException extends \RuntimeException
-{}
-
-
-// working with API exceptions
-
-final class InvalidArgumentException extends BisApiClientLogicException
-{}
-
-final class BadUsageException extends BisApiClientLogicException
-{}
-
-
-// communicating with BIS exceptions
-
-abstract class ConnectionException extends BisApiClientRuntimeException
-{}
-
-final class TransferErrorException extends ConnectionException
-{}
-
-final class NotFoundException extends ConnectionException
-{}
+namespace HnutiBrontosaurus\BisClient;
+
+
+/**
+ * Exception caused by bad usage by developer (preventable)
+ * e.g. called method in a wrong moment
+ * @internal
+ */
+class UsageException extends \LogicException {}
+
+/**
+ * Exception caused by unpredictable circumstances on server (not preventable)
+ * e.g. file does not exist, external system not accessible etc.
+ * @internal
+ */
+class RuntimeException extends \RuntimeException {}
+
+
+// common catch-all exception
+class BisClientRuntimeException extends RuntimeException {}
+
+
+final class UnableToProcessRequest extends BisClientRuntimeException
+{
+	public static function withPrevious(\Throwable $previous): self
+	{
+		return new self($previous->getMessage(), 0, $previous);
+	}
+}
+
+final class UnableToAuthorize extends BisClientRuntimeException
+{
+	public static function withPrevious(\Throwable $previous): self
+	{
+		return new self("You are not authorized to make such request with given secrets.\nCheck that you passed correct secrets or that you have access to the resource you requested.", 0, $previous);
+	}
+}
+
+final class NotFound extends BisClientRuntimeException
+{
+	public static function withPrevious(\Throwable $previous): self
+	{
+		return new self('The target you requested was not found. Check again that you\'ve typed correct URL or that the resource exists.', 0, $previous);
+	}
+}
+final class ConnectionToBisFailed extends BisClientRuntimeException
+{
+	public static function withPrevious(\Throwable $previous): self
+	{
+		return new self($previous->getMessage(), 0, $previous);
+	}
+}
diff --git a/tests/.gitignore b/tests/.gitignore
new file mode 100644
index 0000000..d8dd038
--- /dev/null
+++ b/tests/.gitignore
@@ -0,0 +1 @@
+secret.php
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
new file mode 100644
index 0000000..3ab7d73
--- /dev/null
+++ b/tests/bootstrap.php
@@ -0,0 +1,22 @@
+<?php declare(strict_types = 1);
+
+use HnutiBrontosaurus\BisClient\BisClientFactory;
+use Tracy\Debugger;
+
+
+require_once __DIR__ . '/../vendor/autoload.php';
+
+Debugger::enable();
+
+// client factory
+// wrapped in IIFE not to pollute script with client* variables
+return (function () {
+	$secret = require_once __DIR__ . '/secret.php';
+	['apiUrl' => $apiUrl, 'clientId' => $clientId, 'clientSecret' => $clientSecret] = $secret;
+
+	return (new BisClientFactory(
+		$apiUrl,
+		$clientId,
+		$clientSecret,
+	))->create();
+})();
diff --git a/tests/index.php b/tests/index.php
new file mode 100644
index 0000000..46cf922
--- /dev/null
+++ b/tests/index.php
@@ -0,0 +1,55 @@
+<?php declare(strict_types = 1);
+
+use HnutiBrontosaurus\BisClient\Request\Event\EventAttendee;
+
+$client = require_once __DIR__ . '/bootstrap.php';
+
+
+// -----------------------------
+// add attendee test
+// -----------------------------
+
+$addAttendee = function (int $eventId) use ($client): void
+{
+	$client->addAttendee(new EventAttendee(
+		$eventId,
+		'Jan',
+		'Novák',
+		DateTimeImmutable::createFromFormat('Y-m-d', '2000-05-01'),
+		'123 456 789',
+		'jan.novak@example.com',
+		'prosím, abych tam měl nachystanou teplou peřinu',
+		['odpověď č. 1', '', 'odpověď č. 3'],
+	));
+};
+// uncomment if you need to test it otherwise it would post on every page load
+//$addAttendee(eventId: 9513); // ⚠  do not forget to customize event id not to pollute real events with testing data
+//exit;
+// -----------------------------
+// retrieving information test
+// -----------------------------
+
+echo '<div style="display: grid; grid-template-columns: repeat(3, 1fr)">';
+
+	echo '<div>';
+		echo '<h2>Event</h2>';
+		dump($client->getEvent(13063));
+	echo '</div>';
+
+	echo '<div style="flex-basis: 50%">';
+		echo '<h2>Events</h2>';
+
+		foreach ($client->getEvents() as $event) {
+			dump($event);
+		}
+	echo '</div>';
+
+	echo '<div>';
+		echo '<h2>Organizational units</h2>';
+
+		foreach ($client->getOrganizationalUnits() as $unit) {
+			dump($unit);
+		}
+	echo '</div>';
+
+echo '</div>';
diff --git a/tests/secret.template.php b/tests/secret.template.php
new file mode 100644
index 0000000..dcafece
--- /dev/null
+++ b/tests/secret.template.php
@@ -0,0 +1,7 @@
+<?php declare(strict_types = 1);
+
+return [
+	'apiUrl' => '',
+	'clientId' => '',
+	'clientSecret' => '',
+];