diff --git a/.circleci/config.yml b/.circleci/config.yml
index ff23468..8fb3237 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -5,32 +5,27 @@ orbs:
   ci-php: jobcloud/ci-php@2.4
 
 workflows:
-  php-kafka-schema-registry-client:
+  version: 2
+  test-php-kafka-schema-registry-client:
     jobs:
-      - ci-caching/build-docker-images:
-          dockerComposeFile: "./docker/docker-compose.yml"
+      - ci-caching/build-docker-images
       - ci-php/install-dependencies:
-          dockerComposeFile: "./docker/docker-compose.yml"
           dependencyCheckSumFile: "./composer.json"
           requires:
             - ci-caching/build-docker-images
       - ci-php/coverage:
-          dockerComposeFile: "./docker/docker-compose.yml"
           dependencyCheckSumFile: "./composer.json"
           requires:
             - ci-php/install-dependencies
       - ci-php/code-style:
-          dockerComposeFile: "./docker/docker-compose.yml"
           dependencyCheckSumFile: "./composer.json"
           requires:
             - ci-php/install-dependencies
       - ci-php/static-analysis:
-          dockerComposeFile: "./docker/docker-compose.yml"
           dependencyCheckSumFile: "./composer.json"
           requires:
             - ci-php/install-dependencies
       - ci-php/infection-testing:
-          dockerComposeFile: "./docker/docker-compose.yml"
           dependencyCheckSumFile: "./composer.json"
           requires:
             - ci-php/install-dependencies
diff --git a/.gitignore b/.gitignore
index 161b849..d14e45b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,9 +4,7 @@
 # Packages
 vendor/
 composer.lock
-composer.symlink
 
 # Builds & caches
 /build/
 .phpunit.result.cache
-
diff --git a/README.md b/README.md
index fe6abea..1621089 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ composer require jobcloud/php-kafka-schema-registry-client
 ```
 
 ## Requirements
-- php: >= 7.4
+- php: ^7.4|^8.0
 
 ## Supported API calls
 Currently it supports:
diff --git a/composer.json b/composer.json
index 588582f..00b2a56 100644
--- a/composer.json
+++ b/composer.json
@@ -5,35 +5,42 @@
     "keywords": ["kafka", "schema", "registry", "php"],
     "autoload": {
         "psr-4": {
-            "Jobcloud\\Kafka\\SchemaRegistryClient\\": "src/",
+            "Jobcloud\\Kafka\\SchemaRegistryClient\\": "src/"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
             "Jobcloud\\Kafka\\SchemaRegistryClient\\Tests\\": "tests/"
         }
     },
     "authors": [
         {
-            "name": "Jobcloud AG",
+            "name": "JobCloud AG",
             "homepage": "https://careers.jobcloud.ch/en/our-team/?term=133"
         }
     ],
     "require": {
-        "php": ">=7.4",
+        "php": "^7.4|^8.0",
         "ext-json": "*",
-        "psr/http-message": "^1.0",
+        "psr/http-message": "^1.0.1",
         "psr/http-client": "^1.0.1"
     },
     "require-dev": {
-        "infection/infection": "^0.25",
-        "kriswallsmith/buzz": "^1.0",
-        "nyholm/psr7": "^1.2",
-        "php-mock/php-mock-phpunit": "^2.6",
-        "phpstan/phpstan": "^1.2",
-        "phpunit/phpunit": "^9.5",
-        "pimple/pimple": "^3.2",
+        "infection/infection": "^0.26.6",
+        "kriswallsmith/buzz": "^1.2.1",
+        "nyholm/psr7": "^1.5.1",
+        "php-mock/php-mock-phpunit": "^2.6.0",
+        "phpstan/phpstan": "^1.7.15",
+        "phpunit/phpunit": "^9.5.21",
+        "pimple/pimple": "^3.5.0",
         "rregeer/phpunit-coverage-check": "^0.3.1",
-        "squizlabs/php_codesniffer": "^3.4.2"
+        "squizlabs/php_codesniffer": "^3.7.1"
     },
     "config": {
         "sort-packages": true,
+        "platform": {
+            "php": "7.4.7"
+        },
         "allow-plugins": {
             "infection/extension-installer": true
         }
diff --git a/docker/dev/php/Dockerfile b/docker/dev/php/Dockerfile
index baa4ad3..d87c59f 100644
--- a/docker/dev/php/Dockerfile
+++ b/docker/dev/php/Dockerfile
@@ -1,21 +1,25 @@
-FROM php:7.4-cli-alpine3.15
+FROM php:8.1-cli-alpine3.16
 
-ARG HOST_USER_ID
+ARG USER_ID
+
+COPY files/bin /usr/local/bin/
+COPY files/php /phpIni
 
 # SYS: Install required packages
 RUN apk --no-cache upgrade && \
      apk --no-cache add bash git sudo autoconf gcc g++ make make shadow
 
-COPY dev/php/files/bin/ /usr/local/bin/
-
 # Set host user id if given, to avoid permission conflicts in dev
-RUN /bin/bash -c 'if [ -n "$HOST_USER_ID" ] && [ "$HOST_USER_ID" -lt 60000 ]; then \
-        usermod -u ${HOST_USER_ID} www-data; \
-    fi'
+RUN if [ -n "$USER_ID" ] && [ "$USER_ID" -lt 60001 ]; then \
+        usermod -u ${USER_ID} -o www-data; \
+    fi
 
 RUN usermod -s /bin/bash www-data && \
     echo 'www-data ALL=(ALL) NOPASSWD: ALL' > '/etc/sudoers.d/www-data'
 
+# USER: copy home
+COPY --chown=www-data:www-data files/user-home /home/www-data
+
 # PHP: Install php extensions
 RUN pecl channel-update pecl.php.net && \
     pecl install pcov && \
diff --git a/docker/dev/php/files/php/20-pcov.ini b/docker/dev/php/files/php/20-pcov.ini
new file mode 100644
index 0000000..3a52c5f
--- /dev/null
+++ b/docker/dev/php/files/php/20-pcov.ini
@@ -0,0 +1 @@
+extension=pcov.so
diff --git a/docker/dev/php/files/user-home/.bashrc b/docker/dev/php/files/user-home/.bashrc
new file mode 100644
index 0000000..8c1d66f
--- /dev/null
+++ b/docker/dev/php/files/user-home/.bashrc
@@ -0,0 +1,7 @@
+alias cls='printf "\033c"'
+
+export PS1='\[\e[1;32m\]\h\[\e[0m\] \[\e[1;37m\]\w\[\e[0m\] \[\e[1;32m\]\u\[\e[0m\] \[\e[1;37m\]\$\[\e[0m\] '
+
+if [ -f ~/.bash_aliases ]; then
+    . ~/.bash_aliases
+fi
diff --git a/docker/docker-compose.ci.yml b/docker/docker-compose.ci.yml
new file mode 100644
index 0000000..2a35f96
--- /dev/null
+++ b/docker/docker-compose.ci.yml
@@ -0,0 +1,13 @@
+version: '3.2'
+
+services:
+  php:
+    hostname: kafka-schema-registry-client-php
+    container_name: kafka-schema-registry-client-php
+    build:
+      context: dev/php
+      args:
+        USER_ID: ${USER_ID}
+    volumes:
+      - ../:/var/www/html
+    tty: true
diff --git a/docker/docker-compose.dev.yml b/docker/docker-compose.dev.yml
new file mode 100644
index 0000000..2a35f96
--- /dev/null
+++ b/docker/docker-compose.dev.yml
@@ -0,0 +1,13 @@
+version: '3.2'
+
+services:
+  php:
+    hostname: kafka-schema-registry-client-php
+    container_name: kafka-schema-registry-client-php
+    build:
+      context: dev/php
+      args:
+        USER_ID: ${USER_ID}
+    volumes:
+      - ../:/var/www/html
+    tty: true
diff --git a/docker/docker-compose.yml b/docker/docker-compose.yml
deleted file mode 100644
index 5f46b8a..0000000
--- a/docker/docker-compose.yml
+++ /dev/null
@@ -1,17 +0,0 @@
-version: '3.2'
-services:
-  php:
-    build:
-      context: ./
-      dockerfile: dev/php/Dockerfile
-      args:
-        HOST_USER: ${USER}
-        HOST_USER_ID: ${USER_ID}
-    tty: true
-    hostname: kafka-schema-registry-client-php
-    container_name: kafka-schema-registry-client-php
-    volumes:
-      - ../:/var/www/html
-      - ~/.bash_aliases:/home/${USER}/.bash_aliases:rw
-      - ~/.bash_history:/home/${USER}/.bash_history:rw
-
diff --git a/phpcs.xml b/phpcs.xml
index 72cc772..d44e266 100644
--- a/phpcs.xml
+++ b/phpcs.xml
@@ -1,6 +1,7 @@
 <?xml version="1.0"?>
 <ruleset xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="PHP_CodeSniffer" xsi:noNamespaceSchemaLocation="phpcs.xsd">
     <file>src</file>
+    <file>tests</file>
     <rule ref="PSR12"/>
     <arg name="report-gitblame"/>
     <arg name="report-full"/>
diff --git a/src/ErrorHandler.php b/src/ErrorHandler.php
index 97e5332..4ba8f20 100644
--- a/src/ErrorHandler.php
+++ b/src/ErrorHandler.php
@@ -26,10 +26,6 @@
 class ErrorHandler implements ErrorHandlerInterface
 {
     /**
-     * @param ResponseInterface     $response
-     * @param string|null           $uri
-     * @param RequestInterface|null $request
-     * @return void
      * @throws BackendDatastoreException
      * @throws ClientException
      * @throws CompatibilityException
diff --git a/src/ErrorHandlerInterface.php b/src/ErrorHandlerInterface.php
index aca8580..fa22e2b 100644
--- a/src/ErrorHandlerInterface.php
+++ b/src/ErrorHandlerInterface.php
@@ -11,8 +11,6 @@
 interface ErrorHandlerInterface
 {
     /**
-     * @param ResponseInterface $response
-     * @param string|null       $uri
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
diff --git a/src/HttpClient.php b/src/HttpClient.php
index 6c9bf5e..5d18caf 100644
--- a/src/HttpClient.php
+++ b/src/HttpClient.php
@@ -41,14 +41,6 @@ class HttpClient implements HttpClientInterface
      */
     private $errorHandler;
 
-    /**
-     * @param ClientInterface $client
-     * @param RequestFactoryInterface $requestFactory
-     * @param ErrorHandlerInterface $errorHandler
-     * @param string $baseUrl
-     * @param string|null $username
-     * @param string|null $password
-     */
     public function __construct(
         ClientInterface $client,
         RequestFactoryInterface $requestFactory,
@@ -66,11 +58,8 @@ public function __construct(
     }
 
     /**
-     * @param string $method
-     * @param string $uri
      * @param array<string,mixed> $body
      * @param array<string,mixed> $queryParams
-     * @return RequestInterface
      * @throws JsonException
      */
     private function createRequest(
@@ -108,8 +97,6 @@ private function createRequest(
     }
 
     /**
-     * @param string $method
-     * @param string $uri
      * @param array<string,mixed> $body
      * @param array<string,mixed> $queryParams
      * @return mixed
diff --git a/src/HttpClientInterface.php b/src/HttpClientInterface.php
index 8aa0db0..69b336b 100644
--- a/src/HttpClientInterface.php
+++ b/src/HttpClientInterface.php
@@ -9,8 +9,6 @@
 interface HttpClientInterface
 {
     /**
-     * @param string $method
-     * @param string $uri
      * @param array<string,mixed> $body
      * @param array<string,mixed> $queryParams
      * @return mixed
diff --git a/src/KafkaSchemaRegistryApiClient.php b/src/KafkaSchemaRegistryApiClient.php
index 3a9e1e5..7e5d836 100644
--- a/src/KafkaSchemaRegistryApiClient.php
+++ b/src/KafkaSchemaRegistryApiClient.php
@@ -15,10 +15,6 @@ class KafkaSchemaRegistryApiClient implements KafkaSchemaRegistryApiClientInterf
      */
     private $httpClient;
 
-    /**
-     * KafkaSchemaRegistryApi constructor.
-     * @param HttpClientInterface $httpClient
-     */
     public function __construct(HttpClientInterface $httpClient)
     {
         $this->httpClient = $httpClient;
@@ -36,7 +32,6 @@ public function getSubjects(): array
     }
 
     /**
-     * @param string $subjectName
      * @return array<string,mixed>
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -48,8 +43,6 @@ public function getAllSubjectVersions(string $subjectName): array
     }
 
     /**
-     * @param string $subjectName
-     * @param string $version
      * @return array<string,mixed>
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -63,8 +56,6 @@ public function getSchemaByVersion(string $subjectName, string $version = self::
     }
 
     /**
-     * @param string $subjectName
-     * @param string $version
      * @return array<string, mixed>|string
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -81,9 +72,6 @@ public function getSchemaDefinitionByVersion(string $subjectName, string $versio
     }
 
     /**
-     * @param string $subjectName
-     * @param string $version
-     * @return int|null
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -94,8 +82,6 @@ public function deleteSchemaVersion(string $subjectName, string $version = self:
     }
 
     /**
-     * @param int $id
-     * @return string
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -106,8 +92,6 @@ public function getSchemaById(int $id): string
     }
 
     /**
-     * @param string $schema
-     * @param string $subjectName
      * @return array<string,mixed>
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -125,10 +109,6 @@ public function registerNewSchemaVersion(string $subjectName, string $schema): a
     }
 
     /**
-     * @param string $schema
-     * @param string $subjectName
-     * @param string $version
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -145,17 +125,15 @@ public function checkSchemaCompatibilityForVersion(
                        'POST',
                        sprintf('compatibility/subjects/%s/versions/%s', $subjectName, $version),
                        $this->createRequestBodyFromSchema($schema)
-                   ) ?? [];
+                   );
         } catch (SubjectNotFoundException $e) {
             return true;
         }
 
-        return $results['is_compatible'] === true;
+        return ($results['is_compatible'] ?? false) === true;
     }
 
     /**
-     * @param string $subjectName
-     * @return string|null
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -171,9 +149,6 @@ public function getSubjectCompatibilityLevel(string $subjectName): ?string
     }
 
     /**
-     * @param string $subjectName
-     * @param string $level
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -185,7 +160,6 @@ public function setSubjectCompatibilityLevel(string $subjectName, string $level
     }
 
     /**
-     * @return string
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -197,8 +171,6 @@ public function getDefaultCompatibilityLevel(): string
     }
 
     /**
-     * @param string $level
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -210,9 +182,6 @@ public function setDefaultCompatibilityLevel(string $level = self::LEVEL_FULL):
     }
 
     /**
-     * @param string $subjectName
-     * @param string $schema
-     * @return string|null
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -226,9 +195,9 @@ public function getVersionForSchema(string $subjectName, string $schema): ?strin
                         'POST',
                         sprintf('subjects/%s', $subjectName),
                         $this->createRequestBodyFromSchema($schema)
-                    ) ?? [];
+                    );
 
-            return $results['version'];
+            return $results['version'] ?? null;
         } catch (SubjectNotFoundException $e) {
             return null;
         } catch (SchemaNotFoundException $e) {
@@ -237,9 +206,6 @@ public function getVersionForSchema(string $subjectName, string $schema): ?strin
     }
 
     /**
-     * @param string $subjectName
-     * @param string $schema
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -250,7 +216,6 @@ public function isSchemaAlreadyRegistered(string $subjectName, string $schema):
     }
 
     /**
-     * @param string $subjectName
      * @return array<string,mixed>
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -262,8 +227,6 @@ public function deleteSubject(string $subjectName): array
     }
 
     /**
-     * @param string $subjectName
-     * @return string|null
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -276,8 +239,6 @@ public function getLatestSubjectVersion(string $subjectName): ?string
     }
 
     /**
-     * @param string $mode
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -289,7 +250,6 @@ public function setImportMode(string $mode): bool
     }
 
     /**
-     * @param string $schema
      * @return array<string,mixed>
      * @throws JsonException
      */
diff --git a/src/KafkaSchemaRegistryApiClientInterface.php b/src/KafkaSchemaRegistryApiClientInterface.php
index 81d7966..b582b81 100644
--- a/src/KafkaSchemaRegistryApiClientInterface.php
+++ b/src/KafkaSchemaRegistryApiClientInterface.php
@@ -31,7 +31,6 @@ interface KafkaSchemaRegistryApiClientInterface
     public function getSubjects(): array;
 
     /**
-     * @param string $subjectName
      * @return array<string,mixed>
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -40,8 +39,6 @@ public function getSubjects(): array;
     public function getAllSubjectVersions(string $subjectName): array;
 
     /**
-     * @param string $subjectName
-     * @param string $version
      * @return array<string,mixed>
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -50,8 +47,6 @@ public function getAllSubjectVersions(string $subjectName): array;
     public function getSchemaByVersion(string $subjectName, string $version = 'latest'): array;
 
     /**
-     * @param string $subjectName
-     * @param string $version
      * @return array<string, mixed>|string
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -60,9 +55,6 @@ public function getSchemaByVersion(string $subjectName, string $version = 'lates
     public function getSchemaDefinitionByVersion(string $subjectName, string $version = self::VERSION_LATEST);
 
     /**
-     * @param string $subjectName
-     * @param string $version
-     * @return int|null
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -70,8 +62,6 @@ public function getSchemaDefinitionByVersion(string $subjectName, string $versio
     public function deleteSchemaVersion(string $subjectName, string $version = self::VERSION_LATEST): ?int;
 
     /**
-     * @param int $id
-     * @return string
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -79,8 +69,6 @@ public function deleteSchemaVersion(string $subjectName, string $version = self:
     public function getSchemaById(int $id): string;
 
     /**
-     * @param string $subjectName
-     * @param string $schema
      * @return array<string,mixed>
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -89,10 +77,6 @@ public function getSchemaById(int $id): string;
     public function registerNewSchemaVersion(string $subjectName, string $schema): array;
 
     /**
-     * @param string $subjectName
-     * @param string $schema
-     * @param string $version
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -104,8 +88,6 @@ public function checkSchemaCompatibilityForVersion(
     ): bool;
 
     /**
-     * @param string $subjectName
-     * @return string
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -113,9 +95,6 @@ public function checkSchemaCompatibilityForVersion(
     public function getSubjectCompatibilityLevel(string $subjectName): ?string;
 
     /**
-     * @param string $subjectName
-     * @param string $level
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -123,7 +102,6 @@ public function getSubjectCompatibilityLevel(string $subjectName): ?string;
     public function setSubjectCompatibilityLevel(string $subjectName, string $level = self::LEVEL_FULL): bool;
 
     /**
-     * @return string
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -131,8 +109,6 @@ public function setSubjectCompatibilityLevel(string $subjectName, string $level
     public function getDefaultCompatibilityLevel(): string;
 
     /**
-     * @param string $level
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -140,9 +116,6 @@ public function getDefaultCompatibilityLevel(): string;
     public function setDefaultCompatibilityLevel(string $level = self::LEVEL_FULL): bool;
 
     /**
-     * @param string $subjectName
-     * @param string $schema
-     * @return string|null
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -150,9 +123,6 @@ public function setDefaultCompatibilityLevel(string $level = self::LEVEL_FULL):
     public function getVersionForSchema(string $subjectName, string $schema): ?string;
 
     /**
-     * @param string $subjectName
-     * @param string $schema
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -160,7 +130,6 @@ public function getVersionForSchema(string $subjectName, string $schema): ?strin
     public function isSchemaAlreadyRegistered(string $subjectName, string $schema): bool;
 
     /**
-     * @param string $subjectName
      * @return array<string,mixed>
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
@@ -169,8 +138,6 @@ public function isSchemaAlreadyRegistered(string $subjectName, string $schema):
     public function deleteSubject(string $subjectName): array;
 
     /**
-     * @param string $mode
-     * @return bool
      * @throws ClientExceptionInterface
      * @throws SchemaRegistryExceptionInterface
      * @throws JsonException
@@ -178,8 +145,6 @@ public function deleteSubject(string $subjectName): array;
     public function setImportMode(string $mode): bool;
 
     /**
-     * @param string $subjectName
-     * @return string|null
      * @throws JsonException
      */
     public function getLatestSubjectVersion(string $subjectName): ?string;
diff --git a/src/ServiceProvider/KafkaSchemaRegistryApiClientProvider.php b/src/ServiceProvider/KafkaSchemaRegistryApiClientProvider.php
index 8769bfd..4a6d624 100644
--- a/src/ServiceProvider/KafkaSchemaRegistryApiClientProvider.php
+++ b/src/ServiceProvider/KafkaSchemaRegistryApiClientProvider.php
@@ -30,9 +30,6 @@ class KafkaSchemaRegistryApiClientProvider implements ServiceProviderInterface
     public const API_CLIENT = 'kafka.schema.registry.client.api';
     public const ERROR_HANDLER = 'kafka.schema.registry.error.handler';
 
-    /**
-     * @param Container $container
-     */
     public function register(Container $container): void
     {
         $this->checkRequiredOffsets($container);
@@ -68,8 +65,8 @@ public function register(Container $container): void
                     $requestFactory,
                     $container[self::ERROR_HANDLER],
                     $container[self::CONTAINER_KEY][self::SETTING_KEY_BASE_URL],
-                    $container[self::CONTAINER_KEY][self::SETTING_KEY_USERNAME],
-                    $container[self::CONTAINER_KEY][self::SETTING_KEY_PASSWORD]
+                    $container[self::CONTAINER_KEY][self::SETTING_KEY_USERNAME] ?? null,
+                    $container[self::CONTAINER_KEY][self::SETTING_KEY_PASSWORD] ?? null
                 );
             };
         }
diff --git a/tests/ErrorHandlerTest.php b/tests/ErrorHandlerTest.php
index 2a59bc7..4c9ed13 100644
--- a/tests/ErrorHandlerTest.php
+++ b/tests/ErrorHandlerTest.php
@@ -55,7 +55,8 @@ private function makeResponseInterfaceMock(?string $code = null, ?string $messag
         return $responseMock;
     }
 
-    public function exceptionTestDataProvider(): array{
+    public function exceptionTestDataProvider(): array
+    {
         return [
             [50001, BackendDatastoreException::class],
             [50002, OperationTimeoutException::class],
@@ -83,8 +84,6 @@ public function exceptionTestDataProvider(): array{
     /**
      * @dataProvider exceptionTestDataProvider
      *
-     * @param int $code
-     * @param string $expectedException
      * @throws BackendDatastoreException
      * @throws ClientException
      * @throws CompatibilityException
@@ -139,7 +138,9 @@ public function testExceptionThrowWithRequest(): void
         $errorHandler = new ErrorHandler();
 
         $this->expectException(BackendDatastoreException::class);
-        $this->expectExceptionMessage(self::TEST_MESSAGE . sprintf(' (%s) with request body: %s', 'http://test.com', 'test body'));
+        $this->expectExceptionMessage(
+            self::TEST_MESSAGE . sprintf(' (%s) with request body: %s', 'http://test.com', 'test body')
+        );
 
         $errorHandler->handleError($responseMock, 'http://test.com', $requestMock);
     }
diff --git a/tests/KafkaSchemaRegistryApiClientProviderTest.php b/tests/KafkaSchemaRegistryApiClientProviderTest.php
index 32067ab..eda33b8 100644
--- a/tests/KafkaSchemaRegistryApiClientProviderTest.php
+++ b/tests/KafkaSchemaRegistryApiClientProviderTest.php
@@ -37,7 +37,6 @@ protected function setUp(): void
         );
     }
 
-
     public function testDefaultContainersAndServicesSetWithMinimalConfig(): void
     {
         $this->classExistsMock->expects(self::exactly(2))->withConsecutive(
@@ -87,10 +86,13 @@ public function testDefaultContainersAndServicesSetWithMinimalConfig(): void
 
     public function testSuccessWithMissingAuth(): void
     {
-        $this->classExistsMock->expects(self::exactly(2))->withConsecutive(
-            ['Nyholm\Psr7\Factory\Psr17Factory'],
-            ['Buzz\Client\Curl']
-        )->willReturn(true);
+        $this->classExistsMock
+            ->expects(self::exactly(2))
+            ->withConsecutive(
+                ['Nyholm\Psr7\Factory\Psr17Factory'],
+                ['Buzz\Client\Curl']
+            )
+            ->willReturn(true);
 
         $container = new Container();
 
@@ -103,10 +105,6 @@ public function testSuccessWithMissingAuth(): void
         $client = $container['kafka.schema.registry.client.http'];
 
         self::assertInstanceOf(HttpClientInterface::class, $client);
-        self::assertEquals(
-            $container['kafka.schema.registry']['password'],
-            self::getPropertyValue($client, 'password')
-        );
         self::assertNull(self::getPropertyValue($client, 'username'));
         self::assertNull(self::getPropertyValue($client, 'password'));
     }
@@ -153,6 +151,5 @@ public function testUserNameAndPasswordFromSettingsArePassedToHttpClient(): void
             $container['kafka.schema.registry']['password'],
             self::getPropertyValue($container['kafka.schema.registry.client.http'], 'password')
         );
-
     }
 }
diff --git a/tests/KafkaSchemaRegistryApiClientTest.php b/tests/KafkaSchemaRegistryApiClientTest.php
index 80135ec..61efce3 100644
--- a/tests/KafkaSchemaRegistryApiClientTest.php
+++ b/tests/KafkaSchemaRegistryApiClientTest.php
@@ -21,23 +21,11 @@ class KafkaSchemaRegistryApiClientTest extends TestCase
     private const TEST_SCHEMA = '{}';
     private const TEST_VERSION = 3;
 
-    /**
-     * @return MockObject|HttpClientInterface
-     */
-    private function getHttpClientMock(): MockObject
-    {
-        return $this
-            ->getMockBuilder(HttpClient::class)
-            ->disableOriginalConstructor()
-            ->onlyMethods(['call'])
-            ->getMock();
-    }
-
     public function testGetSubjects(): void
     {
         $httpClientMock = $this->getHttpClientMock();
 
-        $httpClientMock->expects($this->once())->method('call')->with('GET', 'subjects');
+        $httpClientMock->expects(self::once())->method('call')->with('GET', 'subjects');
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $api->getSubjects();
@@ -48,7 +36,7 @@ public function testGetAllSubjectVersions(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('GET', sprintf('subjects/%s/versions', self::TEST_SUBJECT_NAME));
 
@@ -61,7 +49,7 @@ public function testGetSchemaByVersion(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('GET', sprintf('subjects/%s/versions/%s', self::TEST_SUBJECT_NAME, self::TEST_VERSION))
             ->willReturn(['schema' => '{}']);
@@ -69,7 +57,7 @@ public function testGetSchemaByVersion(): void
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getSchemaByVersion(self::TEST_SUBJECT_NAME, self::TEST_VERSION);
 
-        $this->assertSame(['schema' => '{}'], $result);
+        self::assertSame(['schema' => '{}'], $result);
     }
 
     public function testGetSchemaDefinitionByVersionForComplexSchema(): void
@@ -77,7 +65,7 @@ public function testGetSchemaDefinitionByVersionForComplexSchema(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('GET', sprintf('subjects/%s/versions/%s/schema', self::TEST_SUBJECT_NAME, self::TEST_VERSION))
             ->willReturn(['a' => 'b']);
@@ -85,7 +73,7 @@ public function testGetSchemaDefinitionByVersionForComplexSchema(): void
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getSchemaDefinitionByVersion(self::TEST_SUBJECT_NAME, self::TEST_VERSION);
 
-        $this->assertSame(['a' => 'b'], $result);
+        self::assertSame(['a' => 'b'], $result);
     }
 
     public function testGetSchemaDefinitionByVersionForOptimizedPrimitiveSchema(): void
@@ -93,7 +81,7 @@ public function testGetSchemaDefinitionByVersionForOptimizedPrimitiveSchema(): v
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('GET', sprintf('subjects/%s/versions/%s/schema', self::TEST_SUBJECT_NAME, self::TEST_VERSION))
             ->willReturn("string");
@@ -101,7 +89,7 @@ public function testGetSchemaDefinitionByVersionForOptimizedPrimitiveSchema(): v
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getSchemaDefinitionByVersion(self::TEST_SUBJECT_NAME, self::TEST_VERSION);
 
-        $this->assertSame("string", $result);
+        self::assertSame("string", $result);
     }
 
     public function testDeleteSchemaVersion(): void
@@ -109,7 +97,7 @@ public function testDeleteSchemaVersion(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('DELETE', sprintf('subjects/%s/versions/%s', self::TEST_SUBJECT_NAME, self::TEST_VERSION))
             ->willReturn(1);
@@ -117,7 +105,7 @@ public function testDeleteSchemaVersion(): void
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->deleteSchemaVersion(self::TEST_SUBJECT_NAME, self::TEST_VERSION);
 
-        $this->assertSame(1, $result);
+        self::assertSame(1, $result);
     }
 
     public function testGetSchemaById(): void
@@ -125,7 +113,7 @@ public function testGetSchemaById(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('GET', sprintf('schemas/ids/%s', 1))
             ->willReturn(['schema' => '{}']);
@@ -139,7 +127,7 @@ public function testRegisterNewSchemaVersion(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('POST', sprintf('subjects/%s/versions', self::TEST_SUBJECT_NAME), ['schema' => '[]'])
             ->willReturn([]);
@@ -148,12 +136,36 @@ public function testRegisterNewSchemaVersion(): void
         $api->registerNewSchemaVersion(self::TEST_SUBJECT_NAME, self::TEST_SCHEMA);
     }
 
+    public function testCheckSchemaCompatibilityForVersionFalseOnEmptyResponse(): void
+    {
+        $httpClientMock = $this->getHttpClientMock();
+
+        $httpClientMock
+            ->expects(self::once())
+            ->method('call')
+            ->with(
+                'POST',
+                sprintf('compatibility/subjects/%s/versions/%s', self::TEST_SUBJECT_NAME, self::TEST_VERSION),
+                ['schema' => '[]']
+            )
+            ->willReturn([]);
+
+        $api = new KafkaSchemaRegistryApiClient($httpClientMock);
+        $result = $api->checkSchemaCompatibilityForVersion(
+            self::TEST_SUBJECT_NAME,
+            self::TEST_SCHEMA,
+            self::TEST_VERSION
+        );
+
+        self::assertFalse($result);
+    }
+
     public function testCheckSchemaCompatibilityForVersionTrue(): void
     {
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'POST',
@@ -163,8 +175,13 @@ public function testCheckSchemaCompatibilityForVersionTrue(): void
             ->willReturn(['is_compatible' => true]);
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
-        $result = $api->checkSchemaCompatibilityForVersion(self::TEST_SUBJECT_NAME, self::TEST_SCHEMA, self::TEST_VERSION);
-        $this->assertTrue($result);
+        $result = $api->checkSchemaCompatibilityForVersion(
+            self::TEST_SUBJECT_NAME,
+            self::TEST_SCHEMA,
+            self::TEST_VERSION
+        );
+
+        self::assertTrue($result);
     }
 
     public function testCheckSchemaCompatibilityForVersionFalse(): void
@@ -172,7 +189,7 @@ public function testCheckSchemaCompatibilityForVersionFalse(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'POST',
@@ -182,8 +199,13 @@ public function testCheckSchemaCompatibilityForVersionFalse(): void
             ->willReturn(['is_compatible' => false]);
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
-        $result = $api->checkSchemaCompatibilityForVersion(self::TEST_SUBJECT_NAME, self::TEST_SCHEMA, self::TEST_VERSION);
-        $this->assertFalse($result);
+        $result = $api->checkSchemaCompatibilityForVersion(
+            self::TEST_SUBJECT_NAME,
+            self::TEST_SCHEMA,
+            self::TEST_VERSION
+        );
+
+        self::assertFalse($result);
     }
 
     public function testCheckSchemaCompatibilityForVersionNotFound(): void
@@ -191,7 +213,7 @@ public function testCheckSchemaCompatibilityForVersionNotFound(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'POST',
@@ -201,8 +223,12 @@ public function testCheckSchemaCompatibilityForVersionNotFound(): void
             ->willThrowException(new SubjectNotFoundException());
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
-        $result = $api->checkSchemaCompatibilityForVersion(self::TEST_SUBJECT_NAME, self::TEST_SCHEMA, self::TEST_VERSION);
-        $this->assertTrue($result);
+        $result = $api->checkSchemaCompatibilityForVersion(
+            self::TEST_SUBJECT_NAME,
+            self::TEST_SCHEMA,
+            self::TEST_VERSION
+        );
+        self::assertTrue($result);
     }
 
     public function testGetSubjectCompatibilityLevel(): void
@@ -210,7 +236,7 @@ public function testGetSubjectCompatibilityLevel(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'GET',
@@ -220,7 +246,8 @@ public function testGetSubjectCompatibilityLevel(): void
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getSubjectCompatibilityLevel(self::TEST_SUBJECT_NAME);
-        $this->assertSame(KafkaSchemaRegistryApiClientInterface::LEVEL_FULL, $result);
+
+        self::assertSame(KafkaSchemaRegistryApiClientInterface::LEVEL_FULL, $result);
     }
 
     public function testGetDefaultCompatibiltyLeveWhenGetSubjectCompatibilityLevelThrowsException(): void
@@ -243,7 +270,8 @@ public function testGetDefaultCompatibiltyLeveWhenGetSubjectCompatibilityLevelTh
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getSubjectCompatibilityLevel(self::TEST_SUBJECT_NAME);
-        $this->assertSame(KafkaSchemaRegistryApiClientInterface::LEVEL_FULL, $result);
+
+        self::assertSame(KafkaSchemaRegistryApiClientInterface::LEVEL_FULL, $result);
     }
 
     public function testSetSubjectCompatibilityLevel(): void
@@ -251,7 +279,7 @@ public function testSetSubjectCompatibilityLevel(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'PUT',
@@ -265,7 +293,7 @@ public function testSetSubjectCompatibilityLevel(): void
             KafkaSchemaRegistryApiClientInterface::LEVEL_FULL
         );
 
-        $this->assertTrue($result);
+        self::assertTrue($result);
     }
 
     public function testGetDefaultCompatibilityLeve(): void
@@ -273,14 +301,15 @@ public function testGetDefaultCompatibilityLeve(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('GET', sprintf('config'))
             ->willReturn(['compatibilityLevel' => KafkaSchemaRegistryApiClientInterface::LEVEL_FULL]);
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getDefaultCompatibilityLevel();
-        $this->assertSame(KafkaSchemaRegistryApiClientInterface::LEVEL_FULL, $result);
+
+        self::assertSame(KafkaSchemaRegistryApiClientInterface::LEVEL_FULL, $result);
     }
 
     public function testSetDefaultCompatibilityLeve(): void
@@ -288,13 +317,14 @@ public function testSetDefaultCompatibilityLeve(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('PUT', 'config', ['compatibility' => KafkaSchemaRegistryApiClientInterface::LEVEL_FULL]);
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->setDefaultCompatibilityLevel();
-        $this->assertTrue($result);
+
+        self::assertTrue($result);
     }
 
     public function testGetVersionForSchema(): void
@@ -302,7 +332,7 @@ public function testGetVersionForSchema(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'POST',
@@ -313,7 +343,8 @@ public function testGetVersionForSchema(): void
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getVersionForSchema(self::TEST_SUBJECT_NAME, self::TEST_SCHEMA);
-        $this->assertSame((string) self::TEST_VERSION, $result);
+
+        self::assertSame((string) self::TEST_VERSION, $result);
     }
 
     public function testGetVersionForSchemaThrowsSubjectNotFoundExceptionResultsAsNull(): void
@@ -321,7 +352,7 @@ public function testGetVersionForSchemaThrowsSubjectNotFoundExceptionResultsAsNu
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'POST',
@@ -332,7 +363,8 @@ public function testGetVersionForSchemaThrowsSubjectNotFoundExceptionResultsAsNu
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getVersionForSchema(self::TEST_SUBJECT_NAME, self::TEST_SCHEMA);
-        $this->assertNull($result);
+
+        self::assertNull($result);
     }
 
     public function testGetVersionForSchemaThrowsSchematNotFoundExceptionResultsAsNull(): void
@@ -340,7 +372,7 @@ public function testGetVersionForSchemaThrowsSchematNotFoundExceptionResultsAsNu
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'POST',
@@ -351,7 +383,8 @@ public function testGetVersionForSchemaThrowsSchematNotFoundExceptionResultsAsNu
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getVersionForSchema(self::TEST_SUBJECT_NAME, self::TEST_SCHEMA);
-        $this->assertNull($result);
+
+        self::assertNull($result);
     }
 
     public function testSchemaExistsTrue(): void
@@ -359,7 +392,7 @@ public function testSchemaExistsTrue(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'POST',
@@ -370,7 +403,8 @@ public function testSchemaExistsTrue(): void
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->isSchemaAlreadyRegistered(self::TEST_SUBJECT_NAME, self::TEST_SCHEMA);
-        $this->assertTrue($result);
+
+        self::assertTrue($result);
     }
 
     public function testSchemaExistsFalse(): void
@@ -378,7 +412,7 @@ public function testSchemaExistsFalse(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'POST',
@@ -389,7 +423,8 @@ public function testSchemaExistsFalse(): void
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->isSchemaAlreadyRegistered(self::TEST_SUBJECT_NAME, self::TEST_SCHEMA);
-        $this->assertFalse($result);
+
+        self::assertFalse($result);
     }
 
     public function testDeleteSubject(): void
@@ -397,7 +432,7 @@ public function testDeleteSubject(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('DELETE', sprintf('subjects/%s', self::TEST_SUBJECT_NAME))
             ->willReturn([1,2,3,4]);
@@ -405,7 +440,7 @@ public function testDeleteSubject(): void
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->deleteSubject(self::TEST_SUBJECT_NAME);
 
-        $this->assertSame([1,2,3,4], $result);
+        self::assertSame([1,2,3,4], $result);
     }
 
     public function testGetLatestSubjectVersion(): void
@@ -413,14 +448,15 @@ public function testGetLatestSubjectVersion(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with('GET', sprintf('subjects/%s/versions', self::TEST_SUBJECT_NAME))
             ->willReturn([1,2,3,4,5,6]);
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->getLatestSubjectVersion(self::TEST_SUBJECT_NAME);
-        $this->assertSame('6', $result);
+
+        self::assertSame('6', $result);
     }
 
     public function testImportModeFail(): void
@@ -428,7 +464,7 @@ public function testImportModeFail(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'PUT',
@@ -448,7 +484,7 @@ public function testImportModeSuccess(): void
         $httpClientMock = $this->getHttpClientMock();
 
         $httpClientMock
-            ->expects($this->once())
+            ->expects(self::once())
             ->method('call')
             ->with(
                 'PUT',
@@ -458,6 +494,19 @@ public function testImportModeSuccess(): void
 
         $api = new KafkaSchemaRegistryApiClient($httpClientMock);
         $result = $api->setImportMode('ABC');
+
         self::assertTrue($result);
     }
+
+    /**
+     * @return MockObject|HttpClientInterface
+     */
+    private function getHttpClientMock(): MockObject
+    {
+        return $this
+            ->getMockBuilder(HttpClient::class)
+            ->disableOriginalConstructor()
+            ->onlyMethods(['call'])
+            ->getMock();
+    }
 }
diff --git a/tests/ReflectionAccessTrait.php b/tests/ReflectionAccessTrait.php
index 19b25dd..788c624 100644
--- a/tests/ReflectionAccessTrait.php
+++ b/tests/ReflectionAccessTrait.php
@@ -5,10 +5,6 @@
 use ReflectionClass;
 use ReflectionException;
 
-/**
- * Trait ReflectionAccessTrait
- * @package Jobcloud\MarketplaceAdapterMessage\Tests
- */
 trait ReflectionAccessTrait
 {
     /**
@@ -63,4 +59,4 @@ final public function invokeMethod(object $object, string $methodName, array $pa
 
         return $method->invokeArgs($object, $parameters);
     }
-}
\ No newline at end of file
+}