diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
new file mode 100644
index 0000000..f0a3ef1
--- /dev/null
+++ b/.github/workflows/phpstan.yml
@@ -0,0 +1,9 @@
+name: PHPStan
+on:
+    pull_request:
+    push:
+        branches:
+            - dev/2.x
+jobs:
+    phpstan:
+        uses: artemeon/.shared/.github/workflows/phpstan-php84-upwards.yml@main
diff --git a/.github/workflows/pint.yml b/.github/workflows/pint.yml
new file mode 100644
index 0000000..1c6e7f2
--- /dev/null
+++ b/.github/workflows/pint.yml
@@ -0,0 +1,23 @@
+name: Pint
+
+on:
+    pull_request:
+
+jobs:
+    pint:
+        name: Pint (PHP-CS-Fixer)
+        runs-on: ubuntu-latest
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v4
+            - name: Install PHP
+              uses: shivammathur/setup-php@v2
+              with:
+                  php-version: 8.4
+                  coverage: none
+              env:
+                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+            - name: Composer install
+              run: composer install --no-interaction --no-ansi --no-progress
+            - name: Run Pint
+              run: composer run pint
diff --git a/README.md b/README.md
index 27392fa..8d760f5 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,9 @@
 # Mantis 2 GitHub Connector
 
-[![Packagist Version](https://img.shields.io/packagist/v/artemeon/mantis2github)](https://packagist.org/packages/artemeon/mantis2github)
-[![Packagist Downloads](https://img.shields.io/packagist/dt/artemeon/mantis2github)](https://packagist.org/packages/artemeon/mantis2github)
-[![GitHub](https://img.shields.io/github/license/artemeon/mantis2github)](https://packagist.org/packages/artemeon/mantis2github)
+[![Packagist Version](https://img.shields.io/packagist/v/artemeon/mantis2github?style=for-the-badge)](https://packagist.org/packages/artemeon/mantis2github)
+![PHPStan](https://img.shields.io/badge/PHPStan-level%2010-brightgreen.svg?style=for-the-badge)
+[![Packagist Downloads](https://img.shields.io/packagist/dt/artemeon/mantis2github?style=for-the-badge)](https://packagist.org/packages/artemeon/mantis2github)
+[![License](https://img.shields.io/github/license/artemeon/mantis2github?style=for-the-badge)](https://packagist.org/packages/artemeon/mantis2github)
 
 A small CLI tool to create a GitHub issue out of a Mantis issue.
 Creates cross-references, so links the GitHub issue to mantis and vice versa.
@@ -39,11 +40,12 @@ mantis2github [command]
 
 ### Available Commands
 
-| Command                      | Description                               |
-|------------------------------|-------------------------------------------|
-| [`sync`](#sync)              | Create a GitHub issue from a Mantis issue |
-| [`read:github`](#readgithub) | Read details of a GitHub issue            |
-| [`read:mantis`](#readmantis) | Read details of a Mantis issue            |
+| Command                      | Description                                                       |
+|------------------------------|-------------------------------------------------------------------|
+| [`sync`](#sync)              | Create a GitHub issue from a Mantis issue                         |
+| [`read:github`](#readgithub) | Read details of a GitHub issue                                    |
+| [`read:mantis`](#readmantis) | Read details of a Mantis issue                                    |
+| [`issues:list`](#issueslist) | Get a list of Mantis Tickets with their associated GitHub Issues. |
 
 #### `sync`
 
@@ -101,6 +103,20 @@ mantis2github read:mantis <id>
 |----------|----------|-----------------|
 | `id`     | `true`   | Mantis issue id |
 
+#### `issues:list`
+
+Get a list of Mantis Tickets with their associated GitHub Issues.
+
+```shell
+mantis2github issues:list [--output=html]
+```
+
+##### Options
+
+| Option   | Possible values | Description   |
+|----------|-----------------|---------------|
+| `output` | `html`          | Output Format |
+
 ## License
 
 This project is open-sourced software licensed under the [MIT license](LICENSE).
diff --git a/composer.json b/composer.json
index 98e50ff..68485df 100644
--- a/composer.json
+++ b/composer.json
@@ -5,6 +5,11 @@
     "bin": [
         "bin/mantis2github"
     ],
+    "scripts": {
+        "phpstan": "php ./vendor/bin/phpstan analyse --memory-limit=4G",
+        "pint": "php ./vendor/bin/pint --test -v",
+        "pint:fix": "php ./vendor/bin/pint -v"
+    },
     "authors": [
         {
             "name": "Stefan Idler",
@@ -21,9 +26,9 @@
         }
     },
     "require": {
-        "php": ">=8.0",
+        "php": ">=8.2",
         "ext-json": "*",
-        "artemeon/console": "^0.4.1",
+        "artemeon/console": "^0.5.0",
         "guzzlehttp/guzzle": "^7.3.0",
         "symfony/console": "^5.0|^6.0|^7.0",
         "symfony/yaml": "^5.0|^6.0|^7.0",
@@ -32,6 +37,10 @@
         "ahinkle/packagist-latest-version": "^2.0"
     },
     "require-dev": {
-        "roave/security-advisories": "dev-latest"
+        "jetbrains/phpstorm-attributes": "^1.0",
+        "roave/security-advisories": "dev-latest",
+        "phpstan/phpstan": "^2.1.2",
+        "laravel/pint": "^1.14",
+        "rector/rector": "^2.0.7"
     }
 }
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..d20294c
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,10 @@
+includes:
+    - phar://phpstan.phar/conf/bleedingEdge.neon
+
+parameters:
+    level: 10
+    checkUninitializedProperties: true
+    checkImplicitMixed: true
+    rememberPossiblyImpureFunctionValues: false
+    paths:
+        - src
diff --git a/pint.json b/pint.json
new file mode 100644
index 0000000..252be94
--- /dev/null
+++ b/pint.json
@@ -0,0 +1,108 @@
+{
+    "preset": "psr12",
+    "rules": {
+        "align_multiline_comment": true,
+        "array_indentation": true,
+        "array_push": true,
+        "array_syntax": {
+            "syntax": "short"
+        },
+        "assign_null_coalescing_to_coalesce_equal": true,
+        "binary_operator_spaces": true,
+        "blank_line_before_statement": true,
+        "cast_spaces": true,
+        "clean_namespace": true,
+        "combine_consecutive_issets": true,
+        "combine_consecutive_unsets": true,
+        "compact_nullable_typehint": true,
+        "concat_space": {
+            "spacing": "one"
+        },
+        "declare_strict_types": true,
+        "fully_qualified_strict_types": true,
+        "function_to_constant": true,
+        "get_class_to_class_keyword": true,
+        "is_null": true,
+        "lambda_not_used_import": true,
+        "logical_operators": true,
+        "method_chaining_indentation": true,
+        "modernize_types_casting": true,
+        "multiline_whitespace_before_semicolons": true,
+        "no_empty_comment": true,
+        "no_empty_phpdoc": true,
+        "no_empty_statement": true,
+        "no_extra_blank_lines": {
+            "tokens": ["attribute", "break", "case", "continue", "curly_brace_block", "default", "extra", "parenthesis_brace_block", "return", "square_brace_block", "switch", "throw", "use", "use_trait"]
+        },
+        "no_multiline_whitespace_around_double_arrow": true,
+        "no_short_bool_cast": true,
+        "no_singleline_whitespace_before_semicolons": true,
+        "no_superfluous_elseif": false,
+        "no_superfluous_phpdoc_tags": true,
+        "no_trailing_comma_in_singleline": true,
+        "no_unneeded_control_parentheses": true,
+        "no_useless_concat_operator": true,
+        "no_useless_else": true,
+        "no_useless_nullsafe_operator": true,
+        "no_useless_return": true,
+        "no_whitespace_before_comma_in_array": true,
+        "nullable_type_declaration": true,
+        "object_operator_without_whitespace": true,
+        "ordered_imports": {
+            "imports_order": [
+                "class",
+                "function",
+                "const"
+            ],
+            "sort_algorithm": "alpha"
+        },
+        "ordered_interfaces": true,
+        "ordered_types": {
+            "null_adjustment": "always_last"
+        },
+        "phpdoc_align": {
+            "align": "left"
+        },
+        "phpdoc_indent": true,
+        "phpdoc_no_useless_inheritdoc": true,
+        "phpdoc_order": true,
+        "phpdoc_scalar": true,
+        "phpdoc_single_line_var_spacing": true,
+        "phpdoc_summary": true,
+        "phpdoc_tag_casing": true,
+        "phpdoc_trim": true,
+        "phpdoc_trim_consecutive_blank_line_separation": true,
+        "phpdoc_var_without_name": true,
+        "php_unit_construct": true,
+        "php_unit_dedicate_assert": true,
+        "php_unit_dedicate_assert_internal_type": true,
+        "php_unit_internal_class": true,
+        "php_unit_method_casing": true,
+        "return_assignment": true,
+        "return_type_declaration": true,
+        "short_scalar_cast": true,
+        "single_line_comment_spacing": true,
+        "single_line_comment_style": true,
+        "single_quote": true,
+        "single_space_around_construct": true,
+        "ternary_to_null_coalescing": true,
+        "trailing_comma_in_multiline": {
+            "elements": [
+                "arguments",
+                "arrays",
+                "match",
+                "parameters"
+            ]
+        },
+        "trim_array_spaces": true,
+        "type_declaration_spaces": true,
+        "types_spaces": {
+            "space": "single"
+        },
+        "use_arrow_functions": true,
+        "void_return": true,
+        "whitespace_after_comma_in_array": {
+            "ensure_single_space": true
+        }
+    }
+}
diff --git a/rector.php b/rector.php
new file mode 100644
index 0000000..a91d269
--- /dev/null
+++ b/rector.php
@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+
+return RectorConfig::configure()
+    ->withPhpSets()
+    ->withAttributesSets(phpunit: true)
+    ->withRules([
+        Rector\CodeQuality\Rector\Ternary\ArrayKeyExistsTernaryThenValueToCoalescingRector::class,
+        Rector\CodeQuality\Rector\NullsafeMethodCall\CleanupUnneededNullsafeOperatorRector::class,
+        Rector\CodeQuality\Rector\ClassMethod\InlineArrayReturnAssignRector::class,
+        Rector\CodeQuality\Rector\Ternary\UnnecessaryTernaryExpressionRector::class,
+        Rector\DeadCode\Rector\Foreach_\RemoveUnusedForeachKeyRector::class,
+        Rector\TypeDeclaration\Rector\ClassMethod\ReturnTypeFromStrictFluentReturnRector::class,
+        Rector\Php80\Rector\Class_\StringableForToStringRector::class,
+        Rector\CodingStyle\Rector\ArrowFunction\StaticArrowFunctionRector::class,
+        Rector\CodingStyle\Rector\Closure\StaticClosureRector::class,
+        Rector\DeadCode\Rector\Node\RemoveNonExistingVarAnnotationRector::class,
+        Rector\DeadCode\Rector\ClassMethod\RemoveUnusedPrivateMethodParameterRector::class,
+        Rector\TypeDeclaration\Rector\ClassMethod\BoolReturnTypeFromBooleanStrictReturnsRector::class,
+        Rector\TypeDeclaration\Rector\ClassMethod\ReturnTypeFromReturnNewRector::class,
+        Rector\TypeDeclaration\Rector\ClassMethod\ParamTypeByMethodCallTypeRector::class,
+        Rector\TypeDeclaration\Rector\ClassMethod\NumericReturnTypeFromStrictScalarReturnsRector::class,
+        Rector\TypeDeclaration\Rector\ClassMethod\AddMethodCallBasedStrictParamTypeRector::class,
+        Rector\CodeQuality\Rector\If_\ExplicitBoolCompareRector::class,
+        Rector\CodeQuality\Rector\Foreach_\ForeachItemsAssignToEmptyArrayToAssignRector::class,
+        Rector\CodeQuality\Rector\Foreach_\ForeachToInArrayRector::class,
+        Rector\CodeQuality\Rector\BooleanAnd\RemoveUselessIsObjectCheckRector::class,
+    ])
+    ->withPaths([
+        __DIR__ . '/src',
+    ])
+    ->withTypeCoverageLevel(0);
diff --git a/src/Command/CheckUpdateCommand.php b/src/Command/CheckUpdateCommand.php
index 00797bf..b979a38 100644
--- a/src/Command/CheckUpdateCommand.php
+++ b/src/Command/CheckUpdateCommand.php
@@ -5,7 +5,6 @@
 namespace Artemeon\M2G\Command;
 
 use Artemeon\M2G\Helper\VersionHelper;
-
 use Exception;
 use JsonException;
 
diff --git a/src/Command/Command.php b/src/Command/Command.php
index 1100b22..6c54573 100644
--- a/src/Command/Command.php
+++ b/src/Command/Command.php
@@ -6,6 +6,7 @@
 
 use Artemeon\Console\Command as BaseCommand;
 use Artemeon\M2G\Config\ConfigReader;
+use Artemeon\M2G\Config\ConfigValues;
 
 class Command extends BaseCommand
 {
@@ -19,21 +20,22 @@ final public function header(): void
  | |  | || (_| || | | || |_ | |\__ \  <comment>/ __/</comment>  | |_| || || |_ |  _  || |_| || |_) |
  |_|  |_| \__,_||_| |_| \__||_||___/ <comment>|_____|</comment>  \____||_| \__||_| |_| \__,_||_.__/
 
-'
+',
         );
     }
 
     final public function checkConfig(): void
     {
         $config = (new ConfigReader())->read();
+        if ($config instanceof ConfigValues) {
+            return;
+        }
 
-        if (!$config) {
-            $this->newLine();
-            $this->warn('You have not configured mantis2github yet');
-            $this->warn('Please run "mantis2github configure" to get started');
-            $this->newLine();
+        $this->newLine();
+        $this->warn('You have not configured mantis2github yet');
+        $this->warn('Please run "mantis2github configure" to get started');
+        $this->newLine();
 
-            exit(self::INVALID);
-        }
+        exit(self::INVALID);
     }
 }
diff --git a/src/Command/ConfigurationCommand.php b/src/Command/ConfigurationCommand.php
index 64344c5..8bbd439 100644
--- a/src/Command/ConfigurationCommand.php
+++ b/src/Command/ConfigurationCommand.php
@@ -15,7 +15,21 @@ class ConfigurationCommand extends Command
     protected ?string $description = 'Configure the tool';
 
     protected string $configPath = __DIR__ . '/../../../config.yaml';
-    protected array $config = [];
+
+    /**
+     * @var array{
+     *     mantisUrl: string,
+     *     mantisToken: string,
+     *     githubToken: string,
+     *     githubRepository: string,
+     * }
+     */
+    protected array $config = [
+        'mantisUrl' => '',
+        'mantisToken' => '',
+        'githubToken' => '',
+        'githubRepository' => '',
+    ];
 
     public function __invoke(): int
     {
@@ -57,7 +71,7 @@ private function askForMantisUrl(): void
             label: 'The URL of your Mantis installation',
             placeholder: 'E.g. https://tickets.company.tld/',
             required: true,
-            validate: function ($value) {
+            validate: static function (string $value) {
                 $parsedUrl = parse_url($value);
 
                 if ($parsedUrl === false) {
@@ -85,10 +99,12 @@ private function askForMantisUrl(): void
         );
 
         $parsedUrl = parse_url($mantisUrl);
-        $port = isset($parsedUrl['port']) ? ':' . $parsedUrl['port'] : '';
-        $mantisUrl = "{$parsedUrl['scheme']}://{$parsedUrl['host']}$port/";
+        if ($parsedUrl) {
+            $port = isset($parsedUrl['port']) ? ':' . $parsedUrl['port'] : '';
+            $mantisUrl = "{$parsedUrl['scheme']}://{$parsedUrl['host']}$port/";
 
-        $this->config['mantisUrl'] = $mantisUrl;
+            $this->config['mantisUrl'] = $mantisUrl;
+        }
     }
 
     private function askForMantisToken(): void
@@ -108,7 +124,7 @@ private function askForGitHubToken(): void
         $this->config['githubToken'] = $this->password(
             label: 'GitHub Personal Access Token',
             required: true,
-            validate: fn ($value) => !str_starts_with($value, 'ghp_') && str_starts_with($value, 'github_pat_')
+            validate: static fn (string $value) => !str_starts_with($value, 'ghp_') && str_starts_with($value, 'github_pat_')
                 ? 'The provided value is not a valid GitHub PAT.'
                 : null,
         );
@@ -120,7 +136,7 @@ private function askForGitHubRepository(): void
             label: 'GitHub Repository(e.g. user/repository)',
             placeholder: 'E.g. user/repository',
             required: true,
-            validate: fn ($value) => count(explode('/', $value)) !== 2
+            validate: static fn (string $value) => count(explode('/', $value)) !== 2
                 ? 'Invalid repository name.'
                 : null,
         );
@@ -129,10 +145,11 @@ private function askForGitHubRepository(): void
     private function saveConfig(): void
     {
         $stub = file_get_contents(__DIR__ . '/../../stubs/config.yaml.stub');
+        if (!$stub) {
+            return;
+        }
 
-        $configContent = preg_replace_callback('/{{([a-z0-9_]+)}}/i', function ($matches) {
-            return $this->config[$matches[1]] ?? '';
-        }, $stub);
+        $configContent = preg_replace_callback('/{{([a-z0-9_]+)}}/i', fn ($matches) => $this->config[$matches[1]] ?? '', $stub);
 
         file_put_contents($this->configPath, $configContent);
 
@@ -149,19 +166,29 @@ private function saveConfig(): void
 
     private function readExistingConfigFromPath(): void
     {
-        if (!$this->argument('file')) {
+        $file = $this->argument('file');
+
+        if (!$file) {
             return;
         }
 
-        if (!file_exists($this->argument('file'))) {
+        if (!is_string($file) || !file_exists($file)) {
             $this->error('The given config file does not exist.');
 
             exit(1);
         }
 
-        $config = Yaml::parseFile($this->argument('file'));
-
-        if (!$config['MANTIS_URL'] || !$config['MANTIS_TOKEN'] || !$config['GITHUB_TOKEN'] || !$config['GITHUB_REPOSITORY']) {
+        /**
+         * @var array{
+         *     MANTIS_URL?: string,
+         *     MANTIS_TOKEN?: string,
+         *     GITHUB_TOKEN?: string,
+         *     GITHUB_REPOSITORY?: string,
+         * } $config
+         */
+        $config = Yaml::parseFile($file);
+
+        if (!isset($config['MANTIS_URL'], $config['MANTIS_TOKEN'], $config['GITHUB_TOKEN'], $config['GITHUB_REPOSITORY'])) {
             $this->error('The given config file is incomplete.');
             $this->info('Please configure the tool without the file parameter.');
 
diff --git a/src/Command/CreateGithubIssueFromMantisIssue.php b/src/Command/CreateGithubIssueFromMantisIssue.php
index d962d87..7826407 100644
--- a/src/Command/CreateGithubIssueFromMantisIssue.php
+++ b/src/Command/CreateGithubIssueFromMantisIssue.php
@@ -8,7 +8,6 @@
 use Artemeon\M2G\Service\GithubConnector;
 use Artemeon\M2G\Service\MantisConnector;
 use JsonException;
-use Symfony\Component\Console\Helper\ProgressBar;
 use Symfony\Component\Console\Helper\Table;
 
 class CreateGithubIssueFromMantisIssue extends Command
@@ -17,14 +16,9 @@ class CreateGithubIssueFromMantisIssue extends Command
 
     protected ?string $description = 'Synchronize a list of Mantis issues to GitHub';
 
-    private GithubConnector $githubConnector;
-    private MantisConnector $mantisConnector;
-
-    public function __construct(MantisConnector $mantisConnector, GithubConnector $githubConnector)
+    public function __construct(private MantisConnector $mantisConnector, private GithubConnector $githubConnector)
     {
         parent::__construct();
-        $this->mantisConnector = $mantisConnector;
-        $this->githubConnector = $githubConnector;
     }
 
     /**
@@ -35,19 +29,25 @@ public function __invoke(): int
         $this->checkConfig();
 
         $this->title('Mantis 2 GitHub Sync');
+        /** @var string[]|bool|string|null $idsArgument */
+        $idsArgument = $this->argument('ids');
+
+        if (!is_array($idsArgument)) {
+            return self::INVALID;
+        }
 
-        $ids = array_unique($this->argument('ids'));
+        $ids = array_unique($idsArgument);
         $message = count($ids) !== 1 ? 'Creating issues ...' : 'Creating issue ...';
 
         $this->newLine();
 
         $issues = [];
 
-        $this->spin(function () use ($ids, &$issues) {
-            $labels = array_map(static fn ($label) => $label['name'], $this->githubConnector->getLabels());
+        $this->spin(function () use ($ids, &$issues): void {
+            $labels = array_map(static fn (array $label) => $label['name'], $this->githubConnector->getLabels());
 
             foreach ($ids as $id) {
-                $mantisIssue = $this->mantisConnector->readIssue((int)$id);
+                $mantisIssue = $this->mantisConnector->readIssue((int) $id);
 
                 if ($mantisIssue === null) {
                     $issues[] = [
@@ -56,13 +56,21 @@ public function __invoke(): int
                         'message' => '<error>Mantis issue not found.</error>',
                         'issue' => '',
                     ];
+
                     continue;
                 }
 
                 $newGithubIssue = GithubIssue::fromMantisIssue($mantisIssue);
 
+                /**
+                 * @var array{
+                 *     id: int,
+                 *     name: string,
+                 *     color: string,
+                 * }[] $filteredLabels
+                 */
                 $filteredLabels = array_values(
-                    array_filter($labels, static fn ($label) => strtolower($label) === strtolower($mantisIssue->getProject())),
+                    array_filter($labels, static fn (string $label) => strtolower($label) === strtolower($mantisIssue->getProject())),
                 );
 
                 $newGithubIssue->setLabels($filteredLabels);
@@ -75,11 +83,12 @@ public function __invoke(): int
                         'message' => '<error>GitHub issue could not be created.</error>',
                         'issue' => '',
                     ];
+
                     continue;
                 }
 
                 $mantisIssue->setUpstreamTicket(
-                    trim($mantisIssue->getUpstreamTicket() . ' ' . $newGithubIssue->getIssueUrl())
+                    trim($mantisIssue->getUpstreamTicket() . ' ' . $newGithubIssue->getIssueUrl()),
                 );
                 $patched = $this->mantisConnector->patchUpstreamField($mantisIssue);
 
@@ -90,6 +99,7 @@ public function __invoke(): int
                         'message' => '<error>Upstream ticket URL could not be updated.</error>',
                         'issue' => '',
                     ];
+
                     continue;
                 }
 
diff --git a/src/Command/IssuesListCommand.php b/src/Command/IssuesListCommand.php
index 8aeab59..2bdb9b1 100644
--- a/src/Command/IssuesListCommand.php
+++ b/src/Command/IssuesListCommand.php
@@ -16,23 +16,20 @@ class IssuesListCommand extends Command
     protected string $signature = 'issues:list {--output= : Output Format}';
     protected ?string $description = 'Get a list of Mantis Tickets with their associated GitHub Issues.';
 
-    private MantisConnector $mantisConnector;
-    private GithubConnector $githubConnector;
-    private ?ConfigValues $config;
-
-    public function __construct(MantisConnector $mantisConnector, GithubConnector $githubConnector, ?ConfigValues $config)
+    public function __construct(private MantisConnector $mantisConnector, private GithubConnector $githubConnector, private ?ConfigValues $config)
     {
         parent::__construct();
-
-        $this->mantisConnector = $mantisConnector;
-        $this->githubConnector = $githubConnector;
-        $this->config = $config;
     }
 
     public function __invoke(): int
     {
+        if ($this->config === null) {
+            return self::INVALID;
+        }
+
         $mantisIssues = $this->mantisConnector->fetchIssues(410);
 
+        /** @var array<string> $githubIssueIds */
         $githubIssueIds = [];
         foreach ($mantisIssues as $issue) {
             $parsedIssues = array_map(static fn (array $data) => $data['id'], UpstreamIssueParser::parse($issue->getUpstreamTicket()));
@@ -40,6 +37,7 @@ public function __invoke(): int
         }
 
         $parts = [];
+        /** @var string $id */
         foreach (array_unique($githubIssueIds) as $id) {
             $parts[] = <<<GRAPHQL
 issue$id: issue(number: $id) {
@@ -70,16 +68,14 @@ public function __invoke(): int
 $issueFragment
 GRAPHQL;
 
-        $githubResult = $this->githubConnector->graphql($query)['data']['repository'];
-
-        switch ($this->option('output')) {
-            case 'html':
-                HtmlTableConverter::convert($this, $mantisIssues, $githubResult);
+        /** @var array{ repository: array<string, array{ title: string, url: string, closed: bool }> } $result */
+        $result = $this->githubConnector->graphql($query)['data'];
+        $githubResult = $result['repository'];
 
-                break;
-            default:
-                CliTableConverter::convert($this, $mantisIssues, $githubResult);
-        }
+        match ($this->option('output')) {
+            'html' => HtmlTableConverter::convert($this, $mantisIssues, $githubResult),
+            default => CliTableConverter::convert($this, $mantisIssues, $githubResult),
+        };
 
         return self::SUCCESS;
     }
diff --git a/src/Command/ReadGithubIssueCommand.php b/src/Command/ReadGithubIssueCommand.php
index 867b475..8aade13 100644
--- a/src/Command/ReadGithubIssueCommand.php
+++ b/src/Command/ReadGithubIssueCommand.php
@@ -14,15 +14,9 @@ class ReadGithubIssueCommand extends Command
     protected string $signature = 'read:github {id : GitHub issue ID}';
     protected ?string $description = 'Read details of a GitHub issue';
 
-    private GithubConnector $githubConnector;
-
-    /**
-     * @param GithubConnector $mantisConnector
-     */
-    public function __construct(GithubConnector $mantisConnector)
+    public function __construct(private GithubConnector $githubConnector)
     {
         parent::__construct();
-        $this->githubConnector = $mantisConnector;
     }
 
     public function __invoke(): int
@@ -69,9 +63,10 @@ public function __invoke(): int
         );
 
         $assignees = array_map(
-            static fn($assignee
+            static fn (
+                $assignee,
             ) => "<a href=\"{$assignee['html_url']}\" class=\"px-1 bg-blue-500 text-black\">{$assignee['login']}</a>",
-            $issue->getAssignees()
+            $issue->getAssignees(),
         );
 
         if (count($assignees)) {
@@ -98,6 +93,7 @@ public function __invoke(): int
         if (count($labels)) {
             $labels = array_map(static function ($label) {
                 style("label-{$label['id']}")->color('#' . $label['color']);
+
                 return "<span class=\"px-1 bg-label-{$label['id']} text-black\">{$label['name']}</span>";
             }, $labels);
 
@@ -136,9 +132,9 @@ private function fetchIssueDetails(): GithubIssue
 
         $this->info('Fetching issue details...');
 
-        $issue = $this->githubConnector->readIssue((int)$id);
+        $issue = $this->githubConnector->readIssue((int) $id);
 
-        if (!$issue) {
+        if ($issue === null) {
             $this->error('Issue not found.');
 
             if (empty($this->argument('id'))) {
diff --git a/src/Command/ReadMantisIssueCommand.php b/src/Command/ReadMantisIssueCommand.php
index f3408a1..b6deed4 100644
--- a/src/Command/ReadMantisIssueCommand.php
+++ b/src/Command/ReadMantisIssueCommand.php
@@ -14,12 +14,9 @@ class ReadMantisIssueCommand extends Command
     protected string $signature = 'read:mantis {id : The issue ID}';
     protected ?string $description = 'Read details of a Mantis issue';
 
-    private MantisConnector $mantisConnector;
-
-    public function __construct(MantisConnector $mantisConnector)
+    public function __construct(private MantisConnector $mantisConnector)
     {
         parent::__construct();
-        $this->mantisConnector = $mantisConnector;
     }
 
     public function __invoke(): int
@@ -114,9 +111,9 @@ private function fetchIssueDetails(): MantisIssue
 
         $this->info('Fetching issue details...');
 
-        $issue = $this->mantisConnector->readIssue((int)$id);
+        $issue = $this->mantisConnector->readIssue((int) $id);
 
-        if (!$issue) {
+        if ($issue === null) {
             $this->error('Issue not found.');
 
             exit(1);
diff --git a/src/Config/ConfigReader.php b/src/Config/ConfigReader.php
index d15a8e1..73f4ffa 100644
--- a/src/Config/ConfigReader.php
+++ b/src/Config/ConfigReader.php
@@ -4,6 +4,7 @@
 
 namespace Artemeon\M2G\Config;
 
+use RuntimeException;
 use Symfony\Component\Yaml\Yaml;
 
 class ConfigReader
@@ -16,9 +17,22 @@ final public function read(): ?ConfigValues
             return null;
         }
 
-        $config = Yaml::parse(file_get_contents($configFile));
+        $content = file_get_contents($configFile);
+        if (!$content) {
+            throw new RuntimeException('Invalid config file provided.');
+        }
 
-        if (!$config['MANTIS_URL'] || !$config['MANTIS_TOKEN'] || !$config['GITHUB_TOKEN'] || !$config['GITHUB_REPOSITORY']) {
+        /**
+         * @var array{
+         *     MANTIS_URL?: string,
+         *     MANTIS_TOKEN?: string,
+         *     GITHUB_TOKEN?: string,
+         *     GITHUB_REPOSITORY?: string,
+         * } $config
+         */
+        $config = Yaml::parse($content);
+
+        if (!isset($config['MANTIS_URL'], $config['MANTIS_TOKEN'], $config['GITHUB_TOKEN'], $config['GITHUB_REPOSITORY'])) {
             return null;
         }
 
diff --git a/src/Config/ConfigValues.php b/src/Config/ConfigValues.php
index 106f487..860c074 100644
--- a/src/Config/ConfigValues.php
+++ b/src/Config/ConfigValues.php
@@ -6,24 +6,8 @@
 
 class ConfigValues
 {
-    private string $mantisUrl;
-    private string $mantisToken;
-
-    private string $githubToken;
-    private string $githubRepo;
-
-    /**
-     * @param string $mantisUrl
-     * @param string $mantisToken
-     * @param string $githubToken
-     * @param string $githubRepo
-     */
-    public function __construct(string $mantisUrl, string $mantisToken, string $githubToken, string $githubRepo)
+    public function __construct(private string $mantisUrl, private string $mantisToken, private string $githubToken, private string $githubRepo)
     {
-        $this->mantisUrl = $mantisUrl;
-        $this->mantisToken = $mantisToken;
-        $this->githubToken = $githubToken;
-        $this->githubRepo = $githubRepo;
     }
 
     final public function getMantisUrl(): string
diff --git a/src/Dto/GithubIssue.php b/src/Dto/GithubIssue.php
index 0ae8fb2..727b202 100644
--- a/src/Dto/GithubIssue.php
+++ b/src/Dto/GithubIssue.php
@@ -6,6 +6,17 @@
 
 class GithubIssue
 {
+    /**
+     * @param array{
+     *     html_url: string,
+     *     login: string,
+     * }[] $assignees
+     * @param array{
+     *     id: int,
+     *     name: string,
+     *     color: string,
+     * }[] $labels
+     */
     public function __construct(
         private ?int $id = null,
         private ?int $number = null,
@@ -58,11 +69,24 @@ final public function getState(): string
         return $this->state;
     }
 
+    /**
+     * @return array{
+     *     html_url: string,
+     *     login: string,
+     * }[]
+     */
     final public function getAssignees(): array
     {
         return $this->assignees;
     }
 
+    /**
+     * @param array{
+     *     id: int,
+     *     name: string,
+     *     color: string,
+     * }[] $labels
+     */
     final public function setLabels(array $labels = []): self
     {
         $this->labels = $labels;
@@ -70,8 +94,15 @@ final public function setLabels(array $labels = []): self
         return $this;
     }
 
+    /**
+     * @return array{
+     *     id: int,
+     *     name: string,
+     *     color: string,
+     * }[]
+     */
     final public function getLabels(): array
     {
-        return $this->labels ?? [];
+        return $this->labels;
     }
 }
diff --git a/src/Helper/CliTableConverter.php b/src/Helper/CliTableConverter.php
index 505801a..5a09039 100644
--- a/src/Helper/CliTableConverter.php
+++ b/src/Helper/CliTableConverter.php
@@ -5,10 +5,16 @@
 namespace Artemeon\M2G\Helper;
 
 use Artemeon\M2G\Command\IssuesListCommand;
-use Artemeon\M2G\Dto\MantisIssue;
 
 class CliTableConverter implements ConverterInterface
 {
+    /**
+     * @param array<string, array{
+     *     url: string,
+     *     title: string,
+     *     closed: bool,
+     * }> $githubResult
+     */
     public static function convert(IssuesListCommand $command, array $mantisIssues, array $githubResult): void
     {
         $rows = [];
diff --git a/src/Helper/ConverterInterface.php b/src/Helper/ConverterInterface.php
index c9acd76..d410c1d 100644
--- a/src/Helper/ConverterInterface.php
+++ b/src/Helper/ConverterInterface.php
@@ -11,6 +11,7 @@ interface ConverterInterface
 {
     /**
      * @param MantisIssue[] $mantisIssues
+     * @param array<string, mixed> $githubResult
      */
     public static function convert(IssuesListCommand $command, array $mantisIssues, array $githubResult): void;
 }
diff --git a/src/Helper/HtmlTableConverter.php b/src/Helper/HtmlTableConverter.php
index 31df7c8..8797230 100644
--- a/src/Helper/HtmlTableConverter.php
+++ b/src/Helper/HtmlTableConverter.php
@@ -8,6 +8,13 @@
 
 class HtmlTableConverter implements ConverterInterface
 {
+    /**
+     * @param array<string, array{
+     *     url: string,
+     *     title: string,
+     *     closed: bool,
+     * }> $githubResult
+     */
     public static function convert(IssuesListCommand $command, array $mantisIssues, array $githubResult): void
     {
         $rows = [];
@@ -15,6 +22,9 @@ public static function convert(IssuesListCommand $command, array $mantisIssues,
         foreach ($mantisIssues as $issue) {
             $githubIssues = array_map(static function (array $data) use ($githubResult) {
                 $githubIssue = $githubResult['issue' . $data['id']] ?? null;
+                if (!$githubIssue) {
+                    return '';
+                }
 
                 $url = $githubIssue['url'];
                 $title = $githubIssue['title'];
diff --git a/src/Helper/UpstreamIssueParser.php b/src/Helper/UpstreamIssueParser.php
index 8e3f92c..409fb01 100644
--- a/src/Helper/UpstreamIssueParser.php
+++ b/src/Helper/UpstreamIssueParser.php
@@ -6,7 +6,13 @@
 
 class UpstreamIssueParser
 {
-    public static function parse(string $input): array
+    /**
+     * @return array{
+     *     url: string,
+     *     id: int,
+     * }[]
+     */
+    public static function parse(?string $input): array
     {
         if (!$input) {
             return [];
@@ -27,7 +33,7 @@ public static function parse(string $input): array
                 continue;
             }
 
-            $issues[] = ['url' => $part, 'id' => $matches[1]];
+            $issues[] = ['url' => $part, 'id' => (int) $matches[1]];
         }
 
         return $issues;
diff --git a/src/Helper/VersionHelper.php b/src/Helper/VersionHelper.php
index 49ea108..542e38d 100644
--- a/src/Helper/VersionHelper.php
+++ b/src/Helper/VersionHelper.php
@@ -16,14 +16,29 @@ class VersionHelper
      */
     public static function getPackageName(): ?string
     {
-        $packageJson = json_decode(file_get_contents(__DIR__ . '/../../composer.json'), true, 512, JSON_THROW_ON_ERROR);
+        $path = __DIR__ . '/../../composer.json';
+        if (!file_exists($path)) {
+            return null;
+        }
+
+        $content = file_get_contents($path);
+        if (!$content) {
+            return null;
+        }
+
+        /**
+         * @var array{
+         *     name?: string,
+         * } $packageJson
+         */
+        $packageJson = json_decode($content, true, 512, JSON_THROW_ON_ERROR);
 
         return $packageJson['name'] ?? null;
     }
 
     public static function fetchVersion(): string
     {
-        return InstalledVersions::getPrettyVersion('artemeon/mantis2github');
+        return InstalledVersions::getPrettyVersion('artemeon/mantis2github') ?? '';
     }
 
     /**
@@ -32,8 +47,22 @@ public static function fetchVersion(): string
     public static function latestVersion(): ?string
     {
         $packagist = new PackagistLatestVersion();
+        $packageName = self::getPackageName();
+        if (!$packageName) {
+            return null;
+        }
+
+        $latestRelease = $packagist->getLatestRelease($packageName);
+        if (!is_array($latestRelease) || !array_key_exists('version', $latestRelease)) {
+            return null;
+        }
+
+        $version = $latestRelease['version'] ?? null;
+        if (!is_string($version)) {
+            return null;
+        }
 
-        return $packagist->getLatestRelease(self::getPackageName())['version'] ?? null;
+        return $version;
     }
 
     /**
@@ -44,6 +73,10 @@ public static function checkForUpdates(): bool
         $currentVersion = self::fetchVersion();
         $latestVersion = self::latestVersion();
 
+        if (!$currentVersion || !$latestVersion) {
+            return false;
+        }
+
         if (!preg_match("/^\d+\.\d+\.\d+$/", $currentVersion)) {
             return false;
         }
diff --git a/src/Service/GithubConnector.php b/src/Service/GithubConnector.php
index 9018400..d284fce 100644
--- a/src/Service/GithubConnector.php
+++ b/src/Service/GithubConnector.php
@@ -16,18 +16,15 @@ class GithubConnector
 {
     private Client $client;
 
-    public function __construct(private ?ConfigValues $config)
+    public function __construct(?ConfigValues $config)
     {
-        if (!$config) {
-            return;
-        }
         $this->client = new Client([
             'headers' => [
                 'Accept' => 'application/vnd.github.v3+json',
-                'Authorization' => 'token ' . $this->config->getGithubToken(),
+                'Authorization' => 'token ' . $config?->getGithubToken(),
             ],
             'verify' => false,
-            'base_uri' => 'https://api.github.com/repos/' . $config->getGithubRepo() . '/',
+            'base_uri' => 'https://api.github.com/repos/' . $config?->getGithubRepo() . '/',
         ]);
     }
 
@@ -37,8 +34,27 @@ final public function readIssue(int $number): ?GithubIssue
             $response = $this->client->get(
                 'issues/' . $number,
             );
-            $result = json_decode((string)$response->getBody(), true, 512, JSON_THROW_ON_ERROR);
-        } catch (GuzzleException | Exception) {
+            /**
+             * @var array{
+             *     id: int,
+             *     number: int,
+             *     title: string,
+             *     body: ?string,
+             *     html_url: string,
+             *     state: string,
+             *     assignees: array{
+             *         html_url: string,
+             *         login: string,
+             *     }[],
+             *     labels: array{
+             *         id: int,
+             *         name: string,
+             *         color: string,
+             *     }[],
+             * } $result
+             */
+            $result = json_decode((string) $response->getBody(), true, 512, JSON_THROW_ON_ERROR);
+        } catch (Exception | GuzzleException) {
             return null;
         }
 
@@ -70,17 +86,36 @@ final public function createIssue(GithubIssue $issue): ?GithubIssue
                     ], JSON_THROW_ON_ERROR),
                 ],
             );
-        } catch (GuzzleException | Exception) {
+        } catch (Exception | GuzzleException) {
             return null;
         }
 
-        $result = json_decode((string)$response->getBody(), true, 512, JSON_THROW_ON_ERROR);
+        /**
+         * @var array{
+         *     id: int,
+         *     number: int,
+         *     title: string,
+         *     body: ?string,
+         *     html_url: string,
+         *     state: string,
+         *     assignees: array{
+         *         html_url: string,
+         *         login: string,
+         *     }[],
+         *     labels: array{
+         *         id: int,
+         *         name: string,
+         *         color: string,
+         *     }[],
+         * } $result
+         */
+        $result = json_decode((string) $response->getBody(), true, 512, JSON_THROW_ON_ERROR);
 
         return new GithubIssue(
             id: $result['id'],
             number: $result['number'],
             title: $result['title'],
-            description: $result['body'],
+            description: $result['body'] ?? '',
             issueUrl: $result['html_url'],
             state: $result['state'],
             assignees: $result['assignees'],
@@ -88,18 +123,31 @@ final public function createIssue(GithubIssue $issue): ?GithubIssue
         );
     }
 
+    /**
+     * @return array{
+     *     name: string,
+     * }[]
+     */
     final public function getLabels(): array
     {
         try {
             $response = $this->client->get('labels');
-            $result = json_decode((string)$response->getBody(), true, 512, JSON_THROW_ON_ERROR);
-        } catch (GuzzleException | Exception) {
+            /**
+             * @var array{
+             *     name: string,
+             * }[] $result
+             */
+            $result = json_decode((string) $response->getBody(), true, 512, JSON_THROW_ON_ERROR);
+        } catch (Exception | GuzzleException) {
             return [];
         }
 
         return $result ?: [];
     }
 
+    /**
+     * @return array{ data: mixed }
+     */
     final public function graphql(string $query): array
     {
         try {
@@ -109,11 +157,14 @@ final public function graphql(string $query): array
                 ],
             ]);
 
+            /**
+             * @var ?array{ data: mixed } $result
+             */
             $result = json_decode((string) $response->getBody(), true, 512, JSON_THROW_ON_ERROR);
-        } catch (GuzzleException | Exception) {
-            return [];
+        } catch (Exception | GuzzleException) {
+            return ['data' => null];
         }
 
-        return $result ?: [];
+        return $result ?? ['data' => null];
     }
 }
diff --git a/src/Service/MantisConnector.php b/src/Service/MantisConnector.php
index 0d41c50..38713aa 100644
--- a/src/Service/MantisConnector.php
+++ b/src/Service/MantisConnector.php
@@ -9,7 +9,9 @@
 use Exception;
 use GuzzleHttp\Client;
 use GuzzleHttp\Exception\GuzzleException;
+use JetBrains\PhpStorm\ExpectedValues;
 use JsonException;
+use RuntimeException;
 
 class MantisConnector
 {
@@ -17,23 +19,20 @@ class MantisConnector
 
     public function __construct(private ?ConfigValues $config)
     {
-        if (!$config) {
-            return;
-        }
         $this->client = new Client([
             'headers' => [
-                'Authorization' => $this->config->getMantisToken(),
+                'Authorization' => $this->config?->getMantisToken(),
                 'Content-Type' => 'application/json',
             ],
             'verify' => false,
-            'base_uri' => rtrim($this->config->getMantisUrl(), '/') . '/api/rest/issues/',
+            'base_uri' => rtrim($this->config?->getMantisUrl() ?? '', '/') . '/api/rest/issues/',
         ]);
     }
 
     /**
      * @return MantisIssue[]
      */
-    final public function fetchIssues(int $filterId = null): array
+    final public function fetchIssues(?int $filterId = null): array
     {
         try {
             $query = http_build_query(array_filter([
@@ -41,9 +40,39 @@ final public function fetchIssues(int $filterId = null): array
                 'page_size' => 400,
             ], static fn (mixed $value) => $value !== null));
 
-            $response = $this->client->get($query ? '?' . $query : '');
+            $response = $this->client->get($query !== '' && $query !== '0' ? '?' . $query : '');
+            /**
+             * @var array{
+             *     issues: array{
+             *         id: int,
+             *         summary: string,
+             *         description: string,
+             *         project: array{
+             *             name: string,
+             *         },
+             *         status: array{
+             *             name: string,
+             *             label: string,
+             *         },
+             *         resolution: array{
+             *             name: string,
+             *         },
+             *         handler: array{
+             *             real_name: ?string,
+             *             name: ?string,
+             *         },
+             *         custom_fields: array{
+             *             field: array{
+             *                 name: string,
+             *                 id: ?int
+             *             },
+             *             value: string
+             *         }[],
+             *     }[]
+             * } $result
+             */
             $result = json_decode((string) $response->getBody(), true, 512, JSON_THROW_ON_ERROR);
-        } catch (GuzzleException | Exception) {
+        } catch (Exception | GuzzleException) {
             return [];
         }
 
@@ -59,8 +88,38 @@ final public function readIssue(int $number): ?MantisIssue
     {
         try {
             $response = $this->client->get((string) $number);
-            $result = json_decode((string)$response->getBody(), true, 512, JSON_THROW_ON_ERROR);
-        } catch (GuzzleException | Exception) {
+            /**
+             * @var array{
+             *     issues: array{
+             *         id: int,
+             *         summary: string,
+             *         description: string,
+             *         project: array{
+             *             name: string,
+             *         },
+             *         status: array{
+             *             name: string,
+             *             label: string,
+             *         },
+             *         resolution: array{
+             *             name: string,
+             *         },
+             *         handler: array{
+             *             real_name: ?string,
+             *             name: ?string,
+             *         },
+             *         custom_fields: array{
+             *             field: array{
+             *                 name: string,
+             *                 id: ?int
+             *             },
+             *             value: string
+             *         }[],
+             *     }[]
+             * } $result
+             */
+            $result = json_decode((string) $response->getBody(), true, 512, JSON_THROW_ON_ERROR);
+        } catch (Exception | GuzzleException) {
             return null;
         }
 
@@ -91,14 +150,47 @@ final public function patchUpstreamField(MantisIssue $issue): bool
                     'body' => $body,
                 ],
             );
+
             return true;
-        } catch (GuzzleException | Exception) {
+        } catch (Exception | GuzzleException) {
             return false;
         }
     }
 
-    private function mapIssue(array $data, string $status = 'name'): MantisIssue
+    /**
+     * @param array{
+     *     id: int,
+     *     summary: string,
+     *     description: string,
+     *     project: array{
+     *         name: string,
+     *     },
+     *     status: array{
+     *         name: string,
+     *         label: string,
+     *     },
+     *     resolution: array{
+     *         name: string,
+     *     },
+     *     handler: array{
+     *         real_name: ?string,
+     *         name: ?string,
+     *     },
+     *     custom_fields: array{
+     *          field: array{
+     *              name: string,
+     *              id: ?int
+     *          },
+     *          value: string
+     *      }[],
+     * } $data
+     */
+    private function mapIssue(array $data, #[ExpectedValues(['name', 'label'])] string $status = 'name'): MantisIssue
     {
+        if ($this->config === null) {
+            throw new RuntimeException('Config is missing.');
+        }
+
         $mantisBaseUrl = $this->config->getMantisUrl();
         if (!str_ends_with($mantisBaseUrl, '/')) {
             $mantisBaseUrl .= '/';
@@ -119,6 +211,17 @@ private function mapIssue(array $data, string $status = 'name'): MantisIssue
         return $issue;
     }
 
+    /**
+     * @param array{
+     *     custom_fields: array{
+     *         field: array{
+     *             name: string,
+     *             id: ?int
+     *         },
+     *         value: string
+     *     }[],
+     * } $issue
+     */
     private function updateUpstreamFieldsIssue(array $issue, MantisIssue $mantisIssue): void
     {
         foreach ($issue['custom_fields'] as $field) {