diff --git a/.github/workflows/php-qa.yml b/.github/workflows/php-qa.yml
index a822a10..88d697e 100644
--- a/.github/workflows/php-qa.yml
+++ b/.github/workflows/php-qa.yml
@@ -32,3 +32,6 @@ jobs:
 
       - name: Check code styles
         run: composer cs
+
+      - name: Check Static Analysis
+        run: composer psalm
diff --git a/.gitignore b/.gitignore
index fdd2dd2..4af5ac5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+/.psalm
 /.idea/
 /.vscode/
 /build/
diff --git a/.phpstorm.meta.php b/.phpstorm.meta.php
new file mode 100644
index 0000000..914608b
--- /dev/null
+++ b/.phpstorm.meta.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace PHPSTORM_META {
+    override(
+        \Psr\Container\ContainerInterface::get(0),
+        map(
+            [
+                '' => '@',
+                \Inpsyde\Modularity\Package::PROPERTIES => \Inpsyde\Modularity\Properties\Properties::class,
+            ]
+        )
+    );
+}
diff --git a/composer.json b/composer.json
index e2bc079..9c4badf 100644
--- a/composer.json
+++ b/composer.json
@@ -21,7 +21,8 @@
   "require-dev": {
     "inpsyde/modularity": "^1.5",
     "inpsyde/php-coding-standards": "^1.0",
-    "roots/wordpress-no-content": "^6.3"
+    "roots/wordpress-no-content": "^6.3",
+    "vimeo/psalm": "^5.24"
   },
   "config": {
     "platform": {
@@ -33,6 +34,7 @@
   },
   "scripts": {
     "cs": "@php ./vendor/squizlabs/php_codesniffer/bin/phpcs",
-    "cs:fix": "@php ./vendor/squizlabs/php_codesniffer/bin/phpcbf"
+    "cs:fix": "@php ./vendor/squizlabs/php_codesniffer/bin/phpcbf",
+    "psalm": "@php ./vendor/bin/psalm"
   }
 }
diff --git a/plugin.php b/plugin.php
index 8535870..c118a73 100644
--- a/plugin.php
+++ b/plugin.php
@@ -9,12 +9,15 @@
 
 declare(strict_types=1);
 
+namespace Widoz\Wp\EntitiesSearch;
+
 use Inpsyde\Modularity;
 use Widoz\Wp\EntitiesSearch;
 
 function package(): Modularity\Package
 {
-    static $package;
+    /** @var Modularity\Package|null $package */
+    static $package = null;
 
     $projectRoot = __DIR__;
 
@@ -24,6 +27,7 @@ function autoload(string $projectRoot): void
         if (!\is_readable($autoloadFile)) {
             return;
         }
+        /** @psalm-suppress UnresolvableInclude */
         require_once $autoloadFile;
     }
 
diff --git a/psalm.xml b/psalm.xml
new file mode 100644
index 0000000..2b76a7f
--- /dev/null
+++ b/psalm.xml
@@ -0,0 +1,38 @@
+<?xml version="1.0"?>
+<psalm
+    errorLevel="1"
+    resolveFromConfigFile="true"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
+    findUnusedBaselineEntry="true"
+    findUnusedCode="true"
+    cacheDirectory="./.psalm"
+>
+    <projectFiles>
+        <file name="plugin.php" />
+        <directory name="sources/server" />
+        <ignoreFiles>
+            <directory name="vendor" />
+            <directory name="tests" />
+        </ignoreFiles>
+    </projectFiles>
+
+    <!-- https://github.com/vimeo/psalm/issues/5791 -->
+    <!-- Do not stub noop.php -->
+    <stubs>
+        <file name="vendor/roots/wordpress-no-content/wp-includes/l10n.php"/>
+        <file name="vendor/roots/wordpress-no-content/wp-includes/theme.php"/>
+        <file name="vendor/roots/wordpress-no-content/wp-includes/formatting.php"/>
+        <file name="vendor/roots/wordpress-no-content/wp-includes/kses.php"/>
+        <file name="vendor/roots/wordpress-no-content/wp-includes/plugin.php"/>
+        <file name="vendor/roots/wordpress-no-content/wp-includes/blocks.php"/>
+        <file name="vendor/roots/wordpress-no-content/wp-includes/post.php"/>
+        <file name="vendor/roots/wordpress-no-content/wp-includes/functions.wp-scripts.php"/>
+        <file name="vendor/roots/wordpress-no-content/wp-includes/functions.wp-styles.php"/>
+    </stubs>
+
+    <extraFiles>
+        <directory name="vendor/roots/wordpress-no-content"/>
+    </extraFiles>
+</psalm>
diff --git a/sources/server/src/Library.php b/sources/server/src/Library.php
index 0d46660..20ac493 100644
--- a/sources/server/src/Library.php
+++ b/sources/server/src/Library.php
@@ -8,7 +8,7 @@
 
 class Library
 {
-    public static function new(string $baseUrl = null): Library
+    public static function new(string $baseUrl): Library
     {
         return new self($baseUrl);
     }
diff --git a/sources/server/src/Modules/BlockEditor/Module.php b/sources/server/src/Modules/BlockEditor/Module.php
index 86fa957..46e8946 100644
--- a/sources/server/src/Modules/BlockEditor/Module.php
+++ b/sources/server/src/Modules/BlockEditor/Module.php
@@ -26,16 +26,19 @@ final private function __construct()
     public function run(Container\ContainerInterface $container): bool
     {
         \add_action('init', static function () use ($container) {
-            /** @var Modularity\Properties\Properties $properties */
             $properties = $container->get(Modularity\Package::PROPERTIES);
 
             $baseDir = \untrailingslashit($properties->basePath());
             $baseUrl = \untrailingslashit($properties->baseUrl());
 
-            $asset = include "{$baseDir}/build/main.asset.php";
-            $version = $properties->isDebug() ? $asset['version'] : $properties->version();
-            $dependencies = $asset['dependencies'];
+            /**
+             * @var array{dependencies?: array<string>, version?: string} $asset
+             * @psalm-suppress UnresolvableInclude
+             */
+            $asset = (array)include "{$baseDir}/build/main.asset.php";
+            $dependencies = (array)($asset['dependencies'] ?? null);
             self::isInDebugMode() and $dependencies[] = 'wp-entities-search-logging';
+            $version = (string)($asset['version'] ?? null) ?: false;
 
             \wp_register_script(
                 'wp-entities-search',
diff --git a/sources/server/src/Modules/E2e/Module.php b/sources/server/src/Modules/E2e/Module.php
index 937b4eb..136bc4b 100644
--- a/sources/server/src/Modules/E2e/Module.php
+++ b/sources/server/src/Modules/E2e/Module.php
@@ -8,7 +8,7 @@
 use Psr\Container;
 
 /**
- * @internal
+ * @internal \Widoz\Wp\EntitiesSearch
  */
 class Module implements Modularity\Module\ExecutableModule
 {
@@ -52,7 +52,6 @@ public function run(Container\ContainerInterface $container): bool
         // TODO Add WpContext to avoid run if not the right context.
 
         \add_action('init', static function () use ($container) {
-            /** @var Modularity\Properties\Properties $properties */
             $properties = $container->get(Modularity\Package::PROPERTIES);
             self::postTypesExample($properties);
         });
diff --git a/sources/server/src/Modules/Logging/Module.php b/sources/server/src/Modules/Logging/Module.php
index 37249c0..af7b5bf 100644
--- a/sources/server/src/Modules/Logging/Module.php
+++ b/sources/server/src/Modules/Logging/Module.php
@@ -30,18 +30,23 @@ public function run(Container\ContainerInterface $container): bool
         }
 
         \add_action('init', static function () use ($container) {
-            /** @var Modularity\Properties\Properties $properties */
             $properties = $container->get(Modularity\Package::PROPERTIES);
 
             $baseDir = \untrailingslashit($properties->basePath());
             $baseUrl = \untrailingslashit($properties->baseUrl());
-            $asset = include "{$baseDir}/build/logging.asset.php";
-            $version = $properties->isDebug() ? $asset['version'] : $properties->version();
+
+            /**
+             * @var array{dependencies?: array<string>, version?: string} $asset
+             * @psalm-suppress UnresolvableInclude
+             */
+            $asset = (array)include "{$baseDir}/build/logging.asset.php";
+            $dependencies = (array)($asset['dependencies'] ?? null);
+            $version = (string)($asset['version'] ?? null) ?: false;
 
             \wp_register_script(
                 'wp-entities-search-logging',
                 "{$baseUrl}/build/logging.js",
-                $asset['dependencies'],
+                $dependencies,
                 $version,
                 true
             );