diff --git a/composer.json b/composer.json
index a3885e0..75a2f4a 100644
--- a/composer.json
+++ b/composer.json
@@ -4,8 +4,9 @@
     "keywords":          [ ],
 
     "minimum-stability": "stable",
-    "require":           {
-        "php": "~7.4 || ~8.0"
+    "require": {
+        "php":               "~7.4 || ~8.0",
+        "jrosset/singleton": "^1.0"
     },
     "autoload":          {
         "psr-4":                 {
@@ -30,4 +31,4 @@
         "docs":   "https://git.jrosset.ovh/jrosset/PhpEnvReader/wiki",
         "source": "https://git.jrosset.ovh/jrosset/PhpEnvReader"
     }
-}
\ No newline at end of file
+}
diff --git a/composer.lock b/composer.lock
index 80da9e8..e596821 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,8 +4,50 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash":       "2ab889d9a2d5d5b28b48164a73b529b2",
-    "packages":           [ ],
+    "content-hash":       "2f92e58b7bd7a162f29ef03fe018cec6",
+    "packages":           [
+        {
+            "name":             "jrosset/singleton",
+            "version":          "v1.0.0",
+            "source":           {
+                "type":      "git",
+                "url":       "https://git.jrosset.ovh/jrosset/PhpSingleton",
+                "reference": "0fccc3b4b1c46e42656e84e264555e57bf2f27cd"
+            },
+            "require":          {
+                "php": "~7.4 || ~8.0"
+            },
+            "type":             "library",
+            "autoload":         {
+                "psr-4":                 {
+                    "jrosset\\": "src/"
+                },
+                "exclude-from-classmap": [
+                    "tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license":          [
+                "CC-BY-4.0"
+            ],
+            "authors":          [
+                {
+                    "name":  "Julien Rosset",
+                    "email": "jul.rosset@gmail.com"
+                }
+            ],
+            "description":      "PHP Trait to implements the singleton design pattern",
+            "homepage":         "https://git.jrosset.ovh/jrosset/PhpSingleton",
+            "support":          {
+                "docs":   "https://git.jrosset.ovh/jrosset/PhpSingleton/wiki",
+                "email":  "jul.rosset@gmail.com",
+                "issues": "https://git.jrosset.ovh/jrosset/PhpSingleton/issues",
+                "source": "https://git.jrosset.ovh/jrosset/PhpSingleton",
+                "wiki":   "https://git.jrosset.ovh/jrosset/PhpSingleton/wiki"
+            },
+            "time":             "2021-09-03T10:57:30+00:00"
+        }
+    ],
     "packages-dev":       [ ],
     "aliases":            [ ],
     "minimum-stability":  "stable",
diff --git a/src/EnvReader/Env.php b/src/EnvReader/Env.php
new file mode 100644
index 0000000..8fd1089
--- /dev/null
+++ b/src/EnvReader/Env.php
@@ -0,0 +1,235 @@
+<?php
+
+namespace jrosset\EnvReader;
+
+use DateTime;
+use DateTimeInterface;
+use Exception;
+use jrosset\Singleton\TSingleton;
+use RangeException;
+use UnexpectedValueException;
+
+/**
+ * Utility class to get informations from ENV file
+ *
+ * You should overwrite {@see Env::PATH_ENV} to set ENV file path<br>
+ * Overwrite {@see Env::initProperties()} to set initial properties
+ */
+abstract class Env {
+    use TSingleton;
+
+    /**
+     * ENV file path
+     */
+    protected const PATH_ENV = '.env';
+
+    /**
+     * @var string[] Current properties, read from ENV file (&lt;property name&gt; => &lt;property value&gt;)<br>
+     * <b>NOTE:</b> All properties' name are stored in upper-case
+     */
+    private array $properties;
+
+    /**
+     * Initialize initial properties then read ENV file
+     *
+     * @throws Exception If ENV can't be read
+     */
+    protected function __construct () {
+        $this->properties = array_change_key_case($this->initProperties(), CASE_UPPER);
+        $this->readEnv();
+    }
+    /**
+     * Get all properties
+     *
+     * @return string[] Get all properties (properties' name are in upper case)
+     */
+    public function getProperties (): array {
+        return $this->properties;
+    }
+    /**
+     * Check if a property id defined
+     *
+     * @param string $name The property name
+     *
+     * @return bool Is the property defined ?
+     */
+    public function hasProperty (string $name): bool {
+        return array_key_exists(mb_strtoupper($name), $this->getProperties());
+    }
+    /**
+     * Get a property value
+     *
+     * @param string      $name    The property name
+     * @param string|null $default The default value if property is not set
+     *                             Raise an exception if property is not set AND $default is Null
+     *
+     * @return string The property value
+     *
+     * @throws UnexpectedValueException If property is not set AND $default is Null
+     */
+    public function getProperty (string $name, ?string $default = null): string {
+        $name = mb_strtoupper($name);
+        if (!$this->hasProperty($name)) {
+            if ($default === null) {
+                throw new UnexpectedValueException('The "' . $name . '" property is not set');
+            }
+            return $default;
+        }
+
+        return $this->properties[$name];
+    }
+    /**
+     * Get a property value as a boolean
+     *
+     * @param string    $name      The property name
+     * @param bool|null $default   The default value if property is not set
+     *                             Raise an exception if property is not set AND $default is Null
+     *
+     * @return bool The property value
+     *
+     * @throws UnexpectedValueException If property is not set AND $default is Null
+     * @throws RangeException If the property can't be cast to a boolean
+     *
+     * @noinspection PhpUnused
+     */
+    public function getPropertyAsBool (string $name, ?bool $default = null): bool {
+        switch ($value = $this->getProperty($name, $default === null ? null : ($default === true ? '1' : '0'))) {
+            case '1':
+            case 'true':
+                return true;
+
+            case '0':
+            case 'false':
+                return false;
+
+            default:
+                throw new RangeException('The "' . $name . '" property is not a valid boolean : ' . $value);
+        }
+    }
+    /**
+     * Get a property value as an integer
+     *
+     * @param string   $name       The property name
+     * @param int|null $default    The default value if property is not set
+     *                             Raise an exception if property is not set AND $default is Null
+     *
+     * @return int The property value
+     *
+     * @throws UnexpectedValueException If property is not set AND $default is Null
+     * @throws RangeException If the property can't be cast to an integer
+     *
+     * @noinspection PhpUnused
+     */
+    public function getPropertyAsInt (string $name, ?int $default = null): int {
+        $value = $this->getProperty($name, $default === null ? null : (string)$default);
+        if (preg_match('#^\s*(?<value>[0-9]+)\s*$#', $value, $match) !== 1) {
+            throw new RangeException('The "' . $name . '" property is not a valid integer : ' . $value);
+        }
+        return (int)$match['value'];
+    }
+    /**
+     * Get a property value as a float value (the decimal separator is dot)
+     *
+     * @param string     $name     The property name
+     * @param float|null $default  The default value if property is not set
+     *                             Raise an exception if property is not set AND $default is Null
+     *
+     * @return float The property value
+     *
+     * @throws UnexpectedValueException If property is not set AND $default is Null
+     * @throws RangeException If the property can't be cast to a float value
+     *
+     * @noinspection PhpUnused
+     */
+    public function getPropertyAsReal (string $name, ?float $default = null): float {
+        $value = $this->getProperty($name, $default === null ? null : (string)$default);
+        if (preg_match('#^\s*(?<value>[0-9]+(?:\.[0-9]+)?)\s*$#', $value, $match) !== 1) {
+            throw new RangeException('The "' . $name . '" property is not a valid float value : ' . $value);
+        }
+        return (float)$match['value'];
+    }
+    /**
+     * Get a property value as a date and time ({@link https://www.php.net/manual/book.datetime.php DateTime})
+     *
+     * The date <b>must</b> respect {@link https://datatracker.ietf.org/doc/html/rfc3339 RFC339} norm
+     *
+     * @param string        $name    The property name
+     * @param DateTime|null $default The default value if property is not set
+     *                               Raise an exception if property is not set AND $default is Null
+     *
+     * @return DateTime The property value
+     *
+     * @throws UnexpectedValueException If property is not set AND $default is Null
+     * @throws RangeException If the property can't be cast to a date and time
+     *
+     * @noinspection PhpUnused
+     */
+    public function getPropertyAsDateTime (string $name, ?DateTime $default = null): DateTime {
+        $value = DateTime::createFromFormat(
+            DateTimeInterface::RFC3339,
+            $this->getProperty($name, $default === null ? null : $default->format(DateTimeInterface::RFC3339))
+        );
+
+        $errors = DateTime::getLastErrors();
+        if ($errors !== false) {
+            $messages = [];
+
+            if (($nb_error = $errors['error_count']) > 0) {
+                foreach ($errors['errors'] as $idx => $error) {
+                    $messages[] = 'ERREUR #' . $idx . ' : ' . $error;
+                }
+            }
+            if (($nb_warning = $errors['warning_count']) > 0) {
+                foreach ($errors['warnings'] as $idx => $warning) {
+                    $messages[] = 'ALERTE #' . $idx . ' : ' . $warning;
+                }
+            }
+
+            if ($nb_error + $nb_warning > 0) {
+                throw new RangeException('The "' . $name . '" property is not a valid date and time : ' . $value . "\n\n" . implode("\n", $messages));
+            }
+        }
+        if ($value === false) {
+            throw new RangeException('The "' . $name . '" property is not a valid date and time : ' . $value);
+        }
+
+        return $value;
+    }
+    /**
+     * Initialize initial properties
+     *
+     * @return string[] Properties initial values (&lt;property name&gt; => &lt;property value&gt;)
+     */
+    protected function initProperties (): array {
+        return [
+            'APP_DEV' => 0,
+        ];
+    }
+    /**
+     * Read the ENV file
+     *
+     * @throws Exception If ENV can't be read
+     */
+    private function readEnv (): void {
+        if (!file_exists(static::PATH_ENV)) {
+            return;
+        }
+
+        $lines = file(static::PATH_ENV, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
+        if ($lines === false) {
+            throw new Exception('Unable to read environment file "' . static::PATH_ENV . '"');
+        }
+
+        foreach ($lines as $line) {
+            if (preg_match('/^\s*(?:(?<comment>#).+|(?<key>[a-zA-Z0-9_-]+)=(?<value>.+))$/i', $line, $match) !== 1) {
+                continue;           // Ligne invalide
+            }
+
+            if (isset($match['comment']) && trim($match['comment']) !== '') {
+                continue;           // Commentaire
+            }
+
+            $this->properties[mb_strtoupper($match['key'])] = $match['value'];
+        }
+    }
+}
\ No newline at end of file