diff --git a/meta/definitions/http.php b/meta/definitions/http.php
new file mode 100644
index 0000000..e58261d
--- /dev/null
+++ b/meta/definitions/http.php
@@ -0,0 +1,19 @@
+<?php
+
+use function DI\autowire, DI\create, DI\get;
+
+use Psr\Http\Message\ServerRequestInterface;
+
+use Zend\Diactoros\ServerRequestFactory;
+use Zend\HttpHandlerRunner\Emitter\EmitterInterface,
+    Zend\HttpHandlerRunner\Emitter\SapiEmitter;
+
+return [
+    ServerRequestInterface::class => function ($c) {
+        return ServerRequestFactory::fromGlobals(
+            $_SERVER, $_GET, $_POST, $_COOKIE, $_FILES
+        );
+    },
+
+    EmitterInterface::class => create(SapiEmitter::class),
+];
diff --git a/meta/definitions/language.php b/meta/definitions/language.php
new file mode 100644
index 0000000..3eee449
--- /dev/null
+++ b/meta/definitions/language.php
@@ -0,0 +1,31 @@
+<?php
+
+use function DI\autowire, DI\create, DI\get;
+
+use Notes\Tell\LanguageHandler;
+
+return [
+    Tell\I18n::class => create( Tell\I18n::class ) ->constructor(
+        get(Tell\Reader\JsonReader::class),
+        get(Tell\Reader\PhpReader::class),
+        getenv("DEBUG") ? create(Tell\PrintMissingKey::class) : get('tell.fallback')
+    ),
+
+    'tell.fallback' => function($c) {
+        $tell = new Tell\I18n( $c->get(Tell\Reader\PhpReader::class) );
+        $tell->locale = "en_US";
+
+        return $tell;
+    },
+
+    # TODO -- accept folders from Lean Apps
+    Tell\Reader\PhpReader::class => function($c) {
+        return new Tell\Reader\PhpReader($c->get(Lean\Lean::class)->getI18n('php'), true);
+    },
+
+    Tell\Reader\JsonReader::class => function($c) {
+        return new Tell\Reader\JsonReader($c->get(Lean\Lean::class)->getI18n('json'), true);
+    },
+
+    LanguageHandler::class => autowire(LanguageHandler::class),
+];
diff --git a/meta/definitions/routes.php b/meta/definitions/routes.php
new file mode 100644
index 0000000..46757d6
--- /dev/null
+++ b/meta/definitions/routes.php
@@ -0,0 +1,86 @@
+<?php
+
+use function DI\autowire, DI\create, DI\get;
+
+use League\Route\Strategy\ApplicationStrategy,
+    League\Route\Http\Exception\NotFoundException,
+    League\Route\Router;
+
+use Psr\Http\Message\ResponseFactoryInterface,
+    Psr\Container\ContainerInterface,
+    Psr\Http\Message\ResponseInterface,
+    Psr\Http\Message\ServerRequestInterface,
+    Psr\Http\Server\MiddlewareInterface,
+    Psr\Http\Server\RequestHandlerInterface;
+
+use TheBugs\JavascriptMiddleware;
+
+use Cronard\CronardMiddleware;
+
+use Tuupola\Middleware\HttpBasicAuthentication;
+
+use Notes\Route\RouteFetcher;
+
+use Storage\SessionMiddleware;
+
+return [
+    Lean\Routing::class => autowire(Lean\Routing::class),
+
+    RouteFetcher::class => function($c) {
+        $fetcher = new RouteFetcher();
+
+        $fetcher->setFolderList(array_map(function($item) {
+            return getenv("PROJECT_PATH") . $item;
+        }, $c->get(Lean\Lean::class)->getRoutable()));
+
+        return $fetcher;
+    },
+
+    ApplicationStrategy::class => function($c) {
+        return new class($c->get(Picea\Picea::class)) extends ApplicationStrategy {
+
+            public Picea\Picea $picea;
+
+            public function __construct(Picea\Picea $picea) {
+                $this->picea = $picea;
+            }
+
+            public function getNotFoundDecorator(NotFoundException $exception): MiddlewareInterface
+            {
+                return new class($this->picea) implements MiddlewareInterface {
+
+                    protected Picea\Picea $picea;
+
+                    public function __construct(Picea\Picea $picea) {
+                        $this->picea = $picea;
+                    }
+
+                    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+                    {
+                        return new Zend\Diactoros\Response\HtmlResponse($this->picea->renderHtml("lean/error/404", [], $this), 404);
+                    }
+
+                };
+            }
+
+        };
+    },
+
+    'routes.list' => function($c) {
+        return function (ContainerInterface $container) {
+            $router = $container->get(Router::class);
+
+            foreach([ "errorHandler", "dump", SessionMiddleware::class, CronardMiddleware::class, HttpBasicAuthentication::class, JavascriptMiddleware::class ] as $middleware) {
+                if ( $container->has($middleware) ) {
+                    $router->middleware($container->get($middleware));
+                }
+            }
+
+            $routing = $container->get(Lean\Routing::class);
+
+            $routing->registerRoute($container, getenv('URL_BASE'));
+
+            return $router;
+        };
+    },
+];
diff --git a/meta/definitions/software.php b/meta/definitions/software.php
new file mode 100644
index 0000000..6b6984a
--- /dev/null
+++ b/meta/definitions/software.php
@@ -0,0 +1,100 @@
+<?php
+
+use function DI\autowire, DI\create, DI\get;
+
+use Zend\Diactoros\Response\TextResponse;
+
+use TheBugs\JavascriptMiddleware;
+
+use Cronard\CronardMiddleware;
+
+use Lean\Lean;
+
+use Storage\Cookie,
+    Storage\Session,
+    Storage\SessionMiddleware;
+
+return [
+    'lean.default' => [
+        'picea' => [
+            'context' => "Lean\\View",
+
+            'view' => [
+                [
+                    'path' => getenv("VIEW_PATH"),
+                    'order' => 10,
+                ],
+                [
+                    'path' => getenv("PROJECT_PATH") . "/vendor/mcnd/lean/view/",
+                    'order' => 99,
+                ],
+            ],
+        ],
+
+        'ulmus' => [
+            'entities' => [ 'Growlogs\\Entity' ]
+        ],
+
+        'tell' => [
+            'json' => [
+                [
+                    'path' => getenv("META_PATH") . "/i18n",
+                    'order' => 10,
+                ],
+
+                [
+                    'path' => getenv("PROJECT_PATH") . "/vendor/mcnd/lean/meta/i18n",
+                    'order' => 99,
+                ],
+            ],
+
+            'php' => [
+                [
+                    'path' => getenv("CACHE_PATH")."/i18n",
+                    'order' => 0,
+                ]
+            ]
+        ],
+
+        'routes' => [
+            'Growlogs\\Api' => '/src/Api/',
+            'Growlogs\\Dev' => '/src/Dev/',
+            'Growlogs\\Web' => '/src/Web/',
+        ],
+    ],
+
+    Lean::class => autowire(Lean::class),
+
+    CronardMiddleware::class => function($c) {
+        $cronardMiddleware = new CronardMiddleware(getenv('CRON_KEY'), function() : ResponseInterface {
+            return new TextResponse(sprintf("%s - cron task begin...", date('Y-m-d H:i:s')));
+        });
+
+        return $cronardMiddleware->fromFile(getenv("META_PATH")."/crontab.php");
+    },
+
+    JavascriptMiddleware::class => create(JavascriptMiddleware::class),
+
+    Cookie::class => create(Cookie::class)->constructor([ 'secure' => true, 'samesite' => 'Strict' ], getenv("LEAN_RANDOM")),
+
+    Session::class => create(Session::class),
+
+    SessionMiddleware::class => create(SessionMiddleware::class)->constructor(get(Cookie::class), [ 'name' => "lean_sess_" . substr(md5(getenv("LEAN_RANDOM")), 0, 12) ]),
+
+    'git.commit' => function($c) {
+        if ( getenv("DEBUG") ) {
+            return uniqid("debug_");
+        }
+
+        $gitdir = getenv("PROJECT_PATH") . DIRECTORY_SEPARATOR . ".git" . DIRECTORY_SEPARATOR;
+
+        if ( false !== ( $currentBranch = file_get_contents( $gitdir . "HEAD") ) ) {
+            $file = explode(": ", $currentBranch)[1];
+            $path = $gitdir . str_replace("/", DIRECTORY_SEPARATOR, trim($file, " \t\n\r"));
+
+            return trim(file_get_contents( $path ), " \t\n\r");
+        }
+
+        return "gitless-project";
+    },
+];
diff --git a/meta/definitions/template.php b/meta/definitions/template.php
new file mode 100644
index 0000000..02aa194
--- /dev/null
+++ b/meta/definitions/template.php
@@ -0,0 +1,86 @@
+<?php
+
+use function DI\autowire, DI\create, DI\get;
+
+use Zend\Diactoros\Response\HtmlResponse;
+
+use Picea\Picea,
+    Picea\Caching\Cache,
+    Picea\Caching\Opcache,
+    Picea\Compiler,
+    Picea\Compiler\Context,
+    Picea\Compiler\BaseContext,
+    Picea\Extension\LanguageHandler,
+    Picea\Extension\LanguageExtension,
+    Picea\Extension\TitleExtension,
+    Picea\Extension\UrlExtension,
+    Picea\FileFetcher,
+    Picea\Language\DefaultRegistrations,
+    Picea\Method\Request,
+    Picea\Ui\Method,
+    Picea\Ui\Ui;
+
+return [
+    Picea::class => function($c) {
+        return new Picea(function($html) {
+            return new HtmlResponse( $html );
+        }, $c->get(Context::class), $c->get(Cache::class), $c->get(Compiler::class), null, $c->get(FileFetcher::class), null, getenv("DEBUG"));
+    },
+
+    Context::class => function($c) {
+        return new BaseContext( $c->get(Lean\Lean::class)->getPiceaContext() );
+    },
+
+    Compiler::class => function($c) {
+        return new Compiler(new class(null, [
+            $c->get(LanguageExtension::class),
+            $c->get(TitleExtension::class),
+            $c->get(UrlExtension::class),
+            $c->get(Method\Form::class),
+            $c->get(Method\Pagination::class),
+            $c->get(Request::class),
+        ]) extends DefaultRegistrations {
+
+            public function registerAll(Compiler $compiler) : void
+            {
+                parent::registerAll($compiler);
+                ( new Ui() )->registerFormExtension($compiler);
+            }
+
+        });
+    },
+
+    Request::class => autowire(Request::class),
+
+    Method\Form::class => autowire(Method\Form::class),
+
+    Method\Pagination::class => autowire(Method\Pagination::class),
+
+    LanguageExtension::class => create(LanguageExtension::class)->constructor(get(Context::class), get(LanguageHandler::class)),
+
+    LanguageHandler::class => function($c) {
+        return new class( $c->get(Tell\I18n::class) ) implements LanguageHandler {
+
+            public Tell\I18n $tell;
+
+            public function __construct(Tell\I18n $tell) {
+                $this->tell = $tell;
+            }
+
+            public function languageFromKey(string $key, array $variables = []) #: array|string
+            {
+                return $this->tell->fromKey($key, $variables) ?: "";
+            }
+        };
+    },
+
+    TitleExtension::class => autowire(TitleExtension::class),
+
+    UrlExtension::class => create(UrlExtension::class)->constructor(get(Context::class), getenv("URL_BASE"), get('git.commit')),
+
+    Cache::class => create(Opcache::class)->constructor(getenv("CACHE_PATH"), get(Context::class)),
+
+    FileFetcher::class => function($c) {
+        return new FileFetcher($c->get(Lean\Lean::class)->getViewPaths());
+    },
+];
\ No newline at end of file
diff --git a/meta/i18n/en/lean.error.json b/meta/i18n/en/lean.error.json
new file mode 100644
index 0000000..dbb3be1
--- /dev/null
+++ b/meta/i18n/en/lean.error.json
@@ -0,0 +1,9 @@
+{
+  "404": {
+    "title": "Page not found",
+    "page-title": "404 - Page not found",
+    "subtitle": "You may have followed an invalid or expired link...",
+    "message": "It seems like an error occured on the link you visited / action you tried. A notification was sent to the application's developer.",
+    "back": "Return to previous page"
+  }
+}
\ No newline at end of file
diff --git a/meta/i18n/fr/lean.error.json b/meta/i18n/fr/lean.error.json
new file mode 100644
index 0000000..45d1118
--- /dev/null
+++ b/meta/i18n/fr/lean.error.json
@@ -0,0 +1,9 @@
+{
+  "404": {
+    "title": "Page introuvable",
+    "page-title": "404 - Page introuvable",
+    "subtitle": "Vous avez peut-être suivi un lien expiré ou invalide...",
+    "message": "Il semblerait que l'action que vous avez tentez à mener vers une page qui n'existe pas / plus. Une notification a été envoyé au développeur de l'application.",
+    "back": "Revenir à la page précédente"
+  }
+}
\ No newline at end of file
diff --git a/src/Application.php b/src/Application.php
new file mode 100644
index 0000000..e321f84
--- /dev/null
+++ b/src/Application.php
@@ -0,0 +1,55 @@
+<?php
+
+
+namespace Lean;
+
+
+class Application
+{
+    public string $piceaContext;
+
+    public array $views;
+
+    public array $routes;
+
+    public array $entities;
+
+    public array $tellJson;
+
+    public array $tellPhp;
+
+    public function fromArray(array $data) : self
+    {
+        if (is_array($picea = $data['picea'] ?? false)) {
+            if ($picea['context'] ?? false ) {
+                $this->piceaContext = $picea['context'];
+            }
+
+            if ($picea['view'] ?? false) {
+                $this->views = $picea['view'];
+            }
+        }
+
+        if (is_array($ulmus = $data['ulmus'] ?? false)) {
+            if ($ulmus['entities'] ?? false) {
+                $this->entities = $ulmus['entities'];
+            }
+        }
+
+        if (is_array($tell = $data['tell'] ?? false)) {
+            if ($tell['json'] ?? false) {
+                $this->tellJson = $tell['json'];
+            }
+
+            if ($tell['php'] ?? false) {
+                $this->tellPhp = $tell['php'];
+            }
+        }
+
+        if (is_array($routes = $data['routes'] ?? false)) {
+            $this->routes = $data['routes'];
+        }
+
+        return $this;
+    }
+}
\ No newline at end of file
diff --git a/src/ControllerTrait.php b/src/ControllerTrait.php
index b3914fd..6fcd553 100644
--- a/src/ControllerTrait.php
+++ b/src/ControllerTrait.php
@@ -29,7 +29,7 @@ use function file_get_contents;
  */
 trait ControllerTrait {
     
-    public Session $session; 
+    public Session $session;
     
     public ? Picea\Picea $picea;
 
@@ -37,7 +37,7 @@ trait ControllerTrait {
 
     public array $contextList = [];
 
-    public function __construct(? Picea\Picea $picea, Session $session, ? MailerInterface $mailer = null) {
+    public function __construct(? Picea\Picea $picea = null, ? Session $session = null, ? MailerInterface $mailer = null) {
         $this->picea = $picea;
         $this->session = $session;
         $this->mailer = $mailer;
diff --git a/src/Kernel.php b/src/Kernel.php
index 87db266..d78728e 100644
--- a/src/Kernel.php
+++ b/src/Kernel.php
@@ -112,6 +112,7 @@ class Kernel {
     protected function serviceContainer() : self
     {
         $this->container->has(AdapterProxy::class) and $this->container->get(AdapterProxy::class);
+        $this->container->has(Lean::class) and $this->container->get(Lean::class);
 
         return $this;
     }
diff --git a/src/Lean.php b/src/Lean.php
new file mode 100644
index 0000000..d3d91b6
--- /dev/null
+++ b/src/Lean.php
@@ -0,0 +1,99 @@
+<?php
+
+
+namespace Lean;
+
+use Psr\Container\ContainerInterface;
+
+class Lean
+{
+    const DEFAULT_PICEA_CONTEXT  = __NAMESPACE__;
+
+    protected ContainerInterface $container;
+
+    public array $applications = [];
+
+    public function __construct(ContainerInterface $container)
+    {
+        $this->container = $container;
+
+        $this->loadApplications();
+    }
+
+    protected function loadApplications() : void
+    {
+        $list = $this->container->get('config')['lean']['autoload'] ?? [];
+
+        if (! $list ) {
+            throw new \Exception("You must provide at least one application to autoload within your config file ( 'lean' => 'autoload' => [] )");
+        }
+
+        foreach($list as $application) {
+            if ( $this->container->has($application) ) {
+                $this->applications[] = ( new Application() )->fromArray($this->container->get($application));
+            }
+            else {
+                throw new \RuntimeException("Trying to load an application '$application' which have not been configured yet");
+            }
+        }
+    }
+
+    public function getPiceaContext() : string
+    {
+        foreach(array_reverse($this->applications) as $apps) {
+            if ( $apps->piceaContext ) {
+                return $apps->piceaContext;
+            }
+        }
+
+        return static::DEFAULT_PICEA_CONTEXT;
+    }
+
+    public function getRoutable() : array
+    {
+        return array_merge(...array_map(fn($app) => $app->routes ?? [], $this->applications));
+    }
+
+    public function getViewPaths() : array
+    {
+        $list = array_merge(...array_map(fn($app) => $app->views ?? [], $this->applications));
+
+        uasort($list, fn($i1, $i2) => $i1['order'] <=> $i2['order'] );
+
+        return $list;
+    }
+
+    public function getI18n(string $reader) : ? array
+    {
+        switch($reader) {
+            case "php":
+                $list = array_merge(...array_map(fn($app) => $app->tellPhp ?? [], $this->applications));
+            break;
+
+            case "json":
+                $list = array_merge(...array_map(fn($app) => $app->tellJson ?? [], $this->applications));
+            break;
+        }
+
+        if ( $list ?? false ) {
+            uasort($list, fn($i1, $i2) => $i2['order'] <=> $i1['order']);
+
+            return array_map(fn($item) => $item['path'], $list);
+        }
+
+        return null;
+    }
+
+    public static function definitions() : array
+    {
+        $path = dirname(__DIR__) . "/meta/definitions/";
+
+        return array_merge(
+            require($path . "http.php"),
+            require($path . "language.php"),
+            require($path . "routes.php"),
+            require($path . "software.php"),
+            require($path . "template.php"),
+        );
+    }
+}
\ No newline at end of file
diff --git a/view/lean/error/404.phtml b/view/lean/error/404.phtml
new file mode 100644
index 0000000..e2984e0
--- /dev/null
+++ b/view/lean/error/404.phtml
@@ -0,0 +1,24 @@
+{% extends "lean/layout/error" %}
+
+{% language.set "lean.error.404" %}
+
+{% title _('page-title') %}
+
+{% section "content-right" %}
+    <div>
+        <div class="title">{% _ "title" %}</div>
+        <div class="subtitle">{% _ "subtitle" %}</div>
+        <div class="content">{% _ "message" %}</div>
+        <u><a href="#" onclick="history.back()">{% _ "back" %}</a></u>
+    </div>
+{% endsection %}
+
+{% section "content-left" %}
+    <img class="picto-login" src="{% asset 'asset/picto/undraw_lost_bqr2.svg' %}">
+{% endsection %}
+
+{% section "head.css" %}
+    .title {font-size:2rem}
+    .subtitle {font-size:1.25rem; padding-top: 1rem;}
+    .content {padding-top:1rem}
+{% endsection %}
diff --git a/view/lean/layout/error.phtml b/view/lean/layout/error.phtml
new file mode 100644
index 0000000..c3f8de6
--- /dev/null
+++ b/view/lean/layout/error.phtml
@@ -0,0 +1,50 @@
+{% section "layout" %}
+    <!DOCTYPE html>
+    <html>
+        <head>
+            <meta http-equiv="Content-Type" content="text/html; ">
+            <meta name="viewport" content="width=device-width">
+            <title>{{ title() }}</title>
+
+            <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Lato|Ubuntu%20Mono">
+            <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bulma/0.7.1/css/bulma.min.css">
+            <link rel="stylesheet" href='{% asset "asset/css/bulma.extension.css" %}'>
+            <link rel="stylesheet" href="https://cdn.eckinox.net/fontawesome/latest/css/fontawesome-all.min.css">
+
+
+            <style>
+                body {background:#272822}
+                #main-content {min-height: 100vh;width: 100vw;align-items:center;justify-content: center;}
+                #wrapper-content {max-width:960px; max-height:65vh;flex-direction:row-reverse; margin:0 10vw}
+                #wrapper-content .content-right {background:#efefef;padding:5vh 2vw;align-items:center;display:flex;justify-content:center; width:100%;border-radius:6px 0 0 6px}
+                #wrapper-content .content-left {background:#ffffff;padding:5vh 2vw;border-radius:0 6px 6px 0;display:flex;align-items:center;justify-content: center}
+
+                .form-user-login {width:80%;}
+                .picto-login {max-width:80%;}
+
+                {% section "head.css" %}{% endsection %}
+            </style>
+
+        </head>
+
+        <body class="body">
+            <ui-responsive id="full-wrapper">
+                <div id="body-wrapper">
+                    <ui-responsive id="main-content" class="main-content is-flex">
+                        <div id="wrapper-content" class="columns">
+                            <div class="column content-left">
+                                {% section "content-left" %}{% endsection %}
+                            </div>
+                            <div class="column content-right">
+                                {% section "content-right" %}{% endsection %}
+                            </div>
+                        </div>
+                    </ui-responsive>
+                </div>
+            </ui-responsive>
+
+            {% section "javascript-body" %}{% endsection %}
+            {% section "component-template" %}{% endsection %}
+        </body>
+    </html>
+{% endsection %}
\ No newline at end of file