diff --git a/composer.json b/composer.json
index 853fb8e..6a0163a 100644
--- a/composer.json
+++ b/composer.json
@@ -27,7 +27,8 @@
         "nikic/php-parser": "^3.0.0beta1",
         "phpdocumentor/reflection-docblock": "^3.0",
         "sabre/event": "^3.0",
-        "felixfbecker/advanced-json-rpc": "^1.2"
+        "felixfbecker/advanced-json-rpc": "^1.2",
+        "friendsofphp/php-cs-fixer" : "^1.12"
     },
     "minimum-stability": "dev",
     "prefer-stable": true,
diff --git a/fixtures/format.php b/fixtures/format.php
index b45ebab..6f8d734 100644
--- a/fixtures/format.php
+++ b/fixtures/format.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace       TestNamespace;
+namespace TestNamespace;
 
 
 
@@ -9,12 +9,16 @@ class TestClass
 {
     public $testProperty;
 
-                public function testMethod($testParameter)
+    /**
+     * @param $testParameter description
+     */
+    public function     testMethod(   $testParameter)
+
     {
         $testVariable = 123;
-        
-                if (  empty($testParameter)){
-                    echo 'Empty';
+
+        if (  empty($testParameter))    {
+            echo 'Empty';
         }
     }
 }
diff --git a/fixtures/format_expected.php b/fixtures/format_expected.php
index 01ce258..4967030 100644
--- a/fixtures/format_expected.php
+++ b/fixtures/format_expected.php
@@ -5,11 +5,16 @@ namespace TestNamespace;
 class TestClass
 {
     public $testProperty;
+
+    /**
+     * @param $testParameter description
+     */
     public function testMethod($testParameter)
     {
         $testVariable = 123;
+
         if (empty($testParameter)) {
             echo 'Empty';
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/Server/CustomCSFixer.php b/src/Server/CustomCSFixer.php
new file mode 100644
index 0000000..43d0b25
--- /dev/null
+++ b/src/Server/CustomCSFixer.php
@@ -0,0 +1,105 @@
+<?php
+
+namespace LanguageServer\Server;
+
+use Symfony\CS\ConfigAwareInterface;
+use Symfony\CS\ConfigInterface;
+use Symfony\CS\Fixer;
+use Symfony\CS\FixerInterface;
+use Symfony\CS\Tokenizer\Tokens;
+use Symfony\CS\Utils;
+
+class CustomCSFixer extends Fixer
+{
+    /**
+     * @param string          $content
+     * @param string          $uri
+     * @param ConfigInterface $config
+     *
+     * @return string|null formated source code or null if no change was made
+     */
+    public function fixContent(string $content, string $uri, ConfigInterface $config)
+    {
+        $fixers = $this->prepareFixers($config);
+        $fixers = $this->sortFixers($fixers);
+
+        return $this->doFixContent($content, $uri, $fixers);
+    }
+
+    /**
+     * @param string $content
+     * @param string $uri
+     * @param array  $fixers
+     *
+     * @return string|null formated source code or null if no change was made
+     */
+    private function doFixContent(string $content, string $uri, array $fixers)
+    {
+        $new = $old = $content;
+
+        if ('' === $old ||
+        // PHP 5.3 has a broken implementation of token_get_all when the file uses __halt_compiler() starting in 5.3.6
+        (PHP_VERSION_ID >= 50306 && PHP_VERSION_ID < 50400 && false !== stripos($old, '__halt_compiler()'))) {
+            return null;
+        }
+
+        // we do not need Tokens to still caching previously fixed file - so clear the cache
+        Tokens::clearCache();
+
+        try {
+            $file = new \SplFileInfo($uri);
+            foreach ($fixers as $fixer) {
+                if (!$fixer->supports($file)) {
+                    continue;
+                }
+
+                $newest = $fixer->fix($file, $new);
+                $new = $newest;
+            }
+        } catch (\ParseError $e) {
+            return null;
+        } catch (\Error $e) {
+            return null;
+        } catch (\Exception $e) {
+            return null;
+        }
+
+        if ($new !== $old) {
+            return $new;
+        }
+
+        return null;
+    }
+
+    /**
+     * @param FixerInterface[] $fixers
+     *
+     * @return FixerInterface[]
+     */
+    private function sortFixers(array $fixers)
+    {
+        usort($fixers, function (FixerInterface $a, FixerInterface $b) {
+            return Utils::cmpInt($b->getPriority(), $a->getPriority());
+        });
+
+        return $fixers;
+    }
+
+    /**
+     * @param ConfigInterface $config
+     *
+     * @return FixerInterface[]
+     */
+    private function prepareFixers(ConfigInterface $config)
+    {
+        $fixers = $config->getFixers();
+
+        foreach ($fixers as $fixer) {
+            if ($fixer instanceof ConfigAwareInterface) {
+                $fixer->setConfig($config);
+            }
+        }
+
+        return $fixers;
+    }
+}
diff --git a/src/Server/Formatter.php b/src/Server/Formatter.php
new file mode 100644
index 0000000..ab05162
--- /dev/null
+++ b/src/Server/Formatter.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace LanguageServer\Server;
+
+use Symfony\CS\Config;
+use Symfony\CS\ConfigurationResolver;
+use LanguageServer\Protocol\TextEdit;
+use LanguageServer\Protocol\Range;
+use LanguageServer\Protocol\Position;
+
+class Formatter
+{
+    /**
+     * @var CustomCSFixer
+     */
+    private $fixer;
+
+    public function __construct()
+    {
+        $this->fixer = new CustomCSFixer();
+        $this->fixer->registerBuiltInFixers();
+        $this->fixer->registerBuiltInConfigs();
+    }
+
+    /**
+     * @param string $content
+     *
+     * @return TextEdit[]
+     */
+    public function format(string $content, string $uri)
+    {
+        // remove 'file://' prefix
+        $uri = substr($uri, 7);
+
+        $config = new Config();
+
+        // TODO read user configuration from workspace root (.php_cs file)
+
+        // register custom fixers from config
+        $this->fixer->registerCustomFixers($config->getCustomFixers());
+
+        $resolver = new ConfigurationResolver();
+        $resolver->setAllFixers($this->fixer->getFixers())
+        ->setConfig($config)
+        //->setOptions(array('level' => 'psr2'))
+        ->resolve();
+
+        $config->fixers($resolver->getFixers());
+        $formatted = $this->fixer->fixContent($content, $uri, $config);
+        if ($formatted == null) {
+            return [];
+        }
+
+        $edit = new TextEdit();
+        $edit->range = new Range(new Position(0, 0), new Position(PHP_INT_MAX, PHP_INT_MAX));
+        $edit->newText = $formatted;
+        return [$edit];
+    }
+}
diff --git a/src/Server/TextDocument.php b/src/Server/TextDocument.php
index 23c01c0..8190ba7 100644
--- a/src/Server/TextDocument.php
+++ b/src/Server/TextDocument.php
@@ -42,6 +42,13 @@ class TextDocument
      */
     private $client;
 
+    /**
+     * Opened source files content
+     *
+     * @var string[]
+     */
+    private $documents = [];
+    
     public function __construct(LanguageClient $client)
     {
         $this->client = $client;
@@ -103,6 +110,8 @@ class TextDocument
      */
     private function updateAst(string $uri, string $content)
     {
+        $this->documents[$uri] = $content;
+        
         $stmts = $this->parser->parse($content);
         $diagnostics = [];
         foreach ($this->parser->getErrors() as $error) {
@@ -128,24 +137,34 @@ class TextDocument
         }
     }
 
+    /**
+     * The document close notification is sent from the client to the server when
+     * the document got closed in the client. The document's truth now exists where the document's
+     * uri points to (e.g. if the document's uri is a file uri the truth now exists on disk).
+     *
+     * @param TextDocumentIdentifier $textDocument
+     */
+    public function didClose(TextDocumentIdentifier $textDocument)
+    {
+        unset($this->documents[$textDocument->uri]);
+    }
+
     /**
      * The document formatting request is sent from the server to the client to format a whole document.
      *
      * @param TextDocumentIdentifier $textDocument The document to format
-     * @param FormattingOptions $options The format options
+     * @param FormattingOptions      $options      The format options
+     *
      * @return TextEdit[]
      */
     public function formatting(TextDocumentIdentifier $textDocument, FormattingOptions $options)
     {
-        $nodes = $this->asts[$textDocument->uri];
-        if (empty($nodes)) {
+        $formatter = new Formatter();
+        $content = $this->documents[$textDocument->uri];
+        if (!$content) {
             return [];
         }
-        $prettyPrinter = new PrettyPrinter();
-        $edit = new TextEdit();
-        $edit->range = new Range(new Position(0, 0), new Position(PHP_INT_MAX, PHP_INT_MAX));
-        $edit->newText = $prettyPrinter->prettyPrintFile($nodes);
-        return [$edit];
+
+        return $formatter->format($content, $textDocument->uri);
     }
-    
 }