diff --git a/.gitignore b/.gitignore
index 205e437..afc5f8e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 /vendor
 .phpunit.result.cache
 /composer.lock
+/coverage.clover
diff --git a/composer.json b/composer.json
index 9c61914..5f46165 100644
--- a/composer.json
+++ b/composer.json
@@ -22,11 +22,14 @@
     "ext-mbstring" : "*",
     "psr/http-message": ">=1.0",
     "fatcode/annotations": ">=1.0",
-    "zendframework/zend-diactoros": "^2.1"
+    "zendframework/zend-diactoros": ">=2.1",
+    "nikic/php-parser": ">=4.2"
   },
   "require-dev": {
     "phpunit/phpunit": ">=8.0",
-    "mockery/mockery": ">=1.2"
+    "mockery/mockery": ">=1.2",
+    "vimeo/psalm": ">=3.2",
+    "squizlabs/php_codesniffer": ">=3.0"
   },
   "autoload": {
     "psr-4": {
@@ -38,10 +41,10 @@
       "FatCode\\Tests\\OpenApi\\": "tests/"
     }
   },
-  "repositories": [
-    {
-      "type": "vcs",
-      "url": "https://github.com/fat-code/annotations"
-    }
-  ]
+  "scripts": {
+    "phpunit": "vendor/bin/phpunit --coverage-text",
+    "phpcs": "vendor/bin/phpcs --standard=PSR12 --warning-severity=0 src",
+    "phpcsf": "vendor/bin/phpcbf --standard=PSR12 --warning-severity=0 src",
+    "psalm": "vendor/bin/psalm --show-info=false"
+  }
 }
diff --git a/examples/get_route_example.php b/examples/get_exampe/get_route_example.php
similarity index 93%
rename from examples/get_route_example.php
rename to examples/get_exampe/get_route_example.php
index e28be8c..44482d9 100644
--- a/examples/get_route_example.php
+++ b/examples/get_exampe/get_route_example.php
@@ -18,8 +18,8 @@
 class Application
 {
     /**
-     * @Api\PathItem\Get(
-     *     route="/hello/{name<\w>}",
+     * @Api\Operation\Get(
+     *     route="/hello/{name:\w}",
      *     responses=[
      *         @Api\Response(code=200, schema=@Api\Reference(TextPlain::class))
      *     ]
diff --git a/examples/hello_world.php b/examples/hello_world.php
deleted file mode 100644
index bf8e06c..0000000
--- a/examples/hello_world.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php declare(strict_types=1);
-
-use FatCode\OpenApi\Annotation as Api;
-use Psr\Http\Message\ServerRequestInterface;
-use Psr\Http\Message\ResponseInterface;
-use FatCode\OpenApi\Application\OnRequestListener;
-use Zend\Diactoros\Response;
-
-/**
- * Your entry point/front controller.
- *
- * @Api\Application(
- *     title = "Your application title",
- *     version = "1.0.0",
- *     servers = [
- *         @Api\Server(
- *             id = "development",
- *             port = 8080,
- *             host = "localhost"
- *         )
- *     ]
- * )
- */
-class Application implements OnRequestListener
-{
-    public function onRequest(ServerRequestInterface $request) : ResponseInterface
-    {
-        return new Response('Hello world');
-    }
-}
-
-# Run with `open-api run development`
diff --git a/examples/hello_world/hello_world.php b/examples/hello_world/hello_world.php
new file mode 100644
index 0000000..3900b96
--- /dev/null
+++ b/examples/hello_world/hello_world.php
@@ -0,0 +1,75 @@
+<?php declare(strict_types=1);
+
+namespace App\HelloWorld {
+
+    use FatCode\OpenApi\Annotation as Api;
+    use Psr\Http\Message\ServerRequestInterface;
+    use Psr\Http\Message\ResponseInterface;
+    use FatCode\OpenApi\Http\Response;
+
+    /**
+     * Your entry point/front controller.
+     *
+     * @Api\Application(
+     *     title = "Your application title",
+     *     version = "1.0.0",
+     *     servers = [
+     *         @Api\Server(
+     *             id = "development",
+     *             port = 8080,
+     *             host = "localhost"
+     *         )
+     *     ]
+     * )
+     */
+    class Application
+    {
+        /**
+         * @Api\Operation\Get(
+         *     description="Farewell user",
+         *     route="/goodbye/{name}",
+         *     responses=[
+         *         @Api\Response(code=200, schema=@Api\Reference(Greeter::class))
+         *     ]
+         * )
+         */
+        public function sayGoodbye(ServerRequestInterface $request) : ResponseInterface
+        {
+            return new Response(200, new Greeter($request->getAttribute('name')));
+        }
+    }
+
+    /**
+     * @Api\Schema(
+     *     title="Greeter schema",
+     *     type="object"
+     * )
+     */
+    class Greeter
+    {
+        /**
+         * @Api\Property(type="string")
+         */
+        public $name;
+
+        public function __construct(string $name)
+        {
+            $this->name = $name;
+        }
+    }
+
+    /**
+     * @Api\Operation\Get(
+     *     description="Greet user",
+     *     route="/welcome/{name}",
+     *     responses=[
+     *         @Api\Response(code=200, schema=@Api\Reference(Greeter::class))
+     *     ]
+     * )
+     */
+    function sayHello(ServerRequestInterface $request) : ResponseInterface
+    {
+        return new Response(200, new Greeter($request->getAttribute('name')));
+    }
+    # Run with `open-api run development`
+}
diff --git a/examples/multi_directory_project/index.php b/examples/multi_directory_project/index.php
new file mode 100644
index 0000000..a6eebb2
--- /dev/null
+++ b/examples/multi_directory_project/index.php
@@ -0,0 +1,25 @@
+<?php declare(strict_types=1);
+
+namespace MultiDirectory;
+
+use FatCode\OpenApi\Annotation as Api;
+
+/**
+ * Main application class.
+ *
+ * @Api\Application(
+ *     title = "Your application title",
+ *     version = "1.0.0",
+ *     servers = [
+ *         @Api\Server(
+ *             id = "development",
+ *             port = 8080,
+ *             host = "localhost"
+ *         )
+ *     ]
+ * )
+ */
+class Application
+{
+
+}
diff --git a/examples/multi_namespaces_example/index.php b/examples/multi_namespaces_example/index.php
new file mode 100644
index 0000000..f5b2e69
--- /dev/null
+++ b/examples/multi_namespaces_example/index.php
@@ -0,0 +1,38 @@
+<?php declare(strict_types=1);
+
+namespace App {
+
+    use FatCode\OpenApi\Annotation as Api;
+    use Psr\Http\Message\ServerRequestInterface;
+    use Psr\Http\Message\ResponseInterface;
+    use FatCode\OpenApi\Application\OnRequestListener;
+    use Zend\Diactoros\Response;
+
+    /**
+     * Your entry point/front controller.
+     *
+     * @Api\Application(
+     *     title = "Your application title",
+     *     version = "1.0.0",
+     *     servers = [
+     *         @Api\Server(
+     *             id = "development",
+     *             port = 8080,
+     *             host = "localhost"
+     *         )
+     *     ]
+     * )
+     */
+    class Application implements OnRequestListener
+    {
+        public function onRequest(ServerRequestInterface $request): ResponseInterface
+        {
+            return new Response('Hello world');
+        }
+    }
+# Run with `open-api run development`
+}
+
+namespace App\Routes {
+
+}
diff --git a/phpunit.xml b/phpunit.xml
index b8f8f3d..e7c9331 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -7,7 +7,7 @@
          convertWarningsToExceptions="true"
          processIsolation="false"
          stopOnFailure="false"
-         bootstrap="vendor/autoload.php"
+         bootstrap="tests/bootstrap.php"
 >
     <testsuites>
         <testsuite name="All Tests">
diff --git a/src/Analyzer/AnnotationProcessor.php b/src/Analyzer/AnnotationProcessor.php
new file mode 100644
index 0000000..2ec5b0b
--- /dev/null
+++ b/src/Analyzer/AnnotationProcessor.php
@@ -0,0 +1,19 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer;
+
+/**
+ * Class ProjectAnalyser
+ * @package FatCode\OpenApi
+ */
+class AnnotationProcessor
+{
+    public function __construct()
+    {
+    }
+
+    public function process(Project $project) : void
+    {
+
+    }
+}
diff --git a/src/Analyzer/Parser/ClassParser.php b/src/Analyzer/Parser/ClassParser.php
new file mode 100644
index 0000000..5aee7d2
--- /dev/null
+++ b/src/Analyzer/Parser/ClassParser.php
@@ -0,0 +1,54 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer\Parser;
+
+use FatCode\OpenApi\Analyzer\PhpStream;
+
+use function is_array;
+
+use const T_CLASS;
+use const T_NAMESPACE;
+use const T_STRING;
+
+class ClassParser implements StreamAnalyzer
+{
+    use NamespaceParser;
+
+    private $currentNamespace = '';
+
+    /**
+     * @param PhpStream $stream
+     * @return Symbol[]
+     */
+    public function analyze(PhpStream $stream) : array
+    {
+        $results = [];
+
+        foreach ($stream as $index => $token) {
+            if (is_array($token) && $token[0] === T_NAMESPACE) {
+                $this->currentNamespace = $this->parseNamespace($stream);
+            }
+
+            if (!is_array($token) || $token[0] !== T_CLASS) {
+                continue;
+            }
+
+            $results[] = new Symbol(
+                $this->currentNamespace . '\\' . $this->parseClass($stream),
+                SymbolType::TYPE_CLASS()
+            );
+        }
+
+        return $results;
+    }
+
+    private function parseClass(PhpStream $file) : string
+    {
+        $file->seekToken(T_STRING);
+        $className = $file->current()[1];
+        $file->seekStartOfScope();
+        $file->skipScope();
+
+        return $className;
+    }
+}
diff --git a/src/Analyzer/Parser/FunctionParser.php b/src/Analyzer/Parser/FunctionParser.php
new file mode 100644
index 0000000..464f5b0
--- /dev/null
+++ b/src/Analyzer/Parser/FunctionParser.php
@@ -0,0 +1,60 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer\Parser;
+
+use FatCode\OpenApi\Analyzer\PhpStream;
+
+use function is_array;
+
+use const T_FUNCTION;
+use const T_NAMESPACE;
+use const T_STRING;
+
+class FunctionParser implements StreamAnalyzer
+{
+    use NamespaceParser;
+
+    private $currentNamespace = '';
+
+    /**
+     * @param PhpStream $stream
+     * @return Symbol[]
+     */
+    public function analyze(PhpStream $stream) : array
+    {
+        $results = [];
+
+        foreach ($stream as $index => $token) {
+            if (is_array($token) && $token[0] === T_NAMESPACE) {
+                $this->currentNamespace = $this->parseNamespace($stream);
+            }
+
+            if (is_array($token) && $token[0] === T_CLASS) {
+                $stream->seekStartOfScope();
+                $stream->skipScope();
+                continue;
+            }
+
+            if (!is_array($token) || $token[0] !== T_FUNCTION) {
+                continue;
+            }
+
+            $results[] = new Symbol(
+                $this->currentNamespace . '\\' . $this->parseFunction($stream),
+                SymbolType::TYPE_FUNCTION()
+            );
+        }
+
+        return $results;
+    }
+
+    private function parseFunction(PhpStream $file) : string
+    {
+        $file->seekToken(T_STRING);
+        $className = $file->current()[1];
+        $file->seekStartOfScope();
+        $file->skipScope();
+
+        return $className;
+    }
+}
diff --git a/src/Analyzer/Parser/NamespaceParser.php b/src/Analyzer/Parser/NamespaceParser.php
new file mode 100644
index 0000000..aac78d1
--- /dev/null
+++ b/src/Analyzer/Parser/NamespaceParser.php
@@ -0,0 +1,30 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer\Parser;
+
+use FatCode\OpenApi\Exception\ProjectAnalyzerException;
+use FatCode\OpenApi\Analyzer\PhpStream;
+
+use function is_array;
+
+trait NamespaceParser
+{
+    protected function parseNamespace(PhpStream $stream) : string
+    {
+        $namespace = '';
+        while ($stream->valid()) {
+            $stream->next();
+            $token = $stream->current();
+
+            if (is_array($token) && ($token[0] === T_STRING || $token[0] === T_NS_SEPARATOR)) {
+                $namespace .= $token[1];
+            }
+
+            if ($token === ';' || $token === '{') { // End of namespace
+                return $namespace;
+            }
+        }
+
+        throw ProjectAnalyzerException::forInvalidNamespace();
+    }
+}
diff --git a/src/Analyzer/Parser/StreamAnalyzer.php b/src/Analyzer/Parser/StreamAnalyzer.php
new file mode 100644
index 0000000..81dce78
--- /dev/null
+++ b/src/Analyzer/Parser/StreamAnalyzer.php
@@ -0,0 +1,14 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer\Parser;
+
+use FatCode\OpenApi\Analyzer\PhpStream;
+
+interface StreamAnalyzer
+{
+    /**
+     * @param PhpStream $stream
+     * @return Symbol[]
+     */
+    public function analyze(PhpStream $stream) : array;
+}
diff --git a/src/Analyzer/Parser/Symbol.php b/src/Analyzer/Parser/Symbol.php
new file mode 100644
index 0000000..dc51dac
--- /dev/null
+++ b/src/Analyzer/Parser/Symbol.php
@@ -0,0 +1,30 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer\Parser;
+
+class Symbol
+{
+    private $name;
+    private $type;
+
+    public function __construct(string $name, SymbolType $type)
+    {
+        $this->name = $name;
+        $this->type = $type;
+    }
+
+    public function getName() : string
+    {
+        return $this->name;
+    }
+
+    public function getType() : SymbolType
+    {
+        return $this->type;
+    }
+
+    public function __toString() : string
+    {
+        return "{$this->type}:{$this->name}";
+    }
+}
diff --git a/src/Analyzer/Parser/SymbolType.php b/src/Analyzer/Parser/SymbolType.php
new file mode 100644
index 0000000..82e5751
--- /dev/null
+++ b/src/Analyzer/Parser/SymbolType.php
@@ -0,0 +1,26 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer\Parser;
+
+use FatCode\Enum;
+
+/**
+ * @method static SymbolType TYPE_CLASS
+ * @method static SymbolType TYPE_FUNCTION
+ * @method static SymbolType TYPE_NAMESPACE
+ * @method static SymbolType TYPE_METHOD
+ * @method static SymbolType TYPE_INTERFACE
+ */
+class SymbolType extends Enum
+{
+    public const TYPE_CLASS = 'class';
+    public const TYPE_FUNCTION = 'function';
+    public const TYPE_NAMESPACE = 'namespace';
+    public const TYPE_METHOD = 'method';
+    public const TYPE_INTERFACE = 'interface';
+
+    public function __toString() : string
+    {
+        return $this->getValue();
+    }
+}
diff --git a/src/Analyzer/PhpStream.php b/src/Analyzer/PhpStream.php
new file mode 100644
index 0000000..c4069e7
--- /dev/null
+++ b/src/Analyzer/PhpStream.php
@@ -0,0 +1,178 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer;
+
+use FatCode\OpenApi\Exception\FileException;
+use Iterator;
+use Throwable;
+
+use function count;
+use function file_get_contents;
+use function is_file;
+use function is_readable;
+use function token_get_all;
+
+class PhpStream implements Iterator
+{
+    private $cursor;
+    private $tokens;
+    private $length;
+    private $stream;
+    private $context;
+
+    private function __construct(string $stream, string $context = '')
+    {
+        $this->stream = $stream;
+        $this->tokens = token_get_all($stream);
+        $this->length = count($this->tokens);
+        $this->context = $context;
+    }
+
+    public static function fromFile(string $fileName) : PhpStream
+    {
+        self::validateFile($fileName);
+        return new self(file_get_contents($fileName), $fileName);
+    }
+
+    public function getContext() : string
+    {
+        return $this->context;
+    }
+
+    public function current()
+    {
+        return $this->tokens[$this->cursor];
+    }
+
+    public function prev() : void
+    {
+        $this->cursor--;
+    }
+
+    public function next() : void
+    {
+        $this->cursor++;
+    }
+
+    public function key()
+    {
+        return $this->cursor;
+    }
+
+    public function valid() : bool
+    {
+        return $this->cursor >= 0 && $this->cursor < $this->length;
+    }
+
+    public function rewind() : void
+    {
+        $this->cursor = 0;
+    }
+
+    public function getCursor() : int
+    {
+        return $this->cursor;
+    }
+
+    public function getTokens() : array
+    {
+        return $this->tokens;
+    }
+
+    public function getTokenAt(int $cursor)
+    {
+        return $this->tokens[$cursor];
+    }
+
+    public function seekToken(int $token) : bool
+    {
+        while ($this->valid()) {
+            $current = $this->current();
+
+            if (!is_array($current)) {
+                continue;
+            }
+
+            if ($current[0] === $token) {
+                return true;
+            }
+            $this->next();
+        }
+
+        return false;
+    }
+
+    public function seekStartOfScope() : bool
+    {
+        while ($this->valid()) {
+            $current = $this->current();
+
+            if (is_array($current)) {
+                $this->next();
+                continue;
+            }
+
+            if ($current === '{') {
+                return true;
+            }
+            $this->next();
+        }
+
+        return false;
+    }
+
+    public function skipScope() : bool
+    {
+        if ($this->current() === '{') {
+            $this->next();
+        }
+        $depth = 1;
+        while ($this->valid()) {
+            $current = $this->current();
+
+            if (is_array($current)) {
+                $this->next();
+                continue;
+            }
+
+            if ($current === '{') {
+                $depth++;
+                $this->next();
+                continue;
+            }
+
+            if ($current === '}') {
+                $depth--;
+                if ($depth === 0) {
+                    return true;
+                }
+            }
+            $this->next();
+        }
+
+        return false;
+    }
+
+    public function countTokens() : int
+    {
+        return $this->length;
+    }
+
+    public function __toString() : string
+    {
+        return $this->stream;
+    }
+
+    private static function validateFile(string $fileName) : void
+    {
+        if (!is_file($fileName) || !is_readable($fileName)) {
+            throw FileException::notReadable($fileName);
+        }
+
+        try {
+            require_once $fileName;
+        } catch (Throwable $throwable) {
+            throw FileException::invalidFile($fileName);
+        }
+    }
+}
diff --git a/src/Analyzer/Project.php b/src/Analyzer/Project.php
new file mode 100644
index 0000000..7f516dd
--- /dev/null
+++ b/src/Analyzer/Project.php
@@ -0,0 +1,52 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer;
+
+use ArrayIterator;
+use FatCode\OpenApi\Analyzer\Parser\Symbol;
+use FatCode\OpenApi\Analyzer\Parser\SymbolType;
+use Iterator;
+use IteratorAggregate;
+
+class Project implements IteratorAggregate
+{
+    /**
+     * @var Symbol[]
+     */
+    private $symbols;
+
+    public function addSymbol(Symbol ...$symbols) : void
+    {
+        foreach ($symbols as $symbol) {
+            $this->symbols[] = $symbol;
+        }
+    }
+
+    public function getSymbols() : array
+    {
+        return $this->symbols;
+    }
+
+    public function getIterator() : Iterator
+    {
+        return new ArrayIterator($this->symbols);
+    }
+
+    public function listDeclaredFunctions() : iterable
+    {
+        foreach ($this->symbols as $symbol) {
+            if ($symbol->getType() === SymbolType::TYPE_FUNCTION()) {
+                yield $symbol;
+            }
+        }
+    }
+
+    public function listDeclaredClasses() : iterable
+    {
+        foreach ($this->symbols as $symbol) {
+            if ($symbol->getType() === SymbolType::TYPE_CLASS()) {
+                yield $symbol;
+            }
+        }
+    }
+}
diff --git a/src/Analyzer/ProjectFactory.php b/src/Analyzer/ProjectFactory.php
new file mode 100644
index 0000000..d281bd9
--- /dev/null
+++ b/src/Analyzer/ProjectFactory.php
@@ -0,0 +1,47 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Analyzer;
+
+use FatCode\OpenApi\Analyzer\Parser\ClassParser;
+use FatCode\OpenApi\Analyzer\Parser\FunctionParser;
+use FatCode\OpenApi\Analyzer\Parser\StreamAnalyzer;
+use FatCode\OpenApi\Exception\ProjectAnalyzerException;
+use RecursiveDirectoryIterator;
+use RecursiveIteratorIterator;
+use RegexIterator;
+use SplFileInfo;
+
+class ProjectFactory
+{
+    /**
+     * @var StreamAnalyzer[]
+     */
+    private $analyzers;
+
+    public function __construct()
+    {
+        $this->analyzers = [
+            'classes' => new ClassParser(),
+            'functions' => new FunctionParser(),
+        ];
+    }
+
+    public function create(string $dirname) : Project
+    {
+        if (!is_dir($dirname)) {
+            throw ProjectAnalyzerException::forInvalidDirectory($dirname);
+        }
+        $directory = new RecursiveDirectoryIterator($dirname);
+        $allFiles = new RecursiveIteratorIterator($directory);
+        $phpFiles = new RegexIterator($allFiles, '/.*\.php$/i');
+        $project = new Project();
+        /** @var SplFileInfo $file */
+        foreach ($phpFiles as $file) {
+            foreach ($this->analyzers as $analyzer) {
+                $project->addSymbol(...$analyzer->analyze(PhpStream::fromFile($file->getRealPath())));
+            }
+        }
+
+        return $project;
+    }
+}
diff --git a/src/Annotation/Application.php b/src/Annotation/Application.php
index 48b1481..907cbe0 100644
--- a/src/Annotation/Application.php
+++ b/src/Annotation/Application.php
@@ -74,4 +74,3 @@ final class Application
      */
     public $security;
 }
-
diff --git a/src/Annotation/PathItem/CookieParameter.php b/src/Annotation/Operation/CookieParameter.php
similarity index 83%
rename from src/Annotation/PathItem/CookieParameter.php
rename to src/Annotation/Operation/CookieParameter.php
index 6dacc6f..9f27667 100644
--- a/src/Annotation/PathItem/CookieParameter.php
+++ b/src/Annotation/Operation/CookieParameter.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 use FatCode\OpenApi\Annotation\Parameter;
diff --git a/src/Annotation/PathItem/Delete.php b/src/Annotation/Operation/Delete.php
similarity index 86%
rename from src/Annotation/PathItem/Delete.php
rename to src/Annotation/Operation/Delete.php
index 7f5963f..c30a62f 100644
--- a/src/Annotation/PathItem/Delete.php
+++ b/src/Annotation/Operation/Delete.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 
diff --git a/src/Annotation/PathItem/Get.php b/src/Annotation/Operation/Get.php
similarity index 86%
rename from src/Annotation/PathItem/Get.php
rename to src/Annotation/Operation/Get.php
index b34f3a6..f1a2bb5 100644
--- a/src/Annotation/PathItem/Get.php
+++ b/src/Annotation/Operation/Get.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 
diff --git a/src/Annotation/PathItem/Head.php b/src/Annotation/Operation/Head.php
similarity index 86%
rename from src/Annotation/PathItem/Head.php
rename to src/Annotation/Operation/Head.php
index 02cab3e..26a8e7b 100644
--- a/src/Annotation/PathItem/Head.php
+++ b/src/Annotation/Operation/Head.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 
diff --git a/src/Annotation/PathItem/HeaderParameter.php b/src/Annotation/Operation/HeaderParameter.php
similarity index 83%
rename from src/Annotation/PathItem/HeaderParameter.php
rename to src/Annotation/Operation/HeaderParameter.php
index fedc262..6d5a2e0 100644
--- a/src/Annotation/PathItem/HeaderParameter.php
+++ b/src/Annotation/Operation/HeaderParameter.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 use FatCode\OpenApi\Annotation\Parameter;
diff --git a/src/Annotation/PathItem/Operation.php b/src/Annotation/Operation/Operation.php
similarity index 97%
rename from src/Annotation/PathItem/Operation.php
rename to src/Annotation/Operation/Operation.php
index c7c9205..cea0b62 100644
--- a/src/Annotation/PathItem/Operation.php
+++ b/src/Annotation/Operation/Operation.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\OpenApi\Annotation\Parameter;
 use FatCode\OpenApi\Annotation\Request;
diff --git a/src/Annotation/PathItem/Options.php b/src/Annotation/Operation/Options.php
similarity index 86%
rename from src/Annotation/PathItem/Options.php
rename to src/Annotation/Operation/Options.php
index 43368fb..56e7d1b 100644
--- a/src/Annotation/PathItem/Options.php
+++ b/src/Annotation/Operation/Options.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 
diff --git a/src/Annotation/PathItem/Patch.php b/src/Annotation/Operation/Patch.php
similarity index 86%
rename from src/Annotation/PathItem/Patch.php
rename to src/Annotation/Operation/Patch.php
index 4da2299..5ae7d37 100644
--- a/src/Annotation/PathItem/Patch.php
+++ b/src/Annotation/Operation/Patch.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 
diff --git a/src/Annotation/PathItem/PathParameter.php b/src/Annotation/Operation/PathParameter.php
similarity index 83%
rename from src/Annotation/PathItem/PathParameter.php
rename to src/Annotation/Operation/PathParameter.php
index f866412..7a6e1de 100644
--- a/src/Annotation/PathItem/PathParameter.php
+++ b/src/Annotation/Operation/PathParameter.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 use FatCode\OpenApi\Annotation\Parameter;
diff --git a/src/Annotation/PathItem/Post.php b/src/Annotation/Operation/Post.php
similarity index 86%
rename from src/Annotation/PathItem/Post.php
rename to src/Annotation/Operation/Post.php
index 5b69e51..dcdb91e 100644
--- a/src/Annotation/PathItem/Post.php
+++ b/src/Annotation/Operation/Post.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 
diff --git a/src/Annotation/PathItem/Put.php b/src/Annotation/Operation/Put.php
similarity index 86%
rename from src/Annotation/PathItem/Put.php
rename to src/Annotation/Operation/Put.php
index 168254c..4d65e76 100644
--- a/src/Annotation/PathItem/Put.php
+++ b/src/Annotation/Operation/Put.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 
diff --git a/src/Annotation/PathItem/QueryParameter.php b/src/Annotation/Operation/QueryParameter.php
similarity index 83%
rename from src/Annotation/PathItem/QueryParameter.php
rename to src/Annotation/Operation/QueryParameter.php
index 7534616..6d8862d 100644
--- a/src/Annotation/PathItem/QueryParameter.php
+++ b/src/Annotation/Operation/QueryParameter.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 use FatCode\OpenApi\Annotation\Parameter;
diff --git a/src/Annotation/PathItem/Trace.php b/src/Annotation/Operation/Trace.php
similarity index 86%
rename from src/Annotation/PathItem/Trace.php
rename to src/Annotation/Operation/Trace.php
index bf8a871..395271e 100644
--- a/src/Annotation/PathItem/Trace.php
+++ b/src/Annotation/Operation/Trace.php
@@ -1,6 +1,6 @@
 <?php declare(strict_types=1);
 
-namespace FatCode\OpenApi\Annotation\PathItem;
+namespace FatCode\OpenApi\Annotation\Operation;
 
 use FatCode\Annotation\Target;
 
diff --git a/src/Annotation/PathItem.php b/src/Annotation/PathItem.php
index 1352c55..b37e109 100644
--- a/src/Annotation/PathItem.php
+++ b/src/Annotation/PathItem.php
@@ -3,7 +3,7 @@
 namespace FatCode\OpenApi\Annotation;
 
 use FatCode\Annotation\Target;
-use FatCode\OpenApi\Annotation\PathItem\Operation;
+use FatCode\OpenApi\Annotation\Operation\Operation;
 
 /**
  * @Annotation
diff --git a/src/Annotation/SecurityScheme/OAuthFlow.php b/src/Annotation/SecurityScheme/OAuthFlow.php
index 3185626..aae16f6 100644
--- a/src/Annotation/SecurityScheme/OAuthFlow.php
+++ b/src/Annotation/SecurityScheme/OAuthFlow.php
@@ -2,12 +2,10 @@
 
 namespace FatCode\OpenApi\Annotation\SecurityScheme;
 
-use FatCode\OpenApi\Annotation\Annotation;
-
 /**
  * @Annotation
  */
-class OAuthFlow extends Annotation
+class OAuthFlow
 {
     /**
      * The authorization URL to be used for this flow. This MUST be in the form of a URL.
diff --git a/src/Annotation/SecurityScheme/OAuthFlows.php b/src/Annotation/SecurityScheme/OAuthFlows.php
index 1a65f27..c9df94f 100644
--- a/src/Annotation/SecurityScheme/OAuthFlows.php
+++ b/src/Annotation/SecurityScheme/OAuthFlows.php
@@ -2,12 +2,10 @@
 
 namespace FatCode\OpenApi\Annotation\SecurityScheme;
 
-use FatCode\OpenApi\Annotation\Annotation;
-
 /**
  * @Annotation
  */
-class OAuthFlows extends Annotation
+class OAuthFlows
 {
     /**
      * @var OAuthFlow
diff --git a/src/Annotation/SecurityScheme/SecurityRequirement.php b/src/Annotation/SecurityScheme/SecurityRequirement.php
index f33bd63..740f707 100644
--- a/src/Annotation/SecurityScheme/SecurityRequirement.php
+++ b/src/Annotation/SecurityScheme/SecurityRequirement.php
@@ -2,14 +2,12 @@
 
 namespace FatCode\OpenApi\Annotation\SecurityScheme;
 
-use FatCode\OpenApi\Annotation\Annotation;
-
 /**
  * Keeps the required security schemes to execute given operation.
  * @Annotation
  * @see https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#security-requirement-object
  */
-final class SecurityRequirement extends Annotation
+final class SecurityRequirement
 {
     public $requirement;
 
diff --git a/src/Exception/FileException.php b/src/Exception/FileException.php
new file mode 100644
index 0000000..bbb999c
--- /dev/null
+++ b/src/Exception/FileException.php
@@ -0,0 +1,18 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Exception;
+
+use InvalidArgumentException;
+
+class FileException extends InvalidArgumentException
+{
+    public static function notReadable(string $fileName): self
+    {
+        return new self("Passed file `{$fileName}` could not be opened for read.");
+    }
+
+    public static function invalidFile(string $filename) : self
+    {
+        return new self("Passed file `{$filename}` is not valid php file.");
+    }
+}
diff --git a/src/Exception/ProjectAnalyzerException.php b/src/Exception/ProjectAnalyzerException.php
new file mode 100644
index 0000000..75ba022
--- /dev/null
+++ b/src/Exception/ProjectAnalyzerException.php
@@ -0,0 +1,29 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\OpenApi\Exception;
+
+use FatCode\OpenApi\Exception\RuntimeException as FatCodeRuntimeException;
+use RuntimeException;
+
+class ProjectAnalyzerException extends RuntimeException implements FatCodeRuntimeException
+{
+    public static function forInvalidDirectory(string $directory) : self
+    {
+        return new self("Passed directory `{$directory}` is not a valid directory name.");
+    }
+
+    public static function forUnreadableFile(string $filename) : self
+    {
+        return new self("Passed file `{$filename}` could not be opened for read.");
+    }
+
+    public static function forInvalidFile(string $filename) : self
+    {
+        return new self("Passed file `{$filename}` is not valid php file.");
+    }
+
+    public static function forInvalidNamespace() : self
+    {
+        return new self('Could not parse namespace.');
+    }
+}
diff --git a/src/FileAnalyse.php b/src/FileAnalyse.php
deleted file mode 100644
index ff973e6..0000000
--- a/src/FileAnalyse.php
+++ /dev/null
@@ -1,26 +0,0 @@
-<?php declare(strict_types=1);
-
-namespace FatCode\OpenApi;
-
-class FileAnalyse
-{
-    public function getFileComments() : array
-    {
-
-    }
-
-    public function getDeclaredFunctions() : array
-    {
-
-    }
-
-    public function getDeclaredClasses() : array
-    {
-
-    }
-
-    public function getDeclaredInterfaces() : array
-    {
-
-    }
-}
diff --git a/src/Http/Response.php b/src/Http/Response.php
index 58cf2ff..eaeb3c3 100644
--- a/src/Http/Response.php
+++ b/src/Http/Response.php
@@ -80,5 +80,4 @@ public function getReasonPhrase()
     {
         // TODO: Implement getReasonPhrase() method.
     }
-
 }
diff --git a/src/ProjectAnalyser.php b/src/ProjectAnalyser.php
deleted file mode 100644
index c032c38..0000000
--- a/src/ProjectAnalyser.php
+++ /dev/null
@@ -1,22 +0,0 @@
-<?php declare(strict_types=1);
-
-namespace FatCode\OpenApi;
-
-/**
- * Class ProjectAnalyser
- * @package FatCode\OpenApi
- */
-class ProjectAnalyser
-{
-    private $directory;
-
-    public function __construct(string $directory)
-    {
-
-    }
-
-    public function readFromFile(string $filename) : void
-    {
-
-    }
-}
diff --git a/tests/Analyzer/Parser/ClassParserTest.php b/tests/Analyzer/Parser/ClassParserTest.php
new file mode 100644
index 0000000..7b8a717
--- /dev/null
+++ b/tests/Analyzer/Parser/ClassParserTest.php
@@ -0,0 +1,24 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\Tests\OpenApi\Analyzer\Parser;
+
+use FatCode\OpenApi\Analyzer\Parser\ClassParser;
+use FatCode\OpenApi\Analyzer\PhpStream;
+use PHPUnit\Framework\TestCase;
+
+final class ClassParserTest extends TestCase
+{
+    public function testCanInstantiate() : void
+    {
+        self::assertInstanceOf(ClassParser::class, new ClassParser());
+    }
+
+    public function testParse() : void
+    {
+        $parser = new ClassParser();
+        $info = $parser->analyze(PhpStream::fromFile(__FILE__));
+
+        self::assertCount(1, $info);
+        self::assertSame(__CLASS__, $info[0]->getName());
+    }
+}
diff --git a/tests/Analyzer/Parser/FunctionParserTest.php b/tests/Analyzer/Parser/FunctionParserTest.php
new file mode 100644
index 0000000..490acf6
--- /dev/null
+++ b/tests/Analyzer/Parser/FunctionParserTest.php
@@ -0,0 +1,33 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\Tests\OpenApi\Analyzer\Parser;
+
+use FatCode\OpenApi\Analyzer\Parser\FunctionParser;
+use FatCode\OpenApi\Analyzer\PhpStream;
+use PHPUnit\Framework\TestCase;
+
+final class FunctionParserTest extends TestCase
+{
+    public function testCanInstantiate() : void
+    {
+        self::assertInstanceOf(FunctionParser::class, new FunctionParser());
+    }
+
+    public function testParse() : void
+    {
+        $parser = new FunctionParser();
+        $info = $parser->analyze(PhpStream::fromFile(__FILE__));
+
+        self::assertCount(2, $info);
+        self::assertSame(__NAMESPACE__ . '\test_a', $info[0]->getName());
+        self::assertSame(__NAMESPACE__ . '\test_b', $info[1]->getName());
+    }
+}
+
+function test_a()
+{
+}
+
+function test_b()
+{
+}
diff --git a/tests/Analyzer/ProjectAnalyzerTests.php b/tests/Analyzer/ProjectAnalyzerTests.php
new file mode 100644
index 0000000..270070d
--- /dev/null
+++ b/tests/Analyzer/ProjectAnalyzerTests.php
@@ -0,0 +1,19 @@
+<?php declare(strict_types=1);
+
+namespace FatCode\Tests\OpenApi\Analyzer;
+
+use FatCode\OpenApi\Analyzer\Project;
+use FatCode\OpenApi\Analyzer\ProjectFactory;
+use PHPUnit\Framework\TestCase;
+
+class ProjectAnalyzerTests extends TestCase
+{
+    public function testAnalyze() : void
+    {
+        $projectAnalyzer = new ProjectFactory(__DIR__ . '/../../examples/hello_world');
+        $project = $projectAnalyzer->create();
+
+        self::assertInstanceOf(Project::class, $project);
+        self::assertCount(3, $project->getSymbols());
+    }
+}
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
new file mode 100644
index 0000000..a602eda
--- /dev/null
+++ b/tests/bootstrap.php
@@ -0,0 +1,6 @@
+<?php declare(strict_types=1);
+
+require_once __DIR__ . '/../vendor/autoload.php';
+
+const EXAMPLES_DIR = __DIR__ . '/../examples';
+const FIXTURES_DIR = __DIR__ . '/Fixtures';