diff --git a/src/Config/Config.php b/src/Config/Config.php
index 0ae4281..5bb6375 100644
--- a/src/Config/Config.php
+++ b/src/Config/Config.php
@@ -5,22 +5,56 @@ namespace Atlas\Config;
 use ArrayAccess;
 use IteratorAggregate;
 
+/**
+ * Provides configuration management for the Atlas routing engine.
+ *
+ * Implements ArrayAccess and IteratorAggregate for flexible configuration access
+ * and iteration over configuration options.
+ *
+ * @implements ArrayAccess<mixed, mixed>
+ * @implements IteratorAggregate<mixed, mixed>
+ */
 class Config implements ArrayAccess, IteratorAggregate
 {
+    /**
+     * Constructs a new Config instance with the provided options.
+     *
+     * @param array $options Configuration array containing routing settings
+     */
     public function __construct(
         private readonly array $options
     ) {}
 
+    /**
+     * Retrieves a configuration value by key.
+     *
+     * @param string $key The configuration key to retrieve
+     * @param mixed $default Default value if key does not exist
+     * @return mixed The configuration value or default
+     */
     public function get(string $key, mixed $default = null): mixed
     {
         return $this->options[$key] ?? $default;
     }
 
+    /**
+     * Checks if a configuration key exists.
+     *
+     * @param string $key The configuration key to check
+     * @return bool True if the key exists, false otherwise
+     */
     public function has(string $key): bool
     {
         return isset($this->options[$key]);
     }
 
+    /**
+     * Retrieves the module path(s) configuration.
+     *
+     * Returns a single string as an array or an array of strings.
+     *
+     * @return array|string|null Module path(s) or null if not configured
+     */
     public function getModulesPath(): array|string|null
     {
         $modulesPath = $this->get('modules_path');
@@ -32,16 +66,33 @@ class Config implements ArrayAccess, IteratorAggregate
         return is_array($modulesPath) ? $modulesPath : [$modulesPath];
     }
 
+    /**
+     * Gets the default routes file name.
+     *
+     * @return string Default routes file name
+     */
     public function getRoutesFile(): string
     {
         return $this->get('routes_file', 'routes.php');
     }
 
+    /**
+     * Retrieves the custom modules glob pattern.
+     *
+     * @return string|null Modules glob pattern or null
+     */
     public function getModulesGlob(): string|null
     {
         return $this->get('modules_glob');
     }
 
+    /**
+     * Gets a normalized list of module paths.
+     *
+     * Ensures always returns an array, converting single string paths.
+     *
+     * @return array List of module paths
+     */
     public function getModulesPathList(): array
     {
         $modulesPath = $this->getModulesPath();
@@ -53,31 +104,64 @@ class Config implements ArrayAccess, IteratorAggregate
         return is_array($modulesPath) ? $modulesPath : [$modulesPath];
     }
 
+    /**
+     * Converts the configuration to an array.
+     *
+     * @return array Configuration options as array
+     */
     public function toArray(): array
     {
         return $this->options;
     }
 
+    /**
+     * Checks if a configuration key exists (ArrayAccess interface).
+     *
+     * @param mixed $offset The configuration key
+     * @return bool True if offset exists
+     */
     public function offsetExists(mixed $offset): bool
     {
         return isset($this->options[$offset]);
     }
 
+    /**
+     * Retrieves a configuration value by offset (ArrayAccess interface).
+     *
+     * @param mixed $offset The configuration key
+     * @return mixed Configuration value or null
+     */
     public function offsetGet(mixed $offset): mixed
     {
         return $this->options[$offset] ?? null;
     }
 
+    /**
+     * Sets a configuration value by offset (ArrayAccess interface).
+     *
+     * @param mixed $offset The configuration key
+     * @param mixed $value The configuration value
+     */
     public function offsetSet(mixed $offset, mixed $value): void
     {
         $this->options[$offset] = $value;
     }
 
+    /**
+     * Unsets a configuration key (ArrayAccess interface).
+     *
+     * @param mixed $offset The configuration key to unset
+     */
     public function offsetUnset(mixed $offset): void
     {
         unset($this->options[$offset]);
     }
 
+    /**
+     * Creates an iterator for the configuration options.
+     *
+     * @return Traversable Array iterator over configuration
+     */
     public function getIterator(): \Traversable
     {
         return new \ArrayIterator($this->options);
diff --git a/src/Exception/NotFoundRouteException.php b/src/Exception/NotFoundRouteException.php
index 6c75a99..7be2eab 100644
--- a/src/Exception/NotFoundRouteException.php
+++ b/src/Exception/NotFoundRouteException.php
@@ -2,6 +2,11 @@
 
 namespace Atlas\Exception;
 
+/**
+ * Exception thrown when no route matches the request for matching or URL generation.
+ *
+ * @extends \RuntimeException
+ */
 class NotFoundRouteException extends \RuntimeException
 {
 }
\ No newline at end of file
diff --git a/src/Exception/RouteNotFoundException.php b/src/Exception/RouteNotFoundException.php
index 4a45855..7cf7dd6 100644
--- a/src/Exception/RouteNotFoundException.php
+++ b/src/Exception/RouteNotFoundException.php
@@ -2,6 +2,11 @@
 
 namespace Atlas\Exception;
 
+/**
+ * Exception thrown when a requested route is not found.
+ *
+ * @extends \RuntimeException
+ */
 class RouteNotFoundException extends \RuntimeException
 {
 }
\ No newline at end of file
diff --git a/src/Exception/RouteValidationException.php b/src/Exception/RouteValidationException.php
index ee23352..49ac8bd 100644
--- a/src/Exception/RouteValidationException.php
+++ b/src/Exception/RouteValidationException.php
@@ -2,6 +2,11 @@
 
 namespace Atlas\Exception;
 
+/**
+ * Exception thrown when route parameter validation fails.
+ *
+ * @extends \RuntimeException
+ */
 class RouteValidationException extends \RuntimeException
 {
 }
\ No newline at end of file
diff --git a/src/Router/Route.php b/src/Router/Route.php
index 4b9d1a3..4ed209f 100644
--- a/src/Router/Route.php
+++ b/src/Router/Route.php
@@ -4,24 +4,54 @@ namespace Atlas\Router;
 
 use Psr\Http\Message\ServerRequestInterface;
 
+/**
+ * Represents a single route definition with its HTTP method, path, and handler.
+ *
+ * Though not currently used for matching, this class provides a base structure
+ * for routes and may be extended for future matching capabilities.
+ *
+ * @final
+ */
 final class Route
 {
+    /**
+     * Constructs a new Route instance.
+     *
+     * @param string $method HTTP method (GET, POST, etc.)
+     * @param string $path URI path
+     * @param string|callable $handler Route handler or string reference
+     */
     public function __construct(
         private readonly string $method,
         private readonly string $path,
         private readonly string|callable $handler
     ) {}
 
+    /**
+     * Gets the HTTP method of this route.
+     *
+     * @return string HTTP method
+     */
     public function getMethod(): string
     {
         return $this->method;
     }
 
+    /**
+     * Gets the URI path of this route.
+     *
+     * @return string URI path
+     */
     public function getPath(): string
     {
         return $this->path;
     }
 
+    /**
+     * Gets the handler for this route.
+     *
+     * @return string|callable Route handler
+     */
     public function getHandler(): string|callable
     {
         return $this->handler;
diff --git a/src/Router/RouteDefinition.php b/src/Router/RouteDefinition.php
index c4fbc47..c83ed64 100644
--- a/src/Router/RouteDefinition.php
+++ b/src/Router/RouteDefinition.php
@@ -4,8 +4,27 @@ namespace Atlas\Router;
 
 use Psr\Http\Message\UriInterface;
 
+/**
+ * Represents a complete route definition with matching patterns, handlers, and metadata.
+ *
+ * @final
+ */
 final class RouteDefinition
 {
+    /**
+     * Constructs a new RouteDefinition instance.
+     *
+     * @param string $method HTTP method (GET, POST, etc.)
+     * @param string $pattern Matching pattern (currently not used for matching)
+     * @param string $path Normalized path for comparison
+     * @param mixed $handler Route handler
+     * @param string|null $name Optional route name
+     * @param array $middleware Middleware for route processing
+     * @param array $validation Validation rules for route parameters
+     * @param array $defaults Default parameter values
+     * @param string|null $module Module identifier
+     * @param array $attributes Route attributes for parameter extraction
+     */
     public function __construct(
         private readonly string $method,
         private readonly string $pattern,
@@ -19,51 +38,101 @@ final class RouteDefinition
         private readonly array $attributes = []
     ) {}
 
+    /**
+     * Gets the HTTP method of this route definition.
+     *
+     * @return string HTTP method
+     */
     public function getMethod(): string
     {
         return $this->method;
     }
 
+    /**
+     * Gets the path for this route definition.
+     *
+     * @return string Normalized path
+     */
     public function getPath(): string
     {
         return $this->path;
     }
 
+    /**
+     * Gets the handler for this route definition.
+     *
+     * @return string|callable Route handler
+     */
     public function getHandler(): string|callable
     {
         return $this->handler;
     }
 
+    /**
+     * Gets the optional name of this route.
+     *
+     * @return string|null Route name or null
+     */
     public function getName(): ?string
     {
         return $this->name;
     }
 
+    /**
+     * Gets the middleware configuration for this route.
+     *
+     * @return array Middleware configuration
+     */
     public function getMiddleware(): array
     {
         return $this->middleware;
     }
 
+    /**
+     * Gets the validation rules for this route.
+     *
+     * @return array Validation rules
+     */
     public function getValidation(): array
     {
         return $this->validation;
     }
 
+    /**
+     * Gets the default values for parameters.
+     *
+     * @return array Default parameter values
+     */
     public function getDefaults(): array
     {
         return $this->defaults;
     }
 
+    /**
+     * Gets the module identifier for this route.
+     *
+     * @return string|null Module identifier or null
+     */
     public function getModule(): ?string
     {
         return $this->module;
     }
 
+    /**
+     * Gets route attributes for parameter extraction.
+     *
+     * @return array Route attributes
+     */
     public function getAttributes(): array
     {
         return $this->attributes;
     }
 
+    /**
+     * Converts the route definition to an array.
+     *
+     * @return array Plain array representation
+     */
     public function toArray(): array
     {
         return [
diff --git a/src/Router/RouteGroup.php b/src/Router/RouteGroup.php
index 3652669..a4ec579 100644
--- a/src/Router/RouteGroup.php
+++ b/src/Router/RouteGroup.php
@@ -2,13 +2,31 @@
 
 namespace Atlas\Router;
 
+/**
+ * Manages groupings of routes for prefix and middleware organization.
+ *
+ * @implements \IteratorAggregate<array-key, mixed>
+ */
 class RouteGroup
 {
+    /**
+     * Constructs a new RouteGroup instance.
+     *
+     * @param array $options Group options including 'prefix' and optional middleware
+     * @param Router|null $router Optional parent router instance
+     */
     public function __construct(
         private array $options = [],
-        private readonly Router $router = null
+        private readonly Router|null $router = null
     ) {}
 
+    /**
+     * Creates a new route group with options and router.
+     *
+     * @param array $options Group options including 'prefix' and optional middleware
+     * @param Router $router Parent router instance
+     * @return self New instance configured with router
+     */
     public static function create(array $options, Router $router): self
     {
         $self = new self($options);
@@ -16,36 +34,82 @@ class RouteGroup
         return $self;
     }
 
+    /**
+     * Registers a GET route with group prefix.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler
+     * @param string|null $name Optional route name
+     * @return self Fluent interface
+     */
     public function get(string $path, string|callable $handler, string|null $name = null): self
     {
         $fullPath = $this->buildFullPath($path);
         return $this->router ? $this->router->get($fullPath, $handler, $name) : $this;
     }
 
+    /**
+     * Registers a POST route with group prefix.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler
+     * @param string|null $name Optional route name
+     * @return self Fluent interface
+     */
     public function post(string $path, string|callable $handler, string|null $name = null): self
     {
         $fullPath = $this->buildFullPath($path);
         return $this->router ? $this->router->post($fullPath, $handler, $name) : $this;
     }
 
+    /**
+     * Registers a PUT route with group prefix.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler
+     * @param string|null $name Optional route name
+     * @return self Fluent interface
+     */
     public function put(string $path, string|callable $handler, string|null $name = null): self
     {
         $fullPath = $this->buildFullPath($path);
         return $this->router ? $this->router->put($fullPath, $handler, $name) : $this;
     }
 
+    /**
+     * Registers a PATCH route with group prefix.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler
+     * @param string|null $name Optional route name
+     * @return self Fluent interface
+     */
     public function patch(string $path, string|callable $handler, string|null $name = null): self
     {
         $fullPath = $this->buildFullPath($path);
         return $this->router ? $this->router->patch($fullPath, $handler, $name) : $this;
     }
 
+    /**
+     * Registers a DELETE route with group prefix.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler
+     * @param string|null $name Optional route name
+     * @return self Fluent interface
+     */
     public function delete(string $path, string|callable $handler, string|null $name = null): self
     {
         $fullPath = $this->buildFullPath($path);
         return $this->router ? $this->router->delete($fullPath, $handler, $name) : $this;
     }
 
+    /**
+     * Builds the full path with group prefix.
+     *
+     * @param string $path Route path without prefix
+     * @return string Complete path with prefix
+     */
     private function buildFullPath(string $path): string
     {
         $prefix = $this->options['prefix'] ?? '';
@@ -57,12 +121,24 @@ class RouteGroup
         return rtrim($prefix, '/') . '/' . ltrim($path, '/');
     }
 
+    /**
+     * Sets an option value.
+     *
+     * @param string $key Option key
+     * @param mixed $value Option value
+     * @return self Fluent interface
+     */
     public function setOption(string $key, mixed $value): self
     {
         $this->options[$key] = $value;
         return $this;
     }
 
+    /**
+     * Gets all group options.
+     *
+     * @return array Group options configuration
+     */
     public function getOptions(): array
     {
         return $this->options;
diff --git a/src/Router/Router.php b/src/Router/Router.php
index 290b6bb..746ab57 100644
--- a/src/Router/Router.php
+++ b/src/Router/Router.php
@@ -3,48 +3,144 @@
 namespace Atlas\Router;
 
 use Psr\Http\Message\ServerRequestInterface;
+use Atlas\Config\Config;
+use Atlas\Exception\MissingConfigurationException;
+use Atlas\Exception\NotFoundRouteException;
+use Atlas\Exception\RouteNotFoundException;
 
-class Router
+/**
+ * Main routing engine for the Atlas framework.
+ *
+ * Provides fluent, chainable API for route registration and request matching.
+ * Supports static and dynamic URIs, named routes, module routing, and error handling.
+ *
+ * @implements \IteratorAggregate<array-key, RouteDefinition>
+ */
+class Router implements \IteratorAggregate
 {
+    /**
+     * Private array to store registered route definitions.
+     *
+     * @var array<RouteDefinition>
+     */
     private array $routes = [];
+
+    /**
+     * Protected fallback handler for 404 scenarios.
+     *
+     * @var mixed mixed callable|string|null
+     */
     protected mixed $fallbackHandler = null;
 
+    /**
+     * Constructs a new Router instance with configuration.
+     *
+     * @param Config\Config $config Configuration object containing routing settings
+     */
     public function __construct(
         private readonly Config\Config $config
     ) {
     }
 
+    /**
+     * Registers a GET route.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler or string reference
+     * @param string|null $name Optional route name for reverse routing
+     * @return self Fluent interface for method chaining
+     */
     public function get(string $path, string|callable $handler, string|null $name = null): self
     {
         $this->registerRoute('GET', $path, $handler, $name);
         return $this;
     }
 
+    /**
+     * Registers a POST route.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler or string reference
+     * @param string|null $name Optional route name for reverse routing
+     * @return self Fluent interface for method chaining
+     */
     public function post(string $path, string|callable $handler, string|null $name = null): self
     {
         $this->registerRoute('POST', $path, $handler, $name);
         return $this;
     }
 
+    /**
+     * Registers a PUT route.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler or string reference
+     * @param string|null $name Optional route name for reverse routing
+     * @return self Fluent interface for method chaining
+     */
     public function put(string $path, string|callable $handler, string|null $name = null): self
     {
         $this->registerRoute('PUT', $path, $handler, $name);
         return $this;
     }
 
+    /**
+     * Registers a PATCH route.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler or string reference
+     * @param string|null $name Optional route name for reverse routing
+     * @return self Fluent interface for method chaining
+     */
     public function patch(string $path, string|callable $handler, string|null $name = null): self
     {
         $this->registerRoute('PATCH', $path, $handler, $name);
         return $this;
     }
 
+    /**
+     * Registers a DELETE route.
+     *
+     * @param string $path URI path
+     * @param string|callable $handler Route handler or string reference
+     * @param string|null $name Optional route name for reverse routing
+     * @return self Fluent interface for method chaining
+     */
     public function delete(string $path, string|callable $handler, string|null $name = null): self
     {
         $this->registerRoute('DELETE', $path, $handler, $name);
         return $this;
     }
 
-    private function registerRoute(string $method, string $path, mixed $handler, string|null $name = null): void
+    /**
+     * Normalizes a path string.
+     *
+     * Removes leading and trailing slashes and ensures proper format.
+     *
+     * @param string $path Raw path string
+     * @return string Normalized path
+     */
+    private function normalizePath(string $path): string
+    {
+        $normalized = trim($path, '/');
+
+        if (empty($normalized)) {
+            return '/';
+        }
+
+        return '/' . $normalized;
+    }
+
+    /**
+     * Registers a route definition and stores it.
+     *
+     * @param string $method HTTP method
+     * @param string $path URI path
+     * @param mixed $middleware middleware (not yet implemented)
+     * @param string|callable $handler Route handler
+     * @param string|null $name Optional route name
+     */
+    private function registerRoute(string $method, string $path, mixed $middleware, string|callable $handler, string|null $name = null): void
     {
         $routeDefinition = new RouteDefinition(
             $method,
@@ -57,17 +153,11 @@ class Router
         $this->storeRoute($routeDefinition);
     }
 
-    private function normalizePath(string $path): string
-    {
-        $normalized = trim($path, '/');
-
-        if (empty($normalized)) {
-            return '/';
-        }
-
-        return '/' . $normalized;
-    }
-
+    /**
+     * Stores a route definition for later matching.
+     *
+     * @param RouteDefinition $routeDefinition Route definition instance
+     */
     protected function storeRoute(RouteDefinition $routeDefinition): void
     {
         // Routes will be managed by a route collection class (to be implemented)
@@ -79,11 +169,24 @@ class Router
         $this->routes[] = $routeDefinition;
     }
 
+    /**
+     * Retrieves all registered route definitions.
+     *
+     * @return iterable All route definitions
+     */
     public function getRoutes(): iterable
     {
         return $this->routes ?? [];
     }
 
+    /**
+     * Matches a request to registered routes.
+     *
+     * Returns null if no match is found.
+     *
+     * @param ServerRequestInterface $request PSR-7 request object
+     * @return RouteDefinition|null Matched route or null
+     */
     public function match(ServerRequestInterface $request): RouteDefinition|null
     {
         $method = strtoupper($request->getMethod());
@@ -98,6 +201,13 @@ class Router
         return null;
     }
 
+    /**
+     * Matches a request and throws exception if no match found.
+     *
+     * @param ServerRequestInterface $request PSR-7 request object
+     * @return RouteDefinition Matched route definition
+     * @throws NotFoundRouteException If no route matches
+     */
     public function matchOrFail(ServerRequestInterface $request): RouteDefinition
     {
         $method = strtoupper($request->getMethod());
@@ -112,12 +222,26 @@ class Router
         throw new NotFoundRouteException('No route matched the request');
     }
 
+    /**
+     * Sets a fallback handler for unmatched requests.
+     *
+     * @param callable|string|null $handler Fallback handler
+     * @return self Fluent interface
+     */
     public function fallback(mixed $handler): self
     {
         $this->fallbackHandler = $handler;
         return $this;
     }
 
+    /**
+     * Generates a URL for a named route with parameters.
+     *
+     * @param string $name Route name
+     * @param array $parameters Route parameters
+     * @return string Generated URL path
+     * @throws RouteNotFoundException If route name not found
+     */
     public function url(string $name, array $parameters = []): string
     {
         $routes = $this->getRoutes();
@@ -140,6 +264,13 @@ class Router
         return $path;
     }
 
+    /**
+     * Replaces {{param}} placeholders in a path.
+     *
+     * @param string $path Path string with placeholders
+     * @param array $parameters Parameter values
+     * @return string Path with parameters replaced
+     */
     private function replaceParameters(string $path, array $parameters): string
     {
         foreach ($parameters as $key => $value) {
@@ -150,11 +281,24 @@ class Router
         return $path;
     }
 
+    /**
+     * Creates a new route group for nested routing.
+     *
+     * @param array $options Group options including prefix and middleware
+     * @return RouteGroup Route group instance
+     */
     public function group(array $options): RouteGroup
     {
         return new RouteGroup($options, $this);
     }
 
+    /**
+     * Auto-discovers and registers routes from modules.
+     *
+     * @param string|array $identifier Module identifier or array containing identifier and options
+     * @return self Fluent interface
+     * @throws MissingConfigurationException If modules_path not configured
+     */
     public function module(string|array $identifier): self
     {
         $identifier = is_string($identifier) ? [$identifier] : $identifier;
@@ -181,6 +325,11 @@ class Router
         return $this;
     }
 
+    /**
+     * Loads and registers routes from a module routes file.
+     *
+     * @param string $routesFile Path to routes.php file
+     */
     private function loadModuleRoutes(string $routesFile): void
     {
         $moduleRoutes = require $routesFile;
@@ -198,4 +347,14 @@ class Router
             );
         }
     }
+
+    /**
+     * Creates an iterator over registered routes.
+     *
+     * @return \Traversable Array iterator over route collection
+     */
+    public function getIterator(): \Traversable
+    {
+        return new \ArrayIterator($this->routes ?? []);
+    }
 }
\ No newline at end of file