diff --git a/README.md b/README.md
index 0db8c11..20a8609 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,113 @@ Simple routing for WordPress. Designed for usage with [Timber](https://github.co
 [![PHP unit tests](https://github.com/Upstatement/routes/actions/workflows/php-unit-tests.yml/badge.svg?branch=2.x)](https://github.com/Upstatement/routes/actions/workflows/php-unit-tests.yml?query=branch:2.x)
 [![Latest Stable Version](https://img.shields.io/packagist/v/Upstatement/routes.svg?style=flat-square)](https://packagist.org/packages/Upstatement/routes)
 
+## Installation
+
+Install via [Composer](https://getcomposer.org/):
+
+```bash
+composer require upstatement/routes
+```
+
+Then make sure Composer's autoloader is included in your project. In a standard WordPress setup this is typically done in `functions.php` or your plugin's main file:
+
+```php
+require_once __DIR__ . '/vendor/autoload.php';
+```
+
+If you're using a WordPress-specific Composer setup (e.g. [Bedrock](https://roots.io/bedrock/)), the autoloader is usually already loaded for you.
+
+## Upgrading to 1.x
+
+Version 1.0 introduces several breaking changes. If you're upgrading from 0.x, read through the following sections to make sure your code is compatible.
+
+### PHP 8.2+ required
+
+Routes now requires PHP 8.2 or higher.
+
+### Singleton — no direct instantiation
+
+The class is now a singleton. You can no longer instantiate it directly:
+
+```php
+// Before (0.x) — no longer works
+$routes = new Routes();
+
+// After (1.x)
+$instance = Routes::get_instance();
+```
+
+In practice most applications never instantiated `Routes` directly, so this is unlikely to affect you.
+
+### No more global `$upstatement_routes`
+
+The global variable `$upstatement_routes` used internally in 0.x has been removed. If your code accessed called `$upstatement_routes->match_current_request()` directly, update it:
+
+```php
+// Before (0.x)
+global $upstatement_routes;
+$upstatement_routes->match_current_request();
+
+// After (1.x)
+Routes::get_instance()->match_current_request();
+```
+
+### New `add_match_types()` method
+
+Custom AltoRouter match types can now be registered via `Routes::add_match_types()` and may be called before or after `Routes::map()`:
+
+```php
+Routes::add_match_types(['hex' => '[0-9A-Fa-f]+']);
+Routes::map('color/[hex:color]', function($params) {
+    // $params['color'] is guaranteed to be a hex string
+});
+```
+
+### Class is no longer auto-instantiated on include
+
+In 0.x, including `Routes.php` immediately instantiated the class and registered WordPress hooks. In 1.x, the singleton is created lazily on the first call to `Routes::map()` or `Routes::add_match_types()`. No action is required as long as you call `Routes::map()` before `wp_loaded` fires, which is the standard usage pattern.
+
+### Base path handling for subdirectory installs
+
+**⚠️ Potential breaking change for WordPress subdirectory installations**
+
+In 0.x, the base path logic was route-dependent and would detect if you included the subdirectory in your route pattern. In 1.x, the base path is always calculated from your site URL regardless of your route patterns.
+
+If your WordPress site is installed in a subdirectory (e.g., `https://example.com/blog/`) and your routes **included** that subdirectory in the pattern, those routes will break in 1.x.
+
+**Example of code that will break:**
+
+```php
+// Site URL: https://example.com/blog/
+// WordPress installed in /blog/ subdirectory
+
+// This route WILL BREAK in 1.x:
+Routes::map('blog/my-page', function($params) {
+    // This won't match anymore because AltoRouter strips /blog/
+    // and then tries to match the remainder against 'blog/my-page'
+});
+```
+
+**How to fix it:**
+
+Simply remove the subdirectory prefix from your route patterns:
+
+```php
+// Site URL: https://example.com/blog/
+// WordPress installed in /blog/ subdirectory
+
+// ✅ Correct way to define routes in 1.x:
+Routes::map('my-page', function($params) {
+    // This will correctly match https://example.com/blog/my-page
+});
+
+Routes::map('my-users/:userid/edit', function($params) {
+    // This will correctly match https://example.com/blog/my-users/123/edit
+});
+```
+
+**Note:** If your site is **not** in a subdirectory, or if your routes never included the subdirectory prefix, this change does not affect you.
+
 ### Basic Usage
 
 ```php
@@ -127,3 +234,27 @@ The query you want to use, it can accept a string or array just like `Timber::ge
 
 `$status_code`
 Send an optional status code. Defaults to 200 for 'Success/OK'
+
+## add_match_types
+
+This method makes it possible to add custom match types in Routes.
+
+```php
+<?php
+/* functions.php */
+
+Routes::add_match_types([
+	'oldID' => '@[0-9]++',
+]);
+
+Routes::map(
+	'[oldID:id]/[:slug]',
+	function ($params) {
+		$old_id = $params['id'];
+		$slug = $params['slug'];
+
+		/* the rest as normal... */
+		Timber::render('single.php', $context);
+	}
+);
+```
diff --git a/Routes.php b/Routes.php
index aaed4e0..151e1f8 100755
--- a/Routes.php
+++ b/Routes.php
@@ -1,43 +1,70 @@
 <?php
 
 /**
- * Plugin Name:                 Routes
- * Plugin URI:                  http://www.upstatement.com
- * Description:                 Routes makes it easy to add custom routing to your WordPress site. That's why we call it Routes. That is all.
- * Author:                      Jared Novack + Upstatement
- * Author URI:                  http://www.upstatement.com
- * Text Domain:                 routes
- * Version:                     0.9.2
- */
-
-/**
+ * Routes makes it easy to add custom routing to your WordPress site. That's why we call it Routes. That is all.
+ * 
  * The Routes class is responsible for defining the routing functionality of the plugin.
  * It uses the AltoRouter library to match the current request to the defined routes,
  * and to call the appropriate callback function when a route is matched.
  * It also provides a method for loading a template file and sending data to it, which can be used in the callback functions for the routes defined with the map() method.
- *
- * @package Routes
  */
 class Routes
 {
+    /**
+     * The singleton instance of the Routes class.
+     */
+    private static ?self $instance = null;
+
+    /**
+     * The version of the library.
+     */
+    public static $version = '1.0.0'; // x-release-please-version
     /**
      * The AltoRouter instance used to match the current request to the defined routes.
-     *
-     * @var AltoRouter
      */
-    protected $router;
+    protected ?AltoRouter $router = null;
 
     /**
-     * Constructor.
+     * Private constructor to enforce the singleton pattern.
      *
      * Adds the match_current_request function to the init and wp_loaded hooks,
      * which will check if the current request matches any of the routes defined in this plugin,
      * and if so, will call the appropriate callback function.
      */
-    public function __construct()
+    private function __construct()
+    {
+        add_action('init', [$this, 'match_current_request']);
+        add_action('wp_loaded', [$this, 'match_current_request']);
+    }
+
+    /**
+     * Returns the singleton instance, creating it if it does not yet exist.
+     */
+    public static function get_instance(): self
+    {
+        if (null === self::$instance) {
+            self::$instance = new self();
+        }
+
+        return self::$instance;
+    }
+
+    /**
+     * Initializes the AltoRouter instance if it has not been created yet.
+     * Called lazily by map() and add_match_types().
+     */
+    private function ensure_router(): void
     {
-        add_action('init', [self::class, 'match_current_request']);
-        add_action('wp_loaded', [self::class, 'match_current_request']);
+        if (null !== $this->router) {
+            return;
+        }
+        $this->router = new AltoRouter();
+        $site_url = get_bloginfo('url');
+        $site_url_parts = explode('/', $site_url);
+        $site_url_parts = array_slice($site_url_parts, 3);
+        $base_path = implode('/', $site_url_parts);
+        $base_path = $base_path ? '/' . trim($base_path, '/') . '/' : '/';
+        $this->router->setBasePath($base_path);
     }
 
     /**
@@ -46,34 +73,48 @@ public function __construct()
      *
      * @internal
      */
-    public static function match_current_request()
+    public function match_current_request()
     {
-        global $upstatement_routes;
-        if (isset($upstatement_routes->router)) {
-            $route = $upstatement_routes->router->match();
+        if (null == $this->router) {
+            return;
+        }
 
-            unset($upstatement_routes->router);
+        $route = $this->router->match();
+        $this->router = null;
 
-            if ($route && isset($route['target'])) {
-                if (isset($route['params'])) {
-                    call_user_func($route['target'], $route['params']);
-                } else {
-                    call_user_func($route['target']);
-                }
-            }
+        if ($route && isset($route['target'])) {
+            call_user_func($route['target'], ...array_filter([$route['params'] ?? null]));
         }
     }
 
+    /**
+     * Wrapper for AltoRouter's addMatchTypes function. See AltoRouter documentation for more details.
+     *
+     * @api
+     *
+     * @link https://dannyvankooten.github.io/AltoRouter/usage/mapping-routes.html
+     *
+     * @param array $match_types An array of custom match types to add to AltoRouter.
+     *                           Keys are type names and values are regex patterns.
+     *                           ex: Routes::add_match_types(['hex' => '[0-9A-Fa-f]+']);
+     */
+    public static function add_match_types($match_types)
+    {
+        $instance = self::get_instance();
+        $instance->ensure_router();
+        $instance->router->addMatchTypes($match_types);
+    }
+
     /**
      * Maps a route to a callback function.
      *
      * @api
-     * @param string   $route         A string to match (ex: 'myfoo').
-     * @param callable $callback    A callback function to call when the route is matched.
-     *                                    This can be a string for a function name,
-     *                              an array for a class method, or an anonymous function.
-     * @param string   $name        An optional name for the route, which can be used to generate URLs with the url() method.
-     * @return void
+     *
+     * @param string   $route    a string to match (ex: 'myfoo')
+     * @param callable $callback A callback function to call when the route is matched.
+     *                           This can be a string for a function name,
+     *                           an array for a class method, or an anonymous function.
+     * @param string   $name     an optional name for the route, which can be used to generate URLs with the url() method
      *
      * @example
      * ```php
@@ -86,38 +127,25 @@ public static function match_current_request()
      */
     public static function map($route, $callback, $name = '')
     {
-        global $upstatement_routes;
-        if (!isset($upstatement_routes->router)) {
-            $upstatement_routes->router = new AltoRouter();
-            $site_url = get_bloginfo('url');
-            $site_url_parts = explode('/', $site_url);
-            $site_url_parts = array_slice($site_url_parts, 3);
-            $base_path = implode('/', $site_url_parts);
-            if (!$base_path || str_starts_with($route, $base_path)) {
-                $base_path = '/';
-            } else {
-                $base_path = '/' . $base_path . '/';
-            }
-            // Clean any double slashes that have resulted
-            $base_path = str_replace('//', '/', $base_path);
-            $upstatement_routes->router->setBasePath($base_path);
-        }
+        $instance = self::get_instance();
+        $instance->ensure_router();
         $route = self::convert_route($route);
-        $upstatement_routes->router->map('GET|POST|PUT|DELETE|HEAD', trailingslashit($route), $callback, $name);
-        $upstatement_routes->router->map('GET|POST|PUT|DELETE|HEAD', untrailingslashit($route), $callback, $name);
+        $instance->router->map('GET|POST|PUT|DELETE|HEAD', trailingslashit($route), $callback, $name);
+        $instance->router->map('GET|POST|PUT|DELETE|HEAD', untrailingslashit($route), $callback, $name);
     }
 
     /**
-     *
      * Used internally to convert a route string with :param style parameters
      * to the format used by AltoRouter, which is [:param].
      * If the route string already contains [ and ] characters,
      * it is assumed to be in the correct format and is returned unchanged.
      *
      * @internal
-     * @param string $route_string A route string with :param style parameters (ex: 'myfoo/:my_param').
-     * @return string                   A string in a format for AltoRouter
-     *                                  ex: [:my_param]
+     *
+     * @param string $route_string a route string with :param style parameters (ex: 'myfoo/:my_param')
+     *
+     * @return string A string in a format for AltoRouter
+     *                ex: [:my_param]
      */
     public static function convert_route($route_string)
     {
@@ -132,6 +160,7 @@ public static function convert_route($route_string)
         if (str_starts_with($route_string, '/')) {
             $route_string = substr($route_string, 1);
         }
+
         return $route_string;
     }
 
@@ -162,8 +191,8 @@ public static function load($template, $tparams = false, $query = false, $status
                 'status_header',
                 function ($status_header, $header, $text, $protocol) use ($status_code) {
                     $text = get_status_header_desc($status_code);
-                    $header_string = "$protocol $status_code $text";
-                    return $header_string;
+
+                    return "{$protocol} {$status_code} {$text}";
                 },
                 10,
                 4
@@ -216,18 +245,10 @@ function () use ($query) {
                 fn($current_template) => $template,
                 $priority
             );
+
             return true;
         }
+
         return false;
     }
 }
-
-global $upstatement_routes;
-$upstatement_routes = new Routes();
-
-if (
-    file_exists($composer_autoload = __DIR__ . '/vendor/autoload.php')
-    || file_exists($composer_autoload = WP_CONTENT_DIR . '/vendor/autoload.php')
-) {
-    require_once $composer_autoload;
-}
diff --git a/tests/RoutesTest.php b/tests/RoutesTest.php
index b552cae..917b33c 100644
--- a/tests/RoutesTest.php
+++ b/tests/RoutesTest.php
@@ -2,41 +2,45 @@
 
 use Mantle\Testkit\Integration_Test_Case;
 
+/**
+ * @internal
+ *
+ * @coversNothing
+ */
 class RoutesTest extends Integration_Test_Case
 {
-
-	function testThemeRoute()
+	public function testThemeRoute()
 	{
 		$template = Routes::load(__DIR__ . '/Supports/single.php');
 		$this->assertTrue($template);
 	}
 
-	function testThemeRouteDoesntExist()
+	public function testThemeRouteDoesntExist()
 	{
 		$template = Routes::load('singlefoo.php');
 		$this->assertFalse($template);
 	}
 
-	function testFullPathRoute()
+	public function testFullPathRoute()
 	{
 		$hello = WP_CONTENT_DIR . '/plugins/hello.php';
 		$template = Routes::load($hello);
 		$this->assertTrue($template);
 	}
 
-	function testFullPathRouteDoesntExist()
+	public function testFullPathRouteDoesntExist()
 	{
 		$hello = WP_CONTENT_DIR . '/plugins/hello-foo.php';
 		$template = Routes::load($hello);
 		$this->assertFalse($template);
 	}
 
-	function testRouterClass()
+	public function testRouterClass()
 	{
 		$this->assertTrue(class_exists('AltoRouter'));
 	}
 
-	function testAppliedRoute()
+	public function testAppliedRoute()
 	{
 		$_SERVER['REQUEST_METHOD'] = 'GET';
 		global $matches;
@@ -56,7 +60,7 @@ function () use ($phpunit) {
 		$this->assertEquals(1, count($matches));
 	}
 
-	function testRouteWithVariable()
+	public function testRouteWithVariable()
 	{
 		$post_name = 'ziggy';
 		$post = $this->factory->post->create(
@@ -70,7 +74,7 @@ function testRouteWithVariable()
 		$phpunit = $this;
 		Routes::map(
 			'mything/:slug',
-			function ($params) use ($phpunit) {
+			function ($params) {
 				global $matches;
 				$matches = [];
 				if ('ziggy' == $params['slug']) {
@@ -83,7 +87,7 @@ function ($params) use ($phpunit) {
 		$this->assertEquals(1, count($matches));
 	}
 
-	function testRouteWithAltoVariable()
+	public function testRouteWithAltoVariable()
 	{
 		$post_name = 'ziggy';
 		$post = $this->factory->post->create(
@@ -97,7 +101,7 @@ function testRouteWithAltoVariable()
 		$phpunit = $this;
 		Routes::map(
 			'mything/[*:slug]',
-			function ($params) use ($phpunit) {
+			function ($params) {
 				global $matches;
 				$matches = [];
 				if ('ziggy' == $params['slug']) {
@@ -110,18 +114,18 @@ function ($params) use ($phpunit) {
 		$this->assertEquals(1, count($matches));
 	}
 
-	function testRouteWithMultiArguments()
+	public function testRouteWithMultiArguments()
 	{
 		$phpunit = $this;
 		Routes::map(
 			'artist/[:artist]/song/[:song]',
-			function ($params) use ($phpunit) {
+			function ($params) {
 				global $matches;
 				$matches = [];
-				if ($params['artist'] == 'smashing-pumpkins') {
+				if ('smashing-pumpkins' == $params['artist']) {
 					$matches[] = true;
 				}
-				if ($params['song'] == 'mayonaise') {
+				if ('mayonaise' == $params['song']) {
 					$matches[] = true;
 				}
 			}
@@ -132,19 +136,19 @@ function ($params) use ($phpunit) {
 		$this->assertEquals(2, count($matches));
 	}
 
-	function testRouteWithMultiArgumentsOldStyle()
+	public function testRouteWithMultiArgumentsOldStyle()
 	{
 		$phpunit = $this;
 		global $matches;
 		Routes::map(
 			'studio/:studio/movie/:movie',
-			function ($params) use ($phpunit) {
+			function ($params) {
 				global $matches;
 				$matches = [];
-				if ($params['studio'] == 'universal') {
+				if ('universal' == $params['studio']) {
 					$matches[] = true;
 				}
-				if ($params['movie'] == 'brazil') {
+				if ('brazil' == $params['movie']) {
 					$matches[] = true;
 				}
 			}
@@ -154,7 +158,7 @@ function ($params) use ($phpunit) {
 		$this->assertEquals(2, count($matches));
 	}
 
-	function testRouteAgainstPostName()
+	public function testRouteAgainstPostName()
 	{
 		$post_name = 'jared';
 		$post = $this->factory->post->create(
@@ -180,7 +184,7 @@ function () use ($phpunit) {
 		$this->assertEquals(1, count($matches));
 	}
 
-	function testVerySimpleRoute()
+	public function testVerySimpleRoute()
 	{
 		$_SERVER['REQUEST_METHOD'] = 'GET';
 		global $matches;
@@ -188,7 +192,7 @@ function testVerySimpleRoute()
 		$phpunit = $this;
 		Routes::map(
 			'crackers',
-			function () use ($phpunit) {
+			function () {
 				global $matches;
 				$matches = [];
 				$matches[] = true;
@@ -199,7 +203,7 @@ function () use ($phpunit) {
 		$this->assertEquals(1, count($matches));
 	}
 
-	function testVerySimpleRouteTrailingSlash()
+	public function testVerySimpleRouteTrailingSlash()
 	{
 		$_SERVER['REQUEST_METHOD'] = 'GET';
 		global $matches;
@@ -207,7 +211,7 @@ function testVerySimpleRouteTrailingSlash()
 		$phpunit = $this;
 		Routes::map(
 			'bip/',
-			function () use ($phpunit) {
+			function () {
 				global $matches;
 				$matches = [];
 				$matches[] = true;
@@ -218,7 +222,7 @@ function () use ($phpunit) {
 		$this->assertEquals(1, count($matches));
 	}
 
-	function testVerySimpleRouteTrailingSlashInRequest()
+	public function testVerySimpleRouteTrailingSlashInRequest()
 	{
 		$_SERVER['REQUEST_METHOD'] = 'GET';
 		global $matches;
@@ -226,7 +230,7 @@ function testVerySimpleRouteTrailingSlashInRequest()
 		$phpunit = $this;
 		Routes::map(
 			'bopp',
-			function () use ($phpunit) {
+			function () {
 				global $matches;
 				$matches = [];
 				$matches[] = true;
@@ -237,8 +241,7 @@ function () use ($phpunit) {
 		$this->assertEquals(1, count($matches));
 	}
 
-
-	function testVerySimpleRouteTrailingSlashInRequestAndMapping()
+	public function testVerySimpleRouteTrailingSlashInRequestAndMapping()
 	{
 		$_SERVER['REQUEST_METHOD'] = 'GET';
 		global $matches;
@@ -246,7 +249,7 @@ function testVerySimpleRouteTrailingSlashInRequestAndMapping()
 		$phpunit = $this;
 		Routes::map(
 			'zappers',
-			function () use ($phpunit) {
+			function () {
 				global $matches;
 				$matches = [];
 				$matches[] = true;
@@ -265,7 +268,7 @@ function testVerySimpleRoutePrecedingSlash()
 		$phpunit = $this;
 		Routes::map(
 			'/gobbles',
-			function () use ($phpunit) {
+			function () {
 				global $matches;
 				$matches = [];
 				$matches[] = true;
@@ -276,7 +279,7 @@ function () use ($phpunit) {
 		$this->assertEquals(1, count($matches));
 	}
 
-	function testFailedRoute()
+	public function testFailedRoute()
 	{
 		$_SERVER['REQUEST_METHOD'] = 'GET';
 		global $matches;
@@ -295,7 +298,7 @@ function () use ($phpunit) {
 		$this->assertEquals(0, count($matches));
 	}
 
-	function testRouteWithClassCallback()
+	public function testRouteWithClassCallback()
 	{
 		Routes::map('classroute', ['RoutesTest', '_testCallback']);
 		$this->get(home_url('classroute'));
@@ -304,13 +307,55 @@ function testRouteWithClassCallback()
 		$this->assertEquals(1, count($matches_class_test));
 	}
 
-	function matchRoutes()
+	public function testAddMatchTypes()
+	{
+		$_SERVER['REQUEST_METHOD'] = 'GET';
+		global $matches;
+		$matches = [];
+		Routes::add_match_types(['hex' => '[0-9A-Fa-f]+']);
+		Routes::map(
+			'color/[hex:color]',
+			function ($params) {
+				global $matches;
+				$matches = [];
+				if ('ff5733' === $params['color']) {
+					$matches[] = true;
+				}
+			}
+		);
+		$this->get(home_url('/color/ff5733'));
+		$this->matchRoutes();
+		$this->assertEquals(1, count($matches));
+	}
+
+	public function testAddMatchTypesBeforeMap()
+	{
+		$_SERVER['REQUEST_METHOD'] = 'GET';
+		global $matches;
+		$matches = [];
+		// Calling add_match_types before map() should still work
+		Routes::add_match_types(['word' => '\w+']);
+		Routes::map(
+			'tag/[word:name]',
+			function ($params) {
+				global $matches;
+				$matches = [];
+				if ('hello' === $params['name']) {
+					$matches[] = true;
+				}
+			}
+		);
+		$this->get(home_url('/tag/hello'));
+		$this->matchRoutes();
+		$this->assertEquals(1, count($matches));
+	}
+
+	public function matchRoutes()
 	{
-		global $upstatement_routes;
-		$upstatement_routes->match_current_request();
+		Routes::get_instance()->match_current_request();
 	}
 
-	static function _testCallback()
+	public static function _testCallback()
 	{
 		global $matches_class_test;
 		$matches_class_test = [];