diff --git a/CHANGELOG.md b/CHANGELOG.md
index ee4b868..c328b00 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,16 @@ All notable changes to Waygate will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.5.0] - 2026-05-24
+
+### Added
+- AI reasoning and selected pattern slugs are now persisted as post meta (`_waygate_reasoning`, `_waygate_patterns`, `_waygate_generated_at`) on every Waygate-generated page
+- "Waygate" meta box on the page editor sidebar — always shows the AI reasoning sentence; shows generation timestamp and ordered pattern slug list when `WP_ENV=development`
+- Success notice in Tools → Waygate now shows the ordered pattern slugs when `WP_ENV=development`
+
+### Documentation
+- `README.md` updated with AI reasoning and developer debug info features; version badge bumped to 0.5.0
+
 ## [0.4.0] - 2026-05-24
 
 ### Added
diff --git a/README.md b/README.md
index 7258f30..6036c76 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 
 Waygate lets you assemble WordPress pages from block patterns — manually or via a natural-language AI prompt powered by the WordPress AI Client (WordPress 7.0+). Works with any block theme; [Elayne](https://github.com/imagewize/elayne) is the primary supported theme.
 
-> **Beta** — v0.4.0. Use on staging/development sites; not yet recommended for production.
+> **Beta** — v0.5.0. Use on staging/development sites; not yet recommended for production.
 
 ---
 
@@ -12,6 +12,8 @@ Waygate lets you assemble WordPress pages from block patterns — manually or vi
 
 - **Pattern catalog** — Browse registered block patterns with slug, title, and categories; filter by category
 - **AI page generation** — Describe the page you want; the AI picks patterns and creates a draft
+- **AI reasoning** — The AI's one-sentence explanation of its pattern choices is shown after generation and persisted as post meta on the created page
+- **Developer debug info** — When `WP_ENV=development`, the page editor sidebar and the generation notice also show the ordered pattern slugs and generation timestamp
 - **Feature detection** — AI form is hidden automatically when no provider supports text generation
 - **Abilities API** — Exposes `elayne/list-patterns` and `elayne/create-page` abilities for WP 7.0+
 - **Multi-provider** — Works with Mistral, Claude, OpenAI, or Gemini via WP AI Client
diff --git a/includes/class-admin.php b/includes/class-admin.php
index c0cc437..5a1f82e 100644
--- a/includes/class-admin.php
+++ b/includes/class-admin.php
@@ -8,6 +8,7 @@ class Admin {
 
 	public static function init(): void {
 		add_action( 'admin_menu', [ self::class, 'register_menu' ] );
+		add_action( 'add_meta_boxes', [ self::class, 'register_meta_box' ] );
 	}
 
 	public static function register_menu(): void {
@@ -230,6 +231,10 @@ private static function status_notices( bool $ai_available, bool $text_gen_suppo
 		<?php
 	}
 
+	private static function is_dev(): bool {
+		return defined( 'WP_ENV' ) && 'development' === WP_ENV;
+	}
+
 	private static function result_notice( array $result ): void {
 		if ( isset( $result['error'] ) ) {
 			echo '<div class="notice notice-error"><p><strong>Error:</strong> ' . esc_html( $result['error'] ) . '</p></div>';
@@ -245,6 +250,11 @@ private static function result_notice( array $result ): void {
 			<p style="margin:0 0 6px;font-size:12px;color:#555">
 				<strong>AI reasoning:</strong> <?php echo esc_html( $result['reasoning'] ); ?>
 			</p>
+			<?php if ( self::is_dev() ) : ?>
+			<p style="margin:0 0 6px;font-size:12px;color:#888">
+				<strong>Patterns (dev):</strong> <?php echo esc_html( implode( ' → ', $result['patterns'] ) ); ?>
+			</p>
+			<?php endif; ?>
 			<p style="margin:0">
 				<a href="<?php echo esc_url( $result['edit_url'] ); ?>" class="button button-primary">Edit page</a>
 				&nbsp;
@@ -253,4 +263,45 @@ private static function result_notice( array $result ): void {
 		</div>
 		<?php
 	}
+
+	public static function register_meta_box(): void {
+		add_meta_box(
+			'waygate-info',
+			'Waygate',
+			[ self::class, 'render_meta_box' ],
+			'page',
+			'side',
+			'low'
+		);
+	}
+
+	public static function render_meta_box( \WP_Post $post ): void {
+		$reasoning = get_post_meta( $post->ID, '_waygate_reasoning', true );
+
+		if ( ! $reasoning ) {
+			echo '<p style="color:#888;margin:0;font-size:12px">Not generated by Waygate.</p>';
+			return;
+		}
+
+		echo '<p style="margin:0 0 8px;font-size:12px"><strong>AI reasoning</strong><br>' . esc_html( $reasoning ) . '</p>';
+
+		if ( self::is_dev() ) {
+			$patterns_json = get_post_meta( $post->ID, '_waygate_patterns', true );
+			$generated_at  = get_post_meta( $post->ID, '_waygate_generated_at', true );
+			$patterns      = $patterns_json ? json_decode( $patterns_json, true ) : [];
+
+			if ( $generated_at ) {
+				echo '<p style="margin:0 0 6px;font-size:11px;color:#888"><strong>Generated:</strong> ' . esc_html( $generated_at ) . '</p>';
+			}
+
+			if ( $patterns ) {
+				echo '<p style="margin:0 0 4px;font-size:11px;color:#888"><strong>Patterns</strong></p>';
+				echo '<ol style="margin:0;padding-left:16px;font-size:11px;color:#555">';
+				foreach ( $patterns as $slug ) {
+					echo '<li><code>' . esc_html( $slug ) . '</code></li>';
+				}
+				echo '</ol>';
+			}
+		}
+	}
 }
diff --git a/includes/class-ai-integration.php b/includes/class-ai-integration.php
index daa5e7e..7353bb4 100644
--- a/includes/class-ai-integration.php
+++ b/includes/class-ai-integration.php
@@ -137,11 +137,17 @@ public static function generate_page( string $description ): array {
 			return [ 'error' => $post_id->get_error_message() ];
 		}
 
+		$reasoning = $data['reasoning'] ?? '';
+
+		update_post_meta( $post_id, '_waygate_reasoning', $reasoning );
+		update_post_meta( $post_id, '_waygate_patterns', wp_json_encode( $data['patterns'] ) );
+		update_post_meta( $post_id, '_waygate_generated_at', current_time( 'mysql' ) );
+
 		return [
 			'title'         => $data['title'] ?? $description,
 			'patterns'      => $data['patterns'],
 			'pattern_count' => count( $data['patterns'] ),
-			'reasoning'     => $data['reasoning'] ?? '',
+			'reasoning'     => $reasoning,
 			'edit_url'      => get_edit_post_link( $post_id, 'raw' ),
 			'view_url'      => get_permalink( $post_id ),
 		];
diff --git a/waygate.php b/waygate.php
index 4b19d09..2bc21c5 100644
--- a/waygate.php
+++ b/waygate.php
@@ -3,7 +3,7 @@
  * Plugin Name: Waygate
  * Plugin URI:  https://github.com/imagewize/waygate
  * Description: AI-powered pattern page builder for the Elayne block theme. Lists registered patterns, creates pages from pattern slugs, and integrates with WordPress AI Client for natural-language page generation.
- * Version:     0.4.0
+ * Version:     0.5.0
  * Author:      Jasper Frumau
  * Author URI:  https://imagewize.com
  * License:     GPL-2.0-or-later
@@ -16,7 +16,7 @@
 
 defined( 'ABSPATH' ) || exit;
 
-define( 'WAYGATE_VERSION', '0.4.0' );
+define( 'WAYGATE_VERSION', '0.5.0' );
 define( 'WAYGATE_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
 define( 'WAYGATE_PLUGIN_URL', plugin_dir_url( __FILE__ ) );