diff --git a/public/class-peptide-news-public.php b/public/class-peptide-news-public.php
new file mode 100644
index 0000000..275af3a
--- /dev/null
+++ b/public/class-peptide-news-public.php
@@ -0,0 +1,333 @@
+<?php
+/**
+ * Public-facing functionality.
+ *
+ * Registers the [peptide_news] shortcode, the sidebar widget,
+ * and handles AJAX click tracking.
+ *
+ * @since 1.0.0
+ */
+class Peptide_News_Public {
+
+    /** @var string */
+    private $plugin_name;
+
+    /** @var string */
+    private $version;
+
+    public function __construct( $plugin_name, $version ) {
+        $this->plugin_name = $plugin_name;
+        $this->version     = $version;
+    }
+
+    /**
+     * Register front-end CSS (enqueued on demand by the shortcode/widget).
+     */
+    public function enqueue_styles() {
+        wp_register_style(
+            $this->plugin_name,
+            PEPTIDE_NEWS_PLUGIN_URL . 'public/css/public-style.css',
+            array(),
+            $this->version,
+            'all'
+        );
+    }
+
+    /**
+     * Register front-end JS (enqueued on demand by the shortcode/widget).
+     */
+    public function enqueue_scripts() {
+        wp_register_script(
+            $this->plugin_name,
+            PEPTIDE_NEWS_PLUGIN_URL . 'public/js/public-script.js',
+            array( 'jquery' ),
+            $this->version,
+            true
+        );
+
+        wp_localize_script( $this->plugin_name, 'peptideNewsPublic', array(
+            'ajax_url'   => admin_url( 'admin-ajax.php' ),
+            'nonce'      => wp_create_nonce( 'peptide_news_track' ),
+            'session_id' => $this->get_or_create_session_id(),
+        ) );
+    }
+
+    /**
+     * Register the shortcode.
+     */
+    public function register_shortcode() {
+        add_shortcode( 'peptide_news', array( $this, 'render_shortcode' ) );
+    }
+
+    /**
+     * Register the widget.
+     */
+    public function register_widget() {
+        register_widget( 'Peptide_News_Widget' );
+    }
+
+    /**
+     * Render the [peptide_news] shortcode.
+     *
+     * @param array $atts Shortcode attributes.
+     * @return string HTML output.
+     */
+    public function render_shortcode( $atts ) {
+        $atts = shortcode_atts( array(
+            'count'  => get_option( 'peptide_news_articles_count', 10 ),
+            'layout' => 'card', // card | compact | list
+        ), $atts, 'peptide_news' );
+
+        $articles = $this->get_articles( absint( $atts['count'] ) );
+
+        if ( empty( $articles ) ) {
+            return '<div class="pn-no-articles"><p>' . esc_html__( 'No peptide news articles available yet. Check back soon!', 'peptide-news' ) . '</p></div>';
+        }
+
+        // Enqueue assets only when the shortcode is actually rendered.
+        wp_enqueue_style( $this->plugin_name );
+        wp_enqueue_script( $this->plugin_name );
+
+        $fallback_thumb = get_option( 'peptide_news_thumbnail_fallback', '' );
+        $layout         = sanitize_key( $atts['layout'] );
+
+        ob_start();
+        ?>
+        <div class="pn-news-feed pn-layout-<?php echo esc_attr( $layout ); ?>">
+            <?php foreach ( $articles as $article ) :
+                $thumb = ! empty( $article->thumbnail_url ) ? $article->thumbnail_url : $fallback_thumb;
+                $date  = wp_date( 'M j, Y', strtotime( $article->published_at ) );
+            ?>
+                <article class="pn-article" data-article-id="<?php echo esc_attr( $article->id ); ?>">
+                    <?php if ( ! empty( $thumb ) ) : ?>
+                        <div class="pn-article-thumb">
+                            <a href="<?php echo esc_url( $article->source_url ); ?>"
+                               class="pn-track-click"
+                               data-article-id="<?php echo esc_attr( $article->id ); ?>"
+                               target="_blank" rel="noopener noreferrer">
+                                <img src="<?php echo esc_url( $thumb ); ?>"
+                                     alt="<?php echo esc_attr( $article->title ); ?>"
+                                     loading="lazy" />
+                            </a>
+                        </div>
+                    <?php endif; ?>
+
+                    <div class="pn-article-content">
+                        <div class="pn-article-meta">
+                            <span class="pn-source"><?php echo esc_html( $article->source ); ?></span>
+                            <span class="pn-separator">&middot;</span>
+                            <time class="pn-date" datetime="<?php echo esc_attr( $article->published_at ); ?>">
+                                <?php echo esc_html( $date ); ?>
+                            </time>
+                        </div>
+
+                        <h3 class="pn-article-title">
+                            <a href="<?php echo esc_url( $article->source_url ); ?>"
+                               class="pn-track-click"
+                               data-article-id="<?php echo esc_attr( $article->id ); ?>"
+                               target="_blank" rel="noopener noreferrer">
+                                <?php echo esc_html( $article->title ); ?>
+                            </a>
+                        </h3>
+
+                        <p class="pn-article-excerpt">
+                            <?php echo esc_html( $article->excerpt ); ?>
+                        </p>
+
+                        <?php if ( ! empty( $article->author ) ) : ?>
+                            <span class="pn-author">
+                                <?php echo esc_html( $article->author ); ?>
+                            </span>
+                        <?php endif; ?>
+
+                        <?php if ( ! empty( $article->categories ) ) : ?>
+                            <div class="pn-tags">
+                                <?php
+                                $cats = array_map( 'trim', explode( ',', $article->categories ) );
+                                foreach ( array_slice( $cats, 0, 3 ) as $cat ) :
+                                    if ( empty( $cat ) ) continue;
+                                ?>
+                                    <span class="pn-tag"><?php echo esc_html( $cat ); ?></span>
+                                <?php endforeach; ?>
+                            </div>
+                        <?php endif; ?>
+                    </div>
+                </article>
+            <?php endforeach; ?>
+        </div>
+        <?php
+        return ob_get_clean();
+    }
+
+    /**
+     * Handle AJAX click tracking with basic rate limiting.
+     */
+    public function handle_click_tracking() {
+        check_ajax_referer( 'peptide_news_track', 'nonce' );
+
+        $article_id = isset( $_POST['article_id'] ) ? absint( $_POST['article_id'] ) : 0;
+
+        if ( ! $article_id ) {
+            wp_send_json_error( 'Invalid article ID.' );
+        }
+
+        // Rate limit: max 1 click per article per session per 5 seconds.
+        $session_id   = isset( $_POST['session_id'] ) ? sanitize_text_field( wp_unslash( $_POST['session_id'] ) ) : '';
+        $throttle_key = 'pn_click_' . md5( $session_id . '_' . $article_id );
+
+        if ( get_transient( $throttle_key ) ) {
+            wp_send_json_success( array( 'throttled' => true ) );
+        }
+        set_transient( $throttle_key, 1, 5 );
+
+        $meta = array(
+            'ip'         => '',
+            'user_agent' => isset( $_SERVER['HTTP_USER_AGENT'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) ) : '',
+            'referrer'   => isset( $_POST['referrer'] ) ? esc_url_raw( wp_unslash( $_POST['referrer'] ) ) : '',
+            'page_url'   => isset( $_POST['page_url'] ) ? esc_url_raw( wp_unslash( $_POST['page_url'] ) ) : '',
+            'session_id' => $session_id,
+        );
+
+        $result = Peptide_News_Analytics::record_click( $article_id, $meta );
+
+        if ( $result ) {
+            wp_send_json_success();
+        } else {
+            wp_send_json_error( 'Failed to record click.' );
+        }
+    }
+
+    /**
+     * Get active articles from the database.
+     *
+     * @param int $count Number of articles.
+     * @return array
+     */
+    private function get_articles( $count ) {
+        global $wpdb;
+
+        $table = $wpdb->prefix . 'peptide_news_articles';
+
+        // Use transient cache to avoid DB hits on every page load.
+        $cache_key = 'peptide_news_articles_' . $count;
+        $cached    = get_transient( $cache_key );
+
+        if ( false !== $cached ) {
+            return $cached;
+        }
+
+        $articles = $wpdb->get_results( $wpdb->prepare(
+            "SELECT id, source, source_url, title, excerpt, author, thumbnail_url,
+                   published_at, categories
+             FROM {$table}
+             WHERE is_active = 1
+             ORDER BY published_at DESC
+             LIMIT %d",
+             $count
+        ) );
+
+        // Cache for 5 minutes.
+        set_transient( $cache_key, $articles, 5 * MINUTE_IN_SECONDS );
+
+        return $articles;
+    }
+
+    /**
+     * Generate or retrieve a session ID for visitor tracking.
+     *
+     * Sets the cookie in PHP if it doesn't exist so the value
+     * is consistent between the server-side localized script data
+     * and the client-side cookie.
+     *
+     * @return string
+     */
+    private function get_or_create_session_id() {
+        if ( isset( $_COOKIE['pn_session_id'] ) ) {
+            return sanitize_text_field( wp_unslash( $_COOKIE['pn_session_id'] ) );
+        }
+
+        $session_id = wp_generate_uuid4();
+
+        // Set a 30-minute session cookie (matches JS-side behaviour).
+        if ( ! headers_sent() ) {
+            setcookie(
+                'pn_session_id',
+                $session_id,
+                array(
+                    'expires'  => time() + 1800,
+                    'path'     => '/',
+                    'secure'   => is_ssl(),
+                    'httponly' => false,   // JS needs read access for sendBeacon.
+                    'samesite' => 'Lax',
+                )
+            );
+        }
+
+        return $session_id;
+    }
+}
+
+/**
+ * Peptide News Widget.
+ *
+ * @since 1.0.0
+ */
+class Peptide_News_Widget extends WP_Widget {
+
+    public function __construct() {
+        parent::__construct(
+            'peptide_news_widget',
+            __( 'Peptide News', 'peptide-news' ),
+            array(
+                'description' => __( 'Displays the latest peptide research news.', 'peptide-news' ),
+                'classname'   => 'peptide-news-widget',
+            )
+        );
+    }
+
+    public function widget( $args, $instance ) {
+        $title = apply_filters( 'widget_title', $instance['title'] ?? __( 'Peptide News', 'peptide-news' ) );
+        $count = isset( $instance['count'] ) ? absint( $instance['count'] ) : 5;
+
+        echo $args['before_widget'];
+        
+        if ( $title ) {
+            echo $args['before_title'] . esc_html( $title ) . $args['after_title'];
+        }
+
+        $public = new Peptide_News_Public( 'peptide-news', PEPTIDE_NEWS_VERSION );
+        echo $public->render_shortcode( array( 'count' => $count, 'layout' => 'compact' ) );
+
+        echo $args['after_widget'];
+    }
+
+    public function form( $instance ) {
+        $title = isset( $instance['title'] ) ? $instance['title'] : __( 'Peptide News', 'peptide-news' );
+        $count = isset( $instance['count'] ) ? absint( $instance['count'] ) : 5;
+        ?>
+        <p>
+            <label for="<?php echo esc_attr( $this->get_field_id( 'title' ) ); ?>">
+                <?php esc_html_e( 'Title:', 'peptide-news' ); ?>
+            </label>
+            <input class="widefat" id="<?php echo esc_attr( $this->get_field_id( 'title' ) ); ?>"
+                   name="<?php echo esc_attr( $this->get_field_name( 'title' ) ); ?>"
+                   type="text" value="<?php echo esc_attr( $title ); ?>" />
+        </p>
+        <p>
+            <label for="<?php echo esc_attr( $this->get_field_id( 'count' ) ); ?>">
+                <?php esc_html_e( 'Number of articles:'', 'peptide-news' ); ?>
+            </label>
+            <input class="tiny-text" id="<?php echo esc_attr( $this->get_field_id( 'count' ) ); ?>"
+                   name="<?php echo esc_attr( $this->get_field_name( 'count' ) ); ?>"
+                   type="number" min="1" max="50" value="<?php echo esc_attr( $count ); ?>" />
+        </p>
+        <?php
+    }
+
+    public function update( $new_instance, $old_instance ) {
+        $instance          = array();
+        $instance['title'] = sanitize_text_field( $new_instance['title'] ?? '' );
+        $instance['count'] = absint( $new_instance['count'] ?? 5 );
+        return $instance;
+    }
+}