diff --git a/hubzilla/addon/scn01/config.json.template b/hubzilla/addon/scn01/config.json.template
new file mode 100644
index 0000000..328897e
--- /dev/null
+++ b/hubzilla/addon/scn01/config.json.template
@@ -0,0 +1,6 @@
+{
+  "_note": "Copy to config.json. Do not commit config.json — it contains secrets and installation-specific values.",
+  "corpus_builder_group_id": 0,
+  "listings_file": "REPLACE — absolute path to listings.json on the host",
+  "directory_default_tab": "core"
+}
diff --git a/hubzilla/addon/scn01/mod_scn01.pdl b/hubzilla/addon/scn01/mod_scn01.pdl
new file mode 100644
index 0000000..28f1924
--- /dev/null
+++ b/hubzilla/addon/scn01/mod_scn01.pdl
@@ -0,0 +1,14 @@
+[template]default[/template]
+
+[region=aside]
+[widget=scn01][/widget]
+[/region]
+
+[region=content]
+$content
+[/region]
+
+[region=right_aside]
+[widget=notifications][/widget]
+[widget=newmember][/widget]
+[/region]
diff --git a/hubzilla/addon/scn01/scn01.apd b/hubzilla/addon/scn01/scn01.apd
new file mode 100644
index 0000000..ca43bc0
--- /dev/null
+++ b/hubzilla/addon/scn01/scn01.apd
@@ -0,0 +1,7 @@
+version: 2
+url: $baseurl/scn01
+requires: local_channel
+name: Scenarios
+photo: icon:person-lines-fill
+categories: Civic Diagnostics
+desc: Participant intake — browse diagnostic scenarios, submit your account in your own words.
diff --git a/hubzilla/addon/scn01/scn01.php b/hubzilla/addon/scn01/scn01.php
new file mode 100644
index 0000000..06ae1d5
--- /dev/null
+++ b/hubzilla/addon/scn01/scn01.php
@@ -0,0 +1,155 @@
+<?php
+
+/**
+ * Name: SCN01 Vital Signs
+ * Description: Public civic diagnostic — the ten structural preconditions of an HOA association.
+ * Version: 0.1.0
+ * MinVersion: 11.0
+ * MaxVersion: 12.0
+ */
+
+use Zotlabs\Extend\Widget;
+
+function scn01_module() {}
+
+function scn01_load() {
+    register_hook('load_pdl', 'addon/scn01/scn01.php', 'scn01_load_pdl');
+    Widget::register('addon/scn01/Widget/Scn01.php', 'scn01');
+}
+
+function scn01_unload() {
+    unregister_hook('load_pdl', 'addon/scn01/scn01.php', 'scn01_load_pdl');
+    Widget::unregister('addon/scn01/Widget/Scn01.php', 'scn01');
+}
+
+function scn01_load_pdl(&$b) {
+    if (!is_array($b) || empty($b['module']) || $b['module'] !== 'scn01') {
+        return;
+    }
+    $layout = @file_get_contents('addon/scn01/mod_scn01.pdl');
+    if ($layout !== false) {
+        $b['layout'] = $layout;
+    }
+}
+
+// ----------------------------------------------------------------------------
+// HELPERS
+// ----------------------------------------------------------------------------
+
+function scn01_h($value) {
+    return htmlspecialchars((string) $value, ENT_QUOTES, 'UTF-8');
+}
+
+// ----------------------------------------------------------------------------
+// ACCESS
+// ----------------------------------------------------------------------------
+
+function scn01_access_state() {
+    if (!local_channel()) {
+        return 'public';
+    }
+
+    $channel = App::get_channel();
+
+    if (local_channel() === intval($channel['channel_id'])) {
+        return 'operator';
+    }
+
+    $config = scn01_load_config();
+    $gid    = intval($config['corpus_builder_group_id'] ?? 0);
+
+    if ($gid && in_array(get_observer_hash(), group_get_members_xchan($gid))) {
+        return 'participant';
+    }
+
+    return 'denied';
+}
+
+function scn01_access_wall() {
+    return '
+        <div class="scn01-content">
+            <div class="alert alert-info" role="alert">
+                <strong>HOA_MEMBER standing required to submit.</strong>
+                Vital Signs are public and readable by anyone.
+                To submit a Vital Signs record for your association, you must complete the SASE process.
+                Visit <a href="https://directory.diagnostics.kane-il.us/channel/theron">
+                    directory.diagnostics.kane-il.us
+                </a> to begin.
+            </div>
+        </div>
+    ';
+}
+
+// ----------------------------------------------------------------------------
+// CONTENT
+// ----------------------------------------------------------------------------
+
+function scn01_content() {
+    if (function_exists('head_add_css')) {
+        head_add_css('/addon/scn01/view/css/scn01.css');
+    }
+    if (function_exists('head_add_js')) {
+        head_add_js('/addon/scn01/view/js/scn01.js');
+    }
+
+    $access = scn01_access_state();
+
+    // scn01 is public — access wall only gates submission, not reading
+    if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+        if ($access === 'public' || $access === 'denied') {
+            return scn01_access_wall();
+        }
+        // TODO: handle POST submission
+        return scn01_access_wall();
+    }
+
+    return scn01_render_main($access);
+}
+
+// ----------------------------------------------------------------------------
+// RENDER
+// ----------------------------------------------------------------------------
+
+function scn01_render_main($access) {
+    $out  = '<div class="scn01-content">';
+    $out .= '<div class="scn01-header mb-3">';
+    $out .= '<h2>Vital Signs</h2>';
+    $out .= '<p class="text-muted">The ten structural preconditions of an HOA association.</p>';
+    $out .= '</div>';
+
+    // TODO: render the ten Vital Signs
+
+    $out .= '<div class="scn01-placeholder text-muted fst-italic">Content forthcoming.</div>';
+    $out .= '</div>';
+
+    return $out;
+}
+
+// ----------------------------------------------------------------------------
+// CONFIG
+// ----------------------------------------------------------------------------
+
+function scn01_load_config() {
+    $path = 'addon/scn01/config.json';
+    $raw  = @file_get_contents($path);
+    if ($raw === false) return [];
+    $data = json_decode($raw, true);
+    return (json_last_error() === JSON_ERROR_NONE) ? $data : [];
+}
+
+// ----------------------------------------------------------------------------
+// CSRF
+// ----------------------------------------------------------------------------
+
+function scn01_csrf_token() {
+    if (empty($_SESSION['scn01_csrf'])) {
+        $_SESSION['scn01_csrf'] = bin2hex(random_bytes(16));
+    }
+    return '<input type="hidden" name="scn01_csrf" value="'
+         . scn01_h($_SESSION['scn01_csrf']) . '">';
+}
+
+function scn01_verify_csrf() {
+    return isset($_POST['scn01_csrf'], $_SESSION['scn01_csrf'])
+        && hash_equals($_SESSION['scn01_csrf'], $_POST['scn01_csrf']);
+}