diff --git a/api/index.html b/api/index.html
index 9ec1153..2734b0e 100644
--- a/api/index.html
+++ b/api/index.html
@@ -680,6 +680,6 @@ <h2 id="refusals" data-de="Wenn ein Aufruf abgelehnt wird">When a call is refuse
 <script src="../page.js" defer></script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/api/og.sha b/api/og.sha
index f8378eb..e0e8515 100644
--- a/api/og.sha
+++ b/api/og.sha
@@ -1 +1 @@
-aa92a701a2a5275ab72d26f86d51752097b8a99dff54133dbdac5d08fb2df74e
+15cf3d048d17bfc3e8c1f2ce5badf9de045c84fdbb9df876c9f4f4faf54355e4
diff --git a/billing/index.html b/billing/index.html
index 11611ab..eb6dcc0 100644
--- a/billing/index.html
+++ b/billing/index.html
@@ -452,6 +452,6 @@ <h2 data-de="Wie sich die Rechnung verhält">How the bill behaves</h2>
 <script src="../page.js" defer></script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/billing/og.sha b/billing/og.sha
index bc7b11a..3549357 100644
--- a/billing/og.sha
+++ b/billing/og.sha
@@ -1 +1 @@
-3c3795fd14111de07c07addf48e7794a5407f62cfef6ad2092cacb75b2c97530
+84a89393c6a5a007741f50980bdfd072586f7fef2a90b8308447a7a478a8970d
diff --git a/chat.css b/chat.css
index 29d0689..0d92b48 100644
--- a/chat.css
+++ b/chat.css
@@ -309,7 +309,8 @@ figure.rbchat-diagram[data-diagram]{border-top:0;padding-top:0;margin:1.1rem 0 1
 @keyframes rbchat-blink{50%{opacity:0}}
 @media (prefers-reduced-motion:reduce){.rbchat-cur{animation:none}}
 .rbchat-help,.rbchat-hint{margin:.4rem 0 0;color:var(--t-dim)}
-.rbchat-help p{margin:0;display:grid;grid-template-columns:7ch 1fr}
+.rbchat-help{display:grid;grid-template-columns:max-content 1fr;column-gap:1ch}
+.rbchat-help p{margin:0;display:contents}
 .rbchat-help-k{color:var(--t-accent)}
 /* Heard, not seen: the finished answer, said once to a screen reader. */
 .rbchat-say,.rbchat-sr{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
diff --git a/index.html b/index.html
index 5b7a8b2..65a6253 100644
--- a/index.html
+++ b/index.html
@@ -594,6 +594,6 @@ <h2 data-de="Fünf Datensätze, <em>ein Profil</em>.">Five records, <em>one prof
 <script src="page.js" defer></script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/model/index.html b/model/index.html
index b6536e5..8142082 100644
--- a/model/index.html
+++ b/model/index.html
@@ -473,6 +473,6 @@ <h2 data-de="Die Datei hinter dem Diagramm">The file behind the figure</h2>
 <script src="../stage.js"></script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/model/og.sha b/model/og.sha
index 64c2e50..8aa3da1 100644
--- a/model/og.sha
+++ b/model/og.sha
@@ -1 +1 @@
-c90626d4e0109fabc3c4085df49b95fc2c58de227c3844c459b4b79c2e6a6413
+e960a51d4d89aec4ca4c4488cf5da7a63c3ee922d52453b1e19e12cdc6180aa7
diff --git a/og.sha b/og.sha
index b608a4c..8d3599f 100644
--- a/og.sha
+++ b/og.sha
@@ -1 +1 @@
-15288252274e74c18b7019400e29de0f0566dd813a1d86341fd7497420902f49
+0029b5c2a5ec310fd7b819753ca21346206e6268483a7c7371a0214b6d282944
diff --git a/package-lock.json b/package-lock.json
index 98a1ba3..7a31ae2 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,7 +11,7 @@
         "companygraph-meta-model": "github:companygraph/meta-model#v0.94.0"
       },
       "devDependencies": {
-        "@robertblust/design": "github:robertblust/design#v0.158.0",
+        "@robertblust/design": "github:robertblust/design#v0.158.1",
         "companygraph-mcp-server": "github:companygraph/mcp-server#v0.69.0",
         "pdf-lib": "^1.17.1",
         "playwright": "^1.64.1",
@@ -96,8 +96,8 @@
       }
     },
     "node_modules/@robertblust/design": {
-      "version": "0.158.0",
-      "resolved": "git+ssh://git@github.com/robertblust/design.git#f7e9b44fe45ad29e9845db10269abdaed0e12655",
+      "version": "0.158.1",
+      "resolved": "git+ssh://git@github.com/robertblust/design.git#a12abba59e269c0fcff7a2ed364c3cef7365a718",
       "dev": true,
       "license": "Apache-2.0",
       "bin": {
diff --git a/package.json b/package.json
index 074fabb..a9fb65f 100644
--- a/package.json
+++ b/package.json
@@ -25,7 +25,7 @@
     "pin:check": "node pin-check.mjs"
   },
   "devDependencies": {
-    "@robertblust/design": "github:robertblust/design#v0.158.0",
+    "@robertblust/design": "github:robertblust/design#v0.158.1",
     "companygraph-mcp-server": "github:companygraph/mcp-server#v0.69.0",
     "pdf-lib": "^1.17.1",
     "playwright": "^1.64.1",
diff --git a/principles/index.html b/principles/index.html
index 2274bff..7e6c3b8 100644
--- a/principles/index.html
+++ b/principles/index.html
@@ -447,6 +447,6 @@ <h3 data-de="Der Kern bleibt offen">The core stays open</h3>
 <script src="../page.js" defer></script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/principles/og.sha b/principles/og.sha
index 6788642..4413fdc 100644
--- a/principles/og.sha
+++ b/principles/og.sha
@@ -1 +1 @@
-39c530b87640af8223dfe00c26f29b598afbd81767c1924d60f24bbe4302a569
+36c72ab876a857f38bc80304ce6f21c3caa07c4051f29a6db5bf5f279482f6b6
diff --git a/privacy/index.html b/privacy/index.html
index 9ffa99a..9f694bd 100644
--- a/privacy/index.html
+++ b/privacy/index.html
@@ -318,7 +318,7 @@ <h3 data-de="Gar nicht erst verwendet">Not used at all</h3>
             <li><b data-de="Cookies">Cookies</b><i data-de="Keine, gleich welcher Art. Es gibt kein Banner, weil es nichts gibt, dem Sie zustimmen müssten.">None, of any kind. There is no banner because there is nothing to consent to.</i></li>
             <li><b data-de="Webanalyse">Analytics</b><i data-de="Nichts zählt Ihre Besuche, und niemandem wird mitgeteilt, dass Sie hier waren.">Nothing counts you, and nobody is told that you were here.</i></li>
             <li><b data-de="Anfragen an Dritte">Third-party requests</b><i data-de="Schriften, Bilder und Stylesheets kommen alle von dieser Domain. Kein CDN sieht Ihre IP-Adresse. Die einzige Ausnahme ist der Chat, sobald Sie auf Senden drücken. Wohin Ihre Nachricht geht, zeigt das Diagramm <a href='#lineage'>Wohin Ihre Daten gehen</a>.">Fonts, images and styles all come from this origin. No CDN sees your address. The one exception is the chat, once you press send; where your message goes is drawn under <a href="#lineage">Where your data goes</a>.</i></li>
-            <li><b data-de="Formulare und Konten">Forms and accounts</b><i data-de="Nichts auszufüllen, keine Anmeldung, nichts zu speichern.">Nothing to fill in, nothing to sign up for, nothing to store.</i></li>
+            <li><b data-de="Formulare und Registrierung">Forms and sign-ups</b><i data-de="Nichts auszufüllen und nichts, wofür Sie sich registrieren müssten. Ein Konto für den Chat gibt es nur auf Einladung, wie unten beschrieben.">Nothing to fill in and nothing to sign up for. An account for the chat comes only by invitation, as described below.</i></li>
             <li><b data-de="Fingerprinting">Fingerprinting</b><i data-de="Es wird nicht versucht, Sie über Besuche hinweg wiederzuerkennen. Die gespeicherte Sprach- und Darstellungswahl ist kein Erkennungsmerkmal.">No attempt is made to recognize you across visits. The language and theme keys are not identifiers.</i></li>
           </ul>
         </div>
@@ -372,6 +372,9 @@ <h2 data-de="Wohin Ihre Daten gehen">Where your data goes</h2>
       <p class="ln-hint" id="lnhint" data-de="Wählen Sie einen Eintrag, um seiner Linie zu folgen und seine Karte zu lesen.">Choose an entry to follow its line and read its card.</p>
       <p class="figcap" data-de="Links Ihr Besuch; in der Mitte, was Ihre Daten aufbewahrt oder bearbeitet und auf welcher Rechtsgrundlage; rechts die Schlüssel in Ihrem Browser und die Empfänger, jeweils mit dem, was sie erhalten. Jeder Eintrag stammt aus dem Modell im genannten Commit und öffnet seine Karte.">Left, your visit; in the middle, what keeps or handles your data and on what grounds; right, the keys in your browser and the parties that receive something, with what they receive. Every entry comes from the model at the commit named, and opens its card.</p>
       <p class="derived"><span data-de="Erzeugt aus">Generated from</span> <a id="srclink" data-src="model" href="https://github.com/guestgraph/mental-model/tree/HEAD/model">guestgraph/mental-model</a>@<span id="srccommit">HEAD</span> — <code class="mono">model/stored-items/</code>, <code class="mono">model/processing-activities/</code> <span data-de="und">and</span> <code class="mono">model/data-processors/</code>.</p>
+      <div class="rules">
+        <p data-de="<b>Ein Konto gibt es nur auf Einladung.</b> Wer eingeladen wird, kann sich im Chat anmelden und das Modell wählen, das antwortet. Das Konto liegt bei id.blust.ch, in Zürich, mit Name und E-Mail-Adresse. Von einer angemeldeten Person bewahrt der Chat nur den Zähler des laufenden Monats auf, unter einem Schlüssel, aus dem er nicht auf das Konto zurückschliessen kann. Die Zeile, die er zu jeder Frage aufbewahrt, ist für alle gleich, ob angemeldet oder nicht."><b>An account is by invitation only.</b> A reader the owner invites may sign in to the chat to choose the model that answers. The account is held at id.blust.ch, in Zurich, with the reader's name and email address. Of a signed-in reader the chat keeps only a count for the month, under a key it cannot turn back into the account. The line it keeps of each question is the same for every reader, signed in or not.</p>
+      </div>
     </section>
     <section>
       <h2 data-de="Gastdaten, sobald es welche gibt">Guest data, when there is any</h2>
@@ -630,6 +633,6 @@ <h2 data-de="Wer das betreibt">Who runs this</h2>
 <script src="../page.js" defer></script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/privacy/og.png b/privacy/og.png
index 0056e58..02d2b24 100644
Binary files a/privacy/og.png and b/privacy/og.png differ
diff --git a/privacy/og.sha b/privacy/og.sha
index b550af0..8dbfbbf 100644
--- a/privacy/og.sha
+++ b/privacy/og.sha
@@ -1 +1 @@
-ac43b8812f6696e083f6ea760436fd57c2c050eb171501e92f562ff9a200aef2
+642fba3eef151ffd2b197c7301f270960b045ddaadf4780fa7d5fa98ef84f840
diff --git a/problems/index.html b/problems/index.html
index 6ebdc75..fd9e983 100644
--- a/problems/index.html
+++ b/problems/index.html
@@ -461,6 +461,6 @@ <h2 id="internal-error" data-de="Interner Serverfehler">Internal server error</h
 <script src="../page.js" defer></script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/problems/og.sha b/problems/og.sha
index 2b3b935..dbf38ac 100644
--- a/problems/og.sha
+++ b/problems/og.sha
@@ -1 +1 @@
-744cdaa8b7a1182ffc2242aec277375ff9b7a7fa96244dfa64712ae7dd32a69b
+8d21f8d1bdf445a53446c3e5de6424bda18a584171e8c7fcd87ee9757c0a6c40
diff --git a/processes/index.html b/processes/index.html
index d90e299..32b93e9 100644
--- a/processes/index.html
+++ b/processes/index.html
@@ -810,6 +810,6 @@ <h2 data-de="Wie man es liest">How to read it</h2>
 </script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/processes/og.sha b/processes/og.sha
index 07d1645..1d8e5d7 100644
--- a/processes/og.sha
+++ b/processes/og.sha
@@ -1 +1 @@
-779176526169539cec538050d2361ae61b7f2a599b4633e84ca1ac45a029c0d1
+cc151661650d3c670f466019df9d365b0ba02435d2763373630ec235ebf0d0bc
diff --git a/sitemap.xml b/sitemap.xml
index 3af5a45..6f4a7fd 100644
--- a/sitemap.xml
+++ b/sitemap.xml
@@ -5,15 +5,15 @@
   of their own; they no longer do, so there is no second list to keep in step.
 -->
 <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
-  <url><loc>https://guestgraph.io/</loc><lastmod>2026-10-14</lastmod></url>
-  <url><loc>https://guestgraph.io/principles/</loc><lastmod>2026-10-15</lastmod></url>
-  <url><loc>https://guestgraph.io/processes/</loc><lastmod>2026-10-15</lastmod></url>
-  <url><loc>https://guestgraph.io/surfaces/</loc><lastmod>2026-10-15</lastmod></url>
-  <url><loc>https://guestgraph.io/api/</loc><lastmod>2026-10-14</lastmod></url>
-  <url><loc>https://guestgraph.io/model/</loc><lastmod>2026-10-15</lastmod></url>
-  <url><loc>https://guestgraph.io/billing/</loc><lastmod>2026-10-14</lastmod></url>
-  <url><loc>https://guestgraph.io/privacy/</loc><lastmod>2026-10-15</lastmod></url>
-  <url><loc>https://guestgraph.io/problems/</loc><lastmod>2026-10-14</lastmod></url>
-  <url><loc>https://guestgraph.io/talks/</loc><lastmod>2026-10-14</lastmod></url>
-  <url><loc>https://guestgraph.io/talks/intro/</loc><lastmod>2026-10-14</lastmod></url>
+  <url><loc>https://guestgraph.io/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/principles/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/processes/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/surfaces/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/api/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/model/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/billing/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/privacy/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/problems/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/talks/</loc><lastmod>2026-10-24</lastmod></url>
+  <url><loc>https://guestgraph.io/talks/intro/</loc><lastmod>2026-10-24</lastmod></url>
 </urlset>
diff --git a/surfaces/index.html b/surfaces/index.html
index 429bb4d..f5e42ae 100644
--- a/surfaces/index.html
+++ b/surfaces/index.html
@@ -618,6 +618,6 @@ <h2 data-de="Wie man es liest">How to read it</h2>
 </script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/surfaces/og.sha b/surfaces/og.sha
index e1baf4b..0f95c6e 100644
--- a/surfaces/og.sha
+++ b/surfaces/og.sha
@@ -1 +1 @@
-4adff87fc19c05a53fe980dba4279ed9cf2b7ef437274b5edf2ecdc6925b6b73
+a5992b24a5af2b0f943e21bd5f4a81a80350e3ca7233ca4f10408b6340db15fe
diff --git a/talks/index.html b/talks/index.html
index b02c4e5..7d82357 100644
--- a/talks/index.html
+++ b/talks/index.html
@@ -437,6 +437,6 @@ <h1 data-de="<span class='r70'>Vorträge über</span><span class='rcl'>Guest<em>
 <script src="../page.js" defer></script>
 
 <!-- The chat: one tag, the design package's widget. It loads nothing and sends nothing until a visitor opens it; the privacy page says what leaves the browser then. -->
-<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/talks/intro/index.html b/talks/intro/index.html
index 3074a49..5a01c11 100644
--- a/talks/intro/index.html
+++ b/talks/intro/index.html
@@ -879,6 +879,6 @@ <h3><span id="noteslabel">Sprecher-Notiz</span> <span class="time" id="ntime"></
   window.rbDeck = { talk: TALK, ui: UI };
 </script>
 <script src="../../deck.js" defer></script>
-<script src="../../chat.js" data-chat="https://chat.guestgraph.io/chat" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
+<script src="../../chat.js" data-chat="https://chat.guestgraph.io/chat" data-issuer="https://id.blust.ch" data-client="396565550639098224" data-org="396565550320331120" data-project="396565550420994416" data-model="/model/" data-questions="/model.json" data-questions-de="/questions.de.json"></script>
 </body>
 </html>
diff --git a/talks/intro/og.sha b/talks/intro/og.sha
index 535fa01..9623d02 100644
--- a/talks/intro/og.sha
+++ b/talks/intro/og.sha
@@ -1 +1 @@
-387e10b100f8c444a82bfdfbceb2a6628f835c3449ab31211ba9bbcada8b917a
+f573cd393ef66c62f1850e185b7d262d59208c7a63d6da32211f4c872ab98d3d
diff --git a/talks/og.sha b/talks/og.sha
index 90a618d..64b989f 100644
--- a/talks/og.sha
+++ b/talks/og.sha
@@ -1 +1 @@
-51813df1a226976650092651bdf732abe5daecc2bf9b78cda8fd9453dc6adaaa
+ec7b4d3493c6e87581667782e413011c0e0b9d1c128dfa361a2c3afc7f2cf796