adeelahmad · Nov 5, 2026 · Nov 5, 2026
diff --git a/changelog.d/fix-chat-settings-secrets.md b/changelog.d/fix-chat-settings-secrets.md
@@ -0,0 +1,3 @@
+Fixed a crash when opening Telegram, Slack, or Assistant email settings. Their credential fields are now registered
+with the shared form, so tokens and the mailbox password can be saved, replaced, or cleared without exposing stored
+values. Cancel and Undo preserve the saved credentials.
diff --git a/docs/chat-rooms.md b/docs/chat-rooms.md
@@ -9,7 +9,7 @@ Lens's assistant can answer in Slack, Discord, Telegram, Matrix, Mattermost, IRC
 Telegram needs no Matterbridge and no public address: Lens reads its own bot's messages (long polling) and answers.
 
 1. In Telegram, message **@BotFather**, send `/newbot` and copy the token it gives you.
-2. Open **Settings → Telegram**, paste the token and turn on **Answer in Telegram**.
+2. Open **Settings → Telegram**, paste the token, turn on **Answer in Telegram**, and click **Save**.
 3. Message your bot. You show on the settings page under **Wrote to the bot, not let in**: click **Let in**.
 
 Anyone can find a bot, so it answers only the people in **People it talks to** (Telegram user ids or usernames);
@@ -23,6 +23,9 @@ namespace's assistant with **Chats for a namespace's assistant** (`-100123456789
 
 Give Lens a bot of its own: a bot that Matterbridge also reads answers neither reliably (**Check the bot** says so).
 
+The bot token is write-only: reopening Settings shows whether it is set, never its value. Use **Replace** to change
+it or **Clear** to remove it, then **Save**. **Cancel** and **Undo** leave the saved token unchanged.
+
 Telegram is one adapter of the chat-channel layer (`app/domain/channels.py`) that Matterbridge is another of; a new
 chat app adds an adapter (reading, sending, files) and gets everything in a room for free. The assistant's own email
 address is one too ([The assistant by email](assistant-email.md)).
@@ -37,7 +40,8 @@ and answers there.
 2. In the app's page, **Install to Workspace**, then copy the **Bot User OAuth Token** (`xoxb-…`, under OAuth &
    Permissions). Under **Basic Information → App-Level Tokens**, generate one with `connections:write` and copy it
    (`xapp-…`).
-3. Paste both tokens in Settings → Slack and turn on **Answer in Slack**. **Check the app** says whether both work.
+3. Paste both tokens in Settings → Slack, turn on **Answer in Slack**, and click **Save**. **Check the app** says
+   whether both saved tokens work.
 
 Message the app directly (always for Lens), invite it to a channel with `/invite @Lens` and say "Lens, …" or
 @mention it, or type `/lens what did we decide about the launch?` anywhere (the answer shows in that channel).

diff --git a/nextjs-frontend/__tests__/settings-chat-credentials.test.tsx b/nextjs-frontend/__tests__/settings-chat-credentials.test.tsx
@@ -0,0 +1,131 @@
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import "@testing-library/jest-dom";
+
+import { Admin } from "@/app/openapi-client";
+import { fieldId, fieldsOf, toUi, type SectionId, type SettingsView } from "@/components/settings/model";
+import { SettingsSection } from "@/components/settings/section";
+import { TooltipProvider } from "@/components/ui/tooltip";
+
+jest.mock("@/app/openapi-client", () => ({
+  Admin: {
+    updateSettings: jest.fn(),
+    getSecrets: jest.fn(),
+    telegramStatus: jest.fn(),
+    slackStatus: jest.fn(),
+    mailboxStatus: jest.fn(),
+  },
+  Metadata: {},
+}));
+jest.mock("next-auth/react", () => ({ useSession: () => ({ data: { accessToken: "t" } }) }));
+jest.mock("next/navigation", () => ({ useRouter: () => ({ push: jest.fn() }) }));
+jest.mock("@/lib/hooks/session", () => ({ useArchive: () => ({ namespaces: [] }) }));
+jest.mock("@/components/ui/toast", () => ({ useToast: () => jest.fn() }));
+
+const ok = (data: unknown) => Promise.resolve({ data, response: { ok: true, status: 200 } });
+const CREDENTIALS: [SectionId, string, string][] = [
+  ["telegram", "token", "Bot token"],
+  ["slack", "bot_token", "Bot token (xoxb-…, from OAuth & Permissions)"],
+  ["slack", "app_token", "App-level token (xapp-…, from Basic Information, with connections:write)"],
+  ["mailbox", "password", "Password"],
+];
+
+function view(section: SectionId, key: string, saved: boolean): SettingsView {
+  return {
+    [section]: {
+      values: {
+        enabled: false,
+        account: null,
+        name: "Lens",
+        answer: "mention",
+        users: [],
+        rooms: [],
+        approve: "low_risk",
+        api_url: null,
+        token: { secret: true, set: false },
+        bot_token: { secret: true, set: false },
+        app_token: { secret: true, set: false },
+        address: null,
+        password: { secret: true, set: false },
+        username: null,
+        imap_host: null,
+        imap_port: null,
+        imap_security: "ssl",
+        smtp_host: null,
+        smtp_port: null,
+        smtp_security: "starttls",
+        folder: "INBOX",
+        routes: [],
+        imports: "auto",
+        check: "authenticated",
+        auth_server: null,
+        poll_seconds: 30,
+        [key]: { secret: true, set: saved },
+      },
+    },
+  } as SettingsView;
+}
+
+function show(section: SectionId, key: string, saved = false) {
+  const qc = new QueryClient({ defaultOptions: { queries: { retry: false }, mutations: { retry: false } } });
+  return render(
+    <QueryClientProvider client={qc}>
+      <TooltipProvider>
+        <SettingsSection id={section} view={view(section, key, saved)}  => undefined} />
+      </TooltipProvider>
+    </QueryClientProvider>,
+  );
+}
+
+beforeEach(() => {
+  (Admin.updateSettings as jest.Mock).mockReset().mockImplementation(() => ok({ ok: true }));
+  (Admin.getSecrets as jest.Mock)
+    .mockReset()
+    .mockImplementation(() => ok({ providers: [], references: [], fields: [] }));
+  for (const status of [Admin.telegramStatus, Admin.slackStatus, Admin.mailboxStatus])
+    (status as jest.Mock).mockReset().mockImplementation(() => ok({ state: "off", people: [], chats: [] }));
+});
+
+describe.each(CREDENTIALS)("%s.%s", (section, key, label) => {
+  it("registers the custom credential control as a write-only field", () => {
+    const field = fieldsOf(section).find((f) => fieldId(f) === `${section}.${key}`);
+    expect(field).toMatchObject({ section, key, kind: "secret" });
+    expect(toUi(field!, { secret: true, set: true })).toBeUndefined();
+  });
+
+  it("opens without crashing and saves a new credential", async () => {
+    show(section, key);
+    const input = screen.getByLabelText(label);
+    expect(input).toHaveAttribute("type", "password");
+    expect(input).toHaveValue("");
+    expect(screen.queryByRole("button", { name: "Save" })).not.toBeInTheDocument();
+    fireEvent.change(input, { target: { value: "test-credential" } });
+    fireEvent.click(screen.getByRole("button", { name: "Save" }));
+    await waitFor(() => expect(Admin.updateSettings).toHaveBeenCalledTimes(1));
+    expect((Admin.updateSettings as jest.Mock).mock.calls[0][0]).toMatchObject({
+      path: { section },
+      body: { [key]: "test-credential" },
+    });
+    expect((Admin.updateSettings as jest.Mock).mock.calls[0][0].body).toEqual({ [key]: "test-credential" });
+  });
+
+  it("keeps a saved credential unchanged after Cancel and Undo", () => {
+    show(section, key, true);
+    fireEvent.click(screen.getByRole("button", { name: "Replace" }));
+    fireEvent.change(screen.getByLabelText(label), { target: { value: "replacement" } });
+    fireEvent.click(screen.getByRole("button", { name: "Cancel" }));
+    expect(screen.queryByRole("button", { name: "Save" })).not.toBeInTheDocument();
+    fireEvent.click(screen.getByRole("button", { name: "Clear" }));
+    fireEvent.click(screen.getByRole("button", { name: "Undo" }));
+    expect(screen.queryByRole("button", { name: "Save" })).not.toBeInTheDocument();
+    expect(Admin.updateSettings).not.toHaveBeenCalled();
+  });
+
+  it("submits an explicit clear without resubmitting masked secrets", async () => {
+    show(section, key, true);
+    fireEvent.click(screen.getByRole("button", { name: "Clear" }));
+    fireEvent.click(screen.getByRole("button", { name: "Save" }));
+    await waitFor(() => expect(Admin.updateSettings).toHaveBeenCalledTimes(1));
+    expect((Admin.updateSettings as jest.Mock).mock.calls[0][0].body).toEqual({ [key]: "" });
+  });
+});
diff --git a/nextjs-frontend/components/settings/model.ts b/nextjs-frontend/components/settings/model.ts
@@ -1790,6 +1790,7 @@ export const FIELDS: FieldSpec[] = [
   },
   // Telegram (telegram.py)
   { section: "telegram", key: "enabled", label: "Answer in Telegram", kind: "switch" },
+  { section: "telegram", key: "token", label: "Bot token", kind: "secret" },
   {
     section: "telegram",
     key: "account",
@@ -1849,6 +1850,8 @@ export const FIELDS: FieldSpec[] = [
   },
   // Slack (slack.py)
   { section: "slack", key: "enabled", label: "Answer in Slack", kind: "switch" },
+  { section: "slack", key: "bot_token", label: "Bot token", kind: "secret" },
+  { section: "slack", key: "app_token", label: "App-level token", kind: "secret" },
   {
     section: "slack",
     key: "account",
@@ -1898,6 +1901,7 @@ export const FIELDS: FieldSpec[] = [
   },
   // The assistant's mailbox (mailbox.py)
   { section: "mailbox", key: "enabled", label: "Answer email", kind: "switch" },
+  { section: "mailbox", key: "password", label: "Password", kind: "secret" },
   {
     section: "mailbox",
     key: "address",