Name the chat's model and say it can make mistakes

src/features/AGENTS.md

@@ -18,6 +18,7 @@
 - **Tables** (slice 19, `chat/rich-text.tsx`; the parser in `src/lib/markdown.ts`, which only the browser uses): opencode's at 50c5fce (`docs/decisions.md`, Design, 2026-10-20): a real `<table>`, its header's named cells `<th scope="col">` in medium weight over `border-border-strong`, rows over `border-border`, both `0.5px` (Chromium draws 1px on a screen of 1x), cells `p-3 align-top`. Each cell is `min-w-36`, which Chromium honours on table cells, so a wide table scrolls rather than squeezing its columns to a word per line. Every row is padded to the widest row or the header with empty `<td>`s, so the hairlines run the full width; a header's empty name is a `<td>` too, as it names nothing, and a row or header of nothing but empty cells is dropped by the parser. The table sits in `SideScroll`, an `overflow-x-auto` box that a `ResizeObserver` measures, on itself and on the table: while the table is wider, the box is `role="region"`, named "Table, scrolls sideways", with `tabIndex={0}`, so the keyboard reaches it (axe's `scrollable-region-focusable`, which checks only a box that overflows); a table that fits adds no tab stop. A hidden Browser pane delivers the observer's first measure only when it next draws. The cells' runs are built in `RichText`'s render, not inside `SideScroll`, so the fade's character count (`words.at`) keeps the rendered order. The fake model writes no table, so `tests/e2e/chat.spec.ts` opens a kept conversation that holds two.
 - **Stop** (slice 12): while the assistant works, the message box's Send button is Stop, one `<button>` whose label and type change, so focus stays on it; an empty Send is `aria-disabled`, not `disabled`, which would drop focus to the page. A Stop click calls `preventDefault()`: `useChat`'s `stop()` can end the answer and turn the button back into a submit button before the browser's default action, which then sent the draft (found 2026-10-20 by `tests/e2e/chat.spec.ts`; jsdom's `fireEvent` doesn't show it). `stop()` aborts the request, sets the status to `ready` and calls `onFinish` with `isAbort` (ai 7.0.143, `AbstractChat.stop` and `makeRequest` in `node_modules/ai/dist/index.js`, read 2026-10-20; the AI SDK's *Stopping Streams*, through Context7); `afterAnswer` marks the question as stopped only when `stopRequested` says the visitor pressed Stop, since "Start over" aborts too. The route hands the cancel to the model call (`request.signal`), so no further model calls follow; the call in flight is a whole reply, which Cloudflare may still finish and count.
 - **A stopped answer** keeps its parts as they were: its text so far, its finished searches, any section it saved (the PRD keeps it). `stopped` holds the ids of the questions whose answers were stopped, so an answer stopped before its first part still says "You stopped this answer." under its question. A step still running reads as stopped ("Stopped searching the interviews for “…”", "Stopped checking the quotes in …", without a full stop, like the finished step lines), never as running or failed. What goes back to the server is trimmed in the transport (`prepareSendMessagesRequest`, `finishedOnly` in `workspace/stopped-answer.ts`): unfinished steps are dropped, and so is an answer that finished nothing; the server's format check would refuse a half-arrived tool call, and the model would see a call without its result.
+- **Under the message box** (the owner, 2026-10-29): the model's name as visitors see it, `site.model.name` ("OpenAI open model", not the slug), linked to the exact model's page, then a line that it's a free model that can make mistakes and follows short, specific requests best; under that, the demo notice, `#chat-notice`, the box's description. `tests/unit/providers.test.ts` holds the link to `CHAT_MODEL`, so a model change fails it until the name and link follow.
 - **The message box grows** with its text through `field-sizing: content`, from three lines (`min-h-24`) to 180px (`max-h-45`), then scrolls; Chrome 123, Firefox 152 and Safari 26.2 support it (MDN's compatibility data, read 2026-10-20 through Context7), and older browsers keep the three lines. A `ResizeObserver` keeps the chat on its newest message when the conversation's pane gets shorter, as the box grows or the suggestion shows, unless the visitor scrolled up; jsdom has none, so `tests/unit/setup.ts` stubs it.
 - **Scrolling panes are `relative`:** Tailwind's `sr-only` is `position: absolute`. Inside a scrolling pane that isn't positioned, those labels are placed against the page, stretch it and make the whole page scroll (found 2026-10-18). The PRD pane is also focusable (`tabIndex={0}`), or axe reports `scrollable-region-focusable` before it holds a link.
 - **Jump to latest** (slice 14): shows while the chat is 48px or more off its end (`FOLLOW_MARGIN`), after a scroll up or when the conversation grows without one (a `ResizeObserver` on the conversation's `<ol>`, which changes only the button, not whether the chat follows; in Chromium, opening a folded line while the pane gains its scrollbar instead resizes the pane, and the pane's own observer takes the chat to its end). It's the scrolling pane's last child, a zero-height `sticky bottom-0` box whose `-mt-6` cancels the `space-y-6` margin it gives the item before it (Tailwind 4 puts that margin on every child but the last, read 2026-10-20 through Context7), with the button absolute inside; so the pane stays `#chat-title + div` with the same children, which `tests/e2e/layout.spec.ts` measures. `hidden lg:block`, since a phone's chat doesn't scroll on its own. A click sets following, moves focus to the message box (or the chat's heading once the allocation is used up and the box is gone) before the button unmounts, and calls `scrollTo` with `behavior: "smooth"`, or `"instant"` under `prefers-reduced-motion: reduce` (MDN, `Element.scrollTo`, read 2026-10-20 through Context7). While that smooth scroll runs, its downward steps don't count as the visitor leaving the end (`jumping`); a step upward does. If the conversation grows meanwhile, as opened searches still sliding open do, the conversation's observer scrolls on to the new end instead of showing the button; before that, the jump stopped at the old end and stayed there, with no button (found 2026-10-21, `tests/e2e/layout.spec.ts`, 2 runs in 60). It has an opaque background, as it sits over the text. jsdom lays nothing out and has no `matchMedia` or `scrollTo`, so `tests/unit/workspace.test.tsx` gives the pane a size, stubs both and reports the conversation's resizes itself.

src/features/chat/chat.tsx

@@ -14,6 +14,7 @@ import { Button } from "@/components/ui/button";
 import { QuotaNotice, type DayOver } from "@/features/workspace/quota";
 import { DEMO_BUSY, MAX_MESSAGE_LENGTH, type ChatMessage } from "@/lib/chat";
 import type { SectionName } from "@/lib/prd";
+import { site } from "@/lib/site";
 import { cn } from "@/lib/utils";
 import { Conversation } from "./conversation";
 
@@ -361,10 +362,22 @@ export function Chat({
             {working ? "Stop" : "Send"}
           </Button>
         </div>
-        <p id="chat-notice" className="text-sm text-muted-foreground">
-          This is a demo with fictional interviews. Don&apos;t enter personal
-          information.
-        </p>
+        <div className="space-y-1 text-sm text-muted-foreground">
+          <p>
+            <a
+              href={site.model.page}
+              className="font-medium text-foreground underline-offset-4 hover:underline"
+            >
+              {site.model.name}
+            </a>{" "}
+            · A free model: it can make mistakes, and follows short, specific
+            requests best.
+          </p>
+          <p id="chat-notice">
+            This is a demo with fictional interviews. Don&apos;t enter personal
+            information.
+          </p>
+        </div>
       </form>
 
       <p role="status" className="sr-only">

src/lib/site.ts

@@ -7,6 +7,15 @@ export const site = {
   links: {
     repository: "https://github.com/TechNomadCode/prd-assistant",
   },
+  /**
+   * The chat model as visitors see it under the message box: a name that
+   * says what it is, linked to the page of the exact model in
+   * `src/server/ai/models.ts`.
+   */
+  model: {
+    name: "OpenAI open model",
+    page: "https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/",
+  },
 } as const;
 
 /**

tests/e2e/chat.spec.ts

@@ -643,6 +643,24 @@ test.describe("chat", () => {
     ).toBeVisible();
   });
 
+  test("names the model under the message box and says it can make mistakes", async ({
+    page,
+  }) => {
+    await openChat(page);
+
+    await expect(
+      page.getByRole("link", { name: "OpenAI open model", exact: true }),
+    ).toHaveAttribute(
+      "href",
+      "https://developers.cloudflare.com/workers-ai/models/gpt-oss-120b/",
+    );
+    await expect(
+      page.getByText(
+        "A free model: it can make mistakes, and follows short, specific requests best.",
+      ),
+    ).toBeVisible();
+  });
+
   test("marks an answer that breaks off as unfinished, and trying again replaces it", async ({
     page,
   }, testInfo) => {

tests/unit/providers.test.ts

@@ -1,4 +1,5 @@
 import { describe, expect, it } from "vitest";
+import { site } from "@/lib/site";
 import { FAKE_CHAT_MODEL } from "@/server/ai/fake-chat-model";
 import { CHAT_MODEL, EMBEDDING_MODEL } from "@/server/ai/models";
 import { createChatModel, createEmbedder } from "@/server/ai/providers";
@@ -91,6 +92,13 @@ describe("choosing the chat model", () => {
     expect(createChatModel(cloudflare).modelId).toBe("@cf/openai/gpt-oss-120b");
   });
 
+  it("links the model name visitors see to the page of the model the chat runs on", () => {
+    const slug = CHAT_MODEL.split("/").at(-1);
+    expect(site.model.page).toBe(
+      `https://developers.cloudflare.com/workers-ai/models/${slug}/`,
+    );
+  });
+
   it.each([["mistral"], ["openai"], ["Fake"], [undefined]])(
     "rejects an unknown adapter name: %s",
     (provider) => {