@@ -67,12 +67,14 @@
 // ── Why the API-description endpoints are here (#22430) ────────────────────
 //
 // `@objectstack/rest`'s `registerOpenApiEndpoints` mounts the API-description
-// endpoints — the document and its viewer page — and until #22430 neither
-// handler asked who was calling: on a stock boot both answered an
-// unauthenticated caller 200, exactly as they answered a signed-in one, while
-// the record doors beside them answered 401. Both are driven below anonymously
-// (401 in the REST flat envelope, nothing of either served) and with a
-// signed-in member as the 200 control, on this one boot.
+// endpoint — the document — and until #22430 its handler did not ask who was
+// calling: on a stock boot it answered an unauthenticated caller 200, exactly
+// as it answered a signed-in one, while the record doors beside it answered
+// 401. It is driven below anonymously (401 in the REST flat envelope, nothing
+// of it served) and with a signed-in member as the 200 control, on this one
+// boot. Its viewer page, `/docs`, was the second endpoint until #25104 retired
+// it; the retired path is driven below too, and answers the host's ordinary
+// not-found to everyone.
 //
 // ── Why the analytics faces are here (#21061) ──────────────────────────────
 //
@@ -162,19 +164,22 @@ const ANALYTICS_FACES: readonly AnalyticsFace[] = [
 
 // ── #22430 — the API-description endpoints (@objectstack/rest) ──────────────
 //
-// Both register on every base the server mounts; this boot mounts only the
+// It registers on every base the server mounts; this boot mounts only the
 // unscoped one (the showcase does not enable project scoping), and the
-// environment-scoped twin — the same handler closures — is pinned per base in
+// environment-scoped twin — the same handler closure — is pinned per base in
 // `packages/rest/src/rest-api-description-anonymous-deny.test.ts`.
 interface ApiDescriptionEndpoint {
   readonly endpoint: string;
   readonly path: string;
 }
 const API_DESCRIPTION_ENDPOINTS: readonly ApiDescriptionEndpoint[] = [
   { endpoint: 'the API-description document', path: '/openapi.json' },
-  { endpoint: 'the API-description viewer', path: '/docs' },
 ];
 
+/** [#25104] The retired viewer page's path, and a path nothing ever served, for the not-found control. */
+const RETIRED_VIEWER_PATH = '/docs';
+const NEVER_SERVED_PATH = '/this-route-does-not-exist';
+
 // ── #22432 — the translation faces (dispatcher-mounted; runtime domains/i18n.ts)
 //
 // One handler body serves every face, so the floor is its first statement. The
@@ -722,10 +727,10 @@ describe('showcase: anonymous posture is uniform across surfaces (#2567)', () =>
   // ── the API-description endpoints (@objectstack/rest) — #22430 ──────────
   //
   // The refusal is the handler's first act, so the anonymous body is the REST
-  // seam's shared one, whole, and carries nothing of the document or the page.
-  // The member control is the teeth: the same endpoint, with a session, is
-  // served 200 on this boot, so the 401 is the floor's answer and the endpoint
-  // is really mounted here.
+  // seam's shared one, whole, and carries nothing of the document. The member
+  // control is the teeth: the same endpoint, with a session, is served 200 on
+  // this boot, so the 401 is the floor's answer and the endpoint is really
+  // mounted here.
   it.each(API_DESCRIPTION_ENDPOINTS)('an anonymous caller on $endpoint is denied (401) and served nothing', async (ep) => {
     const r = await anon('GET', ep.path);
     expect(r.status, `${ep.endpoint}: an anonymous caller must be refused by the floor`).toBe(ANONYMOUS_DENY_STATUS);
@@ -744,13 +749,22 @@ describe('showcase: anonymous posture is uniform across surfaces (#2567)', () =>
     expect(Object.keys(body.paths ?? {}).length, 'the document describes the mounted surface').toBeGreaterThan(0);
   });
 
-  it('a signed-in member is served the API-description viewer page (200) — the control', async () => {
-    const r = await stack.apiAs(memberToken, 'GET', '/docs');
-    expect(r.status, 'an authenticated member must clear the floor and be served the viewer').toBe(200);
-    expect(r.headers.get('content-type') ?? '', 'the viewer is an HTML page').toContain('text/html');
-    // The page loads its sibling document on the same base — the request that,
-    // from a signed-in browser, carries that browser's session.
-    expect(await r.text(), 'the viewer points at its sibling document').toContain('data-url="/api/v1/openapi.json"');
+  it('[#25104] the retired viewer page is routed NOWHERE — the host\'s ordinary 404 for everyone, not a 401', async () => {
+    // Retired, the path must answer exactly what a path nothing ever served
+    // answers on this boot, to an anonymous caller and to a member alike: a
+    // 401 would mean a door is back (an auth floor only speaks for a door that
+    // exists), and a 200 would mean the page is. The registrar-level absence
+    // pin, on both route shapes, is `rest/src/rest-docs-viewer-retired.pin.test.ts`.
+    const control = await anon('GET', NEVER_SERVED_PATH);
+    expect(control.status, 'CONTROL: a path nothing serves is a 404 on this boot').toBe(404);
+    const controlBody = await control.text();
+    const anonRes = await anon('GET', RETIRED_VIEWER_PATH);
+    expect(anonRes.status, 'the retired viewer path must be unrouted, not auth-refused').toBe(404);
+    expect(await anonRes.text(), 'the retired path answers the ordinary not-found body').toBe(controlBody);
+    const memberRes = await stack.apiAs(memberToken, 'GET', RETIRED_VIEWER_PATH);
+    expect(memberRes.status, 'a session must not change the answer on a route that is gone').toBe(404);
+    expect(memberRes.headers.get('content-type') ?? '', 'no page is served').not.toContain('text/html');
+    expect(await memberRes.text(), 'the retired path answers the ordinary not-found body').toBe(controlBody);
   });
 
   // ── the translation faces (dispatcher-mounted; runtime domains/i18n.ts) — #22432
@@ -888,7 +902,8 @@ describe('showcase: anonymous posture is uniform across surfaces (#2567)', () =>
     // [#21060] The two remaining REST families the checklist item names.
     { seam: 'POST /batch', owner: '@objectstack/rest enforceAuth', family: 'rest-flat', call: () => anon('POST', BATCH, BATCH_PROBE_BODY) },
     { seam: 'GET /security/explain', owner: '@objectstack/rest enforceAuth', family: 'rest-flat', call: () => anon('GET', EXPLAIN) },
-    // [#22430] The API-description endpoints, labelled by endpoint.
+    // [#22430] The API-description endpoint (one since #25104 retired the
+    // viewer page), labelled by endpoint.
     ...API_DESCRIPTION_ENDPOINTS.map((ep) => ({
       seam: ep.endpoint,
       owner: '@objectstack/rest registerOpenApiEndpoints (enforceAuth)',