diff --git a/api/src/routes/wallpaper.js b/api/src/routes/wallpaper.js
index baa70d82..3e632edf 100644
--- a/api/src/routes/wallpaper.js
+++ b/api/src/routes/wallpaper.js
@@ -108,16 +108,49 @@ function mayWrite(req, res) {
 /* Keep the cache. Without it every request, including one sent by a page on
    another site, spends a call of the key's hourly quota. */
 const PHOTO_TTL_MS = 24 * 60 * 60 * 1000;
-/** @type {{ key: string, at: number, url: string } | null} */
+/** @typedef {{ name: string, profile: string, site: string }} PhotoCredit */
+/** @type {{ key: string, at: number, url: string, credit: PhotoCredit|null } | null} */
 let _photo = null;
-/** @type {{ key: string, promise: Promise<{ url: string|null, error?: string }> } | null} */
+/** @type {{ key: string, promise: Promise<{ url: string|null, credit?: PhotoCredit|null, error?: string }> } | null} */
 let _pending = null;
 
+const UTM = 'utm_source=stackyard&utm_medium=referral';
+const USERNAME_RE = /^[A-Za-z0-9_-]{1,64}$/;
+
+/** The photographer and Unsplash links the API terms require beside the photo.
+
+    @param {any} photo a `/photos/random` reply @returns {PhotoCredit|null} */
+function photoCredit(photo) {
+  const username = photo?.user?.username;
+  if (typeof username !== 'string' || !USERNAME_RE.test(username)) return null;
+  const name = typeof photo.user.name === 'string' && photo.user.name.trim() ? photo.user.name.trim() : username;
+  return {
+    name: name.slice(0, 100),
+    profile: `https://unsplash.com/@${username}?${UTM}`,
+    site: `https://unsplash.com/?${UTM}`,
+  };
+}
+
+/** Unsplash counts a photo as used only through this request.
+
+    @param {any} photo @param {string} apiKey */
+function reportDownload(photo, apiKey) {
+  const loc = photo?.links?.download_location;
+  if (typeof loc !== 'string' || !loc.startsWith('https://api.unsplash.com/')) return;
+  const u = new URL(loc);
+  u.searchParams.set('client_id', apiKey);
+  fetchUnchecked(u.href)
+    .then(r => {
+      if (r.status < 200 || r.status >= 300) log.warn('Unsplash download report failed', { status: r.status });
+    })
+    .catch(e => log.warn('Unsplash download report failed', { error: e instanceof Error ? e.message : String(e) }));
+}
+
 /** @param {{ apiKey?: string, collection?: string }} bg */
 function randomPhoto(bg) {
   const key = `${bg.apiKey || ''}\n${bg.collection || ''}`;
   if (_photo && _photo.key === key && Date.now() - _photo.at < PHOTO_TTL_MS)
-    return Promise.resolve({ url: _photo.url });
+    return Promise.resolve({ url: _photo.url, credit: _photo.credit });
   if (_pending?.key === key) return _pending.promise;
   const promise = (async () => {
     const p = new URLSearchParams({ orientation: 'landscape', content_filter: 'high', client_id: bg.apiKey || '' });
@@ -129,8 +162,10 @@ function randomPhoto(bg) {
       return { url: null, error: 'No image returned' };
     }
     const url = `${raw}&w=2800&h=1800&q=85&fm=jpg&fit=crop&crop=entropy`;
-    _photo = { key, at: Date.now(), url };
-    return { url };
+    const credit = photoCredit(r.data);
+    _photo = { key, at: Date.now(), url, credit };
+    reportDownload(r.data, bg.apiKey || '');
+    return { url, credit };
   })().finally(() => {
     if (_pending?.promise === promise) _pending = null;
   });
diff --git a/api/test/wallpaper-unsplash.test.js b/api/test/wallpaper-unsplash.test.js
index 265ddf46..57702689 100644
--- a/api/test/wallpaper-unsplash.test.js
+++ b/api/test/wallpaper-unsplash.test.js
@@ -9,12 +9,21 @@ const http = require('node:http');
 const proxy = require('../src/proxy');
 /** @type {string[]} */
 let calls = [];
-/** @type {(url: string) => Promise<any>} */
-let reply = async () => ({
-  status: 200,
-  data: { urls: { raw: `https://images.unsplash.com/photo-${calls.length}?ixid=x` } },
+/** @type {string[]} */
+let pings = [];
+const photo = (extra = {}) => ({
+  urls: { raw: `https://images.unsplash.com/photo-${calls.length}?ixid=x` },
+  user: { username: 'anniespratt', name: 'Annie Spratt' },
+  links: { download_location: `https://api.unsplash.com/photos/p${calls.length}/download?ixid=x` },
+  ...extra,
 });
+/** @type {(url: string) => Promise<any>} */
+let reply = async () => ({ status: 200, data: photo() });
 proxy.fetchUnchecked = url => {
+  if (url.includes('/download')) {
+    pings.push(url);
+    return Promise.resolve({ status: 200, data: {} });
+  }
   calls.push(url);
   return reply(url);
 };
@@ -52,6 +61,7 @@ after(() => new Promise(r => server.close(r)));
 
 beforeEach(() => {
   calls = [];
+  pings = [];
   _resetPhoto();
   unsplash();
   clock += 1000;
@@ -90,9 +100,61 @@ test("Unsplash's own error text is not passed on, and a failure is not kept", as
     await getWallpaper();
     assert.equal(calls.length, 2);
   } finally {
-    reply = async () => ({
-      status: 200,
-      data: { urls: { raw: `https://images.unsplash.com/photo-${calls.length}?ixid=x` } },
-    });
+    reply = async () => ({ status: 200, data: photo() });
+  }
+});
+
+test('the photo comes with the photographer and Unsplash links', async () => {
+  const r = await getWallpaper();
+  assert.deepEqual(r.credit, {
+    name: 'Annie Spratt',
+    profile: 'https://unsplash.com/@anniespratt?utm_source=stackyard&utm_medium=referral',
+    site: 'https://unsplash.com/?utm_source=stackyard&utm_medium=referral',
+  });
+  assert.deepEqual((await getWallpaper()).credit, r.credit, 'the cached photo keeps its credit');
+});
+
+test('each new photo is reported as used once, with the key', async () => {
+  await getWallpaper();
+  await getWallpaper();
+  await new Promise(r => setImmediate(r));
+  assert.equal(pings.length, 1);
+  const u = new URL(pings[0]);
+  assert.equal(u.origin, 'https://api.unsplash.com');
+  assert.equal(u.pathname, '/photos/p1/download');
+  assert.equal(u.searchParams.get('client_id'), 'key-1');
+  assert.equal(u.searchParams.get('ixid'), 'x');
+});
+
+/* The key goes on this request. Another host would receive it. */
+test('a download link on another host is not followed', async () => {
+  reply = async () => ({
+    status: 200,
+    data: photo({ links: { download_location: 'https://evil.example/photos/p/download' } }),
+  });
+  try {
+    await getWallpaper();
+    await new Promise(r => setImmediate(r));
+    assert.equal(pings.length, 0);
+  } finally {
+    reply = async () => ({ status: 200, data: photo() });
+  }
+});
+
+test('a photographer handle that cannot form a profile link gives no credit', async () => {
+  for (const user of [undefined, {}, { username: '../x', name: 'X' }, { username: 'a b' }]) {
+    _resetPhoto();
+    reply = async () => ({ status: 200, data: photo({ user }) });
+    assert.equal((await getWallpaper()).credit, null, JSON.stringify(user));
+  }
+  reply = async () => ({ status: 200, data: photo() });
+});
+
+test('a photographer with no display name is credited by handle', async () => {
+  reply = async () => ({ status: 200, data: photo({ user: { username: 'anniespratt', name: '  ' } }) });
+  try {
+    assert.equal((await getWallpaper()).credit.name, 'anniespratt');
+  } finally {
+    reply = async () => ({ status: 200, data: photo() });
   }
 });
diff --git a/tsconfig.frontend.json b/tsconfig.frontend.json
index 90d72e0f..369790ac 100644
--- a/tsconfig.frontend.json
+++ b/tsconfig.frontend.json
@@ -338,6 +338,12 @@
       "/js/palette.js?v=*": [
         "./ui/js/palette.js"
       ],
+      "/js/photo-credit.js": [
+        "./ui/js/photo-credit.js"
+      ],
+      "/js/photo-credit.js?v=*": [
+        "./ui/js/photo-credit.js"
+      ],
       "/js/password-strength.js": [
         "./ui/js/password-strength.js"
       ],
diff --git a/ui/admin/index.html b/ui/admin/index.html
index 47b991a8..d60a71ee 100644
--- a/ui/admin/index.html
+++ b/ui/admin/index.html
@@ -319,6 +319,6 @@ <h1 class="sec-title" id="ev-title">General</h1>
   </div></div>
 </div>
 
-<script type="module" src="/js/admin.js?v=6ddbe5c0"></script>
+<script type="module" src="/js/admin.js?v=aeca5dee"></script>
 </body>
 </html>
diff --git a/ui/css/dashboard.css b/ui/css/dashboard.css
index 785783fa..9ea4f33f 100644
--- a/ui/css/dashboard.css
+++ b/ui/css/dashboard.css
@@ -409,6 +409,28 @@
     /* Mirrored by the no-dock reserve in desktopSlots(). */
     body.no-dock:not(.is-mob) #dots { bottom:24px }
 
+    /* ── Photo credit ── */
+    #photo-credit {
+      position:fixed; z-index:300;
+      inset-block-end:calc(14px + env(safe-area-inset-bottom)); inset-inline-start:calc(20px + env(safe-area-inset-left));
+      overflow:hidden; text-overflow:ellipsis; white-space:nowrap;
+      font-weight:500;
+      font-size:var(--fs-caption-2);line-height:var(--lh-caption-2);letter-spacing:var(--tr-caption-2);
+      color:var(--label-color-2); text-shadow:var(--label-shadow);
+      transition:color .2s;
+    }
+    #photo-credit[data-place="top"] { inset-block:calc(12px + env(safe-area-inset-top)) auto }
+    #photo-credit[data-tone="dark"] { color:var(--label-color-2-dark); text-shadow:var(--label-shadow-dark) }
+    #photo-credit:hover, #photo-credit:focus-within { color:var(--label-color) }
+    #photo-credit[data-tone="dark"]:hover, #photo-credit[data-tone="dark"]:focus-within { color:var(--label-color-dark) }
+    #photo-credit a { color:inherit; text-decoration:none }
+    #photo-credit a:hover { text-decoration:underline }
+    #photo-credit a:focus-visible { outline:2px solid currentColor; outline-offset:2px; border-radius:2px }
+    body.is-mob #photo-credit {
+      inset-block:max(4px, calc(var(--sa-top) - 16px)) auto; inset-inline:0;
+      width:fit-content; max-width:70vw; margin-inline:auto;
+    }
+
     /* ── Search pill — mobile only ── */
     #mob-search-pill {
       position:fixed; left:50%; z-index:500;
@@ -981,6 +1003,8 @@ body.is-mob .spot-field:focus-within { outline:2px solid var(--accent); outline-
   }
   .empty-state-mark, .empty-state-title, .empty-state-btn { color:#FFFFFF; }
   .empty-state-mark[data-tone="dark"], .empty-state-title[data-tone="dark"], .empty-state-btn[data-tone="dark"] { color:#000000; }
+  #photo-credit { color:#FFFFFF; }
+  #photo-credit[data-tone="dark"] { color:#000000; }
   .srn  { color:var(--label-primary); }
   .srh, .sr-section { color:rgba(235,235,245,.85); }
   .widget, .mob-widget-card { border-color:rgba(255,255,255,.35); }
diff --git a/ui/i18n/de.json b/ui/i18n/de.json
index 6715c7f3..9f7aa86a 100644
--- a/ui/i18n/de.json
+++ b/ui/i18n/de.json
@@ -316,6 +316,7 @@
     "searchInput": "Apps und Ordner durchsuchen",
     "noResults": "Keine Ergebnisse",
     "pagination": "Dashboard-Seiten",
+    "photoCredit": "Fotonachweis",
     "pageAnnounce": "Seite {page} von {total}",
     "goToPage": "Zu Seite {page} von {total}",
     "appsAndFolders": "Apps & Ordner",
diff --git a/ui/i18n/en.json b/ui/i18n/en.json
index d9a75e52..e4da224a 100644
--- a/ui/i18n/en.json
+++ b/ui/i18n/en.json
@@ -316,6 +316,7 @@
     "searchInput": "Search apps and folders",
     "noResults": "No results",
     "pagination": "Dashboard pages",
+    "photoCredit": "Photo credit",
     "pageAnnounce": "Page {page} of {total}",
     "goToPage": "Go to page {page} of {total}",
     "appsAndFolders": "Apps & Folders",
diff --git a/ui/i18n/es.json b/ui/i18n/es.json
index 38892f33..5ec587f7 100644
--- a/ui/i18n/es.json
+++ b/ui/i18n/es.json
@@ -322,6 +322,7 @@
     "searchInput": "Buscar aplicaciones y carpetas",
     "noResults": "Sin resultados",
     "pagination": "Páginas del panel",
+    "photoCredit": "Crédito de la foto",
     "pageAnnounce": "Página {page} de {total}",
     "goToPage": "Ir a la página {page} de {total}",
     "appsAndFolders": "Aplicaciones y carpetas",
diff --git a/ui/i18n/fa.json b/ui/i18n/fa.json
index 50c02409..85e0fe14 100644
--- a/ui/i18n/fa.json
+++ b/ui/i18n/fa.json
@@ -316,6 +316,7 @@
     "searchInput": "جستجوی برنامه‌ها و پوشه‌ها",
     "noResults": "نتیجه‌ای یافت نشد",
     "pagination": "صفحه‌های داشبورد",
+    "photoCredit": "منبع عکس",
     "pageAnnounce": "صفحه {page} از {total}",
     "goToPage": "رفتن به صفحه {page} از {total}",
     "appsAndFolders": "برنامه‌ها و پوشه‌ها",
diff --git a/ui/i18n/fr.json b/ui/i18n/fr.json
index 956233c2..263bb037 100644
--- a/ui/i18n/fr.json
+++ b/ui/i18n/fr.json
@@ -322,6 +322,7 @@
     "searchInput": "Rechercher des applications et des dossiers",
     "noResults": "Aucun résultat",
     "pagination": "Pages du tableau de bord",
+    "photoCredit": "Crédit photo",
     "pageAnnounce": "Page {page} sur {total}",
     "goToPage": "Aller à la page {page} sur {total}",
     "appsAndFolders": "Applications et dossiers",
diff --git a/ui/i18n/zh-Hans.json b/ui/i18n/zh-Hans.json
index 79372d63..372b5a97 100644
--- a/ui/i18n/zh-Hans.json
+++ b/ui/i18n/zh-Hans.json
@@ -310,6 +310,7 @@
     "searchInput": "搜索应用和文件夹",
     "noResults": "没有结果",
     "pagination": "仪表板页面",
+    "photoCredit": "照片来源",
     "pageAnnounce": "第 {page} 页，共 {total} 页",
     "goToPage": "转到第 {page} 页，共 {total} 页",
     "appsAndFolders": "应用与文件夹",
diff --git a/ui/index.html b/ui/index.html
index 7072cf5f..12c528be 100644
--- a/ui/index.html
+++ b/ui/index.html
@@ -26,7 +26,7 @@
   <script src="/js/admin-theme.js?v=66565254"></script>
   <title>Stackyard</title>
   <link rel="stylesheet" href="/css/tokens.css?v=4333b906">
-  <link rel="stylesheet" href="/css/dashboard.css?v=99f1ff06">
+  <link rel="stylesheet" href="/css/dashboard.css?v=024156b1">
   <link rel="stylesheet" href="/css/config-recovery.css?v=5fa2d249">
 </head>
 <body>
@@ -43,6 +43,7 @@
   <div class="msp-dots"></div>
 </div>
 <nav id="dock" aria-label="Dock" data-i18n-al="home.dock"></nav>
+<div id="photo-credit" role="group" aria-label="Photo credit" data-i18n-al="home.photoCredit" hidden></div>
 <dialog id="spot" aria-label="Search" data-i18n-al="home.searchDialog">
   <div id="sres-live" class="visually-hidden" aria-live="polite"></div>
   <div id="sres"></div>
@@ -56,5 +57,5 @@
     </div>
   </div>
 </dialog>
-<script type="module" src="/js/dashboard.js?v=4f4a5a40"></script>
+<script type="module" src="/js/dashboard.js?v=2a9d3585"></script>
 </body></html>
diff --git a/ui/js/admin-app-form.js b/ui/js/admin-app-form.js
index c3324ba1..167fce41 100644
--- a/ui/js/admin-app-form.js
+++ b/ui/js/admin-app-form.js
@@ -1,4 +1,4 @@
-import { clr, el, focusFirst, initial, inp as inpById, isolate, q as qSel, qa, qi, tgt } from '/js/utils.js?v=017012d7';
+import { clr, el, focusFirst, initial, inp as inpById, isolate, q as qSel, qa, qi, tgt } from '/js/utils.js?v=ab3cac1d';
 import { html, raw, setHtml } from '/js/html.js?v=c71f8903';
 import {
   loadLocalIcons,
@@ -33,10 +33,10 @@ import {
   reveal,
   setTogDisabled,
   swapContent,
-} from '/js/admin-shared.js?v=c509d11e';
-import { createListbox } from '/js/listbox.js?v=42aec241';
+} from '/js/admin-shared.js?v=f4752f33';
+import { createListbox } from '/js/listbox.js?v=b9f71853';
 import { MAX_LABELS } from '/js/badge-logic.js?v=85b1bc96';
-import { renderColorControl, BADGE_DEFAULT } from '/js/admin-color-control.js?v=b47faa12';
+import { renderColorControl, BADGE_DEFAULT } from '/js/admin-color-control.js?v=7d6a7623';
 import { badgeErrorAdvice, TONE } from '/js/admin-error.js?v=1c258dc1';
 import { fluidHoverClear, fluidHoverKb } from '/js/fluid-hover.js?v=eb6cc81c';
 import { iconSvg } from '/js/icon-set.js?v=26655aca';
diff --git a/ui/js/admin-auth.js b/ui/js/admin-auth.js
index 51a0b67d..b50a0c92 100644
--- a/ui/js/admin-auth.js
+++ b/ui/js/admin-auth.js
@@ -1,8 +1,8 @@
-import { apiGet, apiPost } from '/js/admin-shared.js?v=c509d11e';
+import { apiGet, apiPost } from '/js/admin-shared.js?v=f4752f33';
 import { initI18n, t } from '/js/i18n.js?v=ed7c5565';
 import { loginErrorKey } from '/js/admin-error.js?v=1c258dc1';
 import { pwStrength } from '/js/password-strength.js?v=389e0ed0';
-import { el, inp as inpById, qa } from '/js/utils.js?v=017012d7';
+import { el, inp as inpById, qa } from '/js/utils.js?v=ab3cac1d';
 import { blockingScreenFor } from '/js/config-recovery.js?v=85138697';
 
 export async function checkAuth(onLogin) {
diff --git a/ui/js/admin-color-control.js b/ui/js/admin-color-control.js
index 60b50a47..ab10365f 100644
--- a/ui/js/admin-color-control.js
+++ b/ui/js/admin-color-control.js
@@ -1,9 +1,9 @@
-import { PE_SVG, initInlineEdit, toast, reveal } from '/js/admin-shared.js?v=c509d11e';
+import { PE_SVG, initInlineEdit, toast, reveal } from '/js/admin-shared.js?v=f4752f33';
 import { t } from '/js/i18n.js?v=ed7c5565';
 import { html, raw, setHtml } from '/js/html.js?v=c71f8903';
-import { qa, q } from '/js/utils.js?v=017012d7';
+import { qa, q } from '/js/utils.js?v=ab3cac1d';
 import { iconSvg } from '/js/icon-set.js?v=26655aca';
-import { createListbox } from '/js/listbox.js?v=42aec241';
+import { createListbox } from '/js/listbox.js?v=b9f71853';
 import { HUE_NAMES, ROLE_NAMES, TILE_KEYWORDS, pageTheme, tileColor } from '/js/palette.js?v=3fb8ae43';
 
 const CC_SWATCHES = ['#1c1c1e', '#8e8e93', '#f2f2f7', '#ff393c', '#ffcd00', '#35c759', '#0289ff', '#cb30df'];
diff --git a/ui/js/admin-drag.js b/ui/js/admin-drag.js
index 554a59fd..93a2acfc 100644
--- a/ui/js/admin-drag.js
+++ b/ui/js/admin-drag.js
@@ -19,7 +19,7 @@ import {
 import { DOCK_MAX } from '/js/limits.js?v=ea61a441';
 import { state } from '/js/admin-state.js?v=064b9b85';
 import { snapshotItems } from '/js/admin-save-logic.js?v=b83791fb';
-import { qa } from '/js/utils.js?v=017012d7';
+import { qa } from '/js/utils.js?v=ab3cac1d';
 
 /** @type {(before: unknown) => void} */
 let _save = () => {};
diff --git a/ui/js/admin-list.js b/ui/js/admin-list.js
index a72b4075..2cac61d2 100644
--- a/ui/js/admin-list.js
+++ b/ui/js/admin-list.js
@@ -15,14 +15,14 @@ import { collapsedFolders, filter, state } from '/js/admin-state.js?v=064b9b85';
 import { snapshotItems } from '/js/admin-save-logic.js?v=b83791fb';
 import { isShownChild, reorderItems, shownChildren, topLevelRows } from '/js/admin-logic.js?v=28471483';
 import { listGroup } from '/js/admin-drag-logic.js?v=4aae5094';
-import { initDrag, redrawHeld, wireDockZone, wireRowDrag } from '/js/admin-drag.js?v=e2c9c061';
+import { initDrag, redrawHeld, wireDockZone, wireRowDrag } from '/js/admin-drag.js?v=1c4004a0';
 import { DOCK_MAX } from '/js/limits.js?v=ea61a441';
 import { formatNumber } from '/js/format-number.js?v=abcd4ae4';
-import { paintIcon, toast } from '/js/admin-shared.js?v=c509d11e';
-import { clr, el, focusFirst, initial, qa, setUserText } from '/js/utils.js?v=017012d7';
+import { paintIcon, toast } from '/js/admin-shared.js?v=f4752f33';
+import { clr, el, focusFirst, initial, qa, setUserText } from '/js/utils.js?v=ab3cac1d';
 import { html, raw, setHtml } from '/js/html.js?v=c71f8903';
 import { t } from '/js/i18n.js?v=ed7c5565';
-import { sizeLabel } from '/js/admin-widget-form.js?v=b480a481';
+import { sizeLabel } from '/js/admin-widget-form.js?v=a5539971';
 import { widgetGlyph } from '/js/widget-glyphs.js?v=479a53ee';
 import { iconSvg } from '/js/icon-set.js?v=26655aca';
 
diff --git a/ui/js/admin-settings.js b/ui/js/admin-settings.js
index 41f2ba72..0aca9e30 100644
--- a/ui/js/admin-settings.js
+++ b/ui/js/admin-settings.js
@@ -1,4 +1,4 @@
-import { toast, apiGet, apiPost, errorText, reveal, swapContent, wireInlineEdit } from '/js/admin-shared.js?v=c509d11e';
+import { toast, apiGet, apiPost, errorText, reveal, swapContent, wireInlineEdit } from '/js/admin-shared.js?v=f4752f33';
 import { socketProbeAdvice } from '/js/admin-error.js?v=1c258dc1';
 import { pwStrength } from '/js/password-strength.js?v=389e0ed0';
 import { t } from '/js/i18n.js?v=ed7c5565';
@@ -11,11 +11,11 @@ import {
   BLOCK,
 } from '/js/admin-logic.js?v=28471483';
 import { confirmText, promptModal } from '/js/modal.js?v=6b0320bd';
-import { el, inp, setUserText } from '/js/utils.js?v=017012d7';
+import { el, inp, setUserText } from '/js/utils.js?v=ab3cac1d';
 import { formatNumber } from '/js/format-number.js?v=abcd4ae4';
 import { serialWrites } from '/js/admin-save-logic.js?v=b83791fb';
-import { renderColorControl } from '/js/admin-color-control.js?v=b47faa12';
-import { BACKDROP } from '/js/background.js?v=4d651887';
+import { renderColorControl } from '/js/admin-color-control.js?v=7d6a7623';
+import { BACKDROP } from '/js/background.js?v=288bfc2a';
 import {
   ALLOWED_HOSTS_MAX,
   firstBadHost,
diff --git a/ui/js/admin-shared.js b/ui/js/admin-shared.js
index ed926c13..7652e73d 100644
--- a/ui/js/admin-shared.js
+++ b/ui/js/admin-shared.js
@@ -1,6 +1,6 @@
 /* Stateless helpers shared by the admin modules. Mutable state stays out. */
 import { recoversSession, toastHoldMs } from '/js/admin-logic.js?v=28471483';
-import { el, isolate, q } from '/js/utils.js?v=017012d7';
+import { el, isolate, q } from '/js/utils.js?v=ab3cac1d';
 import { t } from '/js/i18n.js?v=ed7c5565';
 import { errorAdvice } from '/js/admin-error.js?v=1c258dc1';
 import { formatList, formatNumber } from '/js/format-number.js?v=abcd4ae4';
diff --git a/ui/js/admin-widget-form.js b/ui/js/admin-widget-form.js
index 4b5affff..a7d63206 100644
--- a/ui/js/admin-widget-form.js
+++ b/ui/js/admin-widget-form.js
@@ -1,11 +1,11 @@
 import { state } from '/js/admin-state.js?v=064b9b85';
-import { PE_SVG, initInlineEdit, swapContent } from '/js/admin-shared.js?v=c509d11e';
-import { createListbox } from '/js/listbox.js?v=42aec241';
-import { renderWidgetConfigForm } from '/js/widget-config-form.js?v=5c591625';
+import { PE_SVG, initInlineEdit, swapContent } from '/js/admin-shared.js?v=f4752f33';
+import { createListbox } from '/js/listbox.js?v=b9f71853';
+import { renderWidgetConfigForm } from '/js/widget-config-form.js?v=92ca09de';
 import { html, raw, setHtml } from '/js/html.js?v=c71f8903';
 import { sizesForView, widgetConfigMode, rejectionLines, carriesTypedValues } from '/js/admin-logic.js?v=28471483';
 import { t } from '/js/i18n.js?v=ed7c5565';
-import { focusFirst, q, qi, qa } from '/js/utils.js?v=017012d7';
+import { focusFirst, q, qi, qa } from '/js/utils.js?v=ab3cac1d';
 import { iconSvg } from '/js/icon-set.js?v=26655aca';
 
 const SIZES_WITH_ICONS = new Set(['small', 'medium', 'large', 'xlarge']);
diff --git a/ui/js/admin.js b/ui/js/admin.js
index 69838c6c..94916cb1 100644
--- a/ui/js/admin.js
+++ b/ui/js/admin.js
@@ -4,10 +4,10 @@ import {
   buildSettingsTileForm,
   captureActLabels,
   serializeKvRows,
-} from '/js/admin-app-form.js?v=63c9ce52';
-import { checkAuth, requireLogin, wirePasswordStrength } from '/js/admin-auth.js?v=d4c794a0';
+} from '/js/admin-app-form.js?v=925a4b11';
+import { checkAuth, requireLogin, wirePasswordStrength } from '/js/admin-auth.js?v=ec5cd673';
 import { recoveryShown } from '/js/config-recovery.js?v=85138697';
-import { focusRow, initList, render, syncFilterUI } from '/js/admin-list.js?v=24b894eb';
+import { focusRow, initList, render, syncFilterUI } from '/js/admin-list.js?v=511689a7';
 import { resolveAdminSection, settleDock } from '/js/admin-logic.js?v=28471483';
 import {
   afterImport,
@@ -31,7 +31,7 @@ import {
   wireUnsplashKey,
   wireProxmox,
   applyHealthChecks,
-} from '/js/admin-settings.js?v=649babe5';
+} from '/js/admin-settings.js?v=8eb7db69';
 import {
   apiGet,
   apiPost,
@@ -45,13 +45,13 @@ import {
   setReauthHandler,
   toast,
   withheldText,
-} from '/js/admin-shared.js?v=c509d11e';
+} from '/js/admin-shared.js?v=f4752f33';
 import { collapsedFolders, filter, state } from '/js/admin-state.js?v=064b9b85';
-import { buildWidgetForm } from '/js/admin-widget-form.js?v=b480a481';
+import { buildWidgetForm } from '/js/admin-widget-form.js?v=a5539971';
 import { initFluidHover } from '/js/fluid-hover.js?v=eb6cc81c';
 import { formatNumber } from '/js/format-number.js?v=abcd4ae4';
 import { initGlideSelect, syncGlideSelect } from '/js/glide-select.js?v=75a71ab4';
-import { createListbox } from '/js/listbox.js?v=42aec241';
+import { createListbox } from '/js/listbox.js?v=b9f71853';
 import { html, raw, setHtml } from '/js/html.js?v=c71f8903';
 import { initI18n, LANGUAGES, t } from '/js/i18n.js?v=ed7c5565';
 import { loadLocalIcons } from '/js/icons.js?v=5ac01d72';
@@ -92,8 +92,8 @@ import {
   storeGet,
   storeSet,
   tgt,
-} from '/js/utils.js?v=017012d7';
-import { applyBackground, resolveBackground } from '/js/background.js?v=4d651887';
+} from '/js/utils.js?v=ab3cac1d';
+import { applyBackground, resolveBackground } from '/js/background.js?v=288bfc2a';
 import { parseYamlTolerant, YamlLiteError, YamlTooLargeError } from '/js/yaml-lite.js?v=a42ef914';
 
 ensureSprite();
diff --git a/ui/js/background.js b/ui/js/background.js
index c1cb427d..9d0cd467 100644
--- a/ui/js/background.js
+++ b/ui/js/background.js
@@ -1,17 +1,18 @@
 // @ts-check
-import { cssColor, sanitizeCssUrl } from '/js/utils.js?v=017012d7';
-import { loadWallpaper, saveWallpaper } from '/js/wallpaper-cache.js?v=c5f8a3e6';
+import { cssColor, sanitizeCssUrl } from '/js/utils.js?v=ab3cac1d';
+import { loadWallpaper, saveWallpaper, validCredit } from '/js/wallpaper-cache.js?v=321c8003';
 
 export const BACKDROP = '#0d1117';
 
 const DEFAULT_BRIGHTNESS = 0.62;
 
+/** @typedef {{ name: string, profile: string, site: string }} PhotoCredit */
 /** @typedef {{ image: string, color: string, brightness: string, size: string,
-                url: string|null, fit: 'fit'|'fill' }} Background */
+                url: string|null, fit: 'fit'|'fill', credit: PhotoCredit|null }} Background */
 
-/** @param {any} bg @param {string|null} [wallpaperUrl]
+/** @param {any} bg @param {string|null} [wallpaperUrl] @param {PhotoCredit|null} [credit]
     @returns {Background|null} */
-export function backgroundFor(bg, wallpaperUrl = null) {
+export function backgroundFor(bg, wallpaperUrl = null, credit = null) {
   const s = bg || {};
   if (s.type === 'color' && s.color) {
     return {
@@ -21,6 +22,7 @@ export function backgroundFor(bg, wallpaperUrl = null) {
       size: 'cover',
       url: null,
       fit: 'fill',
+      credit: null,
     };
   }
   const url = s.type === 'url' ? s.url : s.type === 'unsplash' ? wallpaperUrl : null;
@@ -34,6 +36,7 @@ export function backgroundFor(bg, wallpaperUrl = null) {
     size: fit === 'fit' ? 'contain' : 'cover',
     url: sanitizeCssUrl(url),
     fit,
+    credit: s.type === 'unsplash' ? credit : null,
   };
 }
 
@@ -45,14 +48,16 @@ export function applyBackground(root, b) {
   root.style.setProperty('--bg-size', b.size);
 }
 
-async function unsplashUrl(bg) {
+/** @param {any} bg @returns {Promise<{ url: string, credit: PhotoCredit|null }|null>} */
+async function unsplashPhoto(bg) {
   const cached = loadWallpaper(bg);
   if (cached) return cached;
   const r = await fetch('/api/wallpaper', { cache: 'no-store' });
   const d = await r.json();
-  const url = d.url || null;
-  if (url) saveWallpaper(url, bg);
-  return url;
+  if (typeof d.url !== 'string' || !d.url) return null;
+  const photo = { url: d.url, credit: validCredit(d.credit) };
+  saveWallpaper(photo, bg);
+  return photo;
 }
 
 const decoded = url =>
@@ -67,9 +72,9 @@ const decoded = url =>
 export async function resolveBackground(bg) {
   const s = bg || {};
   if (s.type === 'unsplash') {
-    const url = await unsplashUrl(s);
-    if (!url) return null;
-    return (await decoded(url)) ? backgroundFor(s, url) : null;
+    const photo = await unsplashPhoto(s);
+    if (!photo) return null;
+    return (await decoded(photo.url)) ? backgroundFor(s, photo.url, photo.credit) : null;
   }
   return backgroundFor(s);
 }
diff --git a/ui/js/dashboard.js b/ui/js/dashboard.js
index 91e7e8aa..750c2d98 100644
--- a/ui/js/dashboard.js
+++ b/ui/js/dashboard.js
@@ -28,9 +28,9 @@ import {
   storeSet,
   teardownWidgets,
   titleWhenTruncated,
-} from '/js/utils.js?v=017012d7';
+} from '/js/utils.js?v=ab3cac1d';
 import { initFluidHover } from '/js/fluid-hover.js?v=eb6cc81c';
-import { initSpotlight } from '/js/spotlight.js?v=73fdaf2e';
+import { initSpotlight } from '/js/spotlight.js?v=93d9e423';
 import { html, setHtml, raw } from '/js/html.js?v=c71f8903';
 import { initI18n, t, currentLang } from '/js/i18n.js?v=ed7c5565';
 import { blockingScreenFor, showBlockingScreen } from '/js/config-recovery.js?v=85138697';
@@ -47,7 +47,7 @@ import {
   resetMobileChrome,
   mkFolderGlyph,
   swipePager,
-} from '/js/ui.js?v=9af2a487';
+} from '/js/ui.js?v=dbd45ff7';
 import { badgeMinimum, badgeSignature, computeBadgeVisual, readBadgeUpdate } from '/js/badge-logic.js?v=85b1bc96';
 import { formatNumber } from '/js/format-number.js?v=abcd4ae4';
 import { closeBadgePopover, wireBadgePopover } from '/js/badge-popover.js?v=23793736';
@@ -60,11 +60,12 @@ import {
   restorePage,
   wheelPager,
 } from '/js/dashboard-logic.js?v=5fa66027';
-import { applyBackground, BACKDROP, resolveBackground } from '/js/background.js?v=4d651887';
+import { applyBackground, BACKDROP, resolveBackground } from '/js/background.js?v=288bfc2a';
+import { creditPlacement, showPhotoCredit } from '/js/photo-credit.js?v=1801451c';
 import { repeatJittered } from '/js/jitter.js?v=087a1fcf';
 import { isMobileLayout, onLayoutChange } from '/js/layout.js?v=6680c0bf';
 import { startWakeLock } from '/js/wake-lock.js?v=6b9591cf';
-import { applyLabelTones, loadSamplingImage, sampleImage, toneForColor } from '/js/label-contrast.js?v=4e97555e';
+import { applyLabelTones, loadSamplingImage, sampleImage, toneForColor } from '/js/label-contrast.js?v=46ab91e5';
 import { ensureSprite, iconSvg } from '/js/icon-set.js?v=26655aca';
 import { pageTheme, paletteColor } from '/js/palette.js?v=3fb8ae43';
 import { THEME_KEY, applyTheme, prefersDark, readMode, resolveTheme } from '/js/theme.js?v=eeafa4b5';
@@ -539,8 +540,30 @@ function syncMobPages() {
    the labels as they are. */
 let bgTone = { grid: null, tone: null };
 
+const CREDIT_EDGE = 20;
+
+function placeCredit() {
+  const credit = el('photo-credit');
+  if (!credit || credit.hidden) return;
+  if (document.body.classList.contains('is-mob')) {
+    credit.removeAttribute('data-place');
+    credit.style.removeProperty('max-width');
+    return;
+  }
+  const dock = document.body.classList.contains('no-dock') ? null : el('dock').getBoundingClientRect();
+  const { place, maxWidth } = creditPlacement(
+    window.innerWidth,
+    dock,
+    document.documentElement.dir === 'rtl',
+    CREDIT_EDGE,
+  );
+  credit.dataset.place = place;
+  credit.style.maxWidth = `${maxWidth}px`;
+}
+
 function retone() {
   requestAnimationFrame(() => {
+    placeCredit();
     applyLabelTones(bgTone);
     /* Same frame: both need the layout the build produced, and both re-run on a
        rebuild and a resize for the same reason. */
@@ -582,6 +605,7 @@ async function applyBg() {
   bgTone = { grid: null, tone: themeTone() };
   retone();
   const bg = await resolveBackground(S.background || {});
+  showPhotoCredit(el('photo-credit'), bg?.credit ?? null);
   if (!bg) return;
   applyBackground(root, bg);
   if (bg.url) {
diff --git a/ui/js/label-contrast.js b/ui/js/label-contrast.js
index 34bde3de..6e666b2e 100644
--- a/ui/js/label-contrast.js
+++ b/ui/js/label-contrast.js
@@ -234,8 +234,9 @@ export function loadSamplingImage(url) {
 }
 
 /* The page indicator is chrome over the same wallpaper, and it is tinted rather
-   than inked, so it needs the same reading. So does the empty dashboard's text. */
-const LABEL_SELECTOR = '.ilabel, .dyn-mob-label, .dyn-fold-label, #dots, .empty-state > *';
+   than inked, so it needs the same reading. So do the photo credit and the empty
+   dashboard's text. */
+const LABEL_SELECTOR = '.ilabel, .dyn-mob-label, .dyn-fold-label, #dots, #photo-credit, .empty-state > *';
 
 /* A folder overlay lays its own scrim over the background. */
 const SCRIM = '.folder-overlay, .folder-overlay-mobile';
diff --git a/ui/js/listbox.js b/ui/js/listbox.js
index ebc21c4d..022255c2 100644
--- a/ui/js/listbox.js
+++ b/ui/js/listbox.js
@@ -10,7 +10,7 @@ import { nextActiveIndex, singleChoice } from '/js/admin-logic.js?v=28471483';
 import { fluidHoverClear, fluidHoverKb } from '/js/fluid-hover.js?v=eb6cc81c';
 import { formatList } from '/js/format-number.js?v=abcd4ae4';
 import { html, raw, setHtml } from '/js/html.js?v=c71f8903';
-import { qa } from '/js/utils.js?v=017012d7';
+import { qa } from '/js/utils.js?v=ab3cac1d';
 import { iconSvg } from '/js/icon-set.js?v=26655aca';
 
 const CHEV = iconSvg('chevrons', 22, 'solid', 'dd-chev');
diff --git a/ui/js/photo-credit.js b/ui/js/photo-credit.js
new file mode 100644
index 00000000..783d8e54
--- /dev/null
+++ b/ui/js/photo-credit.js
@@ -0,0 +1,41 @@
+// @ts-check
+
+/** The narrowest bottom slot that still fits a short name. */
+const MIN_SLOT = 120;
+
+/** Where the desktop credit goes: beside the Dock while it fits, else the top
+    corner. Keep the credit off the Dock. It is fixed at the same bottom edge.
+
+    @param {number} vw the viewport width
+    @param {{left:number, right:number}|null} dock the Dock's box, or null with no Dock
+    @param {boolean} rtl
+    @param {number} edge the gap kept from the screen edge and from the Dock
+    @returns {{ place: 'bottom'|'top', maxWidth: number }} */
+export function creditPlacement(vw, dock, rtl, edge) {
+  const room = dock ? (rtl ? vw - dock.right : dock.left) - 2 * edge : vw / 2 - edge;
+  return room >= MIN_SLOT
+    ? { place: 'bottom', maxWidth: Math.floor(room) }
+    : { place: 'top', maxWidth: Math.floor(vw / 2 - edge) };
+}
+
+/** @param {string} text @param {string} href @returns {HTMLAnchorElement} */
+function creditLink(text, href) {
+  const a = document.createElement('a');
+  a.href = href;
+  a.textContent = text;
+  a.target = '_blank';
+  a.rel = 'noopener noreferrer';
+  return a;
+}
+
+/** Shows the photographer and Unsplash links, or hides the element.
+
+    @param {HTMLElement|null} el
+    @param {{ name: string, profile: string, site: string }|null} credit
+    @returns {void} */
+export function showPhotoCredit(el, credit) {
+  if (!el) return;
+  el.replaceChildren();
+  el.hidden = !credit;
+  if (credit) el.append(creditLink(credit.name, credit.profile), ' / ', creditLink('Unsplash', credit.site));
+}
diff --git a/ui/js/spotlight.js b/ui/js/spotlight.js
index c4a124e2..edfc8919 100644
--- a/ui/js/spotlight.js
+++ b/ui/js/spotlight.js
@@ -1,5 +1,5 @@
 import { fluidHoverClear, fluidHoverKb } from '/js/fluid-hover.js?v=eb6cc81c';
-import { mk, clr, el, initial, inp as inpById, q, qa, setUserText } from '/js/utils.js?v=017012d7';
+import { mk, clr, el, initial, inp as inpById, q, qa, setUserText } from '/js/utils.js?v=ab3cac1d';
 import { t } from '/js/i18n.js?v=ed7c5565';
 
 /* Attached to the window so a re-open can undo the previous one. */
diff --git a/ui/js/ui.js b/ui/js/ui.js
index 49b54e9b..a4a31164 100644
--- a/ui/js/ui.js
+++ b/ui/js/ui.js
@@ -17,9 +17,9 @@ import {
   qa,
   setCentredText,
   setUserText,
-} from '/js/utils.js?v=017012d7';
+} from '/js/utils.js?v=ab3cac1d';
 import { t, currentLang } from '/js/i18n.js?v=ed7c5565';
-import { toneForColor } from '/js/label-contrast.js?v=4e97555e';
+import { toneForColor } from '/js/label-contrast.js?v=46ab91e5';
 import { mobileMetrics, gridColumnWidth, gridCellCount, dockFit } from '/js/mobile-metrics.js?v=938a32a2';
 import { smoothRectPath } from '/js/smooth-corner.js?v=b7dda7e1';
 import { mkGlassRim, observeGlass } from '/js/glass-rim.js?v=3faec233';
diff --git a/ui/js/utils.js b/ui/js/utils.js
index e71c5bd7..605ed783 100644
--- a/ui/js/utils.js
+++ b/ui/js/utils.js
@@ -1,5 +1,5 @@
 import { iconChain } from '/js/icons.js?v=5ac01d72';
-import { toneForColor } from '/js/label-contrast.js?v=4e97555e';
+import { toneForColor } from '/js/label-contrast.js?v=46ab91e5';
 import { SETTINGS_ICON, SETTINGS_ICON_LIGHT } from '/js/settings-icon.js?v=4079b66a';
 import { mkGlassRim } from '/js/glass-rim.js?v=3faec233';
 import { smoothRectPath } from '/js/smooth-corner.js?v=b7dda7e1';
diff --git a/ui/js/wallpaper-cache.js b/ui/js/wallpaper-cache.js
index 87d1b355..0585eaca 100644
--- a/ui/js/wallpaper-cache.js
+++ b/ui/js/wallpaper-cache.js
@@ -12,12 +12,29 @@ function wallpaperKey(bg) {
   return `${bg?.type || ''}|${bg?.collection || ''}`;
 }
 
-/** The still-valid wallpaper URL held for these background settings, if any.
+/** @typedef {{ name: string, profile: string, site: string }} PhotoCredit */
+/** @typedef {{ url: string, credit: PhotoCredit|null }} CachedWallpaper */
+
+const UNSPLASH = 'https://unsplash.com/';
+
+/** A credit the page may render as links, or null.
+
+    @param {any} c @returns {PhotoCredit|null} */
+export function validCredit(c) {
+  if (!c || typeof c !== 'object') return null;
+  const { name, profile, site } = c;
+  if (typeof name !== 'string' || !name.trim()) return null;
+  if (typeof profile !== 'string' || !profile.startsWith(UNSPLASH)) return null;
+  if (typeof site !== 'string' || !site.startsWith(UNSPLASH)) return null;
+  return { name, profile, site };
+}
+
+/** The still-valid wallpaper held for these background settings, if any.
 
     @param {string|null|undefined} stored the raw stored entry
     @param {any} bg the background settings the page was built from
     @param {number} now
-    @returns {string|null} */
+    @returns {CachedWallpaper|null} */
 export function readWallpaperCache(stored, bg, now) {
   if (typeof stored !== 'string' || !stored) return null;
   let entry;
@@ -31,15 +48,17 @@ export function readWallpaperCache(stored, bg, now) {
   if (typeof entry.at !== 'number' || !Number.isFinite(entry.at)) return null;
   /* A clock moved backwards would otherwise hold one photo forever. */
   if (now < entry.at || now - entry.at >= WALLPAPER_TTL_MS) return null;
-  return entry.url;
+  /* Keep. An entry stored before credits would show the photo uncredited. */
+  if (!('credit' in entry)) return null;
+  return { url: entry.url, credit: validCredit(entry.credit) };
 }
 
-/** @param {string} url @param {any} bg @param {number} now @returns {string} */
-export function writeWallpaperCache(url, bg, now) {
-  return JSON.stringify({ url, key: wallpaperKey(bg), at: now });
+/** @param {CachedWallpaper} wallpaper @param {any} bg @param {number} now @returns {string} */
+export function writeWallpaperCache(wallpaper, bg, now) {
+  return JSON.stringify({ url: wallpaper.url, credit: wallpaper.credit, key: wallpaperKey(bg), at: now });
 }
 
-/** @param {any} bg @param {number} [now] @returns {string|null} */
+/** @param {any} bg @param {number} [now] @returns {CachedWallpaper|null} */
 export function loadWallpaper(bg, now = Date.now()) {
   let stored = null;
   try {
@@ -50,9 +69,9 @@ export function loadWallpaper(bg, now = Date.now()) {
   return readWallpaperCache(stored, bg, now);
 }
 
-/** @param {string} url @param {any} bg @param {number} [now] @returns {void} */
-export function saveWallpaper(url, bg, now = Date.now()) {
+/** @param {CachedWallpaper} wallpaper @param {any} bg @param {number} [now] @returns {void} */
+export function saveWallpaper(wallpaper, bg, now = Date.now()) {
   try {
-    localStorage.setItem(WALLPAPER_STORE, writeWallpaperCache(url, bg, now));
+    localStorage.setItem(WALLPAPER_STORE, writeWallpaperCache(wallpaper, bg, now));
   } catch {}
 }
diff --git a/ui/js/widget-config-form.js b/ui/js/widget-config-form.js
index b20aadbc..f7aef780 100644
--- a/ui/js/widget-config-form.js
+++ b/ui/js/widget-config-form.js
@@ -3,9 +3,9 @@
 
 import { t } from '/js/i18n.js?v=ed7c5565';
 import { html, raw, setHtml } from '/js/html.js?v=c71f8903';
-import { reveal, wireInlineEdit } from '/js/admin-shared.js?v=c509d11e';
-import { createListbox } from '/js/listbox.js?v=42aec241';
-import { renderColorControl } from '/js/admin-color-control.js?v=b47faa12';
+import { reveal, wireInlineEdit } from '/js/admin-shared.js?v=f4752f33';
+import { createListbox } from '/js/listbox.js?v=b9f71853';
+import { renderColorControl } from '/js/admin-color-control.js?v=7d6a7623';
 import {
   seedCarried,
   applyOptionSet,
@@ -16,7 +16,7 @@ import {
   isPlainField,
 } from '/js/admin-logic.js?v=28471483';
 import { optionsErrorAdvice, TONE } from '/js/admin-error.js?v=1c258dc1';
-import { qi } from '/js/utils.js?v=017012d7';
+import { qi } from '/js/utils.js?v=ab3cac1d';
 import { formatNumber } from '/js/format-number.js?v=abcd4ae4';
 import { SAVED_ROW } from '/js/saved-row.js?v=44039df6';
 
diff --git a/ui/test/photo-credit.test.mjs b/ui/test/photo-credit.test.mjs
new file mode 100644
index 00000000..1b0ea529
--- /dev/null
+++ b/ui/test/photo-credit.test.mjs
@@ -0,0 +1,24 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { register } from 'node:module';
+
+register('./js-root-hooks.mjs', import.meta.url);
+
+const { creditPlacement } = await import('../js/photo-credit.js');
+
+test('the credit sits beside the Dock, limited to the room left of it', () => {
+  assert.deepEqual(creditPlacement(1440, { left: 520, right: 920 }, false, 20), { place: 'bottom', maxWidth: 480 });
+});
+
+test('in a right-to-left layout the room is measured right of the Dock', () => {
+  assert.deepEqual(creditPlacement(1440, { left: 400, right: 1000 }, true, 20), { place: 'bottom', maxWidth: 400 });
+});
+
+/* Both are fixed to the bottom edge, so a credit wider than the room overlaps the Dock. */
+test('a Dock that leaves too little room moves the credit to the top', () => {
+  assert.equal(creditPlacement(800, { left: 100, right: 700 }, false, 20).place, 'top');
+});
+
+test('with no Dock the credit keeps the bottom corner', () => {
+  assert.deepEqual(creditPlacement(1000, null, false, 20), { place: 'bottom', maxWidth: 480 });
+});
diff --git a/ui/test/wallpaper-cache.test.mjs b/ui/test/wallpaper-cache.test.mjs
index d7f2ef6d..0ab6df7b 100644
--- a/ui/test/wallpaper-cache.test.mjs
+++ b/ui/test/wallpaper-cache.test.mjs
@@ -4,7 +4,13 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
 
-import { loadWallpaper, readWallpaperCache, saveWallpaper, writeWallpaperCache } from '../js/wallpaper-cache.js';
+import {
+  loadWallpaper,
+  readWallpaperCache,
+  saveWallpaper,
+  validCredit,
+  writeWallpaperCache,
+} from '../js/wallpaper-cache.js';
 
 /* ── the wallpaper across a reload ────────────────────────────────────────── */
 
@@ -15,27 +21,33 @@ import { loadWallpaper, readWallpaperCache, saveWallpaper, writeWallpaperCache }
 const BG = { type: 'unsplash', collection: '1234' };
 const T0 = 1_760_000_000_000;
 const DAY = 24 * 60 * 60 * 1000;
+const CREDIT = {
+  name: 'Annie Spratt',
+  profile: 'https://unsplash.com/@anniespratt?utm_source=stackyard&utm_medium=referral',
+  site: 'https://unsplash.com/?utm_source=stackyard&utm_medium=referral',
+};
+const PHOTO = { url: 'https://images/a.jpg', credit: CREDIT };
 
 test('a reload inside the cache window keeps the same photo', () => {
-  const stored = writeWallpaperCache('https://images/a.jpg', BG, T0);
-  assert.equal(readWallpaperCache(stored, BG, T0), 'https://images/a.jpg');
-  assert.equal(readWallpaperCache(stored, BG, T0 + DAY - 1), 'https://images/a.jpg');
+  const stored = writeWallpaperCache(PHOTO, BG, T0);
+  assert.deepEqual(readWallpaperCache(stored, BG, T0), PHOTO);
+  assert.deepEqual(readWallpaperCache(stored, BG, T0 + DAY - 1), PHOTO);
 });
 
 test('the photo is replaced once the window has passed', () => {
-  const stored = writeWallpaperCache('https://images/a.jpg', BG, T0);
+  const stored = writeWallpaperCache(PHOTO, BG, T0);
   assert.equal(readWallpaperCache(stored, BG, T0 + DAY), null);
 });
 
 test('changing the background settings picks a new photo', () => {
-  const stored = writeWallpaperCache('https://images/a.jpg', BG, T0);
+  const stored = writeWallpaperCache(PHOTO, BG, T0);
   assert.equal(readWallpaperCache(stored, { ...BG, collection: '9999' }, T0), null);
   assert.equal(readWallpaperCache(stored, { type: 'color' }, T0), null);
 });
 
 /* A clock that moved backwards would otherwise hold one photo indefinitely. */
 test('an entry stamped in the future is discarded', () => {
-  const stored = writeWallpaperCache('https://images/a.jpg', BG, T0);
+  const stored = writeWallpaperCache(PHOTO, BG, T0);
   assert.equal(readWallpaperCache(stored, BG, T0 - 1000), null);
 });
 
@@ -50,5 +62,36 @@ test('a missing or unusable entry asks for a new photo', () => {
    context that loads the module. */
 test('a page with no usable storage falls back to a fresh photo', () => {
   assert.equal(loadWallpaper(BG, T0), null);
-  assert.doesNotThrow(() => saveWallpaper('https://images/a.jpg', BG, T0));
+  assert.doesNotThrow(() => saveWallpaper(PHOTO, BG, T0));
+});
+
+/* An entry stored before credits existed would show an Unsplash photo with no
+   credit for up to a day. */
+test('an entry without a credit field asks for a new photo', () => {
+  const old = JSON.stringify({ url: 'https://images/a.jpg', key: 'unsplash|1234', at: T0 });
+  assert.equal(readWallpaperCache(old, BG, T0), null);
+});
+
+test('a stored credit that is not a pair of Unsplash links is dropped', () => {
+  const stored = JSON.stringify({
+    ...PHOTO,
+    credit: { ...CREDIT, profile: 'javascript:alert(1)' },
+    key: 'unsplash|1234',
+    at: T0,
+  });
+  assert.deepEqual(readWallpaperCache(stored, BG, T0), { url: PHOTO.url, credit: null });
+});
+
+test('only a named credit with two unsplash.com links is valid', () => {
+  assert.deepEqual(validCredit(CREDIT), CREDIT);
+  for (const bad of [
+    null,
+    'x',
+    { ...CREDIT, name: ' ' },
+    { ...CREDIT, profile: 'https://evil.example/@a' },
+    { ...CREDIT, site: 'http://unsplash.com/' },
+    { ...CREDIT, profile: 'https://unsplash.com.evil.example/' },
+  ]) {
+    assert.equal(validCredit(bad), null, JSON.stringify(bad));
+  }
 });