diff --git a/package-lock.json b/package-lock.json
index 9df970b..b953096 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "qortium-explore",
-  "version": "1.4.7",
+  "version": "1.4.9",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "qortium-explore",
-      "version": "1.4.7",
+      "version": "1.4.9",
       "hasInstallScript": true,
       "license": "0BSD",
       "dependencies": {
diff --git a/package.json b/package.json
index fb0e0cf..d73a665 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "qortium-explore",
-  "version": "1.4.8",
+  "version": "1.4.9",
   "private": true,
   "license": "0BSD",
   "description": "Browse, search, inspect, and open public Qortium QDN resources.",
diff --git a/src/App.tsx b/src/App.tsx
index 06f0ccc..825785a 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -8,6 +8,7 @@ import { createTranslator } from './i18n';
 import { detectGitRepositoryLayout } from './qdnGitRepository';
 import { NameOwnerIdentity } from './NameOwnerIdentity';
 import { hasHomeBridge, qdnRequest } from './qdnRequest';
+import { loadResourceDetails } from './resourceDetails';
 import { resourceFetchRequest, resourceFiles } from './resourceFiles';
 import { isBrowserArchiveService, PUBLIC_QDN_SERVICES } from './services';
 import { sortRows, type Sort, updatedOf } from './sort';
@@ -50,7 +51,7 @@ export function App() {
   useEffect(() => { applyDisplaySettings(display); const onMessage = (event: MessageEvent) => setDisplay(current => updateFromHostMessage(event.data, current) ?? current); window.addEventListener('message', onMessage); return () => window.removeEventListener('message', onMessage); }, [display]);
   useEffect(() => { if (!hasHomeBridge()) { setSourcePreviewSupported(false); return; } let active = true; void qdnRequest<unknown>({ action: 'SHOW_ACTIONS' }).then(actions => { if (active) setSourcePreviewSupported(supportsSourcePreview(actions)); }).catch(() => { if (active) setSourcePreviewSupported(false); }); return () => { active = false; }; }, []);
   useEffect(() => { const request = resourceQuery(route); if (!request) return; let active = true; setLoading(true); setFailure(''); void qdnRequest<unknown>(request).then(value => { if (!active) return; const nextResources = asResources(value); const detail = singleResourceDetailRoute(route, nextResources); if (detail) { replace(detail); return; } setResources(nextResources); }).catch(error => { if (active) setFailure(errorText(error)); }).finally(() => { if (active) setLoading(false); }); return () => { active = false; }; }, [route, refresh]);
-  useEffect(() => { setGitFallback(''); if (route.kind !== 'detail') { setDetails(null); return; } let active = true; const resource = { service: route.service, name: route.name, identifier: route.identifier }; void Promise.all([qdnRequest<Record<string, unknown>>({ action: 'GET_QDN_RESOURCE_METADATA', ...resource }), qdnRequest<Record<string, unknown>>({ action: 'GET_QDN_RESOURCE_STATUS', ...resource }), qdnRequest<Record<string, unknown>>({ action: 'GET_QDN_RESOURCE_PROPERTIES', ...resource })]).then(([metadata, status, properties]) => { if (active) setDetails({ metadata, status: status as ResourceDetails['status'], properties }); }).catch(error => { if (active) setFailure(errorText(error)); }); return () => { active = false; }; }, [route]);
+  useEffect(() => { setGitFallback(''); if (route.kind !== 'detail') { setDetails(null); return; } let active = true; setDetails(null); setFailure(''); const resource = { service: route.service, name: route.name, identifier: route.identifier }; void loadResourceDetails(qdnRequest, resource).then(value => { if (active) setDetails(value); }).catch(error => { if (active) setFailure(errorText(error)); }); return () => { active = false; }; }, [route]);
   const folders = useMemo(() => route.kind === 'services' ? groupBy(resources, item => item.service) : route.kind === 'service' ? groupBy(resources, item => item.name) : route.kind === 'name-services' ? groupBy(resources, item => item.service) : [], [resources, route]);
   const shown = searchResults ?? (route.kind === 'resources' ? resources : []);
   const sortedFolders = sortRows(folders, sort, (row, key) => key === 'count' ? row.count : key === 'updated' ? row.updated : row.name);
@@ -63,12 +64,13 @@ export function App() {
     const file = typeof details?.properties?.filename === 'string' ? details.properties.filename : undefined;
     const mime = typeof details?.properties?.mimeType === 'string' ? details.properties.mimeType : undefined;
     const open = dispatchOpen(detailResource, { filename: file, mimeType: mime });
+    const opensInHomeViewer = open.action === 'OPEN_QDN_DOCUMENT_VIEWER' || open.action === 'OPEN_QDN_MEDIA_PLAYER';
     const files = resourceFiles(details?.metadata);
     const selected = files.includes(route.path ?? '') ? route.path : undefined;
     const viewed = { ...detailResource, path: selected };
     const showFiles = files.length > 1;
     const showGit = !selected && !gitFallback && !!detectGitRepositoryLayout(files);
-    return <main className="app"><header className="top"><div><h1>{t('app.title')}</h1><p>{detailResource.service} / {detailResource.name} / {detailResource.identifier || 'default'}{selected ? ` / ${selected}` : ''}</p><NameOwnerIdentity key={detailResource.name} language={display.language} name={detailResource.name} /></div><button onClick={() => history.back()}>{t('action.back')}</button></header><section className="detail"><div className="detail-actions">{open.action === 'INTERNAL_VIEWER' ? null : <button onClick={() => void qdnRequest(open)}>{t('action.open')}</button>}{isBrowserArchiveService(detailResource.service) ? <button onClick={() => void qdnRequest(dispatchOpen(detailResource, { newTab: true }))}>{t('action.openNewTab')}</button> : null}<button onClick={() => void qdnRequest({ action: 'SAVE_QDN_RESOURCE', ...detailResource, filename: file })}>{t('action.download')}</button></div>{failure ? <p className="error">{failure}</p> : null}<div className="detail-grid"><section><h2>{t('label.details')}</h2><dl><dt>{t('label.title')}</dt><dd>{String(details?.metadata?.title || '—')}</dd><dt>{t('label.description')}</dt><dd>{String(details?.metadata?.description || '—')}</dd><dt>{t('label.status')}</dt><dd>{String(details?.status?.status || '—')}</dd><dt>{t('column.size')}</dt><dd>{bytes(details?.status?.size)}</dd><dt>{t('column.updated')}</dt><dd>{date(details?.status?.updated)}</dd></dl>{showFiles ? <><h3>{t('label.files')} <small>{files.length.toLocaleString()}</small></h3><div className="file-list">{files.map(path => <button className={`file-row${path === selected ? ' file-row--active' : ''}`} key={path} type="button" onClick={() => navigate({ ...route, path })}>{path}</button>)}</div></> : null}<h3>{t('label.properties')}</h3><pre className="source">{JSON.stringify(details?.properties || {}, null, 2)}</pre></section><section><h2>{showGit ? t('git.title') : selected || t('viewer.source')}</h2>{selected ? <button className="file-clear" type="button" onClick={() => navigate({ ...route, path: undefined })}>{t('action.allFiles')}</button> : null}{gitFallback ? <p className="viewer-note">{gitFallback}</p> : null}{showGit ? <GitRepositoryViewer key={`${detailResource.service}/${detailResource.name}/${detailResource.identifier || ''}`} files={files} language={display.language} onFallback={setGitFallback} resource={detailResource} /> : showFiles && !selected ? <p className="viewer-note">{t('viewer.selectFile')}</p> : <ContentViewer key={selected ?? ''} resource={viewed} properties={details?.properties} />}</section></div></section></main>;
+    return <main className="app"><header className="top"><div><h1>{t('app.title')}</h1><p>{detailResource.service} / {detailResource.name} / {detailResource.identifier || 'default'}{selected ? ` / ${selected}` : ''}</p><NameOwnerIdentity key={detailResource.name} language={display.language} name={detailResource.name} /></div><button onClick={() => history.back()}>{t('action.back')}</button></header><section className="detail"><div className="detail-actions">{open.action === 'INTERNAL_VIEWER' ? null : <button onClick={() => void qdnRequest(open)}>{t('action.open')}</button>}{isBrowserArchiveService(detailResource.service) ? <button onClick={() => void qdnRequest(dispatchOpen(detailResource, { newTab: true }))}>{t('action.openNewTab')}</button> : null}<button onClick={() => void qdnRequest({ action: 'SAVE_QDN_RESOURCE', ...detailResource, filename: file })}>{t('action.download')}</button></div>{failure ? <p className="error">{failure}</p> : null}<div className="detail-grid"><section><h2>{t('label.details')}</h2><dl><dt>{t('label.title')}</dt><dd>{String(details?.metadata?.title || '—')}</dd><dt>{t('label.description')}</dt><dd>{String(details?.metadata?.description || '—')}</dd><dt>{t('label.status')}</dt><dd>{String(details?.status?.status || '—')}</dd><dt>{t('column.size')}</dt><dd>{bytes(details?.status?.size)}</dd><dt>{t('column.updated')}</dt><dd>{date(details?.status?.updated)}</dd></dl>{showFiles ? <><h3>{t('label.files')} <small>{files.length.toLocaleString()}</small></h3><div className="file-list">{files.map(path => <button className={`file-row${path === selected ? ' file-row--active' : ''}`} key={path} type="button" onClick={() => navigate({ ...route, path })}>{path}</button>)}</div></> : null}<h3>{t('label.properties')}</h3><pre className="source">{JSON.stringify(details?.properties || {}, null, 2)}</pre></section><section><h2>{showGit ? t('git.title') : selected || (opensInHomeViewer ? t('viewer.preview') : t('viewer.source'))}</h2>{selected ? <button className="file-clear" type="button" onClick={() => navigate({ ...route, path: undefined })}>{t('action.allFiles')}</button> : null}{gitFallback ? <p className="viewer-note">{gitFallback}</p> : null}{showGit ? <GitRepositoryViewer key={`${detailResource.service}/${detailResource.name}/${detailResource.identifier || ''}`} files={files} language={display.language} onFallback={setGitFallback} resource={detailResource} /> : showFiles && !selected ? <p className="viewer-note">{t('viewer.selectFile')}</p> : <ContentViewer key={selected ?? ''} resource={viewed} properties={details?.properties} binaryMessage={opensInHomeViewer ? t('viewer.openInHome') : undefined} />}</section></div></section></main>;
   }
   return <main className="app"><header className="top"><div><h1>{t('app.title')}</h1><p>{t('app.subtitle')} <small>{__APP_VERSION__}</small></p></div><div className="top-actions">{sourcePreviewSupported ? <button disabled={previewing} onClick={previewLocalFile}>{previewing ? t('preview.choosing') : t('action.preview')}</button> : null}<button disabled={loading} onClick={() => setRefresh(value => value + 1)}>{t('action.refresh')}</button></div></header>{previewMessage ? <p className="preview-status" aria-live="polite">{previewMessage}</p> : null}{previewFailure ? <p className="error" role="alert">{previewFailure}</p> : null}<section className="search"><input aria-label={t('field.query')} value={search} placeholder={t('field.query')} onChange={event => setSearch(event.target.value)} onKeyDown={event => { if (event.key === 'Enter') doSearch(); }} /><select aria-label={t('field.service')} value={searchService} onChange={event => setSearchService(event.target.value)}><option value="">{t('field.service')}</option>{PUBLIC_QDN_SERVICES.map(service => <option key={service}>{service}</option>)}</select><button disabled={searchLoading} onClick={doSearch}>{t('action.search')}</button>{searchResults ? <button onClick={() => { setSearch(''); setSearchResults(null); }}>{t('action.back')}</button> : null}</section><p className="crumb">{route.kind === 'services' ? 'QDN' : route.kind === 'service' ? route.service : route.kind === 'name-services' ? route.name : `${route.service} / ${route.name}`}</p>{failure ? <section className="error-box"><strong>{t('error.coreOffline')}</strong><p>{failure}</p><button onClick={() => setRefresh(value => value + 1)}>{t('action.retry')}</button></section> : null}{loading && !resources.length ? <p className="loading">{t('loading')}</p> : null}{!searchResults && folders.length > 0 ? <section className="list"><div className="head"><span>{t('label.name')}</span><SortButton active={sort.key === 'count'} onClick={() => toggle('count')}>{t('column.count')}</SortButton><SortButton active={sort.key === 'updated'} onClick={() => toggle('updated')}>{t('column.updated')}</SortButton></div>{sortedFolders.map(row => <button className="row folder" key={row.name} onClick={() => navigate(route.kind === 'services' ? { kind: 'service', service: row.name } : route.kind === 'service' ? { kind: 'resources', service: route.service, name: row.name } : { kind: 'resources', service: row.name, name: route.name })}><span>▸ {row.name}</span><span>{row.count.toLocaleString()}</span><span>{date(row.updated)}</span></button>)}</section> : null}{(searchResults || route.kind === 'resources') && <section className="list"><div className="head resources"><span aria-hidden="true" /><SortButton active={sort.key === 'identifier'} onClick={() => toggle('identifier')}>{t('column.identifier')}</SortButton><SortButton active={sort.key === 'status'} onClick={() => toggle('status')}>{t('column.status')}</SortButton><SortButton active={sort.key === 'size'} onClick={() => toggle('size')}>{t('column.size')}</SortButton><SortButton active={sort.key === 'updated'} onClick={() => toggle('updated')}>{t('column.updated')}</SortButton></div>{sortedResources.map(resource => <button className="row resource" key={`${resource.service}/${resource.name}/${resource.identifier || ''}`} onClick={() => navigate(detailRoute(resource))}><Thumbnail resource={resource} /><span><strong>{resource.identifier || 'default'}</strong><small>{resource.service} · {resource.name}</small></span><span>{resource.status?.status || 'PUBLISHED'}</span><span>{bytes(resource.size)}</span><span>{date(updatedOf(resource))}</span></button>)}</section>}{!loading && !failure && ((searchResults && !searchResults.length) || (!searchResults && !folders.length && route.kind !== 'resources') || (route.kind === 'resources' && !resources.length)) ? <p className="empty">{searchResults ? t('empty.search') : t('empty.resources')}</p> : null}</main>;
 }
diff --git a/src/contentViewer.tsx b/src/contentViewer.tsx
index bf99bd3..df23be2 100644
--- a/src/contentViewer.tsx
+++ b/src/contentViewer.tsx
@@ -1,4 +1,5 @@
 import { useEffect, useState } from 'react';
+import { previewCache, previewCacheKey } from './previewCache';
 import { qdnRequest } from './qdnRequest';
 import { resourceFetchRequest } from './resourceFiles';
 import type { QdnResource } from './types';
@@ -43,8 +44,8 @@ function csvRows(text: string) { return text.split(/\r?\n/).filter(Boolean).map(
  * text for every other kind, matching what ContentViewer fetches; the Git
  * viewer feeds it bytes it read out of a repository instead.
  */
-export function ContentPreview({ kind, data, resource, properties }: { kind: ContentKind; data: string; resource: QdnResource; properties?: Record<string, unknown> }) {
-  if (kind === 'binary') return <p className="viewer-note">This resource cannot be rendered safely in Explore. Use Download to save its original bytes.</p>;
+export function ContentPreview({ kind, data, resource, properties, binaryMessage }: { kind: ContentKind; data: string; resource: QdnResource; properties?: Record<string, unknown>; binaryMessage?: string }) {
+  if (kind === 'binary') return <p className="viewer-note">{binaryMessage || 'This resource cannot be rendered safely in Explore. Use Download to save its original bytes.'}</p>;
   if (kind === 'image') return <img className="content-image" alt={filename(resource, properties)} src={`data:${imageMimeType(resource, properties)};base64,${data}`} />;
   if (kind === 'json') { try { return <pre className="source">{JSON.stringify(JSON.parse(data), null, 2)}</pre>; } catch { return <pre className="source">{data}</pre>; } }
   if (kind === 'csv') { const rows = csvRows(data); return <div className="table-scroll"><table className="csv"><tbody>{rows.map((row, i) => <tr key={i}>{row.map((cell, j) => i === 0 ? <th key={j}>{cell}</th> : <td key={j}>{cell}</td>)}</tr>)}</tbody></table></div>; }
@@ -52,17 +53,24 @@ export function ContentPreview({ kind, data, resource, properties }: { kind: Con
   return <pre className="source">{data}</pre>;
 }
 
-export function ContentViewer({ resource, properties }: { resource: QdnResource; properties?: Record<string, unknown> }) {
+export function ContentViewer({ resource, properties, binaryMessage }: { resource: QdnResource; properties?: Record<string, unknown>; binaryMessage?: string }) {
   const [state, setState] = useState<{ data?: string; error?: string; loading: boolean }>({ loading: true });
   const kind = classifyContent(resource, properties);
+  const cacheKey = previewCacheKey(resource, kind);
   useEffect(() => {
     if (kind === 'binary') { setState({ loading: false }); return; }
+    const cached = previewCache.get(cacheKey);
+    if (cached !== undefined) { setState({ data: cached, loading: false }); return; }
     let active = true;
     setState({ loading: true });
-    void qdnRequest<unknown>(resourceFetchRequest(resource, { binary: kind === 'image', maxBytes: CONTENT_MAX_BYTES })).then(data => { if (active) setState({ data: toText(data), loading: false }); }).catch(error => { if (active) setState({ error: error instanceof Error ? error.message : 'Unable to fetch content.', loading: false }); });
+    void qdnRequest<unknown>(resourceFetchRequest(resource, { binary: kind === 'image', maxBytes: CONTENT_MAX_BYTES })).then(data => {
+      const text = toText(data);
+      previewCache.set(cacheKey, text);
+      if (active) setState({ data: text, loading: false });
+    }).catch(error => { if (active) setState({ error: error instanceof Error ? error.message : 'Unable to fetch content.', loading: false }); });
     return () => { active = false; };
-  }, [kind, resource.identifier, resource.name, resource.path, resource.service]);
-  if (kind === 'binary') return <ContentPreview kind={kind} data="" resource={resource} properties={properties} />;
+  }, [cacheKey, kind, resource.identifier, resource.name, resource.path, resource.service]);
+  if (kind === 'binary') return <ContentPreview kind={kind} data="" resource={resource} properties={properties} binaryMessage={binaryMessage} />;
   if (state.loading) return <p className="loading">Loading preview…</p>;
   if (state.error) return <p className="error">{state.error}</p>;
   return <ContentPreview kind={kind} data={state.data || ''} resource={resource} properties={properties} />;
diff --git a/src/locales/en.ts b/src/locales/en.ts
index 8ed878a..8d29e61 100644
--- a/src/locales/en.ts
+++ b/src/locales/en.ts
@@ -11,6 +11,7 @@ export const EN_STRINGS = {
   'label.status': 'Status', 'label.title': 'Title', 'label.type': 'Type', 'label.unknown': 'Unknown', 'loading': 'Loading…',
   'search.help': 'Search titles, descriptions, and resource fields across public QDN.', 'thumbnail.placeholder': 'Preview unavailable',
   'viewer.download': 'Download resource', 'viewer.binary': 'This resource cannot be rendered safely in Explore.',
-  'viewer.empty': 'This resource has no text content.', 'viewer.json': 'JSON', 'viewer.selectFile': 'Select a file to preview it here.', 'viewer.source': 'Source preview',
+  'viewer.empty': 'This resource has no text content.', 'viewer.json': 'JSON', 'viewer.openInHome': 'Use Open to preview this resource in Home’s built-in viewer, or Download to save its original bytes.',
+  'viewer.preview': 'Preview', 'viewer.selectFile': 'Select a file to preview it here.', 'viewer.source': 'Source preview',
   'preview.canceled': 'File selection was canceled.', 'preview.choosing': 'Choosing file…', 'preview.opened': 'Preview opened in Home.',
 } as const;
diff --git a/src/previewCache.test.ts b/src/previewCache.test.ts
new file mode 100644
index 0000000..8831b97
--- /dev/null
+++ b/src/previewCache.test.ts
@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'vitest';
+import { PreviewCache, previewCacheKey } from './previewCache';
+
+describe('PreviewCache', () => {
+  it('keeps recently used previews and evicts the least recently used entry', () => {
+    const cache = new PreviewCache(2, 100);
+    cache.set('first', 'one');
+    cache.set('second', 'two');
+    expect(cache.get('first')).toBe('one');
+    cache.set('third', 'three');
+    expect(cache.get('second')).toBeUndefined();
+    expect(cache.get('first')).toBe('one');
+    expect(cache.get('third')).toBe('three');
+  });
+
+  it('does not retain a preview larger than the byte budget', () => {
+    const cache = new PreviewCache(2, 4);
+    cache.set('large', 'abc');
+    expect(cache.get('large')).toBeUndefined();
+  });
+
+  it('keys previews by the complete resource and selected path', () => {
+    expect(previewCacheKey({ service: 'IMAGE', name: 'alice', identifier: 'photo', path: 'one.png' }, 'image'))
+      .not.toBe(previewCacheKey({ service: 'IMAGE', name: 'alice', identifier: 'photo', path: 'two.png' }, 'image'));
+  });
+});
diff --git a/src/previewCache.ts b/src/previewCache.ts
new file mode 100644
index 0000000..5611c4a
--- /dev/null
+++ b/src/previewCache.ts
@@ -0,0 +1,47 @@
+const MAX_ENTRIES = 12;
+const MAX_BYTES = 24 * 1024 * 1024;
+
+type PreviewEntry = { data: string; size: number };
+
+export class PreviewCache {
+  private readonly entries = new Map<string, PreviewEntry>();
+  private totalBytes = 0;
+
+  constructor(
+    private readonly maxEntries = MAX_ENTRIES,
+    private readonly maxBytes = MAX_BYTES,
+  ) {}
+
+  get(key: string) {
+    const entry = this.entries.get(key);
+    if (!entry) return undefined;
+    this.entries.delete(key);
+    this.entries.set(key, entry);
+    return entry.data;
+  }
+
+  set(key: string, data: string) {
+    const size = data.length * 2;
+    const old = this.entries.get(key);
+    if (old) {
+      this.totalBytes -= old.size;
+      this.entries.delete(key);
+    }
+    if (size > this.maxBytes) return;
+    this.entries.set(key, { data, size });
+    this.totalBytes += size;
+    while (this.entries.size > this.maxEntries || this.totalBytes > this.maxBytes) {
+      const oldestKey = this.entries.keys().next().value;
+      if (typeof oldestKey !== 'string') break;
+      const oldest = this.entries.get(oldestKey);
+      this.entries.delete(oldestKey);
+      this.totalBytes -= oldest?.size ?? 0;
+    }
+  }
+}
+
+export const previewCache = new PreviewCache();
+
+export function previewCacheKey(resource: { service: string; name: string; identifier?: string; path?: string }, kind: string) {
+  return [resource.service, resource.name, resource.identifier || 'default', resource.path || '', kind].join('\u0000');
+}
diff --git a/src/resourceDetails.test.ts b/src/resourceDetails.test.ts
new file mode 100644
index 0000000..83912e5
--- /dev/null
+++ b/src/resourceDetails.test.ts
@@ -0,0 +1,50 @@
+import { describe, expect, it, vi } from 'vitest';
+import type { QdnRequest } from './qdnRequest';
+import { loadResourceDetails } from './resourceDetails';
+
+const resource = { service: 'IMAGE', name: 'alice', identifier: 'photo' };
+
+describe('loadResourceDetails', () => {
+  it('does not race the properties endpoint against a resource download', async () => {
+    const request = vi.fn(async (value: QdnRequest) => value.action === 'GET_QDN_RESOURCE_STATUS'
+      ? { status: 'PUBLISHED' }
+      : { title: 'Photo' });
+    const details = await loadResourceDetails(request, resource);
+    expect(details.status?.status).toBe('PUBLISHED');
+    expect(request).toHaveBeenCalledTimes(2);
+  });
+
+  it('loads optional properties for a ready resource', async () => {
+    const request = vi.fn(async (value: QdnRequest) => {
+      if (value.action === 'GET_QDN_RESOURCE_STATUS') return { status: 'READY' };
+      if (value.action === 'GET_QDN_RESOURCE_PROPERTIES') return { filename: 'photo.png' };
+      return { title: 'Photo' };
+    });
+    const details = await loadResourceDetails(request, resource);
+    expect(details.properties).toEqual({ filename: 'photo.png' });
+    expect(request).toHaveBeenCalledTimes(3);
+  });
+
+  it('loads optional properties for an already downloaded resource', async () => {
+    const request = vi.fn(async (value: QdnRequest) => value.action === 'GET_QDN_RESOURCE_STATUS'
+      ? { status: 'DOWNLOADED' }
+      : value.action === 'GET_QDN_RESOURCE_PROPERTIES'
+        ? { filename: 'data.json' }
+        : {});
+    const details = await loadResourceDetails(request, resource);
+    expect(details.properties).toEqual({ filename: 'data.json' });
+  });
+
+  it('keeps usable details when an optional response fails', async () => {
+    const request = vi.fn(async (value: QdnRequest) => {
+      if (value.action === 'GET_QDN_RESOURCE_METADATA') throw new Error('metadata unavailable');
+      return { status: 'PUBLISHED' };
+    });
+    await expect(loadResourceDetails(request, resource)).resolves.toMatchObject({ status: { status: 'PUBLISHED' } });
+  });
+
+  it('fails when neither metadata nor status is available', async () => {
+    const request = vi.fn(async () => { throw new Error('Core unavailable'); });
+    await expect(loadResourceDetails(request, resource)).rejects.toThrow('Core unavailable');
+  });
+});
diff --git a/src/resourceDetails.ts b/src/resourceDetails.ts
new file mode 100644
index 0000000..e854457
--- /dev/null
+++ b/src/resourceDetails.ts
@@ -0,0 +1,44 @@
+import type { QdnRequest } from './qdnRequest';
+import type { ResourceDetails } from './types';
+
+type Request = (request: QdnRequest) => Promise<unknown>;
+
+function errorMessage(reason: unknown) {
+  return reason instanceof Error ? reason.message : 'Could not load resource details.';
+}
+
+export async function loadResourceDetails(
+  request: Request,
+  resource: { service: string; name: string; identifier?: string },
+): Promise<ResourceDetails> {
+  const [metadataResult, statusResult] = await Promise.allSettled([
+    request({ action: 'GET_QDN_RESOURCE_METADATA', ...resource }),
+    request({ action: 'GET_QDN_RESOURCE_STATUS', ...resource }),
+  ]);
+  if (metadataResult.status === 'rejected' && statusResult.status === 'rejected') {
+    throw new Error(errorMessage(statusResult.reason || metadataResult.reason));
+  }
+
+  const metadata = metadataResult.status === 'fulfilled' && metadataResult.value && typeof metadataResult.value === 'object'
+    ? metadataResult.value as Record<string, unknown>
+    : undefined;
+  const status = statusResult.status === 'fulfilled' && statusResult.value && typeof statusResult.value === 'object'
+    ? statusResult.value as ResourceDetails['status']
+    : undefined;
+  let properties: Record<string, unknown> | undefined;
+
+  // Core's properties endpoint can initiate a download and return a temporary
+  // 1401 while ContentViewer is already fetching the same resource. Only ask
+  // for optional presentation hints once Core says the resource is ready.
+  if (status?.status === 'READY' || status?.status === 'DOWNLOADED') {
+    try {
+      const value = await request({ action: 'GET_QDN_RESOURCE_PROPERTIES', ...resource });
+      properties = value && typeof value === 'object' ? value as Record<string, unknown> : undefined;
+    } catch {
+      // Filename and MIME hints are optional; a miss must not poison a usable
+      // status, metadata response, or preview.
+    }
+  }
+
+  return { metadata, status, properties };
+}