diff --git a/web/src/api.ts b/web/src/api.ts
index d8d71e2..35663dc 100644
--- a/web/src/api.ts
+++ b/web/src/api.ts
@@ -1,10 +1,16 @@
 import type {
+  AlbumTracks,
+  BackupFile,
   Candidate,
   CollectionResponse,
   DigitalAlbum,
   Item,
+  ItemDetail,
+  Loan,
+  LoansResponse,
   ReleasePreview,
   SettingsView,
+  Stats,
   SyncState,
   User,
 } from './types'
@@ -73,17 +79,18 @@ export const api = {
     ),
   getReleasePreview: (id: number) => request<ReleasePreview>(`/api/lookup/release/${id}`),
 
-  listCollection: (params: { format?: string; ripped?: string; q?: string } = {}) => {
+  listCollection: (params: { format?: string; ripped?: string; q?: string; onLoan?: string } = {}) => {
     const usp = new URLSearchParams()
     if (params.format) usp.set('format', params.format)
     if (params.ripped) usp.set('ripped', params.ripped)
     if (params.q) usp.set('q', params.q)
+    if (params.onLoan) usp.set('onLoan', params.onLoan)
     const qs = usp.toString()
     return request<CollectionResponse>(`/api/collection${qs ? `?${qs}` : ''}`)
   },
   addToCollection: (body: { releaseId: number; barcode?: string; matchAlbumId?: number }) =>
     post<Item>('/api/collection', body),
-  getItem: (id: number) => request<Item>(`/api/collection/${id}`),
+  getItem: (id: number) => request<ItemDetail>(`/api/collection/${id}`),
   deleteItem: (id: number) => request<{ ok: boolean }>(`/api/collection/${id}`, { method: 'DELETE' }),
   setRip: (id: number, ripped: boolean | null) =>
     request<Item>(`/api/collection/${id}/rip`, {
@@ -97,4 +104,18 @@ export const api = {
   syncStatus: () => request<SyncState>('/api/library/sync'),
   startSync: () => request<SyncState>('/api/library/sync', { method: 'POST' }),
   searchAlbums: (q: string) => request<{ albums: DigitalAlbum[] }>(`/api/library/albums?q=${encodeURIComponent(q)}`),
+
+  getAlbumTracks: (subsonicId: string) => request<AlbumTracks>(`/api/album/${encodeURIComponent(subsonicId)}/tracks`),
+  markPlayed: (subsonicId: string) => post<{ ok: boolean }>(`/api/album/${encodeURIComponent(subsonicId)}/played`),
+  streamUrl: (songId: string) => `/api/stream/${encodeURIComponent(songId)}`,
+
+  getStats: () => request<Stats>('/api/stats'),
+  exportUrl: () => '/api/export',
+
+  lendItem: (id: number, borrower: string) => post<Loan>(`/api/collection/${id}/loan`, { borrower }),
+  getLoans: () => request<LoansResponse>('/api/loans'),
+  returnLoan: (id: number) => post<{ ok: boolean }>(`/api/loans/${id}/return`),
+
+  triggerBackup: () => post<{ file: string }>('/api/backup'),
+  getBackups: () => request<{ backups: BackupFile[] }>('/api/backups'),
 }
diff --git a/web/src/types.ts b/web/src/types.ts
index 5492bfb..cd90dba 100644
--- a/web/src/types.ts
+++ b/web/src/types.ts
@@ -68,3 +68,49 @@ export interface DigitalAlbum {
   title: string
   artist: string
 }
+export interface Track {
+  id: string
+  title: string
+  duration: number | null
+  track: number | null
+}
+export interface AlbumTracks {
+  id: string
+  title: string
+  artist: string
+  tracks: Track[]
+}
+export interface MatchedAlbum {
+  id: number
+  subsonicId: string
+  lastPlayedAt: string | null
+}
+export interface Stats {
+  totals: { items: number; ripped: number; notRipped: number; onLoan: number }
+  ripRatio: number
+  formats: { name: string; count: number }[]
+  decades: { name: string; count: number }[]
+  topGenres: { name: string; count: number }[]
+  topArtists: { name: string; count: number }[]
+  addedByMonth: { month: string; count: number }[]
+}
+export interface Loan {
+  id: number
+  itemId: number
+  borrower: string
+  lentAt: string
+  returnedAt: string | null
+}
+export interface LoansResponse {
+  active: Loan[]
+  history: Loan[]
+}
+export interface BackupFile {
+  file: string
+  sizeBytes: number
+  createdAt: string
+}
+export interface ItemDetail extends Item {
+  matchedAlbum: MatchedAlbum | null
+  loan: { id: number; borrower: string; lentAt: string } | null
+}
diff --git a/web/test/api.test.ts b/web/test/api.test.ts
new file mode 100644
index 0000000..50caa56
--- /dev/null
+++ b/web/test/api.test.ts
@@ -0,0 +1,43 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
+import { api, ApiError } from '../src/api'
+
+const fetchMock = vi.fn()
+beforeEach(() => vi.stubGlobal('fetch', fetchMock))
+afterEach(() => vi.unstubAllGlobals())
+
+function jsonOk(body: unknown) {
+  return Promise.resolve(new Response(JSON.stringify(body), { status: 200, headers: { 'content-type': 'application/json' } }))
+}
+
+describe('api additions', () => {
+  it('album tracks + played + stream url', async () => {
+    fetchMock.mockImplementation(() => jsonOk({ id: 'a1', title: 'Motion', artist: 'TCO', tracks: [] }))
+    await api.getAlbumTracks('a1')
+    expect(fetchMock).toHaveBeenCalledWith('/api/album/a1/tracks', expect.anything())
+    await api.markPlayed('a1')
+    expect(fetchMock).toHaveBeenCalledWith('/api/album/a1/played', expect.objectContaining({ method: 'POST' }))
+    expect(api.streamUrl('s 1')).toBe('/api/stream/s%201')
+  })
+
+  it('stats, loans, backups urls', async () => {
+    fetchMock.mockImplementation(() => jsonOk({}))
+    await api.getStats()
+    expect(fetchMock).toHaveBeenCalledWith('/api/stats', expect.anything())
+    await api.lendItem(5, 'Bob')
+    expect(fetchMock).toHaveBeenCalledWith('/api/collection/5/loan', expect.objectContaining({ method: 'POST' }))
+    await api.returnLoan(7)
+    expect(fetchMock).toHaveBeenCalledWith('/api/loans/7/return', expect.objectContaining({ method: 'POST' }))
+    await api.getBackups()
+    expect(fetchMock).toHaveBeenCalledWith('/api/backups', expect.anything())
+    expect(api.exportUrl()).toBe('/api/export')
+  })
+
+  it('surfaces subsonic errors as ApiError', async () => {
+    fetchMock.mockReturnValue(
+      Promise.resolve(new Response(JSON.stringify({ error: 'no_subsonic_config' }), { status: 409 }))
+    )
+    const err = await api.getAlbumTracks('a1').catch((e) => e)
+    expect(err).toBeInstanceOf(ApiError)
+    expect((err as ApiError).code).toBe('no_subsonic_config')
+  })
+})