diff --git a/frontend/src/stores/sources.js b/frontend/src/stores/sources.js
new file mode 100644
index 0000000..48a9c59
--- /dev/null
+++ b/frontend/src/stores/sources.js
@@ -0,0 +1,109 @@
+import { defineStore } from 'pinia'
+import { ref, computed } from 'vue'
+import { useApi } from '../composables/useApi.js'
+
+export const useSourcesStore = defineStore('sources', () => {
+  const api = useApi()
+
+  // keyed cache: null => all sources, number => artist_id filtered
+  const byArtist = ref(new Map())
+  const platforms = ref([])
+  const platformsLoaded = ref(false)
+  const loading = ref(false)
+  const error = ref(null)
+
+  const allSources = computed(() => byArtist.value.get(null) ?? [])
+
+  async function loadAll() {
+    loading.value = true
+    error.value = null
+    try {
+      const body = await api.get('/api/sources')
+      byArtist.value.set(null, body)
+    } catch (e) {
+      error.value = e
+    } finally {
+      loading.value = false
+    }
+  }
+
+  async function loadForArtist(artistId) {
+    loading.value = true
+    error.value = null
+    try {
+      const body = await api.get('/api/sources', { params: { artist_id: artistId } })
+      byArtist.value.set(artistId, body)
+    } catch (e) {
+      error.value = e
+    } finally {
+      loading.value = false
+    }
+  }
+
+  async function loadPlatforms() {
+    if (platformsLoaded.value) return
+    const body = await api.get('/api/sources/platforms')
+    platforms.value = body.platforms
+    platformsLoaded.value = true
+  }
+
+  function _invalidate(artistId) {
+    byArtist.value.delete(null)
+    if (artistId != null) byArtist.value.delete(artistId)
+  }
+
+  async function create(payload) {
+    const body = await api.post('/api/sources', { body: payload })
+    _invalidate(payload.artist_id)
+    return body
+  }
+
+  async function update(id, patch, artistIdHint = null) {
+    const body = await api.patch(`/api/sources/${id}`, { body: patch })
+    _invalidate(artistIdHint ?? body.artist_id)
+    return body
+  }
+
+  async function remove(id, artistIdHint = null) {
+    await api.delete(`/api/sources/${id}`)
+    _invalidate(artistIdHint)
+  }
+
+  async function findOrCreateArtist(name) {
+    const body = await api.post('/api/artists', { body: { name } })
+    return { artist: { id: body.id, name: body.name, slug: body.slug }, created: body.created }
+  }
+
+  async function autocompleteArtist(query, limit = 20) {
+    if (!query || !query.trim()) return []
+    return await api.get('/api/artists/autocomplete', { params: { q: query, limit } })
+  }
+
+  function sourcesByArtistGrouped() {
+    // returns [{artist: {id,name,slug}, sources: [...]}, ...]
+    const arr = byArtist.value.get(null) ?? []
+    const groups = new Map()
+    for (const s of arr) {
+      const key = s.artist_id
+      if (!groups.has(key)) {
+        groups.set(key, {
+          artist: { id: s.artist_id, name: s.artist_name, slug: s.artist_slug },
+          sources: [],
+        })
+      }
+      groups.get(key).sources.push(s)
+    }
+    return Array.from(groups.values()).sort(
+      (a, b) => a.artist.name.localeCompare(b.artist.name)
+    )
+  }
+
+  return {
+    byArtist, platforms, platformsLoaded, loading, error,
+    allSources,
+    loadAll, loadForArtist, loadPlatforms,
+    create, update, remove,
+    findOrCreateArtist, autocompleteArtist,
+    sourcesByArtistGrouped,
+  }
+})
diff --git a/frontend/test/sources.spec.js b/frontend/test/sources.spec.js
new file mode 100644
index 0000000..3949928
--- /dev/null
+++ b/frontend/test/sources.spec.js
@@ -0,0 +1,91 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
+import { setActivePinia, createPinia } from 'pinia'
+import { useSourcesStore } from '../src/stores/sources.js'
+
+function stubFetch(handler) {
+  globalThis.fetch = vi.fn(async (url, init) => {
+    const { status, body } = handler(url, init)
+    return {
+      ok: status >= 200 && status < 300,
+      status, statusText: String(status),
+      text: async () => (body == null ? '' : JSON.stringify(body)),
+    }
+  })
+}
+
+describe('sources store', () => {
+  beforeEach(() => setActivePinia(createPinia()))
+  afterEach(() => vi.restoreAllMocks())
+
+  it('loadAll caches under the "all" key', async () => {
+    const s = useSourcesStore()
+    stubFetch(() => ({
+      status: 200,
+      body: [{ id: 1, artist_id: 5, artist_name: 'Alice', artist_slug: 'alice',
+               platform: 'patreon', url: 'https://p/a', enabled: true,
+               config_overrides: null, last_checked_at: null,
+               last_error: null, check_interval_override: null }],
+    }))
+    await s.loadAll()
+    expect(s.allSources.map(r => r.id)).toEqual([1])
+  })
+
+  it('loadForArtist filters by artist_id', async () => {
+    const s = useSourcesStore()
+    const calls = []
+    stubFetch((url) => {
+      calls.push(url)
+      return { status: 200, body: [] }
+    })
+    await s.loadForArtist(7)
+    expect(calls[0]).toContain('artist_id=7')
+  })
+
+  it('loadPlatforms caches the platforms list', async () => {
+    const s = useSourcesStore()
+    let n = 0
+    stubFetch(() => { n++; return { status: 200, body: { platforms: ['patreon'] } } })
+    await s.loadPlatforms()
+    await s.loadPlatforms()  // second call should hit cache
+    expect(n).toBe(1)
+    expect(s.platforms).toEqual(['patreon'])
+  })
+
+  it('create invalidates the all-cache and the artist-cache', async () => {
+    const s = useSourcesStore()
+    s.byArtist.set(null, [])
+    s.byArtist.set(5, [])
+    stubFetch(() => ({
+      status: 201,
+      body: { id: 1, artist_id: 5, artist_name: 'Alice', artist_slug: 'alice',
+              platform: 'patreon', url: 'https://p/a', enabled: true,
+              config_overrides: null, last_checked_at: null,
+              last_error: null, check_interval_override: null },
+    }))
+    await s.create({ artist_id: 5, platform: 'patreon', url: 'https://p/a' })
+    expect(s.byArtist.has(null)).toBe(false)
+    expect(s.byArtist.has(5)).toBe(false)
+  })
+
+  it('findOrCreateArtist posts to /api/artists', async () => {
+    const s = useSourcesStore()
+    const calls = []
+    stubFetch((url, init) => {
+      calls.push({ url, body: init.body ? JSON.parse(init.body) : null })
+      return { status: 201, body: { id: 1, name: 'Alice', slug: 'alice', created: true } }
+    })
+    const out = await s.findOrCreateArtist('Alice')
+    expect(out.artist.name).toBe('Alice')
+    expect(out.created).toBe(true)
+    expect(calls[0].body).toEqual({ name: 'Alice' })
+  })
+
+  it('autocompleteArtist hits /api/artists/autocomplete', async () => {
+    const s = useSourcesStore()
+    const urls = []
+    stubFetch((url) => { urls.push(url); return { status: 200, body: [] } })
+    await s.autocompleteArtist('al')
+    expect(urls[0]).toContain('/api/artists/autocomplete')
+    expect(urls[0]).toContain('q=al')
+  })
+})