diff --git a/frontend/src/components/credentials/CredentialUploadDialog.vue b/frontend/src/components/credentials/CredentialUploadDialog.vue
new file mode 100644
index 0000000..8b2edae
--- /dev/null
+++ b/frontend/src/components/credentials/CredentialUploadDialog.vue
@@ -0,0 +1,76 @@
+<template>
+  <v-dialog :model-value="modelValue" max-width="640"
+            @update:model-value="$emit('update:modelValue', $event)">
+    <v-card v-if="platform">
+      <v-card-title>
+        Upload {{ platform.name }} {{ platform.auth_type }}
+      </v-card-title>
+      <v-card-text>
+        <v-textarea
+          v-if="platform.auth_type === 'cookies'"
+          v-model="text"
+          label="Netscape cookies.txt content"
+          rows="8" auto-grow spellcheck="false"
+          :error-messages="error"
+          placeholder="# Netscape HTTP Cookie File&#10;.patreon.com&#9;TRUE&#9;/&#9;TRUE&#9;1700000000&#9;session_id&#9;..."
+        />
+        <v-text-field
+          v-else
+          v-model="text"
+          label="Token"
+          type="password"
+          :error-messages="error"
+        />
+        <p v-if="platform.notes" class="text-caption mt-2" style="opacity: 0.75">
+          {{ platform.notes }}
+        </p>
+        <p class="text-caption mt-2" style="opacity: 0.6">
+          Tip: the GallerySubscriber browser extension can push this automatically.
+        </p>
+      </v-card-text>
+      <v-card-actions>
+        <v-spacer />
+        <v-btn variant="text" @click="$emit('update:modelValue', false)">Cancel</v-btn>
+        <v-btn color="accent" variant="flat" :loading="busy" :disabled="!text.trim()" @click="save">
+          Save
+        </v-btn>
+      </v-card-actions>
+    </v-card>
+  </v-dialog>
+</template>
+
+<script setup>
+import { ref, watch } from 'vue'
+import { useCredentialsStore } from '../../stores/credentials.js'
+
+const props = defineProps({
+  modelValue: { type: Boolean, default: false },
+  platform: { type: Object, default: null },
+})
+const emit = defineEmits(['update:modelValue', 'saved'])
+const store = useCredentialsStore()
+
+const text = ref('')
+const error = ref('')
+const busy = ref(false)
+
+watch(() => props.modelValue, (open) => {
+  if (open) { text.value = ''; error.value = '' }
+})
+
+async function save() {
+  if (!props.platform) return
+  error.value = ''
+  if (!text.value.trim()) { error.value = 'Required'; return }
+  busy.value = true
+  try {
+    await store.upload(props.platform.key, props.platform.auth_type, text.value)
+    emit('saved')
+    emit('update:modelValue', false)
+  } catch (e) {
+    error.value = String(e?.detail || e?.message || e)
+  } finally {
+    busy.value = false
+  }
+}
+</script>
diff --git a/frontend/src/components/credentials/ExtensionKeyBar.vue b/frontend/src/components/credentials/ExtensionKeyBar.vue
new file mode 100644
index 0000000..cf56b3c
--- /dev/null
+++ b/frontend/src/components/credentials/ExtensionKeyBar.vue
@@ -0,0 +1,75 @@
+<template>
+  <div class="fc-extkey-bar">
+    <span class="fc-extkey-bar__label">Extension API key:</span>
+    <code class="fc-extkey-bar__value">{{ store.extensionKey || '…' }}</code>
+    <v-btn size="small" variant="text" @click="copyKey" :disabled="!store.extensionKey">
+      Copy
+    </v-btn>
+    <v-btn size="small" variant="outlined" color="warning" @click="confirmRotate">
+      Rotate
+    </v-btn>
+    <v-dialog v-model="showRotateConfirm" max-width="420">
+      <v-card>
+        <v-card-title>Rotate extension API key?</v-card-title>
+        <v-card-text>
+          The old key stops working immediately. Update your browser extension
+          with the new key after rotating.
+        </v-card-text>
+        <v-card-actions>
+          <v-spacer />
+          <v-btn variant="text" @click="showRotateConfirm = false">Cancel</v-btn>
+          <v-btn color="warning" variant="flat" @click="doRotate">Rotate</v-btn>
+        </v-card-actions>
+      </v-card>
+    </v-dialog>
+  </div>
+</template>
+
+<script setup>
+import { onMounted, ref } from 'vue'
+import { useCredentialsStore } from '../../stores/credentials.js'
+
+const store = useCredentialsStore()
+const showRotateConfirm = ref(false)
+
+onMounted(() => store.loadKey())
+
+async function copyKey() {
+  if (!store.extensionKey) return
+  try {
+    await navigator.clipboard.writeText(store.extensionKey)
+    globalThis.window?.__fcToast?.({ text: 'Copied', type: 'success' })
+  } catch {
+    globalThis.window?.__fcToast?.({ text: 'Copy failed', type: 'error' })
+  }
+}
+
+function confirmRotate() { showRotateConfirm.value = true }
+
+async function doRotate() {
+  showRotateConfirm.value = false
+  await store.rotateKey()
+  globalThis.window?.__fcToast?.({ text: 'Key rotated', type: 'success' })
+}
+</script>
+
+<style scoped>
+.fc-extkey-bar {
+  display: flex; align-items: center; gap: 0.75rem;
+  padding: 0.75rem 1rem; margin-bottom: 1rem;
+  background: rgb(var(--v-theme-surface));
+  border: 1px solid rgb(var(--v-theme-on-surface-variant) / 0.18);
+  border-radius: 6px;
+}
+.fc-extkey-bar__label {
+  color: rgb(var(--v-theme-on-surface-variant));
+  font-size: 0.85rem;
+}
+.fc-extkey-bar__value {
+  font-family: 'JetBrains Mono', monospace;
+  font-size: 0.85rem;
+  flex: 0 1 auto;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+</style>
diff --git a/frontend/src/components/credentials/PlatformCredentialRow.vue b/frontend/src/components/credentials/PlatformCredentialRow.vue
new file mode 100644
index 0000000..07225d8
--- /dev/null
+++ b/frontend/src/components/credentials/PlatformCredentialRow.vue
@@ -0,0 +1,68 @@
+<template>
+  <section class="fc-cred-row">
+    <header class="fc-cred-row__head">
+      <span class="fc-cred-row__name">{{ platform.name }}</span>
+      <v-chip size="x-small" variant="tonal">{{ platform.auth_type }}</v-chip>
+    </header>
+    <div class="fc-cred-row__body">
+      <template v-if="credential">
+        <span class="fc-cred-row__status">
+          ✓ Stored · captured {{ fmtDate(credential.captured_at) }}
+          <template v-if="credential.expires_at">
+            · expires {{ fmtDate(credential.expires_at) }}
+          </template>
+        </span>
+        <v-spacer />
+        <v-btn size="small" variant="outlined" @click="$emit('replace', platform)">
+          Replace
+        </v-btn>
+        <v-btn size="small" variant="text" color="error" @click="$emit('remove', platform)">
+          ×
+        </v-btn>
+      </template>
+      <template v-else>
+        <span class="fc-cred-row__status fc-cred-row__status--empty">○ No credential</span>
+        <v-spacer />
+        <v-btn size="small" variant="flat" color="accent" @click="$emit('replace', platform)">
+          {{ platform.auth_type === 'cookies' ? 'Paste cookies.txt' : 'Paste token' }}
+        </v-btn>
+      </template>
+    </div>
+  </section>
+</template>
+
+<script setup>
+defineProps({
+  platform: { type: Object, required: true },
+  credential: { type: Object, default: null },
+})
+defineEmits(['replace', 'remove'])
+
+function fmtDate(iso) {
+  if (!iso) return '—'
+  return iso.slice(0, 10)
+}
+</script>
+
+<style scoped>
+.fc-cred-row {
+  border: 1px solid rgb(var(--v-theme-on-surface-variant) / 0.18);
+  border-radius: 6px;
+  padding: 0.75rem 1rem;
+  margin-bottom: 0.75rem;
+}
+.fc-cred-row__head {
+  display: flex; align-items: center; gap: 0.5rem; margin-bottom: 0.5rem;
+}
+.fc-cred-row__name { font-weight: 600; }
+.fc-cred-row__body {
+  display: flex; align-items: center; gap: 0.5rem;
+}
+.fc-cred-row__status {
+  font-size: 0.9rem;
+  color: rgb(var(--v-theme-on-surface));
+}
+.fc-cred-row__status--empty {
+  color: rgb(var(--v-theme-on-surface-variant));
+}
+</style>
diff --git a/frontend/src/router.js b/frontend/src/router.js
index 6115b25..31224b4 100644
--- a/frontend/src/router.js
+++ b/frontend/src/router.js
@@ -8,6 +8,7 @@ import ArtistView from './views/ArtistView.vue'
 import SeriesManageView from './views/SeriesManageView.vue'
 import SeriesReaderView from './views/SeriesReaderView.vue'
 import SubscriptionsView from './views/SubscriptionsView.vue'
+import CredentialsView from './views/CredentialsView.vue'
 
 // The application's front door. `/` redirects here. Changing the front door
 // is a one-line edit (e.g. '/gallery' or '/tags').
@@ -31,7 +32,7 @@ const routes = [
 
   // FC-3: subscription backbone
   { path: '/subscriptions', name: 'subscriptions', component: SubscriptionsView, meta: { title: 'Subscriptions' } },
-  { path: '/credentials',   name: 'credentials',   component: PlaceholderView, meta: { title: 'Credentials'   } },
+  { path: '/credentials',   name: 'credentials',   component: CredentialsView, meta: { title: 'Credentials'   } },
   { path: '/downloads',     name: 'downloads',     component: PlaceholderView, meta: { title: 'Downloads'     } }
 ]
 
diff --git a/frontend/src/views/CredentialsView.vue b/frontend/src/views/CredentialsView.vue
new file mode 100644
index 0000000..5501d1d
--- /dev/null
+++ b/frontend/src/views/CredentialsView.vue
@@ -0,0 +1,79 @@
+<template>
+  <v-container fluid class="py-6">
+    <ExtensionKeyBar />
+
+    <v-alert v-if="credentialsStore.error" type="error" variant="tonal" closable class="mb-4">
+      {{ String(credentialsStore.error) }}
+    </v-alert>
+
+    <PlatformCredentialRow
+      v-for="p in platformsStore.list"
+      :key="p.key"
+      :platform="p"
+      :credential="credentialsStore.byPlatform.get(p.key) || null"
+      @replace="openUpload"
+      @remove="confirmRemove"
+    />
+
+    <CredentialUploadDialog
+      v-model="showUpload"
+      :platform="uploadPlatform"
+      @saved="onSaved"
+    />
+
+    <v-dialog v-model="removeConfirm.open" max-width="420">
+      <v-card>
+        <v-card-title>Delete {{ removeConfirm.platform?.name }} credential?</v-card-title>
+        <v-card-text>
+          The encrypted credential will be removed permanently. You'll need to
+          re-upload to use this platform again.
+        </v-card-text>
+        <v-card-actions>
+          <v-spacer />
+          <v-btn variant="text" @click="removeConfirm.open = false">Cancel</v-btn>
+          <v-btn color="error" variant="flat" @click="doRemove">Delete</v-btn>
+        </v-card-actions>
+      </v-card>
+    </v-dialog>
+  </v-container>
+</template>
+
+<script setup>
+import { onMounted, reactive, ref } from 'vue'
+import { usePlatformsStore } from '../stores/platforms.js'
+import { useCredentialsStore } from '../stores/credentials.js'
+import ExtensionKeyBar from '../components/credentials/ExtensionKeyBar.vue'
+import PlatformCredentialRow from '../components/credentials/PlatformCredentialRow.vue'
+import CredentialUploadDialog from '../components/credentials/CredentialUploadDialog.vue'
+
+const platformsStore = usePlatformsStore()
+const credentialsStore = useCredentialsStore()
+
+const showUpload = ref(false)
+const uploadPlatform = ref(null)
+const removeConfirm = reactive({ open: false, platform: null })
+
+onMounted(async () => {
+  await Promise.all([platformsStore.loadAll(), credentialsStore.loadAll()])
+})
+
+function openUpload(platform) {
+  uploadPlatform.value = platform
+  showUpload.value = true
+}
+
+async function onSaved() {
+  await credentialsStore.loadAll()
+}
+
+function confirmRemove(platform) {
+  removeConfirm.platform = platform
+  removeConfirm.open = true
+}
+
+async function doRemove() {
+  await credentialsStore.remove(removeConfirm.platform.key)
+  removeConfirm.open = false
+  await credentialsStore.loadAll()
+}
+</script>