diff --git a/document-parser/infra/settings.py b/document-parser/infra/settings.py
index 1d2a952..4f15384 100644
--- a/document-parser/infra/settings.py
+++ b/document-parser/infra/settings.py
@@ -10,6 +10,7 @@ from dataclasses import dataclass, field
 class Settings:
     app_version: str = "dev"
     conversion_engine: str = "local"  # "local" or "remote"
+    deployment_mode: str = "self-hosted"  # "self-hosted" or "huggingface"
     docling_serve_url: str = "http://localhost:5001"
     docling_serve_api_key: str | None = None
     conversion_timeout: int = 600
@@ -27,6 +28,7 @@ class Settings:
         return cls(
             app_version=os.environ.get("APP_VERSION", "dev"),
             conversion_engine=os.environ.get("CONVERSION_ENGINE", "local"),
+            deployment_mode=os.environ.get("DEPLOYMENT_MODE", "self-hosted"),
             docling_serve_url=os.environ.get("DOCLING_SERVE_URL", "http://localhost:5001"),
             docling_serve_api_key=os.environ.get("DOCLING_SERVE_API_KEY"),
             conversion_timeout=int(os.environ.get("CONVERSION_TIMEOUT", "600")),
diff --git a/document-parser/main.py b/document-parser/main.py
index 654c88e..957cada 100644
--- a/document-parser/main.py
+++ b/document-parser/main.py
@@ -117,5 +117,6 @@ async def health() -> dict[str, str]:
         "status": status,
         "version": settings.app_version,
         "engine": settings.conversion_engine,
+        "deploymentMode": settings.deployment_mode,
         "database": db_status,
     }
diff --git a/document-parser/tests/test_settings.py b/document-parser/tests/test_settings.py
index 1326901..ffe6a2a 100644
--- a/document-parser/tests/test_settings.py
+++ b/document-parser/tests/test_settings.py
@@ -10,6 +10,7 @@ class TestSettingsDefaults:
         s = Settings()
         assert s.app_version == "dev"
         assert s.conversion_engine == "local"
+        assert s.deployment_mode == "self-hosted"
         assert s.docling_serve_url == "http://localhost:5001"
         assert s.docling_serve_api_key is None
         assert s.conversion_timeout == 600
@@ -30,6 +31,7 @@ class TestSettingsFromEnv:
     def test_reads_env_vars(self, monkeypatch):
         monkeypatch.setenv("APP_VERSION", "1.2.3")
         monkeypatch.setenv("CONVERSION_ENGINE", "remote")
+        monkeypatch.setenv("DEPLOYMENT_MODE", "huggingface")
         monkeypatch.setenv("DOCLING_SERVE_URL", "http://serve:9000")
         monkeypatch.setenv("DOCLING_SERVE_API_KEY", "secret-key")
         monkeypatch.setenv("CONVERSION_TIMEOUT", "120")
@@ -41,6 +43,7 @@ class TestSettingsFromEnv:
 
         assert s.app_version == "1.2.3"
         assert s.conversion_engine == "remote"
+        assert s.deployment_mode == "huggingface"
         assert s.docling_serve_url == "http://serve:9000"
         assert s.docling_serve_api_key == "secret-key"
         assert s.conversion_timeout == 120
@@ -53,6 +56,7 @@ class TestSettingsFromEnv:
         for key in (
             "APP_VERSION",
             "CONVERSION_ENGINE",
+            "DEPLOYMENT_MODE",
             "DOCLING_SERVE_URL",
             "DOCLING_SERVE_API_KEY",
             "CONVERSION_TIMEOUT",
diff --git a/frontend/src/app/App.vue b/frontend/src/app/App.vue
index f8b29d2..a75d8be 100644
--- a/frontend/src/app/App.vue
+++ b/frontend/src/app/App.vue
@@ -29,6 +29,13 @@
       </button>
     </header>
 
+    <div v-if="showDisclaimer" class="disclaimer-banner" role="alert">
+      {{ t('disclaimer.banner') }}
+      <button class="disclaimer-close" @click="dismissDisclaimer" aria-label="Close">
+        &times;
+      </button>
+    </div>
+
     <div class="app-body">
       <AppSidebar :open="sidebarOpen" />
       <main class="main">
@@ -39,11 +46,12 @@
 </template>
 
 <script setup lang="ts">
-import { ref } from 'vue'
+import { ref, computed } from 'vue'
 import { RouterView, useRouter } from 'vue-router'
 import { AppSidebar } from '../shared/ui/index'
 import { useSettingsStore } from '../features/settings/store'
 import { useDocumentStore } from '../features/document/store'
+import { useFeatureFlag } from '../features/feature-flags'
 import { useI18n } from '../shared/i18n'
 
 useSettingsStore()
@@ -52,6 +60,13 @@ const router = useRouter()
 const documentStore = useDocumentStore()
 
 const sidebarOpen = ref(true)
+const disclaimerEnabled = useFeatureFlag('disclaimer')
+const disclaimerDismissed = ref(false)
+const showDisclaimer = computed(() => disclaimerEnabled.value && !disclaimerDismissed.value)
+
+function dismissDisclaimer() {
+  disclaimerDismissed.value = true
+}
 
 function newAnalysis() {
   documentStore.selectedId = null
@@ -143,6 +158,36 @@ body {
   height: 100vh;
 }
 
+.disclaimer-banner {
+  background: #f59e0b;
+  color: #1a1a1d;
+  font-size: 13px;
+  font-weight: 500;
+  text-align: center;
+  padding: 8px 40px 8px 16px;
+  position: relative;
+  flex-shrink: 0;
+}
+
+.disclaimer-close {
+  position: absolute;
+  right: 12px;
+  top: 50%;
+  transform: translateY(-50%);
+  background: none;
+  border: none;
+  color: #1a1a1d;
+  font-size: 18px;
+  cursor: pointer;
+  padding: 0 4px;
+  line-height: 1;
+  opacity: 0.7;
+}
+
+.disclaimer-close:hover {
+  opacity: 1;
+}
+
 .topbar {
   height: var(--topbar-height);
   min-height: var(--topbar-height);
diff --git a/frontend/src/features/feature-flags/store.test.ts b/frontend/src/features/feature-flags/store.test.ts
index aa5f7fb..02b6a6c 100644
--- a/frontend/src/features/feature-flags/store.test.ts
+++ b/frontend/src/features/feature-flags/store.test.ts
@@ -17,6 +17,7 @@ describe('useFeatureFlagStore', () => {
     const store = useFeatureFlagStore()
     expect(store.loaded).toBe(false)
     expect(store.isEnabled('chunking')).toBe(false)
+    expect(store.isEnabled('disclaimer')).toBe(false)
   })
 
   it('enables chunking when engine is local', async () => {
@@ -36,6 +37,37 @@ describe('useFeatureFlagStore', () => {
     expect(store.isEnabled('chunking')).toBe(false)
   })
 
+  it('enables disclaimer when deploymentMode is huggingface', async () => {
+    mockApiFetch.mockResolvedValue({
+      status: 'ok',
+      engine: 'local',
+      deploymentMode: 'huggingface',
+    })
+    const store = useFeatureFlagStore()
+    await store.load()
+    expect(store.deploymentMode).toBe('huggingface')
+    expect(store.isEnabled('disclaimer')).toBe(true)
+  })
+
+  it('disables disclaimer when deploymentMode is self-hosted', async () => {
+    mockApiFetch.mockResolvedValue({
+      status: 'ok',
+      engine: 'local',
+      deploymentMode: 'self-hosted',
+    })
+    const store = useFeatureFlagStore()
+    await store.load()
+    expect(store.isEnabled('disclaimer')).toBe(false)
+  })
+
+  it('defaults deploymentMode to self-hosted when missing', async () => {
+    mockApiFetch.mockResolvedValue({ status: 'ok', engine: 'local' })
+    const store = useFeatureFlagStore()
+    await store.load()
+    expect(store.deploymentMode).toBe('self-hosted')
+    expect(store.isEnabled('disclaimer')).toBe(false)
+  })
+
   it('handles health endpoint failure gracefully', async () => {
     mockApiFetch.mockRejectedValue(new Error('Network error'))
     const store = useFeatureFlagStore()
@@ -43,5 +75,6 @@ describe('useFeatureFlagStore', () => {
     expect(store.loaded).toBe(true)
     expect(store.error).toBe('Network error')
     expect(store.isEnabled('chunking')).toBe(false)
+    expect(store.isEnabled('disclaimer')).toBe(false)
   })
 })
diff --git a/frontend/src/features/feature-flags/store.ts b/frontend/src/features/feature-flags/store.ts
index b3b3721..ac790a1 100644
--- a/frontend/src/features/feature-flags/store.ts
+++ b/frontend/src/features/feature-flags/store.ts
@@ -3,13 +3,15 @@ import { ref, computed } from 'vue'
 import { apiFetch } from '../../shared/api/http'
 
 type ConversionEngine = 'local' | 'remote'
+type DeploymentMode = 'self-hosted' | 'huggingface'
 
 interface HealthResponse {
   status: string
   engine: ConversionEngine
+  deploymentMode?: DeploymentMode
 }
 
-export type FeatureFlag = 'chunking'
+export type FeatureFlag = 'chunking' | 'disclaimer'
 
 interface FeatureFlagDef {
   description: string
@@ -18,6 +20,7 @@ interface FeatureFlagDef {
 
 interface FeatureFlagContext {
   engine: ConversionEngine | null
+  deploymentMode: DeploymentMode | null
 }
 
 const featureRegistry: Record<FeatureFlag, FeatureFlagDef> = {
@@ -25,15 +28,21 @@ const featureRegistry: Record<FeatureFlag, FeatureFlagDef> = {
     description: 'Document chunking for RAG preparation',
     isEnabled: (ctx) => ctx.engine === 'local',
   },
+  disclaimer: {
+    description: 'Show shared-instance disclaimer banner',
+    isEnabled: (ctx) => ctx.deploymentMode === 'huggingface',
+  },
 }
 
 export const useFeatureFlagStore = defineStore('feature-flags', () => {
   const engine = ref<ConversionEngine | null>(null)
+  const deploymentMode = ref<DeploymentMode | null>(null)
   const loaded = ref(false)
   const error = ref<string | null>(null)
 
   const context = computed<FeatureFlagContext>(() => ({
     engine: engine.value,
+    deploymentMode: deploymentMode.value,
   }))
 
   function isEnabled(flag: FeatureFlag): boolean {
@@ -46,6 +55,7 @@ export const useFeatureFlagStore = defineStore('feature-flags', () => {
     try {
       const data = await apiFetch<HealthResponse>('/api/health')
       engine.value = data.engine
+      deploymentMode.value = data.deploymentMode ?? 'self-hosted'
       loaded.value = true
       error.value = null
     } catch (e) {
@@ -54,5 +64,5 @@ export const useFeatureFlagStore = defineStore('feature-flags', () => {
     }
   }
 
-  return { engine, loaded, error, isEnabled, load }
+  return { engine, deploymentMode, loaded, error, isEnabled, load }
 })
diff --git a/frontend/src/shared/i18n.ts b/frontend/src/shared/i18n.ts
index 3aab273..defe902 100644
--- a/frontend/src/shared/i18n.ts
+++ b/frontend/src/shared/i18n.ts
@@ -129,6 +129,10 @@ const messages: Messages = {
     'settings.themeDark': 'Sombre',
     'settings.themeLight': 'Clair',
     'settings.language': 'Langue',
+
+    // Disclaimer
+    'disclaimer.banner':
+      'Instance de d\u00e9monstration \u2014 les documents upload\u00e9s sont partag\u00e9s et temporaires. Ne pas envoyer de fichiers confidentiels.',
   },
   en: {
     'nav.home': 'Home',
@@ -242,6 +246,10 @@ const messages: Messages = {
     'settings.themeDark': 'Dark',
     'settings.themeLight': 'Light',
     'settings.language': 'Language',
+
+    // Disclaimer
+    'disclaimer.banner':
+      'Demo instance \u2014 uploaded documents are shared and temporary. Do not upload confidential files.',
   },
 }