diff --git a/lib/__tests__/plugin-host-features.test.ts b/lib/__tests__/plugin-host-features.test.ts
index 9e0dc0abf..bea136c3a 100644
--- a/lib/__tests__/plugin-host-features.test.ts
+++ b/lib/__tests__/plugin-host-features.test.ts
@@ -85,21 +85,21 @@ describe('host bridge', () => {
     const plugin = { id: 'p', name: 'P', version: '1.0.0', permissions: [], settings: {}, settingsSchema: {} } as never;
     const instance = createBackgroundInstance({ plugin, tier: 'privileged', code: '', locale: 'en' });
     const pending = (instance as unknown as { pendingInit: { hostFeatures?: unknown } | null }).pendingInit;
-    expect(pending?.hostFeatures).toEqual({ externalSenderLabel: true, externalRecipientWarning: false, noThirdPartyTraffic: false });
+    expect(pending?.hostFeatures).toEqual(withAssistant({ externalSenderLabel: true, externalRecipientWarning: false, noThirdPartyTraffic: false }));
 
     // Before init has gone out a change lands in the payload ...
     setExternalMail({});
-    expect(pending?.hostFeatures).toEqual({ externalSenderLabel: false, externalRecipientWarning: false, noThirdPartyTraffic: false });
+    expect(pending?.hostFeatures).toEqual(withAssistant({ externalSenderLabel: false, externalRecipientWarning: false, noThirdPartyTraffic: false }));
 
     // ... after it, as a host-change message.
     const sent: unknown[] = [];
     (instance as unknown as { pendingInit: unknown }).pendingInit = null;
     (instance as unknown as { send: (m: unknown) => void }).send = (m) => sent.push(m);
     setExternalMail({ recipientWarning: true });
-    expect(sent).toEqual([{ type: 'host-change', features: { externalSenderLabel: false, externalRecipientWarning: true, noThirdPartyTraffic: false } }]);
+    expect(sent).toEqual([{ type: 'host-change', features: withAssistant({ externalSenderLabel: false, externalRecipientWarning: true, noThirdPartyTraffic: false }) }]);
     // The admin turns third-party traffic off: running plugins hear it.
     setNoThirdPartyTraffic(true);
-    expect(sent[1]).toEqual({ type: 'host-change', features: { externalSenderLabel: false, externalRecipientWarning: true, noThirdPartyTraffic: true } });
+    expect(sent[1]).toEqual({ type: 'host-change', features: withAssistant({ externalSenderLabel: false, externalRecipientWarning: true, noThirdPartyTraffic: true }) });
     setNoThirdPartyTraffic(false);
     instance.destroy();
   }, 30_000);
@@ -165,5 +165,12 @@ describe('api.host in the sandbox runtime', () => {
     expect(kept.externalSenderLabel).toBe(true);
     expect((kept as { noThirdPartyTraffic?: boolean }).noThirdPartyTraffic).toBe(true);
     expect(changes).toEqual([{ externalSenderLabel: true, externalRecipientWarning: false, noThirdPartyTraffic: true }]);
+
+    // The assistant's flags (lib/plugin-sandbox/assistant) reach the plugin too.
+    expect((kept as { sidePanel?: boolean }).sidePanel).toBeUndefined();
+    post(hostWindow, HOST_ORIGIN, { type: 'host-change', features: { externalSenderLabel: true, externalRecipientWarning: false, noThirdPartyTraffic: true, sidePanel: true } });
+    expect((kept as { sidePanel?: boolean }).sidePanel).toBe(true);
+    post(hostWindow, HOST_ORIGIN, { type: 'host-change', features: { externalSenderLabel: true, externalRecipientWarning: false, noThirdPartyTraffic: true, sidePanel: 'yes' } });
+    expect((kept as { sidePanel?: boolean }).sidePanel).toBe(false);
   }, 30_000);
 });
diff --git a/lib/plugin-sandbox/runtime.tsx b/lib/plugin-sandbox/runtime.tsx
index 63b0b361a..ab741c7a9 100644
--- a/lib/plugin-sandbox/runtime.tsx
+++ b/lib/plugin-sandbox/runtime.tsx
@@ -161,6 +161,11 @@ function applyHostFeatures(next: HostFeaturesView | undefined): void {
   hostFeaturesState.externalRecipientWarning = next.externalRecipientWarning === true;
   // A host older than 1.20 doesn't send it, and never let such a plugin run in the mode.
   hostFeaturesState.noThirdPartyTraffic = next.noThirdPartyTraffic === true;
+  // The AI assistant's flags (lib/plugin-sandbox/assistant): whatever the host names, true or false.
+  const flags = hostFeaturesState as unknown as Record<string, boolean>;
+  for (const [key, value] of Object.entries(next)) {
+    if (key !== 'externalSenderLabel' && key !== 'externalRecipientWarning' && key !== 'noThirdPartyTraffic') flags[key] = value === true;
+  }
   for (const listener of hostFeatureListeners) {
     try { listener(hostFeaturesState); } catch (err) { console.error('[plugin] host feature listener failed', err); }
   }