diff --git a/src/praisonai-desktop/engine/server.py b/src/praisonai-desktop/engine/server.py
index 542e22cee..abe49c72a 100644
--- a/src/praisonai-desktop/engine/server.py
+++ b/src/praisonai-desktop/engine/server.py
@@ -1606,8 +1606,14 @@ def do_DELETE(self):
             return
         try:
             _chat_path(self.path.rsplit("/", 1)[-1]).unlink(missing_ok=True)
-        except (OSError, ValueError):
-            pass
+        except ValueError as exc:
+            self._json({"ok": False, "error": str(exc)}, 400)
+            return
+        except OSError as exc:
+            # Reporting a delete that did not happen is how a conversation
+            # closed on screen and was back in the sidebar on reopen.
+            self._json({"ok": False, "error": str(exc)}, 500)
+            return
         self._json({"ok": True})
 
     def do_POST(self):
diff --git a/src/praisonai-desktop/engine/test_train_routes.py b/src/praisonai-desktop/engine/test_train_routes.py
index 85ae021e6..e58d26081 100644
--- a/src/praisonai-desktop/engine/test_train_routes.py
+++ b/src/praisonai-desktop/engine/test_train_routes.py
@@ -508,5 +508,53 @@ def test_quitting_the_engine_kills_the_running_trainer(self):
                         f"the trainer (pid {pid}) outlived the engine quit")
 
 
+class DeleteChats(unittest.TestCase):
+    """DELETE /chats/<id> must answer for the delete that actually happened."""
+
+    def setUp(self):
+        self.engine = EngineProcess(_python(SHORT_RUN))
+        self.chats_dir = pathlib.Path(self.engine.home) / "chats"
+        self.chats_dir.mkdir(parents=True, exist_ok=True)
+
+    def tearDown(self):
+        self.engine.close()
+
+    def _write_chat(self, cid):
+        (self.chats_dir / f"{cid}.json").write_text(
+            json.dumps({"id": cid, "title": cid, "messages": []}))
+
+    def _listed_ids(self):
+        _, body = self.engine.request("/chats")
+        return {c["id"] for c in body.get("chats", [])}
+
+    def test_a_delete_that_succeeds_removes_the_chat(self):
+        self._write_chat("good1")
+        self.assertIn("good1", self._listed_ids())
+        status, body = self.engine.request("/chats/good1", method="DELETE")
+        self.assertEqual(status, 200, body)
+        self.assertNotIn("good1", self._listed_ids())
+
+    def test_a_delete_that_cannot_happen_is_not_reported_as_done(self):
+        # The read-only data dir and the synced folder mid-conflict from the
+        # report both surface as an OSError from unlink(). A directory standing
+        # where the chat file would be reproduces that deterministically -- even
+        # for root, unlink() refuses it -- where a chmod'd dir does not, since
+        # root ignores the permission bit. Answering 200 here is how the
+        # conversation closed on screen and was back in the sidebar on reopen.
+        blocker = self.chats_dir / "stuck.json"
+        blocker.mkdir()
+        status, body = self.engine.request("/chats/stuck", method="DELETE")
+        self.assertNotEqual(status, 200, "a delete that did not happen was reported done")
+        self.assertFalse(body.get("ok", True))
+        self.assertTrue(blocker.is_dir(), "the blocker vanished; the test proves nothing")
+
+    def test_an_empty_id_is_refused_rather_than_silently_ok(self):
+        # An id that reduces to nothing (the report's `../..` after the route
+        # is stripped) raised a ValueError that used to be swallowed as 200.
+        status, body = self.engine.request("/chats/..", method="DELETE")
+        self.assertEqual(status, 400, body)
+        self.assertFalse(body.get("ok", True))
+
+
 if __name__ == "__main__":
     unittest.main(verbosity=2)
diff --git a/src/praisonai-desktop/frontend/tests/buttons.test.mjs b/src/praisonai-desktop/frontend/tests/buttons.test.mjs
index 13efd254d..28f9f7953 100644
--- a/src/praisonai-desktop/frontend/tests/buttons.test.mjs
+++ b/src/praisonai-desktop/frontend/tests/buttons.test.mjs
@@ -332,3 +332,129 @@ test('Stop discards the queue rather than silently starting the next turn', asyn
   assert.equal(doc.querySelectorAll('.qrow').length, 0,
     'stopping a turn left the queue armed, so the next prompt runs unasked');
 });
+
+// ---- deleting a conversation --------------------------------------------
+// A DELETE the engine could not perform (read-only or synced data dir) must
+// not blank the open transcript: doing so is how a conversation closed on
+// screen and reappeared in the sidebar on the next refresh.
+async function bootWithDelete(deleteOk) {
+  const calls = [];
+  const dom = new JSDOM(HTML, {
+    runScripts: 'dangerously', resources: 'usable', url: ORIGIN + '/',
+    beforeParse(w) {
+      w.__TAURI__ = { core: { invoke: async () => ({ state: 'ready', port: PORT }) } };
+      w.fetch = async (url, opts = {}) => {
+        const method = opts.method || 'GET';
+        calls.push(`${method} ${String(url).replace(`http://127.0.0.1:${PORT}`, '')}`);
+        const u = String(url);
+        if (method === 'DELETE') {
+          return { ok: deleteOk, status: deleteOk ? 200 : 500,
+                   json: async () => ({ ok: deleteOk }), text: async () => '' };
+        }
+        const body =
+          u.includes('/chats/') ? { id: 'c1', title: 'Hi', messages: [
+              { role: 'user', content: 'hi' },
+              { role: 'assistant', content: '**hello**' }] }
+          : u.includes('/chats')  ? { chats: [{ id: 'c1', title: 'Hi', updated: 1, count: 2, project: '' }] }
+          : { ok: true, model: 'gpt-4o-mini', theme: 'system' };
+        return { ok: true, status: 200, json: async () => body, text: async () => '' };
+      };
+      w.requestAnimationFrame = (cb) => setTimeout(cb, 0);
+      w.navigator.clipboard = { writeText: async () => {} };
+      w.confirm = () => true; w.prompt = () => ''; w.alert = () => {};
+      Object.defineProperty(w.HTMLElement.prototype, 'scrollIntoView', { value() {} });
+    },
+  });
+  const { window } = dom;
+  for (let i = 0; i < 60; i++) {
+    await new Promise((r) => setTimeout(r, 25));
+    if (!window.document.getElementById('p').disabled) break;
+  }
+  // The confirm dialog is a custom overlay, not window.confirm; auto-accept it.
+  window.askConfirm = async () => true;
+  return { doc: window.document, window, calls };
+}
+
+test('a failed DELETE keeps the open transcript rather than blanking it', async () => {
+  const { doc, window } = await bootWithDelete(false);
+  await settle();
+  // Open the conversation so the transcript has children and is the active id.
+  click(doc.querySelector('#chats .chat'));
+  await settle();
+  assert.ok(doc.getElementById('turns').children.length > 0, 'transcript did not open');
+  const before = doc.getElementById('turns').children.length;
+  click(doc.querySelector('#chats .chat .x'));
+  await settle();
+  assert.equal(doc.getElementById('turns').children.length, before,
+    'a delete the engine refused still blanked the open transcript');
+});
+
+test('a successful DELETE clears the open transcript', async () => {
+  const { doc, window } = await bootWithDelete(true);
+  await settle();
+  click(doc.querySelector('#chats .chat'));
+  await settle();
+  assert.ok(doc.getElementById('turns').children.length > 0, 'transcript did not open');
+  click(doc.querySelector('#chats .chat .x'));
+  await settle();
+  assert.equal(doc.getElementById('turns').children.length, 0,
+    'a successful delete left the deleted conversation on screen');
+});
+
+// ---- Clear-all with a partial failure ------------------------------------
+// The open transcript must follow storage, not the batch result: if the active
+// conversation was deleted but another one failed, the transcript must still be
+// blanked -- otherwise it lingers on screen while gone on disk.
+async function bootWithClear(failIds) {
+  const calls = [];
+  const dom = new JSDOM(HTML, {
+    runScripts: 'dangerously', resources: 'usable', url: ORIGIN + '/',
+    beforeParse(w) {
+      w.__TAURI__ = { core: { invoke: async () => ({ state: 'ready', port: PORT }) } };
+      w.fetch = async (url, opts = {}) => {
+        const method = opts.method || 'GET';
+        const path = String(url).replace(`http://127.0.0.1:${PORT}`, '');
+        calls.push(`${method} ${path}`);
+        const u = String(url);
+        if (method === 'DELETE') {
+          const id = path.split('/').pop();
+          const ok = !failIds.includes(id);
+          return { ok, status: ok ? 200 : 500, json: async () => ({ ok }), text: async () => '' };
+        }
+        const body =
+          u.includes('/chats/') ? { id: u.split('/').pop(), title: 'Hi', messages: [
+              { role: 'user', content: 'hi' },
+              { role: 'assistant', content: '**hello**' }] }
+          : u.includes('/chats')  ? { chats: [
+              { id: 'c1', title: 'One', updated: 2, count: 2, project: '' },
+              { id: 'c2', title: 'Two', updated: 1, count: 2, project: '' }] }
+          : { ok: true, model: 'gpt-4o-mini', theme: 'system' };
+        return { ok: true, status: 200, json: async () => body, text: async () => '' };
+      };
+      w.requestAnimationFrame = (cb) => setTimeout(cb, 0);
+      w.navigator.clipboard = { writeText: async () => {} };
+      w.confirm = () => true; w.prompt = () => ''; w.alert = () => {};
+      Object.defineProperty(w.HTMLElement.prototype, 'scrollIntoView', { value() {} });
+    },
+  });
+  const { window } = dom;
+  for (let i = 0; i < 60; i++) {
+    await new Promise((r) => setTimeout(r, 25));
+    if (!window.document.getElementById('p').disabled) break;
+  }
+  window.askConfirm = async () => true;
+  return { doc: window.document, window, calls };
+}
+
+test('clear-all blanks the active transcript even when another delete fails', async () => {
+  const { doc, window } = await bootWithClear(['c2']);
+  await settle();
+  // Open c1 so it is the active transcript; c2's delete will fail.
+  click(doc.querySelector('#chats .chat'));
+  await settle();
+  assert.ok(doc.getElementById('turns').children.length > 0, 'transcript did not open');
+  window.runAction({ action: 'clear' });
+  await settle();
+  assert.equal(doc.getElementById('turns').children.length, 0,
+    'the active conversation was deleted from storage but its transcript stayed on screen');
+});
diff --git a/src/praisonai-desktop/ui/index.html b/src/praisonai-desktop/ui/index.html
index a413a9fe3..b08acefe0 100644
--- a/src/praisonai-desktop/ui/index.html
+++ b/src/praisonai-desktop/ui/index.html
@@ -1043,7 +1043,9 @@ <h2>Fine-tune a model</h2>
         ev.stopPropagation();
         if(CFG.confirm_delete!==false && !await askConfirm(
              `Delete \u201c${c.title}\u201d? This cannot be undone.`)) return;
-        await fetch(`http://127.0.0.1:${PORT}/chats/${c.id}`,{method:'DELETE'});
+        const r=await fetch(`http://127.0.0.1:${PORT}/chats/${c.id}`,{method:'DELETE'})
+                  .catch(()=>null);
+        if(!r||!r.ok){ toast('Could not delete that conversation.'); return; }
         if(c.id===chatId){ chatId=rid(); turns.innerHTML=''; syncEmpty(); }
         refreshChats();
       };
@@ -1924,8 +1926,20 @@ <h2>Fine-tune a model</h2>
     closeOverlay();
   } else if(def.action==='clear'){
     const {chats}=await (await fetch('http://127.0.0.1:'+PORT+'/chats')).json();
-    for(const c of chats) await fetch('http://127.0.0.1:'+PORT+'/chats/'+c.id,{method:'DELETE'});
-    chatId=rid(); turns.innerHTML=''; syncEmpty(); refreshChats(); closeOverlay();
+    let failed=0, activeGone=false;
+    for(const c of chats){
+      const r=await fetch('http://127.0.0.1:'+PORT+'/chats/'+c.id,{method:'DELETE'})
+                .catch(()=>null);
+      if(!r||!r.ok) failed++;
+      else if(c.id===chatId) activeGone=true;
+    }
+    // The open transcript follows storage, not the batch result: if the active
+    // conversation was one of the deletes that succeeded, blank it even when a
+    // *different* one failed -- otherwise it lingers on screen while gone on disk.
+    if(activeGone){ chatId=rid(); turns.innerHTML=''; syncEmpty(); }
+    if(failed){ toast(`Could not delete ${failed} conversation(s).`); refreshChats(); closeOverlay(); return; }
+    if(!activeGone){ chatId=rid(); turns.innerHTML=''; syncEmpty(); }
+    refreshChats(); closeOverlay();
   } else if(def.action==='reveal'){
     const where=await actualDataFolder();
     await navigator.clipboard.writeText(where);