diff --git a/nginx.conf b/nginx.conf
index 1e0b9dc..b9f469b 100644
--- a/nginx.conf
+++ b/nginx.conf
@@ -52,6 +52,10 @@
             proxy_set_header X-Real-IP $remote_addr;
             proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
             proxy_set_header X-Forwarded-Proto $proxy_x_forwarded_proto;
+
+            # Streaming optimization
+            proxy_buffering off;
+            proxy_read_timeout 300s;
         }
 
         # Health check
diff --git a/ui/client-app/src/services/apiService.js b/ui/client-app/src/services/apiService.js
index 8524cb5..d995fb4 100644
--- a/ui/client-app/src/services/apiService.js
+++ b/ui/client-app/src/services/apiService.js
@@ -349,10 +349,18 @@
       method: "POST",
       headers: { "Content-Type": "application/json", "X-User-ID": userId },
       body: JSON.stringify({ text }),
+    }).catch(err => {
+      console.error("Fetch transport error:", err);
+      throw new Error(`Network transport failed: ${err.message}`);
     });
 
     if (!response.ok) {
-      throw new Error(`HTTP error! Status: ${response.status}`);
+      let detail = `HTTP error! Status: ${response.status}`;
+      try {
+        const errBody = await response.json();
+        detail = errBody.detail || detail;
+      } catch { }
+      throw new Error(detail);
     }
 
     const totalChunks = parseInt(response.headers.get("X-TTS-Chunk-Count") || "0");
@@ -360,37 +368,36 @@
     let leftover = new Uint8Array(0);
     let chunkIndex = 0;
 
-    while (true) {
-      const { done, value: chunk } = await reader.read();
-      if (done) {
-        if (leftover.length > 0) {
-          console.warn("Leftover bytes discarded:", leftover.length);
-        }
-        break;
+    try {
+      while (true) {
+        const { done, value: chunk } = await reader.read();
+        if (done) break;
+
+        let combined = new Uint8Array(leftover.length + chunk.length);
+        combined.set(leftover);
+        combined.set(chunk, leftover.length);
+
+        let length = combined.length;
+        if (length % 2 !== 0) length -= 1;
+
+        const toConvert = combined.slice(0, length);
+        leftover = combined.slice(length);
+        const float32Raw = convertPcmToFloat32(toConvert);
+
+        onData(float32Raw, totalChunks, ++chunkIndex);
       }
-
-      let combined = new Uint8Array(leftover.length + chunk.length);
-      combined.set(leftover);
-      combined.set(chunk, leftover.length);
-
-      let length = combined.length;
-      if (length % 2 !== 0) {
-        length -= 1;
-      }
-
-      const toConvert = combined.slice(0, length);
-      leftover = combined.slice(length);
-      const float32Raw = convertPcmToFloat32(toConvert);
-
-      // Pass the raw float32 data plus chunk indices for progress tracking
-      onData(float32Raw, totalChunks, ++chunkIndex);
+    } catch (readError) {
+      console.error("Error reading response body stream:", readError);
+      throw new Error(`Stream interrupted: ${readError.message}`);
     }
   } catch (error) {
     console.error("Failed to stream speech:", error);
     throw error;
   } finally {
-    // We call the onDone callback to let the hook know the stream has ended.
-    onDone();
+    if (onDone) {
+      // await onDone to ensure persistent storage is finished before resolving
+      await Promise.resolve(onDone());
+    }
   }
 };