added back end concurrency and front end paste feature.

.note/concurrency_plan.md

@@ -0,0 +1,188 @@
+# Chatterbox TTS Backend: Bounded Concurrency + File I/O Offload Plan
+
+Date: 2025-08-14
+Owner: Backend
+Status: Proposed (ready to implement)
+
+## Goals
+
+- Increase GPU utilization and reduce wall-clock time for dialog generation.
+- Keep model lifecycle stable (leveraging current `ModelManager`).
+- Minimal-risk changes: no API shape changes to clients.
+
+## Scope
+
+- Implement bounded concurrency for per-line speech chunk generation within a single dialog request.
+- Offload audio file writes to threads to overlap GPU compute and disk I/O.
+- Add configuration knobs to tune concurrency.
+
+## Current State (References)
+
+- `backend/app/services/dialog_processor_service.py`
+  - `DialogProcessorService.process_dialog()` iterates items and awaits `tts_service.generate_speech(...)` sequentially (lines ~171–201).
+- `backend/app/services/tts_service.py`
+  - `TTSService.generate_speech()` runs the TTS forward and calls `torchaudio.save(...)` on the event loop thread (blocking).
+- `backend/app/services/model_manager.py`
+  - `ModelManager.using()` tracks active work; prevents idle eviction during requests.
+- `backend/app/routers/dialog.py`
+  - `process_dialog_flow()` expects ordered `segment_files` and then concatenates; good to keep order stable.
+
+## Design Overview
+
+1) Bounded concurrency at dialog level
+
+- Plan all output segments with a stable `segment_idx` (including speech chunks, silence, and reused audio).
+- For speech chunks, schedule concurrent async tasks with a global semaphore set by config `TTS_MAX_CONCURRENCY` (start at 3–4).
+- Await all tasks and collate results by `segment_idx` to preserve order.
+
+2) File I/O offload
+
+- Replace direct `torchaudio.save(...)` with `await asyncio.to_thread(torchaudio.save, ...)` in `TTSService.generate_speech()`.
+- This lets the next GPU forward start while previous file writes happen on worker threads.
+
+## Configuration
+
+Add to `backend/app/config.py`:
+
+- `TTS_MAX_CONCURRENCY: int` (default: `int(os.getenv("TTS_MAX_CONCURRENCY", "3"))`).
+- Optional (future): `TTS_ENABLE_AMP_ON_CUDA: bool = True` to allow mixed precision on CUDA only.
+
+## Implementation Steps
+
+### A. Dialog-level concurrency
+
+- File: `backend/app/services/dialog_processor_service.py`
+- Function: `DialogProcessorService.process_dialog()`
+
+1. Planning pass to assign indices
+
+- Iterate `dialog_items` and build a list `planned_segments` entries:
+  - For silence or reuse: immediately append a final result with assigned `segment_idx` and continue.
+  - For speech: split into `text_chunks`; for each chunk create a planned entry: `{ segment_idx, type: 'speech', speaker_id, text_chunk, abs_speaker_sample_path, tts_params }`.
+  - Increment `segment_idx` for every planned segment (speech chunk or silence/reuse) to preserve final order.
+
+2. Concurrency setup
+
+- Create `sem = asyncio.Semaphore(config.TTS_MAX_CONCURRENCY)`.
+- For each planned speech segment, create a task with an inner wrapper:
+
+  ```python
+  async def run_one(planned):
+      async with sem:
+          try:
+              out_path = await self.tts_service.generate_speech(
+                  text=planned.text_chunk,
+                  speaker_sample_path=planned.abs_speaker_sample_path,
+                  output_filename_base=planned.filename_base,
+                  output_dir=dialog_temp_dir,
+                  exaggeration=planned.exaggeration,
+                  cfg_weight=planned.cfg_weight,
+                  temperature=planned.temperature,
+              )
+              return planned.segment_idx, {"type": "speech", "path": str(out_path), "speaker_id": planned.speaker_id, "text_chunk": planned.text_chunk}
+          except Exception as e:
+              return planned.segment_idx, {"type": "error", "message": f"Error generating speech: {e}", "text_chunk": planned.text_chunk}
+  ```
+
+- Schedule with `asyncio.create_task(run_one(p))` and collect tasks.
+
+3. Await and collate
+
+- `results_map = {}`; for each completed task, set `results_map[idx] = payload`.
+- Merge: start with all previously final (silence/reuse/error) entries placed by `segment_idx`, then fill speech results by `segment_idx` into a single `segment_results` list sorted ascending by index.
+- Keep `processing_log` entries for each planned segment (queued, started, finished, errors).
+
+4. Return value unchanged
+
+- Return `{"log": ..., "segment_files": segment_results, "temp_dir": str(dialog_temp_dir)}`. This maintains router and concatenator behavior.
+
+### B. Offload audio writes
+
+- File: `backend/app/services/tts_service.py`
+- Function: `TTSService.generate_speech()`
+
+1. After obtaining `wav` tensor, replace:
+
+```python
+# torchaudio.save(str(output_file_path), wav, self.model.sr)
+```
+
+with:
+
+```python
+await asyncio.to_thread(torchaudio.save, str(output_file_path), wav, self.model.sr)
+```
+
+- Keep the rest of cleanup logic (delete `wav`, `gc.collect()`, cache emptying) unchanged.
+
+2. Optional (CUDA-only AMP)
+
+- If CUDA is used and `config.TTS_ENABLE_AMP_ON_CUDA` is True, wrap forward with AMP:
+
+```python
+with torch.cuda.amp.autocast(dtype=torch.float16):
+    wav = self.model.generate(...)
+```
+
+- Leave MPS/CPU code path as-is.
+
+## Error Handling & Ordering
+
+- Every planned segment owns a unique `segment_idx`.
+- On failure, insert an error record at that index; downstream concatenation will skip missing/nonexistent paths already.
+- Preserve exact output order expected by `routers/dialog.py::process_dialog_flow()`.
+
+## Performance Expectations
+
+- GPU util should increase from ~50% to 75–90% depending on dialog size and line lengths.
+- Wall-clock reduction is workload-dependent; target 1.5–2.5x on multi-line dialogs.
+
+## Metrics & Instrumentation
+
+- Add timestamped log entries per segment: planned→queued→started→saved.
+- Log effective concurrency (max in-flight), and cumulative GPU time if available.
+- Optionally add a simple timing summary at end of `process_dialog()`.
+
+## Testing Plan
+
+1. Unit-ish
+
+- Small dialog (3 speech lines, 1 silence). Ensure ordering is stable and files exist.
+- Introduce an invalid speaker to verify error propagation doesn’t break the rest.
+
+2. Integration
+
+- POST `/api/dialog/generate` with 20–50 mixed-length lines and a couple silences.
+- Validate: response OK, concatenated file exists, zip contains all generated speech segments, order preserved.
+- Compare runtime vs. sequential baseline (before/after).
+
+3. Stress/limits
+
+- Long lines split into many chunks; verify no OOM with `TTS_MAX_CONCURRENCY`=3.
+- Try `TTS_MAX_CONCURRENCY`=1 to simulate sequential; compare metrics.
+
+## Rollout & Config Defaults
+
+- Default `TTS_MAX_CONCURRENCY=3`.
+- Expose via environment variable; no client changes needed.
+- If instability observed, set `TTS_MAX_CONCURRENCY=1` to revert to sequential behavior quickly.
+
+## Risks & Mitigations
+
+- OOM under high concurrency → Mitigate with low default, easy rollback, and chunking already in place.
+- Disk I/O saturation → Offload to threads; if disk is a bottleneck, decrease concurrency.
+- Model thread safety → We call `model.generate` concurrently only up to semaphore cap; if underlying library is not thread-safe for forward passes, consider serializing forwards but still overlapping with file I/O; early logs will reveal.
+
+## Follow-up (Out of Scope for this change)
+
+- Dynamic batching queue inside `TTSService` for further GPU efficiency.
+- CUDA AMP enablement and profiling.
+- Per-speaker sub-queues if batching requires same-speaker inputs.
+
+## Acceptance Criteria
+
+- `TTS_MAX_CONCURRENCY` is configurable; default=3.
+- File writes occur via `asyncio.to_thread`.
+- Order of `segment_files` unchanged relative to sequential output.
+- End-to-end works for both small and large dialogs; error cases logged.
+- Observed GPU utilization and runtime improve on representative dialog.

backend/app/config.py

@@ -67,6 +67,10 @@ if CORS_ORIGINS != ["*"] and _frontend_host and _frontend_port:
 # Device configuration
 DEVICE = os.getenv("DEVICE", "auto")
  
+# Concurrency configuration
+# Max number of concurrent TTS generation tasks per dialog request
+TTS_MAX_CONCURRENCY = int(os.getenv("TTS_MAX_CONCURRENCY", "3"))
+
 # Model idle eviction configuration
 # Enable/disable idle-based model eviction
 MODEL_EVICTION_ENABLED = os.getenv("MODEL_EVICTION_ENABLED", "true").lower() == "true"

backend/app/services/dialog_processor_service.py

@@ -1,6 +1,8 @@
 from pathlib import Path
 from typing import List, Dict, Any, Union
 import re
+import asyncio
+from datetime import datetime
 
 from .tts_service import TTSService
 from .speaker_service import SpeakerManagementService
@@ -92,24 +94,72 @@ class DialogProcessorService:
 
         import shutil
         segment_idx = 0
+        tasks = []
+        results_map: Dict[int, Dict[str, Any]] = {}
+        sem = asyncio.Semaphore(getattr(config, "TTS_MAX_CONCURRENCY", 2))
+
+        async def run_one(planned: Dict[str, Any]):
+            async with sem:
+                text_chunk = planned["text_chunk"]
+                speaker_id = planned["speaker_id"]
+                abs_speaker_sample_path = planned["abs_speaker_sample_path"]
+                filename_base = planned["filename_base"]
+                params = planned["params"]
+                seg_idx = planned["segment_idx"]
+                start_ts = datetime.now()
+                start_line = (
+                    f"[{start_ts.isoformat(timespec='seconds')}] [TTS-TASK] START seg_idx={seg_idx} "
+                    f"speaker={speaker_id} chunk_len={len(text_chunk)} base={filename_base}"
+                )
+                try:
+                    out_path = await self.tts_service.generate_speech(
+                        text=text_chunk,
+                        speaker_id=speaker_id,
+                        speaker_sample_path=str(abs_speaker_sample_path),
+                        output_filename_base=filename_base,
+                        output_dir=dialog_temp_dir,
+                        exaggeration=params.get('exaggeration', 0.5),
+                        cfg_weight=params.get('cfg_weight', 0.5),
+                        temperature=params.get('temperature', 0.8),
+                    )
+                    end_ts = datetime.now()
+                    duration = (end_ts - start_ts).total_seconds()
+                    end_line = (
+                        f"[{end_ts.isoformat(timespec='seconds')}] [TTS-TASK] END   seg_idx={seg_idx} "
+                        f"dur={duration:.2f}s -> {out_path}"
+                    )
+                    return seg_idx, {
+                        "type": "speech",
+                        "path": str(out_path),
+                        "speaker_id": speaker_id,
+                        "text_chunk": text_chunk,
+                    }, start_line + "\n" + f"Successfully generated segment: {out_path}" + "\n" + end_line
+                except Exception as e:
+                    end_ts = datetime.now()
+                    err_line = (
+                        f"[{end_ts.isoformat(timespec='seconds')}] [TTS-TASK] ERROR seg_idx={seg_idx} "
+                        f"speaker={speaker_id} err={repr(e)}"
+                    )
+                    return seg_idx, {
+                        "type": "error",
+                        "message": f"Error generating speech for chunk '{text_chunk[:50]}...': {repr(e)}",
+                        "text_chunk": text_chunk,
+                    }, err_line
+
         for i, item in enumerate(dialog_items):
             item_type = item.get("type")
             processing_log.append(f"Processing item {i+1}: type='{item_type}'")
 
-            # --- Universal: Handle reuse of existing audio for both speech and silence ---
+            # --- Handle reuse of existing audio ---
             use_existing_audio = item.get("use_existing_audio", False)
             audio_url = item.get("audio_url")
             if use_existing_audio and audio_url:
-                # Determine source path (handle both absolute and relative)
-                # Map web URL to actual file location in tts_generated_dialogs
                 if audio_url.startswith("/generated_audio/"):
                     src_audio_path = config.DIALOG_OUTPUT_DIR / audio_url[len("/generated_audio/"):]
                 else:
                     src_audio_path = Path(audio_url)
                     if not src_audio_path.is_absolute():
-                        # Assume relative to the generated audio root dir
                         src_audio_path = config.DIALOG_OUTPUT_DIR / audio_url.lstrip("/\\")
-                # Now src_audio_path should point to the real file in tts_generated_dialogs
                 if src_audio_path.is_file():
                     segment_filename = f"{output_base_name}_seg{segment_idx}_reused.wav"
                     dest_path = (self.temp_audio_dir / output_base_name / segment_filename)
@@ -123,22 +173,18 @@ class DialogProcessorService:
                             processing_log.append(f"[REUSE] Destination audio file was not created: {dest_path}")
                         else:
                             processing_log.append(f"[REUSE] Destination audio file created: {dest_path}, size={dest_path.stat().st_size} bytes")
-                        # Only include 'type' and 'path' so the concatenator always includes this segment
+                        results_map[segment_idx] = {"type": item_type, "path": str(dest_path)}
-                        segment_results.append({
-                            "type": item_type,
-                            "path": str(dest_path)
-                        })
                         processing_log.append(f"Reused existing audio for item {i+1}: copied from {src_audio_path} to {dest_path}")
                     except Exception as e:
                         error_message = f"Failed to copy reused audio for item {i+1}: {e}"
                         processing_log.append(error_message)
-                        segment_results.append({"type": "error", "message": error_message})
+                        results_map[segment_idx] = {"type": "error", "message": error_message}
                     segment_idx += 1
                     continue
                 else:
                     error_message = f"Audio file for reuse not found at {src_audio_path} for item {i+1}."
                     processing_log.append(error_message)
-                    segment_results.append({"type": "error", "message": error_message})
+                    results_map[segment_idx] = {"type": "error", "message": error_message}
                     segment_idx += 1
                     continue
 
@@ -147,70 +193,81 @@ class DialogProcessorService:
                 text = item.get("text")
                 if not speaker_id or not text:
                     processing_log.append(f"Skipping speech item {i+1} due to missing speaker_id or text.")
-                    segment_results.append({"type": "error", "message": "Missing speaker_id or text"})
+                    results_map[segment_idx] = {"type": "error", "message": "Missing speaker_id or text"}
+                    segment_idx += 1
                     continue
 
-                # Validate speaker_id and get speaker_sample_path
                 speaker_info = self.speaker_service.get_speaker_by_id(speaker_id)
                 if not speaker_info:
                     processing_log.append(f"Speaker ID '{speaker_id}' not found. Skipping item {i+1}.")
-                    segment_results.append({"type": "error", "message": f"Speaker ID '{speaker_id}' not found"})
+                    results_map[segment_idx] = {"type": "error", "message": f"Speaker ID '{speaker_id}' not found"}
+                    segment_idx += 1
                     continue
                 if not speaker_info.sample_path:
                     processing_log.append(f"Speaker ID '{speaker_id}' has no sample path defined. Skipping item {i+1}.")
-                    segment_results.append({"type": "error", "message": f"Speaker ID '{speaker_id}' has no sample path defined"})
+                    results_map[segment_idx] = {"type": "error", "message": f"Speaker ID '{speaker_id}' has no sample path defined"}
+                    segment_idx += 1
                     continue
 
-                # speaker_info.sample_path is relative to config.SPEAKER_DATA_BASE_DIR
                 abs_speaker_sample_path = config.SPEAKER_DATA_BASE_DIR / speaker_info.sample_path
                 if not abs_speaker_sample_path.is_file():
                     processing_log.append(f"Speaker sample file not found or is not a file at '{abs_speaker_sample_path}' for speaker ID '{speaker_id}'. Skipping item {i+1}.")
-                    segment_results.append({"type": "error", "message": f"Speaker sample not a file or not found: {abs_speaker_sample_path}"})
+                    results_map[segment_idx] = {"type": "error", "message": f"Speaker sample not a file or not found: {abs_speaker_sample_path}"}
+                    segment_idx += 1
                     continue
 
                 text_chunks = self._split_text(text)
                 processing_log.append(f"Split text for speaker '{speaker_id}' into {len(text_chunks)} chunk(s).")
 
                 for chunk_idx, text_chunk in enumerate(text_chunks):
-                    segment_filename_base = f"{output_base_name}_seg{segment_idx}_spk{speaker_id}_chunk{chunk_idx}"
+                    filename_base = f"{output_base_name}_seg{segment_idx}_spk{speaker_id}_chunk{chunk_idx}"
-                    processing_log.append(f"Generating speech for chunk: '{text_chunk[:50]}...' using speaker '{speaker_id}'")
+                    processing_log.append(f"Queueing TTS for chunk: '{text_chunk[:50]}...' using speaker '{speaker_id}'")
-                    
+                    planned = {
-                    try:
+                        "segment_idx": segment_idx,
-                        segment_output_path = await self.tts_service.generate_speech(
-                            text=text_chunk,
-                            speaker_id=speaker_id, # For metadata, actual sample path is used by TTS
-                            speaker_sample_path=str(abs_speaker_sample_path),
-                            output_filename_base=segment_filename_base,
-                            output_dir=dialog_temp_dir, # Save to the dialog's temp dir
-                            exaggeration=item.get('exaggeration', 0.5), # Default from Gradio, Pydantic model should provide this
-                            cfg_weight=item.get('cfg_weight', 0.5),     # Default from Gradio, Pydantic model should provide this
-                            temperature=item.get('temperature', 0.8)  # Default from Gradio, Pydantic model should provide this
-                        )
-                        segment_results.append({
-                            "type": "speech", 
-                            "path": str(segment_output_path), 
                         "speaker_id": speaker_id,
-                            "text_chunk": text_chunk
+                        "text_chunk": text_chunk,
-                        })
+                        "abs_speaker_sample_path": abs_speaker_sample_path,
-                        processing_log.append(f"Successfully generated segment: {segment_output_path}")
+                        "filename_base": filename_base,
-                    except Exception as e:
+                        "params": {
-                        error_message = f"Error generating speech for chunk '{text_chunk[:50]}...': {repr(e)}"
+                            'exaggeration': item.get('exaggeration', 0.5),
-                        processing_log.append(error_message)
+                            'cfg_weight': item.get('cfg_weight', 0.5),
-                        segment_results.append({"type": "error", "message": error_message, "text_chunk": text_chunk})
+                            'temperature': item.get('temperature', 0.8),
+                        },
+                    }
+                    tasks.append(asyncio.create_task(run_one(planned)))
                     segment_idx += 1
 
             elif item_type == "silence":
                 duration = item.get("duration")
                 if duration is None or duration < 0:
                     processing_log.append(f"Skipping silence item {i+1} due to invalid duration.")
-                    segment_results.append({"type": "error", "message": "Invalid duration for silence"})
+                    results_map[segment_idx] = {"type": "error", "message": "Invalid duration for silence"}
+                    segment_idx += 1
                     continue
-                segment_results.append({"type": "silence", "duration": float(duration)})
+                results_map[segment_idx] = {"type": "silence", "duration": float(duration)}
                 processing_log.append(f"Added silence of {duration}s.")
+                segment_idx += 1
 
             else:
                 processing_log.append(f"Unknown item type '{item_type}' at item {i+1}. Skipping.")
-                segment_results.append({"type": "error", "message": f"Unknown item type: {item_type}"})
+                results_map[segment_idx] = {"type": "error", "message": f"Unknown item type: {item_type}"}
+                segment_idx += 1
+
+        # Await all TTS tasks and merge results
+        if tasks:
+            processing_log.append(
+                f"Dispatching {len(tasks)} TTS task(s) with concurrency limit "
+                f"{getattr(config, 'TTS_MAX_CONCURRENCY', 2)}"
+            )
+            completed = await asyncio.gather(*tasks, return_exceptions=False)
+            for idx, payload, maybe_log in completed:
+                results_map[idx] = payload
+                if maybe_log:
+                    processing_log.append(maybe_log)
+
+        # Build ordered list
+        for idx in sorted(results_map.keys()):
+            segment_results.append(results_map[idx])
 
         # Log the full segment_results list for debugging
         processing_log.append("[DEBUG] Final segment_results list:")
@@ -220,7 +277,7 @@ class DialogProcessorService:
         return {
             "log": "\n".join(processing_log),
             "segment_files": segment_results,
-            "temp_dir": str(dialog_temp_dir) # For cleanup or zipping later
+            "temp_dir": str(dialog_temp_dir)
         }
 
 if __name__ == "__main__":

backend/app/services/tts_service.py

@@ -1,11 +1,14 @@
 import torch
 import torchaudio
+import asyncio
 from typing import Optional
 from chatterbox.tts import ChatterboxTTS
 from pathlib import Path
 import gc # Garbage collector for memory management
 import os
 from contextlib import contextmanager
+from datetime import datetime
+import time
 
 # Import configuration
 try:
@@ -114,7 +117,11 @@ class TTSService:
         # output_filename_base from DialogProcessorService is expected to be comprehensive (e.g., includes speaker_id, segment info)
         output_file_path = target_output_dir / f"{output_filename_base}.wav"
 
-        print(f"Generating audio for text: \"{text[:50]}...\" with speaker sample: {speaker_sample_path}")
+        start_ts = datetime.now()
+        print(f"[{start_ts.isoformat(timespec='seconds')}] [TTS] START generate+save base={output_filename_base} len={len(text)} sample={speaker_sample_path}")
+        try:
+            def _gen_and_save() -> Path:
+                t0 = time.perf_counter()
                 wav = None
                 try:
                     with torch.no_grad():  # Important for inference
@@ -126,18 +133,15 @@ class TTSService:
                             temperature=temperature,
                         )
 
+                    # Save the audio synchronously in the same thread
                     torchaudio.save(str(output_file_path), wav, self.model.sr)
-            print(f"Audio saved to: {output_file_path}")
+                    t1 = time.perf_counter()
+                    print(f"[TTS-THREAD] Saved {output_file_path.name} in {t1 - t0:.2f}s")
                     return output_file_path
-        except Exception as e:
-            print(f"Error during TTS generation or saving: {e}")
-            raise
                 finally:
-            # Explicitly delete the wav tensor to free memory
+                    # Cleanup in the same thread that created the tensor
                     if wav is not None:
                         del wav
-            
-            # Force garbage collection and cache cleanup
                     gc.collect()
                     if self.device == "cuda":
                         torch.cuda.empty_cache()
@@ -145,11 +149,20 @@ class TTSService:
                         if hasattr(torch.mps, "empty_cache"):
                             torch.mps.empty_cache()
 
-            # Unload the model if requested
+            out_path = await asyncio.to_thread(_gen_and_save)
+            end_ts = datetime.now()
+            print(f"[{end_ts.isoformat(timespec='seconds')}] [TTS] END   generate+save base={output_filename_base} dur={(end_ts - start_ts).total_seconds():.2f}s -> {out_path}")
+
+            # Optionally unload model after generation
             if unload_after:
                 print("Unloading TTS model after generation...")
                 self.unload_model()
 
+            return out_path
+        except Exception as e:
+            print(f"Error during TTS generation or saving: {e}")
+            raise
+
 # Example usage (for testing, not part of the service itself)
 if __name__ == "__main__":
     async def main_test():

frontend/index.html

@@ -11,6 +11,29 @@
         <div class="container">
             <h1>Chatterbox TTS</h1>
         </div>
+
+     <!-- Paste Script Modal -->
+     <div id="paste-script-modal" class="modal" style="display: none;">
+         <div class="modal-content">
+             <div class="modal-header">
+                 <h3>Paste Dialog Script</h3>
+                 <button class="modal-close" id="paste-script-close">&times;</button>
+             </div>
+             <div class="modal-body">
+                 <p>Paste JSONL content (one JSON object per line). Example lines:</p>
+                 <pre style="white-space:pre-wrap; background:#f6f8fa; padding:8px; border-radius:4px;">
+{"type":"speech","speaker_id":"alice","text":"Hello there!"}
+{"type":"silence","duration":0.5}
+{"type":"speech","speaker_id":"bob","text":"Hi!"}
+                 </pre>
+                 <textarea id="paste-script-text" rows="10" style="width:100%;" placeholder='Paste JSONL here'></textarea>
+             </div>
+             <div class="modal-footer">
+                 <button id="paste-script-load" class="btn-primary">Load</button>
+                 <button id="paste-script-cancel" class="btn-secondary">Cancel</button>
+             </div>
+         </div>
+     </div>
     </header>
 
     <!-- Global inline notification area -->
@@ -55,6 +78,7 @@
                     <button id="save-script-btn">Save Script</button>
                     <input type="file" id="load-script-input" accept=".jsonl" style="display: none;">
                     <button id="load-script-btn">Load Script</button>
+                    <button id="paste-script-btn">Paste Script</button>
                 </div>
             </section>
         </div>

frontend/js/app.js

@@ -201,6 +201,12 @@ async function initializeDialogEditor() {
     const saveScriptBtn = document.getElementById('save-script-btn');
     const loadScriptBtn = document.getElementById('load-script-btn');
     const loadScriptInput = document.getElementById('load-script-input');
+    const pasteScriptBtn = document.getElementById('paste-script-btn');
+    const pasteModal = document.getElementById('paste-script-modal');
+    const pasteText = document.getElementById('paste-script-text');
+    const pasteLoadBtn = document.getElementById('paste-script-load');
+    const pasteCancelBtn = document.getElementById('paste-script-cancel');
+    const pasteCloseBtn = document.getElementById('paste-script-close');
 
     // Results Display Elements
     const generationLogPre = document.getElementById('generation-log-content'); // Corrected ID
@@ -891,6 +897,71 @@ async function initializeDialogEditor() {
         reader.readAsText(file);
     }
 
+    // Load dialog script from pasted JSONL text
+    async function loadDialogScriptFromText(text) {
+        if (!text || !text.trim()) {
+            showNotice('Please paste JSONL content to load.', 'warning', { timeout: 4000 });
+            return false;
+        }
+        try {
+            const lines = text.trim().split('\n');
+            const loadedItems = [];
+
+            for (let i = 0; i < lines.length; i++) {
+                const line = lines[i].trim();
+                if (!line) continue; // Skip empty lines
+                try {
+                    const item = JSON.parse(line);
+                    const validatedItem = validateDialogItem(item, i + 1);
+                    if (validatedItem) {
+                        loadedItems.push(normalizeDialogItem(validatedItem));
+                    }
+                } catch (parseError) {
+                    console.error(`Error parsing line ${i + 1}:`, parseError);
+                    showNotice(`Error parsing line ${i + 1}: ${parseError.message}`, 'error');
+                    return false;
+                }
+            }
+
+            if (loadedItems.length === 0) {
+                showNotice('No valid dialog items found in the pasted content.', 'warning', { timeout: 4000 });
+                return false;
+            }
+
+            // Confirm replacement if existing items
+            if (dialogItems.length > 0) {
+                const confirmed = await confirmAction(
+                    `This will replace your current dialog (${dialogItems.length} items) with the pasted script (${loadedItems.length} items). Continue?`
+                );
+                if (!confirmed) return false;
+            }
+
+            // Ensure speakers are loaded before rendering
+            if (availableSpeakersCache.length === 0) {
+                try {
+                    availableSpeakersCache = await getSpeakers();
+                } catch (error) {
+                    console.error('Error fetching speakers:', error);
+                    showNotice('Could not load speakers. Dialog loaded but speaker names may not display correctly.', 'warning', { timeout: 5000 });
+                }
+            }
+
+            // Replace current dialog
+            dialogItems.splice(0, dialogItems.length, ...loadedItems);
+            // Persist loaded script
+            saveDialogToLocalStorage();
+            renderDialogItems();
+
+            console.log(`Loaded ${loadedItems.length} dialog items from pasted text`);
+            showNotice(`Successfully loaded ${loadedItems.length} dialog items.`, 'success', { timeout: 3000 });
+            return true;
+        } catch (error) {
+            console.error('Error loading dialog script from text:', error);
+            showNotice(`Error loading dialog script: ${error.message}`, 'error');
+            return false;
+        }
+    }
+
     function validateDialogItem(item, lineNumber) {
         if (!item || typeof item !== 'object') {
             throw new Error(`Line ${lineNumber}: Invalid item format`);
@@ -946,14 +1017,41 @@ async function initializeDialogEditor() {
             const file = e.target.files[0];
             if (file) {
                 loadDialogScript(file);
-                // Reset input so same file can be loaded again
-                e.target.value = '';
             }
         });
     }
 
+    // --- Paste Script (JSONL) Modal Handlers ---
+    if (pasteScriptBtn && pasteModal && pasteText && pasteLoadBtn && pasteCancelBtn && pasteCloseBtn) {
+        let escHandler = null;
+        const closePasteModal = () => {
+            pasteModal.style.display = 'none';
+            pasteLoadBtn.onclick = null;
+            pasteCancelBtn.onclick = null;
+            pasteCloseBtn.onclick = null;
+            pasteModal.onclick = null;
+            if (escHandler) {
+                document.removeEventListener('keydown', escHandler);
+                escHandler = null;
+            }
+        };
+        const openPasteModal = () => {
+            pasteText.value = '';
+            pasteModal.style.display = 'flex';
+            escHandler = (e) => { if (e.key === 'Escape') closePasteModal(); };
+            document.addEventListener('keydown', escHandler);
+            pasteModal.onclick = (e) => { if (e.target === pasteModal) closePasteModal(); };
+            pasteCloseBtn.onclick = closePasteModal;
+            pasteCancelBtn.onclick = closePasteModal;
+            pasteLoadBtn.onclick = async () => {
+                const ok = await loadDialogScriptFromText(pasteText.value);
+                if (ok) closePasteModal();
+            };
+        };
+        pasteScriptBtn.addEventListener('click', openPasteModal);
+    }
+
     // --- Clear Dialog Button ---
-    // Prefer an existing button with id if present; otherwise, create and insert beside Save/Load.
     let clearDialogBtn = document.getElementById('clear-dialog-btn');
     if (!clearDialogBtn) {
         clearDialogBtn = document.createElement('button');
@@ -970,6 +1068,7 @@ async function initializeDialogEditor() {
         }
     }
 
+    if (clearDialogBtn) {
         clearDialogBtn.addEventListener('click', async () => {
             if (dialogItems.length === 0) {
                 showNotice('Dialog is already empty.', 'info', { timeout: 2500 });
@@ -985,6 +1084,7 @@ async function initializeDialogEditor() {
             renderDialogItems();
             showNotice('Dialog cleared.', 'success', { timeout: 2500 });
         });
+    }
 
     console.log('Dialog Editor Initialized');
     renderDialogItems(); // Initial render (empty)