A powerful, real-time Chain-of-Thought dataset generator with a beautiful browser UI.
Generate high-quality synthetic training data for LLMs with structured Cold Start + Hot Start reasoning — perfect for creating wop/XXXXXL-style CoT datasets.
- Modern Web UI – Clean, dark-themed interface with live streaming
- True Parallel Generation – Up to 6 concurrent workers using
ThreadPoolExecutor - Real SSE Streaming – Watch tokens appear in real time
- Live Statistics – Progress, speed (chars/sec), ETA, success rate
- Smart Estimator – Accurate remaining time prediction
- Robust Error Handling – Graceful recovery and detailed logging
- JSONL Export – Ready-to-use
train.jsonlwith optional ASCII cleaning - One-Click Actions – Copy JSONL, download, refresh, copy streams
- Safe Output – Automatic punctuation normalization & ASCII conversion
pip install requestsEdit the top section of cot_generator.py:
API_URL = "http://127.0.0.1:1234/v1/chat/completions" # Your local LLM server
MODEL = "qwen/qwen3.5-9b" # Change to your model
PORT = 8080
MAX_WORKERS = 6 # Adjust based on your hardwarepython cot_generator.pyThen open your browser and go to: http://localhost:8080
- Enter your questions (one per line) in the input box
- Click ▶ Generate Batch
- Watch live generation in the stream panel
- Use the buttons to:
- Copy JSONL (cleaned & validated)
- Download
train.jsonl - Refresh loaded entries
| Variable | Description | Default |
|---|---|---|
API_URL |
Local LLM API endpoint | http://127.0.0.1:1234/... |
MODEL |
Model name to use | qwen/qwen3.5-9b |
MAX_WORKERS |
Number of parallel generations | 6 |
DATA_FILE |
Output JSONL file | train.jsonl |
The generator uses a carefully designed system prompt that forces the model to output structured thinking with:
- Cold Start – Initial analysis and context awareness
- Hot Start – Step-by-step reasoning
<think>...</think>tags (as requested)
You can easily customize the SYSTEM_PROMPT variable in the script.
Each entry follows this structure:
{
"messages": [
{
"role": "system",
"content": "Enable thinking features: INTUITION, COLD START, HOT START"
},
{
"role": "user",
"content": "How many R in strawberry"
},
{
"role": "assistant",
"content": "<think>\n### Cold start\n...\n</think>\n\n**Final Answer**"
}
]
}- Use a strong reasoning model (Qwen2.5, Llama-3.1/3.3, etc.)
- Keep temperature around 0.7
- Start with 5–20 questions to test
- For very large batches, increase
MAX_WORKERS(if your hardware allows)
.
├── cot_generator.py # Main script (self-contained)
├── train.jsonl # Generated dataset (auto-created)
└── README.md
Feel free to open issues or PRs! Especially welcome:
- Better UI components
- Support for OpenAI/Anthropic APIs
- Prompt engineering improvements
- Export format options
Made for high-quality synthetic CoT data generation.
Happy dataset building! 🧠