Added llama stack-langChain integration example scripts

Author: omaryashraf5

docs/notebooks/langChain/README.md

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+# LangChain + Llama Stack Document Processing
+
+This repository contains two different implementations of document processing using LangChain and Llama Stack:
+
+1. **`langchain_llamastack.py`** - Interactive CLI version
+2. **`langchain_llamastack_ray.py`** - Ray Serve API version
+
+Both versions provide AI-powered document processing capabilities including summarization, fact extraction, and question-answering.
+
+---
+
+## 📋 Prerequisites
+
+### System Requirements
+- Python 3.12+
+- Ray Serve (for API version)
+- Llama Stack server running on `http://localhost:8321/`
+- Ollama or compatible model server
+
+### Required Python Packages
+```bash
+pip install llama-stack-client langchain langchain-core langchain-community
+pip install beautifulsoup4 markdownify readability-lxml requests
+pip install ray[serve] starlette  # For Ray Serve version only
+```
+
+### Environment Setup
+```bash
+# Create and activate virtual environment
+python3.12 -m venv llama-env-py312
+source llama-env-py312/bin/activate
+
+# Install dependencies
+pip install llama-stack-client langchain langchain-core langchain-community beautifulsoup4 markdownify readability-lxml requests ray[serve] starlette
+```
+
+---
+
+## 🚀 Quick Start
+
+### Start Llama Stack Server
+Before running either version, ensure your Llama Stack server is running:
+```bash
+# Start Llama Stack server (example)
+llama stack run your-config --port 8321
+```
+
+---
+
+## 📖 Option 1: Interactive CLI Version (`langchain_llamastack_updated.py`)
+
+### Features
+- ✅ Interactive command-line interface
+- ✅ Document loading from URLs and PDFs
+- ✅ AI-powered summarization and fact extraction
+- ✅ Question-answering based on document content
+- ✅ Session-based document storage
+
+### How to Run
+```bash
+# Activate environment
+source llama-env-py312/bin/activate
+
+# Run the interactive CLI
+cd /home/omara/langchain_llamastack
+python langchain_llamastack_updated.py
+```
+
+### Usage Commands
+Once running, you can use these interactive commands:
+
+```
+🎯 Interactive Document Processing Demo
+Commands:
+  load <url_or_path>  - Process a document
+  ask <question>      - Ask about the document
+  summary            - Show document summary
+  facts              - Show extracted facts
+  help               - Show commands
+  quit               - Exit demo
+```
+
+### Example Session
+```
+> load https://en.wikipedia.org/wiki/Artificial_intelligence
+📄 Loading document from: https://en.wikipedia.org/wiki/Artificial_intelligence
+✅ Loaded 45,832 characters
+📝 Generating summary...
+🔍 Extracting key facts...
+✅ Processing complete!
+
+> summary
+📝 Summary:
+Artificial intelligence (AI) is the simulation of human intelligence...
+
+> ask What are the main types of AI?
+💬 Q: What are the main types of AI?
+📝 A: Based on the document, the main types of AI include...
+
+> facts
+🔍 Key Facts:
+- AI was founded as an academic discipline in 1956
+- Machine learning is a subset of AI...
+
+> quit
+👋 Thanks for exploring LangChain chains!
+```
+
+---
+
+## 🌐 Option 2: Ray Serve API Version (`langchain_llamastack_ray.py`)
+
+### Features
+- ✅ RESTful HTTP API
+- ✅ Persistent service (runs indefinitely)
+- ✅ Multiple endpoints for different operations
+- ✅ JSON request/response format
+- ✅ Concurrent request handling
+
+### How to Run
+```bash
+# Activate environment
+source llama-env-py312/bin/activate
+
+# Start the Ray Serve API
+cd /home/omara/langchain_llamastack
+python langchain_llamastack_ray.py
+```
+
+### Service Endpoints
+
+| Method | Endpoint | Description | Parameters |
+|--------|----------|-------------|------------|
+| GET | `/` | Service status | None |
+| POST | `/process` | Process document | `{"source": "url_or_path"}` |
+| POST | `/ask` | Ask question | `{"question": "text", "source": "optional"}` |
+| GET | `/summary` | Get summary | `?source=url` (optional) |
+| GET | `/facts` | Get facts | `?source=url` (optional) |
+| GET | `/docs` | List documents | None |
+
+### API Usage Examples
+
+#### Using curl:
+```bash
+# Check service status
+curl http://localhost:8000/
+
+# Process a document
+curl -X POST http://localhost:8000/process \
+     -H 'Content-Type: application/json' \
+     -d '{"source": "https://en.wikipedia.org/wiki/Machine_learning"}'
+
+# Ask a question
+curl -X POST http://localhost:8000/ask \
+     -H 'Content-Type: application/json' \
+     -d '{"question": "What is machine learning?"}'
+
+# Get summary
+curl http://localhost:8000/summary
+
+# Get facts
+curl http://localhost:8000/facts
+
+# List all processed documents
+curl http://localhost:8000/docs
+```
+
+#### Using Python requests:
+```python
+import requests
+
+# Process a document
+response = requests.post(
+    "http://localhost:8000/process",
+    json={"source": "https://en.wikipedia.org/wiki/Deep_learning"}
+)
+print(response.json())
+
+# Ask a question
+response = requests.post(
+    "http://localhost:8000/ask",
+    json={"question": "What are neural networks?"}
+)
+print(response.json())
+
+# Get facts
+response = requests.get("http://localhost:8000/facts")
+print(response.json())
+```
+
+---
+
+## 🔧 Configuration
+
+### Model Configuration
+Both versions use these models by default:
+- **Model ID**: `llama3.2:3b`
+- **Llama Stack URL**: `http://localhost:8321/`
+
+To change the model, edit the `model_id` parameter in the respective files.
+
+### Supported Document Types
+- ✅ **URLs**: Any web page (extracted using readability)
+- ✅ **PDF files**: Local or remote PDF documents
+- ❌ Plain text files (can be added if needed)
+
+---
+
+## 🛠️ Troubleshooting
+
+### Common Issues
+
+#### 1. Connection Refused to Llama Stack
+**Error**: `Connection refused to http://localhost:8321/`
+**Solution**:
+- Ensure Llama Stack server is running
+- Check if port 8321 is correct
+- Verify network connectivity
+
+#### 2. Model Not Found
+**Error**: `Model not found: llama3.2:3b`
+**Solution**:
+- Check available models: `curl http://localhost:8321/models/list`
+- Update `model_id` in the code to match available models
+
+#### 3. Ray Serve Port Already in Use
+**Error**: `Port 8000 already in use`
+**Solution**:
+```bash
+# Kill process using port 8000
+lsof -ti :8000 | xargs kill -9
+
+# Or use a different port by modifying the code
+```
+
+#### 4. Missing Dependencies
+**Error**: `ModuleNotFoundError: No module named 'ray'`
+**Solution**:
+```bash
+pip install ray[serve] starlette
+```
+
+### Debug Mode
+To enable verbose logging, add this to the beginning of either file:
+```python
+import logging
+logging.basicConfig(level=logging.DEBUG)
+```
+
+---
+
+## 📊 Performance Notes
+
+### CLI Version
+- **Pros**: Simple to use, interactive, good for testing
+- **Cons**: Single-threaded, session-based only
+- **Best for**: Development, testing, manual document analysis
+
+### Ray Serve Version
+- **Pros**: Concurrent requests, persistent service, API integration
+- **Cons**: More complex setup, requires Ray
+- **Best for**: Production, integration with other services, high throughput
+
+---
+
+## 🛑 Stopping Services
+
+### CLI Version
+- Press `Ctrl+C` or type `quit` in the interactive prompt
+
+### Ray Serve Version
+- Press `Ctrl+C` in the terminal running the service
+- The service will gracefully shutdown and clean up resources
+
+---
+
+## 📝 Examples
+
+### CLI Workflow
+1. Start: `python langchain_llamastack_updated.py`
+2. Load document: `load https://arxiv.org/pdf/2103.00020.pdf`
+3. Get summary: `summary`
+4. Ask questions: `ask What are the main contributions?`
+5. Exit: `quit`
+
+### API Workflow
+1. Start: `python langchain_llamastack_ray.py`
+2. Process: `curl -X POST http://localhost:8000/process -d '{"source": "https://example.com"}'`
+3. Query: `curl -X POST http://localhost:8000/ask -d '{"question": "What is this about?"}'`
+4. Stop: `Ctrl+C`
+
+---
+
+## 🤝 Contributing
+
+To extend functionality:
+1. Add new prompt templates for different analysis types
+2. Support additional document formats
+3. Add caching for processed documents
+4. Implement user authentication for API version
+
+---
+
+## 📜 License
+
+This project is for educational and research purposes.