API_SERVER_README.md

Flask API Server for main.py

A simple Flask API server that provides REST endpoints for the main.py RAG system without duplicating model loading or initialization.

How It Works

The app.py server acts as a lightweight wrapper around main.py:

• No Model Loading: The server doesn't load models, parsers, or RAG components
• Subprocess Calls: Uses subprocess to call main.py with command line arguments
• Localhost Only: Runs only on 127.0.0.1 for security
• Simple Interface: Provides basic GET/POST endpoints

API Endpoints

1. Health Check

GET http://127.0.0.1:5000/health

Check if the Flask server is running.

Response:

{
  "status": "healthy",
  "message": "Flask server is running"
}

2. System Status

GET http://127.0.0.1:5000/hackrx/status

Check if main.py is ready and working.

Response:

{
  "status": "ready",
  "message": "main.py is ready"
}

3. Document Upload

POST http://127.0.0.1:5000/hackrx/upload

Upload and process a document using main.py.

Form Data:

• file: The document file to upload

Response:

{
  "success": true,
  "message": "Document processed successfully",
  "chunks_processed": 45,
  "processing_time": 2.34,
  "filename": "document.pdf"
}

4. Query Processing

POST http://127.0.0.1:5000/hackrx/run

Process questions about uploaded documents using main.py.

Request Body:

{
  "questions": [
    "What is covered under this policy?",
    "What is the maximum coverage amount?"
  ]
}

Response:

{
  "answers": [
    {
      "question": "What is covered under this policy?",
      "answer": "Based on the policy document, the following are covered...",
      "decision": "COVERED",
      "confidence": 0.85,
      "processing_time": 1.23
    }
  ]
}

How the Server Works

Document Upload Process:

1. Flask receives uploaded file
2. Saves file to uploads/ directory
3. Calls: python main.py --upload /path/to/file
4. Parses output from main.py
5. Returns JSON response

Query Processing Process:

1. Flask receives JSON with questions
2. For each question:
   • Creates temporary file with question
   • Calls: python main.py --query /path/to/question.txt
   • Parses structured output from main.py
   • Extracts decision, confidence, justification
3. Returns JSON with all answers

Status Check Process:

1. Calls: python main.py --status
2. Checks if main.py responds successfully
3. Returns status JSON

Usage Examples

Python Example

import requests

BASE_URL = "http://127.0.0.1:5000"

# 1. Upload a document
with open("document.pdf", "rb") as f:
    files = {"file": f}
    response = requests.post(f"{BASE_URL}/hackrx/upload", files=files)
    print("Upload response:", response.json())

# 2. Process queries
questions = [
    "What is covered under this policy?",
    "What is the maximum coverage amount?"
]

payload = {"questions": questions}
response = requests.post(
    f"{BASE_URL}/hackrx/run",
    json=payload,
    headers={"Content-Type": "application/json"}
)

answers = response.json()["answers"]
for answer in answers:
    print(f"Q: {answer['question']}")
    print(f"A: {answer['answer']}")
    print(f"Decision: {answer['decision']}")
    print(f"Confidence: {answer['confidence']}")
    print("---")

cURL Examples

Health Check:

curl http://127.0.0.1:5000/health

System Status:

curl http://127.0.0.1:5000/hackrx/status

Upload Document:

curl -X POST -F "file=@document.pdf" http://127.0.0.1:5000/hackrx/upload

Process Queries:

curl -X POST \
     -H "Content-Type: application/json" \
     -d '{"questions": ["What is covered under this policy?"]}' \
     http://127.0.0.1:5000/hackrx/run

Running the Server

1. Start the server:

   python app.py
   

2. Test the API:

   python test_api.py
   

Command Line Interface

The main.py now supports command line arguments:

# Process a single query
python main.py --query question.txt

# Upload and process a document
python main.py --upload document.pdf

# Check system status
python main.py --status

# Interactive mode (default)
python main.py

Advantages

1. No Duplication: Doesn't load models or initialize RAG system
2. Lightweight: Minimal memory footprint
3. Simple: Easy to understand and maintain
4. Secure: Localhost only
5. Reliable: Uses existing main.py functionality

Error Handling

• File Not Found: Returns 400 if file doesn't exist
• Unsupported Format: Returns 400 for unsupported file types
• Processing Errors: Returns 500 with error details
• Timeouts: 60 seconds for queries, 120 seconds for uploads

Notes

• main.py Required: The server requires main.py to be in the same directory
• Python Path: Assumes python command is available
• File Cleanup: Temporary files are automatically cleaned up
• Upload Directory: Creates uploads/ directory if it doesn't exist