Market Data Service

A lightweight Python microservice that provides stock market data via REST API, powered by yfinance.

Features

• 🔍 ISIN Search: Search for financial instruments by ISIN code
• 🛡️ Robust Lookup: Automatic fallback to multiple exchanges and alternative sources (justETF) for accurate results
• ⚡ Redis Caching: High-performance metadata caching to reduce external API calls and latency
• 🔌 Circuit Breaker: Resilient web scraping with automatic lockout on 403 errors to protect IP reputation
• 💰 Real-time Quotes: Get current stock prices for any symbol
• 📦 Batch Operations: Search multiple ISINs or get multiple quotes in parallel
• 🌐 Global Coverage: Supports US, UK, EU, Asian markets
• 🚀 Fast: Built with FastAPI for high performance
• 🐳 Docker Ready: Production-ready containerization with Redis support

API Endpoints

Method	Endpoint	Description
GET	/health	Health check
GET	/api/v1/search/{isin}	Search instrument by ISIN
POST	/api/v1/search/batch	Search multiple instruments by ISIN
GET	/api/v1/quote/{symbol}	Get current quote for symbol
POST	/api/v1/quote/batch	Get quotes for multiple symbols
GET	/docs	OpenAPI documentation

Examples

Search by ISIN:

curl http://localhost:8000/api/v1/search/US0378331005

Response:

{
  "isin": "US0378331005",
  "symbol": "AAPL",
  "name": "Apple Inc.",
  "type": "stock",
  "currency": "USD",
  "exchange": "NASDAQ"
}

Get Quote:

curl http://localhost:8000/api/v1/quote/AAPL

Response:

{
  "symbol": "AAPL",
  "price": "195.5000",
  "currency": "USD",
  "time": "2024-12-24T15:00:00+00:00"
}

Batch Search by ISIN:

curl -X POST http://localhost:8000/api/v1/search/batch \
  -H "Content-Type: application/json" \
  -d '{"isins": ["US0378331005", "DE0007164600", "INVALID123"]}'

Response:

{
  "results": [
    {
      "isin": "US0378331005",
      "symbol": "AAPL",
      "name": "Apple Inc.",
      "type": "stock",
      "currency": "USD",
      "exchange": "NASDAQ"
    },
    {
      "isin": "DE0007164600",
      "symbol": "SAP",
      "name": "SAP SE",
      "type": "stock",
      "currency": "EUR",
      "exchange": "XETRA"
    }
  ],
  "errors": [
    {
      "isin": "INVALID123",
      "error": "No instrument found for ISIN"
    }
  ]
}

Batch Get Quotes:

curl -X POST http://localhost:8000/api/v1/quote/batch \
  -H "Content-Type: application/json" \
  -d '{"symbols": ["AAPL", "SAP", "INVALID"]}'

Response:

{
  "results": [
    {
      "symbol": "AAPL",
      "price": "193.4200",
      "currency": "USD",
      "time": "2025-12-26T10:30:00Z"
    },
    {
      "symbol": "SAP",
      "price": "142.5000",
      "currency": "EUR",
      "time": "2025-12-26T10:30:00Z"
    }
  ],
  "errors": [
    {
      "symbol": "INVALID",
      "error": "No quote data available"
    }
  ]
}

Quick Start

Docker (Recommended)

docker compose up --build

The service will be available at http://localhost:8000

Local Development

1. Create virtual environment:

python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

2. Install dependencies:

pip install -r requirements.txt

3. Run the service:

uvicorn src.main:app --reload --host 0.0.0.0 --port 8000

Configuration

Environment variables (see .env.example):

Variable	Description	Default
PORT	Service port	8000
HOST	Service host	0.0.0.0
LOG_LEVEL	Logging level	INFO
DEBUG	Enable debug mode	false
REDIS_HOST	Redis host for caching	localhost
REDIS_PORT	Redis port	6379
REDIS_DB	Redis database number	0

Testing

Unit and Integration Tests

Run standard tests:

pytest tests/ -v

Run integration tests (requires internet):

pytest tests/ -v -m integration

End-to-End Tests (Docker)

These tests build a real Docker container of the application and perform HTTP requests against it, simulating a real production environment:

pytest tests/test_container_integration.py -v -m container

Note: Requires Docker to be running.

Local CI Simulation

To verify your code before creating a Pull Request, you can run the same checks performed by the GitHub Actions CI (linting, security, types, tests):

Windows (PowerShell):

.\verify.ps1

Linux/macOS (Bash):

chmod +x verify.sh
./verify.sh

Kubernetes Deployment

Example K8s deployment:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: market-data-service
spec:
  replicas: 2
  selector:
    matchLabels:
      app: market-data-service
  template:
    metadata:
      labels:
        app: market-data-service
    spec:
      containers:
      - name: market-data-service
        image: ghcr.io/your-username/market-data-service:latest
        ports:
        - containerPort: 8000
        livenessProbe:
          httpGet:
            path: /health
            port: 8000
          initialDelaySeconds: 10
          periodSeconds: 30
        resources:
          limits:
            memory: "256Mi"
            cpu: "500m"
          requests:
            memory: "128Mi"
            cpu: "100m"
---
apiVersion: v1
kind: Service
metadata:
  name: market-data-service
spec:
  selector:
    app: market-data-service
  ports:
  - port: 8000
    targetPort: 8000
  type: ClusterIP

Integration with StockTracker

To use this service with your Go StockTracker application:

1. Deploy this service to your K3s cluster
2. Configure the StockTracker to use this as the market data provider
3. The Go client will call:
   • GET /api/v1/search/{isin} for SearchByISIN
   • GET /api/v1/quote/{symbol} for GetQuote

License

MIT