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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+Trading Data Daemon - A modular Python daemon system for downloading and storing trading data from German stock exchanges (EIX, Lang & Schwarz, Deutsche Börse, Gettex, Stuttgart, Börsenag regional exchanges) into QuestDB.
+
+**Language:** Python 3.12+ | **Database:** QuestDB (time-series via Influx Line Protocol)
+
+## Commands
+
+```bash
+# Docker Compose (primary deployment method)
+docker-compose up -d                    # Start all 5 services
+docker-compose logs -f fetcher          # Watch fetcher logs
+docker-compose down                     # Stop all services
+
+# Manual Python execution
+python3 daemon.py                       # Run main fetcher
+python -m src.analytics.worker          # Run analytics worker
+python src/metadata/fetcher.py          # Run metadata fetcher
+python dashboard/server.py              # Run dashboard API (port 8000)
+
+# Dependencies
+pip install -r requirements.txt
+```
+
+## Architecture
+
+Five microservices orchestrated via Docker Compose:
+
+```
+┌─────────────────────────────────────────────────────────────────┐
+│                         QuestDB                                  │
+│              (9000=HTTP, 8812=PostgreSQL, 9009=ILP)             │
+└──────────┬──────────────┬──────────────┬──────────────┬─────────┘
+           │              │              │              │
+    ┌──────┴──────┐ ┌─────┴─────┐ ┌──────┴──────┐ ┌─────┴─────┐
+    │   fetcher   │ │ analytics │ │  metadata   │ │ dashboard │
+    │ daemon.py   │ │  worker   │ │  fetcher    │ │  :8080    │
+    └─────────────┘ └───────────┘ └─────────────┘ └───────────┘
+```
+
+**Fetcher (`daemon.py`):** Main orchestrator. Fetches trades from all exchanges daily at 23:00. Uses streaming for EIX (large files), batch processing for others. Handles deduplication via MD5 hash caching.
+
+**Analytics Worker (`src/analytics/worker.py`):** Calculates aggregated tables (`analytics_exchange_daily`) for time periods: 7, 30, 42, 69, 180, 365 days.
+
+**Metadata Fetcher (`src/metadata/fetcher.py`):** Enriches ISINs with company/sector data via OpenFIGI API and yfinance.
+
+**Dashboard (`dashboard/server.py`):** FastAPI server serving REST endpoints and static UI from `dashboard/public/`.
+
+## Exchange Extensibility Pattern
+
+All exchanges extend `src/exchanges/base.py:BaseExchange`. To add a new exchange:
+
+1. Create subclass in `src/exchanges/`
+2. Implement `fetch_latest_trades()` returning list of `Trade` objects
+3. Implement `name` property
+4. Register in `daemon.py` in `STREAMING_EXCHANGES` (large data) or `STANDARD_EXCHANGES` (batch)
+
+Currently registered:
+- **Streaming:** EIX (European Investor Exchange)
+- **Standard:** LS, Xetra, Frankfurt, Quotrix, Gettex, Stuttgart, Börsenag (DUSA/DUSB/DUSC/DUSD/HAMA/HAMB/HANA/HANB)
+
+## Database Schema
+
+- `trades`: exchange, symbol, isin, price, quantity, timestamp
+- `analytics_exchange_daily`: timestamp, exchange, trade_count, volume
+- `metadata`: isin, name, country, continent, sector
+
+## Environment Variables
+
+```bash
+DB_USER=admin              # QuestDB user (default: admin)
+DB_PASSWORD=quest          # QuestDB password (default: quest)
+DB_HOST=questdb            # QuestDB hostname (default: questdb for Docker)
+```
+
+## Code Conventions
+
+- German-language comments and commit messages
+- Memory-efficient patterns: streaming/generators for large files, explicit `del` after processing
+- Rate limiting: User-Agent rotation, 0.3-0.5s delays between requests, retry with backoff for 429s