The-Ouroboros/docs/architecture.md

System Architecture

Overview

Self-evolving AI trading agent for global stock markets via KIS (Korea Investment & Securities) API. The main loop in src/main.py orchestrates four components in a 60-second cycle per stock across multiple markets.

Core Components

1. Broker (src/broker/)

KISBroker (kis_api.py) — Async KIS API client for domestic Korean market

• Automatic OAuth token refresh (valid for 24 hours)
• Leaky-bucket rate limiter (10 requests per second)
• POST body hash-key signing for order authentication
• Custom SSL context with disabled hostname verification for VTS (virtual trading) endpoint due to known certificate mismatch

OverseasBroker (overseas.py) — KIS overseas stock API wrapper

• Reuses KISBroker infrastructure (session, token, rate limiter) via composition
• Supports 9 global markets: US (NASDAQ/NYSE/AMEX), Japan, Hong Kong, China (Shanghai/Shenzhen), Vietnam (Hanoi/HCM)
• Different API endpoints for overseas price/balance/order operations

Market Schedule (src/markets/schedule.py) — Timezone-aware market management

• MarketInfo dataclass with timezone, trading hours, lunch breaks
• Automatic DST handling via zoneinfo.ZoneInfo
• is_market_open() checks weekends, trading hours, lunch breaks
• get_open_markets() returns currently active markets
• get_next_market_open() finds next market to open and when

2. Brain (src/brain/gemini_client.py)

GeminiClient — AI decision engine powered by Google Gemini

• Constructs structured prompts from market data
• Parses JSON responses into TradeDecision objects (action, confidence, rationale)
• Forces HOLD when confidence < threshold (default 80)
• Falls back to safe HOLD on any parse/API error
• Handles markdown-wrapped JSON, malformed responses, invalid actions

3. Risk Manager (src/core/risk_manager.py)

RiskManager — Safety circuit breaker and order validation

⚠️ READ-ONLY by policy (see docs/agents.md)

• Circuit Breaker: Halts all trading via SystemExit when daily P&L drops below -3.0%
  • Threshold may only be made stricter, never relaxed
  • Calculated as (total_eval - purchase_total) / purchase_total * 100
• Fat-Finger Protection: Rejects orders exceeding 30% of available cash
  • Must always be enforced, cannot be disabled

4. Evolution (src/evolution/optimizer.py)

StrategyOptimizer — Self-improvement loop

• Analyzes high-confidence losing trades from SQLite
• Asks Gemini to generate new BaseStrategy subclasses
• Validates generated strategies by running full pytest suite
• Simulates PR creation for human review
• Only activates strategies that pass all tests

Data Flow

┌─────────────────────────────────────────────────────────────┐
│ Main Loop (60s cycle per stock, per market)                │
└─────────────────────────────────────────────────────────────┘
                           │
                           ▼
        ┌──────────────────────────────────┐
        │ Market Schedule Check             │
        │ - Get open markets                │
        │ - Filter by enabled markets       │
        │ - Wait if all closed              │
        └──────────────────┬────────────────┘
                           │
                           ▼
        ┌──────────────────────────────────┐
        │ Broker: Fetch Market Data        │
        │ - Domestic: orderbook + balance  │
        │ - Overseas: price + balance      │
        └──────────────────┬────────────────┘
                           │
                           ▼
        ┌──────────────────────────────────┐
        │ Calculate P&L                     │
        │ pnl_pct = (eval - cost) / cost   │
        └──────────────────┬────────────────┘
                           │
                           ▼
        ┌──────────────────────────────────┐
        │ Brain: Get Decision               │
        │ - Build prompt with market data   │
        │ - Call Gemini API                 │
        │ - Parse JSON response             │
        │ - Return TradeDecision            │
        └──────────────────┬────────────────┘
                           │
                           ▼
        ┌──────────────────────────────────┐
        │ Risk Manager: Validate Order      │
        │ - Check circuit breaker           │
        │ - Check fat-finger limit          │
        │ - Raise if validation fails       │
        └──────────────────┬────────────────┘
                           │
                           ▼
        ┌──────────────────────────────────┐
        │ Broker: Execute Order             │
        │ - Domestic: send_order()          │
        │ - Overseas: send_overseas_order() │
        └──────────────────┬────────────────┘
                           │
                           ▼
        ┌──────────────────────────────────┐
        │ Database: Log Trade               │
        │ - SQLite (data/trades.db)         │
        │ - Track: action, confidence,      │
        │   rationale, market, exchange     │
        └───────────────────────────────────┘

Database Schema

SQLite (src/db.py)

CREATE TABLE trades (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    timestamp TEXT NOT NULL,
    stock_code TEXT NOT NULL,
    action TEXT NOT NULL,          -- BUY | SELL | HOLD
    confidence INTEGER NOT NULL,   -- 0-100
    rationale TEXT,
    quantity INTEGER,
    price REAL,
    pnl REAL DEFAULT 0.0,
    market TEXT DEFAULT 'KR',       -- KR | US_NASDAQ | JP | etc.
    exchange_code TEXT DEFAULT 'KRX' -- KRX | NASD | NYSE | etc.
);

Auto-migration: Adds market and exchange_code columns if missing for backward compatibility.

Configuration

Pydantic Settings (src/config.py)

Loaded from .env file:

# Required
KIS_APP_KEY=your_app_key
KIS_APP_SECRET=your_app_secret
KIS_ACCOUNT_NO=XXXXXXXX-XX
GEMINI_API_KEY=your_gemini_key

# Optional
MODE=paper                    # paper | live
DB_PATH=data/trades.db
CONFIDENCE_THRESHOLD=80
MAX_LOSS_PCT=3.0
MAX_ORDER_PCT=30.0
ENABLED_MARKETS=KR,US_NASDAQ  # Comma-separated market codes

Tests use in-memory SQLite (DB_PATH=":memory:") and dummy credentials via tests/conftest.py.

Error Handling

Connection Errors (Broker API)

• Retry with exponential backoff (2^attempt seconds)
• Max 3 retries per stock
• After exhaustion, skip stock and continue with next

API Quota Errors (Gemini)

• Return safe HOLD decision with confidence=0
• Log error but don't crash
• Agent continues trading on next cycle

Circuit Breaker Tripped

• Immediately halt via SystemExit
• Log critical message
• Requires manual intervention to restart

Market Closed

• Wait until next market opens
• Use get_next_market_open() to calculate wait time
• Sleep until market open time