This skill enables you to perform stock trading operations through the Longbridge FS file-based trading system. All operations are performed by reading and writing files, making it natural for AI agents.

The system implements a five-layer Harness architecture:

L1 Research → L2 Signal → L3 Portfolio → L4 Risk → L5 Execution

Each layer communicates through files, so you can read, write, or inject data at any layer without modifying code.

When to Use This Skill

Use this skill when the user wants to:

Buy or sell stocks (HK/US markets)
Check stock quotes and market data
View account balance and positions
Monitor portfolio performance and P&L
Set up signal definitions (SMA_CROSS, RSI, PRICE_CHANGE)
Configure portfolio targets and trigger rebalancing
Set up risk control rules (stop-loss/take-profit, pre-trade limits)
Run end-to-end pipeline: research → signal → portfolio → execution
Query trading history

Prerequisites

Before using this skill, verify:

Controller is running: Check if the Longbridge FS controller daemon is active
```
ps aux | grep longbridge-fs
```
File system is initialized: The fs/ directory should exist with proper structure
```
ls -la fs/
```
Permissions: Ensure you have read/write access to the fs/ directory

If the controller is not running, start it:

# Mock mode (for testing, no real API calls — enables full pipeline simulation)
./build/longbridge-fs controller --root ./fs --mock --interval 2s &

# Real mode (requires API credentials)
./build/longbridge-fs controller --root ./fs --credential ./configs/credential --interval 2s &

L1 Research Layer

The research layer aggregates news, topics and custom data feeds for the symbols in your watchlist.

Configure Watchlist

cat > fs/research/watchlist.json << 'EOF'
{
  "symbols": ["AAPL.US", "TSLA.US", "700.HK"],
  "refresh_interval": "5m",
  "feeds": ["news", "topics"]
}
EOF

Controller behavior:

In real mode: fetches live news/topics from Content API for each symbol.
In mock mode: generates synthetic feeds automatically to enable full pipeline testing.

Read Research Feeds

# Latest news for a symbol
cat fs/research/feeds/news/AAPL.US/latest.json

# Community topics for a symbol
cat fs/research/feeds/topics/AAPL.US/latest.json

# Aggregated research summary across all symbols
cat fs/research/summary.json

Inject Custom Research Data

AI agents can write custom research data directly:

mkdir -p fs/research/feeds/custom
cat > fs/research/feeds/custom/my_analysis.json << 'EOF'
{
  "name": "sector_rotation_analysis",
  "created_at": "2026-04-01T07:00:00Z",
  "author": "claude-agent",
  "data": {
    "recommendation": "overweight_tech",
    "confidence": 0.82
  }
}
EOF

L2 Signal Layer

The signal layer converts market data into actionable trading signals.

Create Signal Definitions

Signal definitions are JSON files in fs/signal/definitions/. The controller evaluates builtin signals every cycle.

Built-in Signal: SMA Crossover

cat > fs/signal/definitions/sma_cross.json << 'EOF'
{
  "name": "sma_crossover",
  "type": "builtin",
  "enabled": true,
  "symbols": ["AAPL.US", "TSLA.US"],
  "params": {
    "indicator": "SMA_CROSS",
    "fast_period": 5,
    "slow_period": 20
  }
}
EOF

Built-in Signal: RSI

cat > fs/signal/definitions/rsi.json << 'EOF'
{
  "name": "rsi_signal",
  "type": "builtin",
  "enabled": true,
  "symbols": ["AAPL.US"],
  "params": {
    "indicator": "RSI",
    "period": 14,
    "overbought": 70,
    "oversold": 30
  }
}
EOF

Built-in Signal: Price Change

cat > fs/signal/definitions/price_change.json << 'EOF'
{
  "name": "price_momentum",
  "type": "builtin",
  "enabled": true,
  "symbols": ["TSLA.US"],
  "params": {
    "indicator": "PRICE_CHANGE",
    "threshold_pct": 5.0,
    "window": 5
  }
}
EOF

External Signal (Agent-computed)

# Agent writes signal output directly
mkdir -p fs/signal/output/AAPL.US
cat > fs/signal/output/AAPL.US/latest.json << 'EOF'
{
  "symbol": "AAPL.US",
  "updated_at": "2026-04-01T08:00:00Z",
  "signals": [
    {
      "name": "llm_sentiment",
      "value": "BULLISH",
      "strength": 0.78,
      "detail": "Positive earnings sentiment detected",
      "computed_at": "2026-04-01T08:00:00Z"
    }
  ]
}
EOF

Read Signal Output

# All active signals across all symbols
cat fs/signal/active.json

# Per-symbol signal output
cat fs/signal/output/AAPL.US/latest.json

# Signal history (append-only JSONL)
cat fs/signal/output/AAPL.US/history.jsonl

active.json example:

{
  "updated_at": "2026-04-01T08:05:00Z",
  "signals": [
    { "symbol": "AAPL.US", "name": "sma_crossover", "value": "BULLISH", "strength": 0.72 },
    { "symbol": "AAPL.US", "name": "rsi_signal",    "value": "NEUTRAL", "strength": 0.45 },
    { "symbol": "TSLA.US", "name": "sma_crossover", "value": "BEARISH", "strength": 0.61 }
  ]
}

Signal values: BULLISH, BEARISH, NEUTRAL, OVERBOUGHT, OVERSOLD, SURGE, DROP

L3 Portfolio Layer

The portfolio layer manages target allocations and rebalancing.

Set Portfolio Target

cat > fs/portfolio/target.json << 'EOF'
{
  "version": 1,
  "updated_at": "2026-04-01T00:00:00Z",
  "total_capital_pct": 0.90,
  "cash_reserve_pct": 0.10,
  "positions": {
    "AAPL.US": { "weight": 0.40 },
    "TSLA.US": { "weight": 0.35 },
    "700.HK":  { "weight": 0.15 },
    "NVDA.US": { "weight": 0.10 }
  }
}
EOF

Read Portfolio State

# Current portfolio positions and weights
cat fs/portfolio/current.json

# Target vs current comparison
cat fs/portfolio/diff.json

# Historical snapshots
ls fs/portfolio/history/

diff.json example:

{
  "updated_at": "2026-04-01T08:10:00Z",
  "target_version": 1,
  "requires_rebalance": true,
  "adjustments": [
    {
      "symbol": "AAPL.US",
      "current_weight": 0.28,
      "target_weight": 0.40,
      "drift": -0.12,
      "action": "BUY",
      "estimated_value": 12000
    }
  ]
}

Trigger Rebalance

Manual rebalance (write pending orders):

cat > fs/portfolio/rebalance/pending.json << 'EOF'
{
  "rebalance_id": "rebal-20260401-001",
  "created_at": "2026-04-01T08:10:00Z",
  "orders": [
    {
      "symbol": "AAPL.US",
      "side": "BUY",
      "qty": 50,
      "order_type": "MARKET",
      "tif": "DAY"
    }
  ]
}
EOF

Auto-rebalance mode (controller creates pending orders automatically when drift exceeds threshold):

./build/longbridge-fs controller --root ./fs --mock --auto-rebalance &

L4 Risk Control Layer

The risk layer enforces pre-trade checks and monitors trading limits.

Configure Risk Policy

cat > fs/trade/risk/policy.json << 'EOF'
{
  "version": 1,
  "enabled": true,
  "mode": "ENFORCE",
  "pre_trade_checks": true,
  "post_trade_monitoring": true,
  "daily_loss_limit": {
    "enabled": true,
    "max_loss_pct": 0.03,
    "action": "HALT"
  },
  "order_frequency": {
    "enabled": true,
    "max_orders_per_hour": 20,
    "max_orders_per_day": 100
  }
}
EOF

Risk modes:

ENFORCE (default): reject orders that violate rules
WARN: log violations but allow orders through
DISABLED: skip all pre-trade checks

Configure Pre-Trade Rules

cat > fs/trade/risk/pre_trade.json << 'EOF'
{
  "max_single_order_pct": 0.10,
  "max_single_order_value": 50000,
  "allowed_symbols": [],
  "blocked_symbols": ["MEME.US"],
  "allowed_sides": ["BUY", "SELL"],
  "require_limit_price": false,
  "max_deviation_from_market_pct": 0.05
}
EOF

Configure Position Limits

cat > fs/trade/risk/position_limits.json << 'EOF'
{
  "max_position_pct": 0.25,
  "max_positions_count": 15,
  "sector_limits": {},
  "per_symbol_limits": {
    "TSLA.US": { "max_pct": 0.10 }
  }
}
EOF

Configure Stop-Loss / Take-Profit (Legacy Risk Control)

cat > fs/trade/risk_control.json << 'EOF'
{
  "AAPL.US": {
    "stop_loss": 170.00,
    "take_profit": 200.00,
    "qty": "100"
  },
  "TSLA.US": {
    "stop_loss": 200.00,
    "take_profit": 350.00
  }
}
EOF

Read Risk Status

# Current risk state and counters
cat fs/trade/risk/status.json

# Today's order/loss counters
cat fs/trade/risk/daily_limits.json

# Violations log (append-only)
cat fs/trade/risk/violations.jsonl

L5 Execution Layer

Submit Standard Orders

Append ORDER entries to fs/trade/beancount.txt:

Market Order:

cat >> fs/trade/beancount.txt << 'EOF'
2026-04-01 * "ORDER" "BUY AAPL.US"
  ; intent_id: 20260401-001
  ; side: BUY
  ; symbol: AAPL.US
  ; qty: 100
  ; type: MARKET
  ; tif: DAY

EOF

Limit Order with traceability:

cat >> fs/trade/beancount.txt << 'EOF'
2026-04-01 * "ORDER" "BUY AAPL.US from signal"
  ; intent_id: 20260401-002
  ; side: BUY
  ; symbol: AAPL.US
  ; qty: 100
  ; type: LIMIT
  ; price: 180.50
  ; tif: DAY
  ; source: rebalance
  ; rebalance_id: rebal-20260401-001
  ; signal_refs: sma_crossover,rsi_signal

EOF

Submit Algorithmic Orders

TWAP (Time-Weighted Average Price):

cat >> fs/trade/beancount.txt << 'EOF'
2026-04-01 * "ORDER" "BUY AAPL.US via TWAP"
  ; intent_id: 20260401-003
  ; side: BUY
  ; symbol: AAPL.US
  ; qty: 500
  ; type: LIMIT
  ; price: 182.00
  ; tif: DAY
  ; algo: TWAP
  ; algo_duration: 30m
  ; algo_slices: 5

EOF

ICEBERG (hidden quantity):

cat >> fs/trade/beancount.txt << 'EOF'
2026-04-01 * "ORDER" "BUY AAPL.US via ICEBERG"
  ; intent_id: 20260401-004
  ; side: BUY
  ; symbol: AAPL.US
  ; qty: 1000
  ; type: LIMIT
  ; price: 182.00
  ; tif: GTC
  ; algo: ICEBERG
  ; algo_slices: 10

EOF

Check Order Results

# Wait for controller to process
sleep 3

# Check for EXECUTION or REJECTION
grep -A 10 "intent_id: 20260401-001" fs/trade/beancount.txt

EXECUTION example:

2026-04-01 * "EXECUTION" "BUY AAPL.US @ 180.25"
  ; intent_id: 20260401-001
  ; order_id: 1234567890
  ; side: BUY
  ; symbol: AAPL.US
  ; filled_qty: 100
  ; avg_price: 180.25
  ; status: FILLED
  ; executed_at: 2026-04-01T10:30:15Z

REJECTION example:

2026-04-01 * "REJECTION" "BUY AAPL.US"
  ; intent_id: 20260401-001
  ; reason: max_single_order_pct exceeded

Common Workflows

Workflow 1: Full Harness Pipeline (Research → Signal → Portfolio → Execution)

# Step 1: Initialize FS
./build/longbridge-fs init --root ./fs

# Step 2: Configure watchlist (L1)
cat > fs/research/watchlist.json << 'EOF'
{"symbols": ["AAPL.US", "TSLA.US"], "refresh_interval": "5m", "feeds": ["news", "topics"]}
EOF

# Step 3: Define signals (L2)
cat > fs/signal/definitions/sma.json << 'EOF'
{"name": "sma_crossover", "type": "builtin", "enabled": true,
 "symbols": ["AAPL.US"], "params": {"indicator": "SMA_CROSS", "fast_period": 5, "slow_period": 20}}
EOF

# Step 4: Set portfolio target (L3)
cat > fs/portfolio/target.json << 'EOF'
{"version": 1, "total_capital_pct": 0.90, "cash_reserve_pct": 0.10,
 "positions": {"AAPL.US": {"weight": 0.40}}}
EOF

# Step 5: Start controller in mock mode (enables full pipeline simulation)
./build/longbridge-fs controller --root ./fs --mock --interval 2s &

# Step 6: Wait and inspect pipeline output
sleep 5
cat fs/research/summary.json
cat fs/signal/active.json
cat fs/portfolio/diff.json

# Step 7: Submit orders (L5)
cat >> fs/trade/beancount.txt << 'EOF'
2026-04-01 * "ORDER" "BUY AAPL.US"
  ; intent_id: 20260401-100
  ; side: BUY
  ; symbol: AAPL.US
  ; qty: 50
  ; type: MARKET
  ; tif: DAY

EOF
sleep 3
tail -20 fs/trade/beancount.txt

# Step 8: Stop controller
touch fs/.kill

Workflow 2: Signal-Driven Order Submission

# Read active signals and submit orders for BULLISH signals
SIGNALS=$(cat fs/signal/active.json)
echo "$SIGNALS" | python3 -c "
import json, sys
active = json.load(sys.stdin)
for s in active.get('signals', []):
    if s['value'] == 'BULLISH' and s['strength'] > 0.6:
        print(f\"Buy signal: {s['symbol']} ({s['name']}, strength={s['strength']:.2f})\")
"

Workflow 3: Buy Stock at Market Price

# Step 1: Check current price
touch fs/quote/track/AAPL.US
sleep 3
cat fs/quote/hold/AAPL.US/overview.json

# Step 2: Submit market buy order
cat >> fs/trade/beancount.txt << 'EOF'
2026-04-01 * "ORDER" "BUY AAPL.US"
  ; intent_id: 20260401-001
  ; side: BUY
  ; symbol: AAPL.US
  ; qty: 100
  ; type: MARKET
  ; tif: DAY

EOF

# Step 3: Wait and check result
sleep 3
tail -20 fs/trade/beancount.txt

# Step 4: Verify position
cat fs/account/pnl.json

Workflow 4: Set Stop-Loss for Existing Position

# Set stop-loss at 5% below current price for AAPL.US
touch fs/quote/track/AAPL.US
sleep 3
CURRENT_PRICE=$(jq -r '.last' fs/quote/hold/AAPL.US/overview.json)
STOP_PRICE=$(echo "$CURRENT_PRICE * 0.95" | bc)

jq --arg symbol "AAPL.US" --argjson stop "$STOP_PRICE" \
  '.[$symbol] = {"stop_loss": $stop}' \
  fs/trade/risk_control.json > /tmp/risk.json && \
  mv /tmp/risk.json fs/trade/risk_control.json

Quick Reference: All Layer Files

fs/
├── research/                         # L1 Research
│   ├── watchlist.json                #   <- WRITE: symbols to track
│   ├── summary.json                  #   -> READ:  aggregated feed status
│   └── feeds/
│       ├── news/{SYMBOL}/latest.json #   -> READ:  news articles
│       ├── topics/{SYMBOL}/latest.json#  -> READ:  community topics
│       └── custom/{name}.json        #   <- WRITE: agent custom data
│
├── signal/                           # L2 Signal
│   ├── definitions/{name}.json       #   <- WRITE: signal configs
│   ├── active.json                   #   -> READ:  current signals
│   └── output/{SYMBOL}/
│       ├── latest.json               #   -> READ:  per-symbol output
│       └── history.jsonl             #   -> READ:  signal history
│
├── portfolio/                        # L3 Portfolio
│   ├── target.json                   #   <- WRITE: target weights
│   ├── current.json                  #   -> READ:  actual weights
│   ├── diff.json                     #   -> READ:  drift / actions
│   └── rebalance/pending.json        #   <- WRITE: pending orders
│
├── account/
│   ├── state.json                    #   -> READ:  balances and orders
│   └── pnl.json                      #   -> READ:  per-position P&L
│
├── trade/
│   ├── beancount.txt                 #   <- WRITE ORDER / -> READ EXECUTION
│   ├── risk_control.json             #   <- WRITE: stop-loss/take-profit
│   ├── blocks/                       #   -> READ:  archived orders
│   └── risk/                         # L4 Risk
│       ├── policy.json               #   <- WRITE: risk policy
│       ├── pre_trade.json            #   <- WRITE: order limits
│       ├── position_limits.json      #   <- WRITE: position caps
│       ├── daily_limits.json         #   -> READ:  daily counters
│       ├── status.json               #   -> READ:  risk gate status
│       └── violations.jsonl          #   -> READ:  violation log
│
└── quote/
    ├── track/                        #   <- CREATE: request a quote
    ├── hold/{SYMBOL}/
    │   ├── overview.json             #   -> READ:  current price
    │   ├── D.json                    #   -> READ:  daily kline (120d)
    │   └── intraday.json             #   -> READ:  intraday ticks
    └── portfolio.json                #   -> READ:  portfolio with quotes

Controller Options

Flag	Default	Description
`--root`	`.`	FS root directory
`--interval`	`2s`	Poll interval
`--mock`	`false`	Mock mode — no API calls, full pipeline
`--auto-rebalance`	`false`	Auto-create rebalance orders on drift
`--compact-after`	`10`	Compact ledger after N executions
`--credential`	`credential`	Credential file (real mode)

In mock mode (--mock):

All five layers run without API calls
Research feeds are populated with synthetic data
Kline data is generated automatically for signal computation
Orders are simulated with realistic mock fills
Fully self-contained for testing and development

Stock Symbol Format

US Stocks: AAPL.US, MSFT.US, TSLA.US, NVDA.US HK Stocks: 700.HK, 9988.HK, 0001.HK CN Stocks: 600519.SH, 000001.SZ

Tips for AI Agents

Always wait after operations: Controller needs 2-3 seconds per cycle to process files
Mock mode for development: Use --mock to test the full pipeline without credentials
Read before acting: Check signal/active.json and portfolio/diff.json before submitting orders
Append, don't overwrite: Always append to beancount.txt, never overwrite
Use unique intent_ids: Use timestamp-based IDs to avoid conflicts
Signal to order traceability: Always include signal_refs in orders for audit trail
Stop gracefully: Use touch fs/.kill to stop the controller cleanly

Additional Resources

README - Project overview and quick start
End-to-End Demo - Full pipeline demo script (mock mode)
Basic Demo - Basic execution demo
Spec - Full architecture specification

name	longbridge-trading
description	Execute stock trading operations using Longbridge FS file-based trading system for HK/US stocks

Longbridge Trading Skill