Ran-Vain — Spark × Claude Desktop Bridge
Ask Claude "What is my unrealized P&L?" and get a live, data-driven answer sourced directly from Spark — in under two seconds.
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What Is This?
Ran-Vain bridges Spark (a professional ASX trading platform) with Claude Desktop using Anthropic's Model Context Protocol (MCP). Spark delivers live market data via Dynamic Data Exchange (DDE) — a Windows-native protocol that Excel understands but AI systems don't. This project builds a four-layer translation stack so Claude can answer natural language trading questions using live ASX data.
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Architecture
Spark (live ASX feed via DDE)
│
▼
dde_client.py ← polls 6 stocks every 2 seconds
│
┌────┴────┐
▼ ▼
Redis SQLite ← real-time snapshots + historical data
└────┬────┘
▼
api/main.py ← 15 authenticated REST endpoints (FastAPI)
│
▼
spark_mcp.py ← 18 Claude tools (MCP server over stdio)
│
▼
Claude Desktop ← natural language query interface
| Layer | Component | Responsibility | |---|---|---| | 1 — DDE Listener | dde_client.py | Subscribes to Spark DDE feeds; writes to Redis & SQLite | | 2 — Data Store | Redis + SQLite | Redis for real-time snapshots; SQLite for historical data | | 3 — API Layer | api/main.py | 15 authenticated REST endpoints | | 4 — MCP Server | spark_mcp.py | 18 Claude tools registered with Claude Desktop |
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Prerequisites
- Windows 10 or 11 (DDE is Windows-only)
- Spark — installed and logged in
- Python 3.11 — python.org/downloads
- Claude Desktop — claude.ai/download
- Docker Desktop — for Redis
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Installation
Step 1 — Virtual environment ``powershell cd D:\spark-dde-bot python -m venv venv venv\Scripts\Activate.ps1 ``
Step 2 — Dependencies ``powershell pip install pywin32 redis loguru python-dotenv fastapi uvicorn httpx mcp ``
Step 3 — Configure .env ``env REDIS_URL=redis://localhost:6379/0 SQLITE_PATH=dde_listener/spark_data.db API_BASE=http://localhost:8000 API_KEY=your-strong-api-key-here DDE_POLL_MS=2000 ``
Step 4 — Start Redis ``powershell docker-compose up -d ``
Step 5 — Seed dummy data (first run only) ``powershell python seed_dummy_data.py ``
Step 6 — Start the DDE listener (open Spark first) ``powershell python dde_listener\dde_client.py ``
Step 7 — Start the API ``powershell uvicorn api.main:app --port 8000 --reload ``
Step 8 — Register MCP with Claude Desktop
Edit claude_desktop_config.json: ``json { "mcpServers": { "spark-trader": { "command": "D:\\spark-dde-bot\\venv\\Scripts\\python.exe", "args": ["D:\\spark-dde-bot\\mcp_server\\spark_mcp.py"], "env": { "API_BASE": "http://localhost:8000", "API_KEY": "your-strong-api-key-here" } } } } ``
Step 9 — Restart Claude Desktop
Fully close and reopen Claude Desktop. The hammer icon in the toolbar confirms the MCP server is connected.
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Startup Checklist
| # | Action | Verification | |---|---|---| | 1 | Start Spark and log in | Live market data visible in watchlist | | 2 | Start Redis via Docker | docker ps shows redis container running | | 3 | Activate venv | Terminal prompt shows (venv) | | 4 | Run dde_client.py | Logs show: Snapshot updated — 6 stocks | | 5 | Run uvicorn | http://localhost:8000 returns {status: ok} | | 6 | Open Claude Desktop | Hammer icon visible in toolbar | | 7 | Test: "Show my positions" | Claude returns 6 stocks with live P&L |
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Project Structure
D:\spark-dde-bot\
├── .env # Secrets and config (never commit this)
├── claude_desktop_config.json # Claude Desktop MCP registration
├── docker-compose.yml # Redis container
├── seed_dummy_data.py # One-time dummy data seeder
│
├── dde_listener/
│ ├── dde_client.py # DDE → Redis/SQLite listener
│ ├── spark_data.db # SQLite database
│ └── logs/ # Rotating logs (7-day retention)
│
├── api/
│ └── main.py # FastAPI — all 15 endpoints
│
├── mcp_server/
│ └── spark_mcp.py # MCP server — 18 Claude tools
│
└── venv/ # Python 3.11 virtual environment
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API Endpoints
All endpoints require the X-API-Key header. Full docs at http://localhost:8000/docs.
| Endpoint | Source | Description | |---|---|---| | GET /quotes | Redis | All stocks — live prices, bid, ask, change, volume | | GET /quotes/{symbol} | Redis | Single stock live quote | | GET /movers/up?n=5 | Redis | Top N gainers by % change | | GET /movers/down?n=5 | Redis | Top N losers by % change | | GET /movers/volume | Redis | Stocks ranked by volume | | GET /summary | Redis | Count of stocks up / down / flat | | GET /historical/{symbol} | SQLite | Price history over last N hours | | GET /historical/{symbol}/range | SQLite | High / low / avg / peak volume | | GET /positions | SQLite + Redis | All positions with live P&L | | GET /positions/{symbol} | SQLite + Redis | Single position with live P&L | | GET /pnl/today | SQLite | Today's P&L snapshot | | GET /pnl/history?days=30 | SQLite | Daily P&L history with win rate | | GET /orders | SQLite | Order history — filterable | | GET /orders/{symbol} | SQLite | All orders for a specific stock | | GET /analytics/exposure | SQLite + Redis | Portfolio exposure % breakdown | | GET /analytics/best-performer | SQLite | Highest unrealized P&L position | | GET /analytics/worst-performer | SQLite | Lowest unrealized P&L position | | GET /analytics/drawdown?days=7 | SQLite | Max drawdown from peak P&L |
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Claude Tools (18)
| Category | Tools | |---|---| | Live Quotes | get_all_quotes, get_quote, get_top_gainers, get_top_losers, get_by_volume, get_market_summary | | Historical | get_historical, get_price_range | | Positions | get_positions, get_position | | P&L | get_today_pnl, get_pnl_history | | Orders | get_orders, get_orders_by_symbol | | Analytics | get_portfolio_exposure, get_best_performer, get_worst_performer, get_drawdown |
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Example Queries
"Show my open positions"
"What is my P&L today?"
"Which stocks are up today?"
"Show my BHP orders this month"
"What is my portfolio exposure?"
"What was my best trading day?"
"What is my drawdown this week?"
"Which stock has the most volume?"
"Summarise my month and tell me my biggest risk"
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Security
- API key authentication on every endpoint via
X-API-Keyheader - FastAPI binds to
localhost:8000only — not network-exposed by default - All secrets stored in
.env— nothing hardcoded - All endpoints are read-only
GET— no write operations
Before production: change the API key to a strong random value (32+ characters), add
.envto.gitignore, enable Redis password auth, and add HTTPS via nginx if exposing beyond localhost.
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Known Limitations
| Limitation | Detail | |---|---| | Windows only | DDE is Windows-exclusive — the listener cannot run on macOS or Linux | | Dummy data | Positions, orders, and P&L use seeded synthetic data pending broker API integration | | Fixed watchlist | Hardcoded to 6 symbols (BHP, FMG, CBA, NAB, PLS, WOW) | | Pull-only | Claude queries are on-demand — no price alerts or real-time push | | Read-only | Cannot place, modify, or cancel orders |
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Troubleshooting
| Symptom | Resolution | |---|---| | DDE connect failed on all symbols | Open Spark and log in before running dde_client.py | | Redis connection refused | Run docker-compose up -d and check REDIS_URL in .env | | FastAPI returns 503 | DDE listener isn't running or hasn't completed first poll — wait 2 seconds | | No hammer icon in Claude Desktop | Check paths in claude_desktop_config.json and fully restart Claude Desktop | | FastAPI returns 403 | API_KEY in .env must match the key in claude_desktop_config.json | | P&L shows dummy values | Expected — replace seeded data with real broker data when ready |
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Tech Stack
| Technology | Version | Purpose | |---|---|---| | Python | 3.11.9 | Primary runtime | | pywin32 | 306 | Windows DDE client | | Redis | 7.x | Real-time price snapshots | | SQLite | Built-in | Historical data store | | FastAPI | 0.110+ | REST API framework | | uvicorn | 0.29+ | ASGI server | | httpx | 0.27+ | Async HTTP client | | MCP SDK | Latest | Anthropic Model Context Protocol | | loguru | 0.7+ | Structured logging | | Docker | Latest | Containerised Redis |
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Roadmap
- Replace dummy positions/P&L with live broker API or CSV export
- Register
dde_client.pyas a Windows Service for auto-start and crash recovery - Read watchlist symbols from a config file or database table
- Use Spark's Watchlist DDE topic to query all symbols in a single DDE call
- Add price alert monitoring that Claude can query
- Expand beyond 6 ASX symbols
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Ran-Vain is a read-only analytics and query tool. It does not place, modify, or cancel orders.











