Vynn Backtester

Backtest any trading strategy with natural language. Get Sharpe ratio, returns, drawdown, and full equity curves in seconds.

What it does

• Natural language strategies: Describe your strategy in plain English and Vynn translates it into a runnable backtest
• Structured strategies: Power users can pass precise entry/exit rules as JSON
• Full metrics: Sharpe ratio, total return, max drawdown, win rate, trade count, and equity curve
• Multi-ticker: Backtest across any combination of stocks, ETFs, or indices
• Strategy comparison: Compare multiple strategies head-to-head, ranked by Sharpe ratio
• No infrastructure: No local data downloads, no dependencies beyond Python stdlib

Setup

1. Get a free API key at the-vynn.com (10 backtests/month, no credit card)
2. Set VYNN_API_KEY in your environment or skill config
3. Run /backtest "your strategy here" from any OpenClaw agent

Quick start

# Sign up (instant, returns your API key)
curl -X POST https://the-vynn.com/v1/signup -H "Content-Type: application/json" -d '{"email": "you@example.com"}'

# Set the key
export VYNN_API_KEY="vynn_free_..."

Usage examples

Simple natural language backtest

/backtest "RSI mean reversion on AAPL, 2 year lookback"

Momentum strategy

/backtest "MACD crossover on SPY with 20/50 EMA filter"

Multi-ticker portfolio

/backtest --tickers AAPL,MSFT,GOOGL --strategy "momentum top 3"

Structured entry/exit rules

/backtest '{"entries": [{"indicator": "RSI", "op": "<", "value": 30}], "exits": [{"indicator": "RSI", "op": ">", "value": 70}]}' --tickers AAPL

Compare strategies

from plugin import VynnBacktesterPlugin

vynn = VynnBacktesterPlugin()
results = vynn.compare(
    strategies=[
        "RSI mean reversion",
        "MACD crossover",
        "Bollinger band breakout",
    ],
    tickers=["SPY"],
)
for r in results:
    print(f"{r.strategy}: Sharpe={r.sharpe_ratio}, Return={r.total_return_pct}%")

Environment Variables

Variable	Required	Description	Default
VYNN_API_KEY	Yes	Your API key from the-vynn.com	--
VYNN_BASE_URL	No	Override API base URL (for self-hosted instances)	https://the-vynn.com/v1

External Endpoints

Endpoint	Purpose	Data Sent
https://the-vynn.com/v1/backtest	Execute a strategy backtest	Strategy text, ticker list, lookback period
https://the-vynn.com/v1/signup	Free API key registration	Email address

Security & Privacy

• All requests authenticated via X-API-Key header
• Strategy descriptions and ticker lists are sent to the Vynn API for backtest execution
• No trading data, portfolio holdings, or personal information is stored beyond the backtest run
• Backtest results are ephemeral and not persisted on Vynn servers
• No credentials are stored by the skill -- only your API key in environment variables
• Source code is fully open: github.com/beee003/astrai-openclaw

Model Invocation

This skill does not invoke any LLM models. It sends strategy descriptions to the Vynn backtest engine, which is a quantitative execution engine (not an AI model). No prompts or completions are generated.

Pricing

• Free: 10 backtests/month, all features, no credit card required
• Pro ($29/mo): Unlimited backtests, priority execution, extended lookback periods