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

Get a free API key at the-vynn.com (10 backtests/month, no credit card)
Set VYNN_API_KEY in your environment or skill config
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

vynn-backtester

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