API Docs

Basics

Metering: 1 compute credit = 1 ticker × 1 forecast. A request with N tickers consumes N compute credits (portfolio stress tests likewise charge per ticker).

Integrations

QuantConnect strategies can call the API with a simple self.Download — see the QuantConnect integration guide.

What you can do on the Free plan

Sign up to get an API key and 50 compute credits every month — no card required. With 50 credits you can run roughly:

• 50 single-ticker forecasts, or
• 12 portfolio stress tests with 4 tickers each, or
• one 1-year, 4-ticker monthly backtest (~48 credits).

A 3-year, 4-ticker monthly backtest costs 144 credits, so it needs the Pro plan (800 credits/mo) or purchased credits. When you run out of credits the API returns 402; rate limiting is 3 compute credits/min on Free. Upgrade or top up from the dashboard at any time.

1. Portfolio stress test

Run a set of tickers through a historical stress scenario and get the portfolio-level expected drawdown, the most vulnerable holdings, and a stability measure — the primary defensive-composition workflow. See the Portfolio Stress Testing API landing page for a walkthrough.

curl -X POST https://blackswan-api.9cstar.com/api/v1/portfolio/forecast \
  -H "Content-Type: application/json" \
  -H "X-API-Key: YOUR_KEY" \
  -d '{
    "tickers": ["SPY", "AAPL", "MSFT", "JPM"],
    "scenario_id": "financial_crisis_2008",
    "current_prices": {"SPY": 500, "AAPL": 200, "MSFT": 400, "JPM": 150}
  }'

Response includes per-ticker drawdown ranges and a portfolio summary: weighted max drawdown, most vulnerable / most resilient holdings, and stability (std-dev of per-ticker drawdowns). Charges 1 compute credit per ticker.

2. Single / batch ticker forecast

Given tickers and an optional stress scenario, returns the expected drawdown range, recovery horizon, profit probability and tail-risk score for each ticker.

curl -X POST https://blackswan-api.9cstar.com/api/v1/forecast \
  -H "Content-Type: application/json" \
  -H "X-API-Key: YOUR_KEY" \
  -d '{
    "tickers": ["SPY", "AAPL"],
    "scenario_id": "covid_crash_2020",
    "current_prices": {"SPY": 500, "AAPL": 200}
  }'

GET version (QuantConnect Download compatible, params in query string):

curl "https://blackswan-api.9cstar.com/api/v1/forecast?tickers=SPY,AAPL\
  &scenario_id=covid_crash_2020&current_prices=SPY:500,AAPL:200\
  &as_of_date=2026-08-01" \
  -H "X-API-Key: YOUR_KEY"

Charges N compute credits for N tickers. Duplicate tickers are rejected with 422.

3. Historical market-path match

Compare a recent price path to historical long-drawdown events and get the most similar episodes — useful for regime detection and early-warning flags.

curl "https://blackswan-api.9cstar.com/api/v1/market/match?ticker=SPY\
  &days=30&as_of_date=2026-08-01" -H "X-API-Key: YOUR_KEY"

4. Usage and rate limits

• GET /api/v1/plans — plan list (monthly compute credits, credits/min, concurrency)
• GET /api/v1/me/usage — current user usage
• POST /api/v1/subscribe — create Stripe checkout

Rate limits are measured in compute credits per minute, not HTTP requests. A Pro plan at 10 credits/min can send one 10-ticker forecast and then must wait for the window to reset before more credits are consumed.