# QuantX402, powered by Kronos

> Kronos candlestick forecasts as agent-readable fact lists, paid per call with x402 (USDC, no account or API key). Probabilistic model output for research and education. Not financial advice. Past results do not guarantee future results.

Kronos is an open-source (MIT) foundation model for financial candlesticks by its original authors (arXiv 2508.02739). This service is not affiliated with them. Every hour, Kronos-small samples 30 future price paths per symbol from the last 360 closed 1h candles; we turn those paths into facts.

## API
- [GET /api/v1/forecast](https://quantx402.app/api/v1/forecast?symbol=BTC-USD&tf=1h): Kronos Forecast, latest fact list, $0.02 per call via x402. Returns HTTP 402 with a PAYMENT-REQUIRED header until paid. Errors and stale data (2+ candles old) are never charged.
- [GET /api/v1/sample](https://quantx402.app/api/v1/sample?symbol=BTC-USD&tf=1h): free fact list, at least 2 hours old.
- [GET /api/v1/signal](https://quantx402.app/api/v1/signal?symbol=BTC-USD&tf=1h): Signal Blend, $0.03 per call via x402. The latest Kronos forecast merged with current market context (spot, 24h momentum, invalidation check) into a stance (LEAN_UP / LEAN_DOWN / NO_EDGE) with plain-English reasons. Sentiment slot is null until a licensed source is added.
- [GET /api/v1/signal/sample](https://quantx402.app/api/v1/signal/sample?symbol=BTC-USD&tf=1h): free Signal Blend preview on a run at least 2 hours old.
- [GET /api/v1/track-record](https://quantx402.app/api/v1/track-record): free. Every stored forecast and, once scored, whether it was right.
- [GET /api/v1/chart](https://quantx402.app/api/v1/chart?symbol=BTC-USD&tf=1h): free per-step percentiles, at least 2 hours old.
- [GET /api/v1/health](https://quantx402.app/api/v1/health): data freshness and worker status.
- [OpenAPI](https://quantx402.app/openapi.json): canonical machine-readable contract.
- [Usage stats](https://quantx402.app/stats): live request counts and track record.

## Pages
- [Guide](https://quantx402.app/guide): curl examples, a Node x402 client, the free skill, and running Kronos yourself.
- [Free skill](https://quantx402.app/skills): run Kronos locally and get the same fact list (free download, email required).
- [Blog](https://quantx402.app/blog): notes on Kronos forecasts and x402 payments.
- [Data sources](https://quantx402.app/data-sources): what feeds the forecasts today, and what is planned.
- [Agent activity](https://quantx402.app/agents): which agents and x402 clients call this API (real logs only).

Symbols: BTC-USD, ETH-USD. Timeframes: 1h.

## Optional
- [Full field reference](https://quantx402.app/llms-full.txt)

## Fields (GET /api/v1/forecast)
- symbol, venue, asset_class, timeframe
- as_of: open time (UTC) of the last input candle. horizon_end: open time of the last forecast candle (24 bars ahead).
- last_close: close of the last input candle.
- direction: UP if prob_up >= 0.6, DOWN if <= 0.4, else NEUTRAL.
- prob_up: share of the 30 sampled paths whose final close is above last_close (moves in ~0.033 steps).
- expected_move_pct: median final return across paths, in percent.
- band_80_pct: 10th and 90th percentile final return, in percent. expected_range: the same in price terms.
- band_calibrated: false until enough outcomes are scored. The band is raw model spread.
- confidence: MEDIUM if |prob_up - 0.5| >= 0.3, else LOW. HIGH is disabled until calibration.
- invalidation_level: for UP, the 10th percentile of path lows; for DOWN, the 90th percentile of path highs; null for NEUTRAL.
- p_close_above: share of paths whose final close is above each nearby round strike. Useful to compare with Kalshi or Polymarket "above $X" contracts.
- hist_vol_over_horizon_pct: realized std of 24-bar log returns over the lookback, in percent.
- percentiles: per-step p10, p25, p50, p75, p90 closes with times_utc.
- model, sampling (T, top_p, paths, seed), context_bars, data_source, disclaimer.
- stale: true if one candle behind (still served and charged). Two or more behind returns 503 FORECAST_STALE (not charged).

## How x402 payment works
1. GET /api/v1/forecast. The server answers 402 with a PAYMENT-REQUIRED header listing accepted options (exact scheme, USDC, Base and Solana).
2. Sign a payment for one option and retry with the PAYMENT-SIGNATURE header.
3. You get 200 with the fact list. Payment settles only on success.

## Not advice
Probabilistic model output for research and education. Not financial advice. Past results do not guarantee future results.