# Kronos Signals VWM Spot Price API

> Kronos Signals VWM Spot Price API is a paid API for AI agents from kronossignals.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Returns a volume-weighted median spot price for a given crypto asset, aggregated from Binance, Coinbase, Kraken, and OKX with outlier rejection and confidence grading.

## Facts

- Endpoint: GET https://kronossignals.com/api/v1/price/btc
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/kronos-signals-vwm-spot-price-api-ac57d9ab
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QoRnCET2jJAgOj_fUeO49

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability kronos-signals-vwm-spot-price-api-ac57d9ab
```

Example prompt: What's the volume-weighted median spot price for Bitcoin right now, including the confidence grade and cross-exchange spread across Binance, Coinbase, Kraken, and OKX?

## When to prefer this

Prefer this endpoint when you need a robust, manipulation-resistant reference price for a major crypto asset that accounts for exchange-specific volume and rejects outliers. Ideal as a Kaiko-style fair-value benchmark rather than a single-exchange price. Best when confidence grading and spread visibility matter, e.g. for trade sizing, risk management, or cross-exchange arbitrage detection. Choose over a single-exchange price feed when you need multi-source validation and a trust score on the price.

## Known failure modes

- Insufficient sources available (fewer than 2 exchanges respond within 2s timeout) — may return low confidence or error
- Unsupported asset ticker — returns 404 or error if asset not in the 16 supported list
- All source exchanges timeout — no price returned
- Payment not processed (x402) — 402 response requiring USDC payment
- Rate limiting or network errors from upstream exchanges causing degraded confidence

## How this service works

Multi-source volume-weighted median (VWM) spot price for 16 crypto assets (BTC/ETH/SOL/BNB/XRP/DOGE/ADA/AVAX/LINK/DOT/LTC/TRX/BCH/ATOM/NEAR/APT). Aggregates Binance, Coinbase, Kraken, and OKX in parallel (2 s timeout per source). Includes 1% outlier rejection, cross-exchange spread %, confidence grading (high/medium/low), and per-source USD volume weights. Kaiko-style reference pricing — $0.02/call.

## Output

Returns a volume-weighted median (VWM) USD spot price for the requested crypto asset, aggregated from up to four exchanges (Binance, Coinbase, Kraken, OKX) with a 2-second timeout per source. Response includes: the VWM price, cross-exchange spread percentage, a confidence grade (high/medium/low), per-source USD volume weights used in the calculation, and notes on any outliers rejected via the 1% outlier filter.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "as_of": "2026-07-02T10:00:00.000Z",
  "asset": "BTC-USD",
  "price": 107500,
  "sources": [
   {
    "price": 107510,
    "volume": 1200000000,
    "exchange": "binance",
    "included": true,
    "vol_weight": 0.45
   },
   {
    "price": 107490,
    "volume": 800000000,
    "exchange": "coinbase",
    "included": true,
    "vol_weight": 0.3
   },
   {
    "price": 107500,
    "volume": 400000000,
    "exchange": "kraken",
    "included": true,
    "vol_weight": 0.15
   },
   {
    "price": 107480,
    "volume": 270000000,
    "exchange": "okx",
    "included": true,
    "vol_weight": 0.1
   }
  ],
  "confidence": "high",
  "disclaimer": "Volume-weighted median price from up to 4 exchanges. Informational only, not financial advice.",
  "data_age_seconds": 0,
  "outliers_rejected": 0,
  "price_simple_median": 107480,
  "cross_exchange_spread_pct": 0.08
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/kronos-signals-vwm-spot-price-api-ac57d9ab/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kronossignals.com](https://www.zero.xyz/host/kronossignals.com/llms.txt)