# Kronos CEX Premium Spread API

> Kronos CEX Premium Spread API is a paid API for AI agents from kronossignals.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Returns the cross-exchange price premium of a crypto asset on Coinbase versus a global composite median across OKX, Kraken, and Binance, with an interpretive label indicating US/institutional demand bias.

## Facts

- Endpoint: GET https://kronossignals.com/api/v1/cex-premium/%7Basset%7D
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/kronos-cex-premium-spread-api-45ea9feb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HH3SbwQB3A9HNzNUzaXPm

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-cex-premium-spread-api-45ea9feb
```

Example prompt: What's the current Coinbase premium for BTC-USD right now — is it trading above or below the global composite median across OKX, Kraken, and Binance, and what does that signal about US demand?

## When to prefer this

Choose this endpoint when you need a real-time, point-in-time view of how Coinbase's price compares to a global composite of major non-US exchanges (OKX, Kraken, Binance), specifically to gauge US or institutional demand bias. Prefer it over generic price feeds when the cross-exchange premium signal — not just the raw price — is what matters for your analysis or trading context.

## Known failure modes

- Unsupported asset symbol returns an error or available:false
- Downstream exchange feed unavailable may reduce composite_source_count or mark available:false
- Payment failure via x402 protocol blocks the response
- Stale data if exchange APIs are delayed — timestamp reflects data age
- Malformed asset parameter (e.g. missing '-USD' suffix) may return error

## How this service works

Paid market-intelligence API over x402

## Output

A JSON object containing the asset symbol, timestamp, Coinbase spot price, composite median price (from OKX, Kraken, Binance), premium percentage (positive = Coinbase above composite), number of sources used, a human-readable interpretation string (e.g. 'Mild US/institutional demand bias'), availability flag, and a disclaimer. Point-in-time only — no historical percentile or z-score included.

## 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",
  "available": true,
  "disclaimer": "Cross-exchange premium is informational only. Spread may reflect latency, liquidity, or fees — not a pure demand signal. Not financial advice.",
  "premium_pct": 0.2,
  "sources_used": [
   {
    "role": "reference",
    "price": 61320.5,
    "exchange": "coinbase"
   },
   {
    "role": "composite",
    "price": 61195.2,
    "exchange": "okx"
   },
   {
    "role": "composite",
    "price": 61201.4,
    "exchange": "kraken"
   },
   {
    "role": "composite",
    "price": 61198.3,
    "exchange": "binance"
   }
  ],
  "coinbase_price": 61320.5,
  "interpretation": "Coinbase is trading at a +0.20% premium to global composite. Mild US/institutional demand bias.",
  "historical_note": "Point-in-time only — no 24h percentile or 30d z-score (no historical baseline stored).",
  "composite_median": 61198.3,
  "composite_source_count": 3
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/kronos-cex-premium-spread-api-45ea9feb/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)