# APEX Runner Cross Exchange Spread Signal

> APEX Runner Cross Exchange Spread Signal is a paid API for AI agents from apexrunner.ai, paid per call via x402, $0.007/call, status unknown (last checked 2026-09-14).

Returns a real-time cross-exchange spread signal indicating arbitrage or price divergence opportunities across crypto trading venues

## Facts

- Endpoint: GET https://apexrunner.ai/signals/cross-exchange-spread
- Price: $0.007/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/apex-runner-cross-exchange-spread-signal-1f12d898
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oyD9FLIl6M1WAQ6ETLD8X

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 apex-runner-cross-exchange-spread-signal-1f12d898
```

Example prompt: What's the current cross-exchange spread signal for BTC/USDT right now — is there a meaningful arbitrage opportunity between major exchanges?

## When to prefer this

Use this endpoint when you need a quantitative, pre-computed signal for cross-exchange price spreads rather than raw order book data. Ideal for algorithmic trading agents that want a ready-to-use signal without building their own spread detection logic. Choose this over raw exchange APIs when you want a normalized, comparable signal across multiple venues.

## Known failure modes

- Invalid or unsupported trading pair returns error
- Payment of $3 USDC not fulfilled results in 402 Payment Required
- Exchange data feed temporarily unavailable returns service error
- Rate limiting if called too frequently
- No significant spread detected may return null or zero signal

## How this service works

APEX Runner: Cross Exchange Spread Signal

## Output

A structured signal object indicating the magnitude and direction of price spread across exchanges, including signal strength or score that traders can use to identify arbitrage or divergence opportunities.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "pairs": "object — keyed by asset (BTC/ETH), each with direction, gross/net spread %, kr_mid, hl_mid, arb_active bool, spread_vs_threshold",
 "example": {
  "pairs": {
   "BTC": {
    "asset": "BTC",
    "hl_mid": 63762.5,
    "kr_mid": 63695.45,
    "direction": "kr_buy_hl_sell",
    "arb_active": false,
    "net_spread_pct": -0.2,
    "gross_spread_pct": 0.11,
    "spread_vs_threshold": -0.55
   },
   "ETH": {
    "asset": "ETH",
    "hl_mid": 1681.45,
    "kr_mid": 1678.8,
    "direction": "kr_buy_hl_sell",
    "arb_active": false,
    "net_spread_pct": -0.15,
    "gross_spread_pct": 0.16,
    "spread_vs_threshold": -0.5
   }
  },
  "cached_at": "2026-06-13T12:00:00+00:00",
  "active_arbs": 0,
  "interpretation": "No arb opportunities above 0.35% — best spread: ETH at -0.150%",
  "arb_threshold_pct": 0.35,
  "best_spread_asset": "BTC",
  "best_net_spread_pct": -0.15
 },
 "cached_at": "ISO8601 timestamp",
 "active_arbs": "int — count of pairs above threshold",
 "interpretation": "string — plain-English arb summary",
 "arb_threshold_pct": "float — arb threshold (0.35%)",
 "best_spread_asset": "string — asset with highest net spread",
 "best_net_spread_pct": "float — best net spread %"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/apex-runner-cross-exchange-spread-signal-1f12d898/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from apexrunner.ai](https://www.zero.xyz/host/apexrunner.ai/llms.txt)