# Carbon & Cashmere DEX-CEX Spread API (BTC)

> Carbon & Cashmere DEX-CEX Spread API (BTC) is a paid API for AI agents from api.carbon-cashmere.de, paid per call via x402, $0.05/call, status down (last checked 2026-09-14).

Returns the spread between decentralized exchange (DEX) and centralized exchange (CEX) prices for BTC, including pool-level details and spread statistics.

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/dex-cex-spread/BTC
- Price: $0.05/call
- Payment: x402
- Status: down
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/carbon-cashmere-dex-cex-spread-api-btc-93a1f3dd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_epO6HMiDlfcu6xsLMzMfr

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 carbon-cashmere-dex-cex-spread-api-btc-93a1f3dd
```

Example prompt: What's the current DEX versus CEX price spread for BTC right now — which pools have the biggest discrepancy, and is DEX priced higher or lower than the centralized exchange?

## When to prefer this

Use this endpoint when you need real-time arbitrage intelligence specifically between DEX and CEX venues for BTC, particularly when you want pool-level granularity including liquidity, pair address, and directional spread. Prefer this over generic price APIs when the goal is identifying DEX-CEX price discrepancies or arbitrage signals rather than just a single reference price.

## Known failure modes

- Unsupported coin symbol returns 404 or empty pools array
- No trusted DEX pools found for the requested coin returns empty results
- CEX price feed unavailable causes null cex_price_usd
- Stale or low-liquidity pools may produce unreliable spread data
- Payment not processed (x402) results in 402 Payment Required response

## How this service works

Professional crypto market intelligence. Real-time prices, signals, and market scoring.

## Output

A JSON object containing the coin identifier, a list of DEX pools with their chain, spread percentage, spread direction (dex_lower or dex_higher), DEX and CEX prices in USD, pool pair address, quote symbol, and liquidity in USD, plus aggregate stats including CEX price, trusted pool count, median spread, and maximum absolute spread.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "coin": "ATOM",
  "pools": [
   {
    "dex": "uniswap",
    "chain": "ethereum",
    "direction": "dex_lower",
    "spread_pct": -10.82,
    "pair_address": "0x...",
    "quote_symbol": "WETH",
    "cex_price_usd": 1.94,
    "dex_price_usd": 1.73,
    "liquidity_usd": 86938000
   }
  ],
  "stats": {
   "cex_price_usd": 1.94,
   "trusted_pools": 1,
   "median_spread_pct": -10.82,
   "abs_max_spread_pct": 10.82
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/carbon-cashmere-dex-cex-spread-api-btc-93a1f3dd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.carbon-cashmere.de](https://www.zero.xyz/host/api.carbon-cashmere.de/llms.txt)