# Carbon Cashmere Crypto Correlation Matrix

> Carbon Cashmere Crypto Correlation Matrix is a paid API for AI agents from api.carbon-cashmere.de, paid per call via x402, $0.01/call, status down (last checked 2026-09-14).

Computes Pearson correlation matrix for 2–10 crypto assets over a configurable lookback window (7–90 days), returning a full NxN matrix and unique pair list.

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/correlation
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-carbon-cashmere-de-de0c5882
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_v5x0xtMSm3FMutOUcUi4f

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 api-carbon-cashmere-de-de0c5882
```

Example prompt: Show me the 30-day Pearson correlation matrix for BTC, ETH, SOL, BNB, and AVAX — I want to see which coins move together so I can reduce overlap in my portfolio.

## When to prefer this

Use this endpoint when you need quantitative daily-return correlations across multiple crypto assets for portfolio diversification, risk decomposition, or hedging analysis. Prefer this over generic price endpoints when you specifically need the pairwise Pearson correlation structure. Supports up to 10 coins simultaneously across 116 tracked assets with flexible 7–90 day windows.

## Known failure modes

- Fewer than 2 or more than 10 coins specified — request rejected
- Coin symbol not among the 116 tracked coins — unknown coin error
- Invalid days value not in [7, 14, 30, 60, 90] — enum validation error
- Payment not provided or insufficient — 402 Payment Required
- Insufficient historical data for the requested window — partial or error response

## How this service works

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

## Output

Returns a full NxN Pearson correlation matrix for the requested coins, a flat list of unique pairwise correlations, the list of coins analyzed, and the lookback period used. Values range from -1 (perfect inverse) to +1 (perfect positive correlation).

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "days": 30,
  "coins": [
   "BTC",
   "ETH",
   "SOL"
  ],
  "pairs": [
   {
    "pair": "BTC/ETH",
    "correlation": 0.87
   }
  ],
  "matrix": [
   [
    1,
    0.87,
    0.72
   ],
   [
    0.87,
    1,
    0.81
   ],
   [
    0.72,
    0.81,
    1
   ]
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-carbon-cashmere-de-de0c5882/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)