# Carbon & Cashmere Cointegration Analysis API (ETH-SOL)

> Carbon & Cashmere Cointegration Analysis API (ETH-SOL) is a paid API for AI agents from api.carbon-cashmere.de, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Returns cointegration test results and mean-reversion analytics for the ETH-SOL trading pair, including Engle-Granger statistics, z-scores, and half-life estimates.

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/cointegration/ETH-SOL
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/carbon-cashmere-cointegration-analysis-api-eth-sol-a0b55110
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TxwPXhLipUIfO8qFQ7ema

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-cointegration-analysis-api-eth-sol-a0b55110
```

Example prompt: Run a cointegration test on ETH and SOL — I want to know if they're cointegrated at the 5% level, what the current spread z-score is, and how many days it typically takes for the spread to revert to the mean.

## When to prefer this

Use this endpoint when you need rigorous statistical cointegration testing between ETH and SOL specifically, especially for pairs trading strategies, statistical arbitrage signal generation, or validating a long-run equilibrium relationship. Prefer this over simple correlation metrics when you need formal hypothesis testing (Engle-Granger) and mean-reversion half-life estimates.

## Known failure modes

- Invalid or unsupported trading pair returns error
- Insufficient historical data for lookback period
- Payment not included or invalid results in 402 Payment Required
- Rate limit exceeded returns 429 error
- Service downtime returns 5xx error

## How this service works

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

## Output

Returns a JSON object with the base/quote pair labels, Engle-Granger test statistic and p-value with critical values, whether cointegration is confirmed at 5% and 10% significance, the current spread value and z-score, beta coefficient, ADF p-value for mean reversion, and estimated half-life in days over a 90-day lookback window.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "base": "BTC",
  "pair": "BTC-ETH",
  "_meta": {
   "disclaimer": "Informational research data only — not investment advice."
  },
  "quote": "ETH",
  "spread": {
   "current": 0.023,
   "zscore_current": 1.42,
   "beta_coefficient": 0.89
  },
  "engle_granger": {
   "p_value": 0.012,
   "test_statistic": -3.42,
   "critical_values": {
    "5pct": -3.38
   }
  },
  "lookback_days": 90,
  "mean_reversion": {
   "adf_p_value": 0.018,
   "half_life_days": 4.2
  },
  "is_cointegrated_at_5pct": true,
  "is_cointegrated_at_10pct": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/carbon-cashmere-cointegration-analysis-api-eth-sol-a0b55110/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)