# Carbon & Cashmere ETH Volatility API

> Carbon & Cashmere ETH Volatility API is a paid API for AI agents from api.carbon-cashmere.de, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-16).

Returns ETH volatility metrics including realized volatility, range-based estimators, downside risk, and vol-of-vol for use in crypto market intelligence workflows.

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/volatility/ETH
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/carbon-cashmere-eth-volatility-api-1b8eaeee
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_L0RI12wYQdTmtNy2qBihJ

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-eth-volatility-api-1b8eaeee
```

Example prompt: What's the current realized volatility and downside risk for ETH — give me the 7-day, 30-day, and Parkinson/Garman-Klass range-based estimates from Carbon & Cashmere?

## When to prefer this

Use this endpoint when you need quantitative ETH volatility estimates across multiple methodologies (realized, range-based, downside) in a single call — especially when building risk dashboards, options pricing tools, or portfolio monitoring workflows that require more than just spot price.

## Known failure modes

- Invalid or unsupported asset symbol returns an error
- Network timeout if upstream price feeds are delayed
- Malformed request returns 4xx with schema validation error
- Missing x402 payment header results in payment-required error

## How this service works

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

## Output

A JSON object with realized volatility at 7d, 30d, and full-period horizons; range-based estimators (Parkinson, Garman-Klass); 30-day downside risk; and vol-of-vol at 30 days — all for ETH, with a disclaimer that data is informational only.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "_meta": {
   "disclaimer": "Informational research data only — not investment advice."
  },
  "symbol": "BTC",
  "range_based": {
   "parkinson": 0.41,
   "garman_klass": 0.4
  },
  "downside_30d": 0.28,
  "realized_vol": {
   "7d": 0.32,
   "30d": 0.38,
   "full_period": 0.42
  },
  "vol_of_vol_30d": 0.09
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/carbon-cashmere-eth-volatility-api-1b8eaeee/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)