# Carbon Cashmere Realized Volatility Analytics

> Carbon Cashmere Realized Volatility Analytics is a paid API for AI agents from api.carbon-cashmere.de, paid per call via x402, $0.12/call, status unknown (last checked 2026-09-15).

Returns multi-estimator realized volatility metrics for a cryptocurrency using 4h bars, including realized vol (7d/30d/full), Parkinson, Garman-Klass, downside semi-variance, and vol-of-vol, all annualized.

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/volatility/:coin
- Price: $0.12/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-carbon-cashmere-de-86f9c2a2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_E5NsFQlpnMw6yvDYElvej

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-86f9c2a2
```

Example prompt: Can you pull the full realized volatility breakdown for ETH — including Parkinson, Garman-Klass, downside semi-variance, and vol-of-vol, all annualized from 4h bars?

## When to prefer this

Choose this endpoint when you need multiple professional-grade realized volatility estimators (not just simple standard deviation) for a cryptocurrency, especially when you want Parkinson or Garman-Klass range-based estimates, downside semi-variance for risk analysis, or vol-of-vol as a second-order risk metric, all properly annualized from 4h bars.

## Known failure modes

- Unknown or unsupported coin symbol returns a 404 or error response
- Network timeout if the underlying data source is unavailable
- Invalid coin path parameter returns a 400 bad request
- Stale or insufficient bar data may affect accuracy of shorter-window estimates

## How this service works

Multi-estimator realized volatility analytics — realized vol (7d/30d/full), Parkinson range-based (high-low log), Garman-Klass (O/H/L/C), downside semi-variance, vol-of-vol. All annualized for 4h bars (× sqrt(2190)). Informational research data — not investment advice.

## Output

Returns annualized volatility estimates across multiple estimators: realized vol at 7d, 30d, and full lookback windows; Parkinson high-low log range vol; Garman-Klass open/high/low/close vol; downside semi-variance; and volatility-of-volatility — all computed from 4-hour OHLC bars scaled by sqrt(2190).

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-carbon-cashmere-de-86f9c2a2/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)