# Carbon & Cashmere Hurst Exponent API – SOL

> Carbon & Cashmere Hurst Exponent API – SOL is a paid API for AI agents from api.carbon-cashmere.de, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Returns Hurst exponent values and trend/random-walk interpretations for Solana (SOL) across multiple time windows (7d, 30d, full history).

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/hurst/SOL
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/carbon-cashmere-hurst-exponent-api-sol-0620952d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ji1Q3Jzv0ECb-4S2MD012

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-hurst-exponent-api-sol-0620952d
```

Example prompt: What's the Hurst exponent for SOL right now — is it trending or acting like a random walk over the last 7 and 30 days?

## When to prefer this

Use this endpoint when you need to characterize the statistical regime of SOL's price series — specifically whether it is trending (Hurst > 0.5), mean-reverting (Hurst < 0.5), or behaving as a random walk (Hurst ≈ 0.5). Prefer this over simple momentum or moving-average endpoints when you need a rigorous fractal / long-memory measure of market structure. Useful for strategy selection (trend-following vs. mean-reversion) or regime filtering.

## Known failure modes

- Invalid or unsupported symbol in URL path — 404 or empty response
- Insufficient price history for the requested coin — may return null or partial fields
- Network timeout or upstream data feed outage — 5xx error
- Malformed request path — 400 bad request

## How this service works

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

## Output

A JSON object containing Hurst exponent values for SOL at three time horizons (7d, 30d, full history) along with plain-language interpretations ('trending', 'random_walk', 'mean_reverting') for each window, plus a disclaimer that this is informational research data and not investment advice.

## 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",
  "hurst_7d": 0.48,
  "hurst_30d": 0.55,
  "hurst_full": 0.52,
  "interpretation_7d": "random_walk",
  "interpretation_30d": "trending",
  "interpretation_full": "random_walk"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/carbon-cashmere-hurst-exponent-api-sol-0620952d/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)