# BTC-Gold 14-Day Rolling Pearson Correlation API

> BTC-Gold 14-Day Rolling Pearson Correlation API is a paid API for AI agents from nonvisceral-eloisa-mousily.ngrok-free.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Returns the 14-day rolling Pearson correlation (rho) between Bitcoin and gold spot price, with regime classification and interpretation for macro cross-asset signal generation.

## Facts

- Endpoint: GET https://nonvisceral-eloisa-mousily.ngrok-free.dev/api/btc-gold-correlation
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nonvisceral-eloisa-mousily-ngrok-free-dev-b0d02e5b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ngUmIe6aUCpnZrnh3R8O1

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 nonvisceral-eloisa-mousily-ngrok-free-dev-b0d02e5b
```

Example prompt: What's the current 14-day Pearson correlation between Bitcoin and gold — is BTC in a hedge or liquidity-driven regime right now, and what does the interpretation say about its behavior as digital gold versus a risk asset?

## When to prefer this

Use this endpoint when you need a quantitative, rolling cross-asset correlation signal between BTC and gold to classify Bitcoin's macro regime (hedge vs liquidity/risk asset). Prefer this over generic price feeds when you need the regime label and interpretation ready for decision logic in rotation strategies, risk-on/risk-off signals, or when building AI agents that must reason about BTC's role in a macro portfolio. It complements the sibling BTC/ETH regime direction and liquidation endpoints on the same host for a bundled macro signal.

## Known failure modes

- Upstream price data unavailable — may return stale or error response
- ngrok tunnel down or unreachable — HTTP 502 or connection timeout
- No data for sufficient 14-day window — may return null rho or partial result
- Rate limit or payment validation failure — HTTP 402 if x402 payment not processed correctly

## How this service works

Bitcoin Gold correlation API: 14-day rolling Pearson correlation between BTC and gold spot. Returns rho, regime (LIQUIDITY_STRONG, LIQUIDITY_MILD, DECOUPLED, HEDGE_MILD, HEDGE_STRONG), interpretation. Cross-asset macro signal for risk-on/risk-off rotation strategies and AI agents tracking BTC's behavior as digital gold versus risk asset.

## Output

Returns a JSON object with rho_14d (Pearson correlation coefficient over the last 14 days), a regime label (one of LIQUIDITY_STRONG, LIQUIDITY_MILD, DECOUPLED, HEDGE_MILD, HEDGE_STRONG), a human-readable interpretation string, the window_days value (14), and an updated_at timestamp indicating data freshness.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "regime": {
       "type": "string"
      },
      "rho_14d": {
       "type": "number"
      },
      "updated_at": {
       "type": "string"
      },
      "window_days": {
       "type": "number"
      },
      "interpretation": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nonvisceral-eloisa-mousily-ngrok-free-dev-b0d02e5b/health.json
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