# Carbon & Cashmere BTC Whale Activity API

> Carbon & Cashmere BTC Whale Activity API 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 24-hour Bitcoin whale transaction activity metrics including transaction counts, output volumes, fee rates, and 30-day trend z-score regime classification.

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/btc/whale-activity
- 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-btc-whale-activity-api-461ecef9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZqqqW7ygaytrYYzhkcyEZ

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-btc-whale-activity-api-461ecef9
```

Example prompt: What does Bitcoin whale activity look like right now — how many large transactions happened in the last 24 hours, what's the trend regime, and is the z-score showing anything unusual compared to the 30-day baseline?

## When to prefer this

Choose this endpoint when you need real-time, node-sourced Bitcoin whale transaction activity with statistical trend context (z-score, regime classification) rather than just raw price data. Prefer over generic price APIs when the user wants on-chain large-wallet movement signals, activity regime detection, or fee rate intelligence directly from a Bitcoin Core node.

## Known failure modes

- Bitcoin Core node sync lag may cause stale data during network disruptions
- Malformed or missing query parameters may return a 400 error
- Payment not processed or invalid x402 header results in 402 Payment Required
- Node connectivity issues may result in 503 Service Unavailable
- The total_output_btc_sum includes change outputs and is NOT net value transferred — misinterpretation is a semantic failure mode

## How this service works

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

## Output

Returns a JSON object with: 24-hour whale tx count, tx-per-hour rate, average and median BTC output sizes, total output BTC sum, largest single transaction (txid, timestamp, output BTC), average vbyte size, average fee rate in sat/vb, and a 30-day trend block containing z-score, regime label (e.g. 'neutral_activity'), current vs baseline tx-per-hour, plus metadata indicating the data source (local Bitcoin Core node).

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "fees": {
   "avg_fee_rate_sat_vb": 4.22
  },
  "_meta": {
   "source": "btc_zmq_whale_txs (local Bitcoin Core node)"
  },
  "activity": {
   "tx_count": 5851,
   "largest_tx": {
    "ts": "2026-04-25T12:15:36+00:00",
    "txid": "abc123...",
    "output_btc": 20215.24
   },
   "avg_size_vb": 650,
   "tx_per_hour": 243.79,
   "avg_output_btc": 104.89,
   "avg_output_count": 9,
   "median_output_btc": 22.31,
   "total_output_btc_sum": 613709.46
  },
  "trend_30d": {
   "_meta": "z-score on tx-count (activity proxy), NOT BTC-value-transferred",
   "regime": "neutral_activity",
   "z_score_30d": -0.272,
   "current_tx_per_hour": 243.79,
   "baseline_tx_per_hour": 261.66
  },
  "_disclaimer": "total_output_btc_sum includes change-outputs. NOT net value transferred. Activity indicator only.",
  "window_hours": 24,
  "min_output_btc_threshold": 10
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/carbon-cashmere-btc-whale-activity-api-461ecef9/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)