# Carbon & Cashmere BTC Block Details API

> Carbon & Cashmere BTC Block Details API is a paid API for AI agents from api.carbon-cashmere.de, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Returns on-chain statistics for a specific Bitcoin block by height, including transaction count, miner pool, Taproot/SegWit adoption, inscriptions, coinbase reward, and fee percentiles.

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/btc-derivatives/blocks/%7Bheight%7D
- Price: $0.02/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-block-details-api-9679a731
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nYdUVoQUnwH-E_wySyA7m

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-block-details-api-9679a731
```

Example prompt: Pull the on-chain block stats from Carbon & Cashmere for Bitcoin block height 949815 — I want to see who mined it, the Taproot percentage, fee percentiles, and how many inscriptions were included.

## When to prefer this

Use this endpoint when you need granular per-block Bitcoin on-chain analytics including miner attribution, script type adoption (Taproot/SegWit), inscription activity, and fee market data for a specific block height. Prefer over generic blockchain explorers when fee percentile breakdowns and miner pool identification are needed programmatically at low cost.

## Known failure modes

- Block height not found or not yet mined returns 404
- Invalid or non-integer height parameter returns 400
- Payment not completed or x402 flow not fulfilled returns 402
- Rate limit exceeded returns 429
- Service unavailable returns 503

## How this service works

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

## Output

A JSON object containing the block height, transaction count, miner pool name, Taproot adoption percentage, SegWit witness percentage, OP_RETURN count, inscription count, coinbase reward in BTC, and fee percentiles (p10, p50, p90) in sat/vB.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "height": 949815,
  "tx_count": 1898,
  "miner_pool": "MARA Pool",
  "taproot_pct": 0.84,
  "witness_pct": 99.42,
  "op_return_count": 1844,
  "inscriptions_count": 3,
  "coinbase_reward_btc": 3.1287,
  "fee_percentiles_sat_vb": {
   "p10": 1,
   "p50": 1.8,
   "p90": 7.1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/carbon-cashmere-btc-block-details-api-9679a731/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)