# Carbon Cashmere Gas Price API

> Carbon Cashmere Gas Price API is a paid API for AI agents from api.carbon-cashmere.de, paid per call via x402, $0.005/call, status down (last checked 2026-09-14).

Returns real-time Ethereum gas prices (slow/standard/fast in gwei with base fee) and Bitcoin transaction fee estimates (sat/vB with mempool stats)

## Facts

- Endpoint: GET https://api.carbon-cashmere.de/v1/gas
- Price: $0.005/call
- Payment: x402
- Status: down
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-carbon-cashmere-de-3aeb25e7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_a4ZXk8MeKAO-c0PM8hYYD

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-3aeb25e7
```

Example prompt: What are the current Ethereum gas prices — slow, standard, and fast in gwei — and the current base fee, plus Bitcoin fee estimates in sat/vB with mempool stats so I can decide when to submit my transactions?

## When to prefer this

Use this endpoint when you need real-time, dual-chain (ETH + BTC) fee data in a single call, especially for AI agent workflows focused on transaction cost optimization or timing. Ideal when you need both Ethereum gwei tiers with base fee and Bitcoin sat/vB estimates together rather than querying separate APIs.

## Known failure modes

- Upstream node unavailable — returns 5xx with service unavailable error
- Rate limit exceeded — returns 429 Too Many Requests
- Payment required — returns 402 if x402 micropayment not included
- Malformed request parameters — returns 400 with validation error

## How this service works

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

## Output

Returns an object with eth_gas containing slow/standard/fast gas prices in gwei and base fee for Ethereum, plus btc_fees containing fee estimates in sat/vB and current mempool statistics for Bitcoin.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "eth_gas": {
   "fast_gwei": "0.08",
   "slow_gwei": "0.03",
   "standard_gwei": "0.05"
  },
  "btc_fees": {
   "fee_estimates": {
    "1": 12,
    "6": 5
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-carbon-cashmere-de-3aeb25e7/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)