# QuantaFlow x402 API Gateway – CoinMarketCap

> QuantaFlow x402 API Gateway – CoinMarketCap is a paid API for AI agents from quanta-roan.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-09).

Proxies requests to CoinMarketCap's API through a pay-per-call x402 micropayment gateway for cryptocurrency market data

## Facts

- Endpoint: POST https://quanta-roan.vercel.app/api/service/coinmarketcap?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-09
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quantaflow-x402-api-gateway-coinmarketcap-084a503e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AQSeQ4cvtyRp1lMkfQgPN

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 quantaflow-x402-api-gateway-coinmarketcap-084a503e -d '<json body>'
```

Example prompt: Can you pull the current price and market cap for Ethereum from CoinMarketCap — use the /v1/cryptocurrency/quotes/latest path with symbol ETH?

## When to prefer this

Choose this endpoint when you need CoinMarketCap market data without managing a CoinMarketCap API key subscription, preferring a pay-per-call micropayment model via x402 protocol instead. Ideal for AI agents in web3/DeFi contexts that already use USDC micropayments and want to avoid monthly API subscription overhead.

## Known failure modes

- Payment failure if USDC balance is insufficient or x402 payment header is malformed
- Upstream CoinMarketCap API errors (rate limits, invalid API key, unknown symbol) passed through as-is
- Invalid path parameter resulting in 404 from upstream
- Malformed query object causing upstream 400 error
- Gateway timeout if CoinMarketCap is slow to respond

## How this service works

Every request, a quantum of value. x402 protocol-based payment endpoint for web3/DeFi tools.

## Output

The raw upstream CoinMarketCap API response body is passed through, including cryptocurrency quotes, metadata, market rankings, or any other CoinMarketCap endpoint data, along with the content type header from the upstream service.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "body": {
   "type": "string",
   "description": "Optional JSON body forwarded to POST requests."
  },
  "path": {
   "type": "string",
   "description": "Path below the selected upstream origin."
  },
  "query": {
   "type": "object"
  },
  "method": {
   "enum": [
    "GET",
    "POST"
   ],
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "description": "The upstream response body and content type are passed through after successful payment."
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/quantaflow-x402-api-gateway-coinmarketcap-084a503e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from quanta-roan.vercel.app](https://www.zero.xyz/host/quanta-roan.vercel.app/llms.txt)