# QuantaFlow CoinCap Proxy - x402 API Gateway

> QuantaFlow CoinCap Proxy - x402 API Gateway is a paid API for AI agents from quanta-roan.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-18).

Proxies requests to the CoinCap cryptocurrency data API via the x402 micropayment protocol, charging $0.01 USDC per call

## Facts

- Endpoint: POST https://quanta-roan.vercel.app/api/service/coincap?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quantaflow-coincap-proxy-x402-api-gateway-faccbc22
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_To5W-DU7al5GOuViyS3uh

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-coincap-proxy-x402-api-gateway-faccbc22 -d '<json body>'
```

Example prompt: Pull the current price and 24-hour volume for Bitcoin from CoinCap — I want the latest market data including market cap and percent change.

## When to prefer this

Choose this endpoint when you need real-time or historical cryptocurrency market data from CoinCap and are operating in a web3/DeFi agent context where paying per-call via x402 USDC micropayments is acceptable. Prefer this over direct CoinCap API access when you want a pay-as-you-go model without managing API keys, or when building autonomous agents that need programmable crypto payments.

## Known failure modes

- Payment failure: insufficient USDC balance or x402 payment header rejected — returns 402 Payment Required
- Invalid path: unrecognized CoinCap API path returns 404 or upstream error
- Malformed query parameters: upstream CoinCap returns 400 bad request
- CoinCap upstream outage: gateway may return 502 or 503
- Rate limiting from upstream CoinCap API: may return 429

## How this service works

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

## Output

The raw upstream CoinCap API response, passed through as-is after successful x402 micropayment — typically JSON containing cryptocurrency asset data such as price in USD, market cap, volume, supply, and percent change fields.

## 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-coincap-proxy-x402-api-gateway-faccbc22/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)