# QuantaFlow x402 API Gateway - rapid-medium2

> QuantaFlow x402 API Gateway - rapid-medium2 is a paid API for AI agents from quanta-roan.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-12).

Proxies HTTP requests to upstream web3/DeFi tools via the x402 payment protocol, charging $0.01 USDC per call

## Facts

- Endpoint: POST https://quanta-roan.vercel.app/api/service/rapid-medium2?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quantaflow-x402-api-gateway-rapid-medium2-cf59348d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QYN2WYGqGDkK3XHNB5fVF

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-rapid-medium2-cf59348d -d '<json body>'
```

Example prompt: Forward a POST request to the rapid-medium2 upstream path '/prices' with query params for token 'ETH' and pay the $0.01 USDC x402 fee to get the response back.

## When to prefer this

Choose this endpoint when you need pay-per-call access to a web3 or DeFi upstream API without committing to a subscription, and your agent runtime supports the x402 micropayment protocol for automatic USDC settlement. Prefer it over direct upstream calls when you want metered billing at $0.01 per call.

## Known failure modes

- Payment verification failure — insufficient USDC balance or malformed x402 payment header returns 402 Payment Required
- Invalid upstream path — upstream service returns 404 if the path does not exist
- Upstream service unavailable — gateway may return 502 or 503 if the upstream is down
- Malformed JSON body — upstream rejects the forwarded body with 400 Bad Request
- Query parameter errors — upstream returns validation errors if required params are missing

## How this service works

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

## Output

The raw response body and content-type from the upstream web3/DeFi service, passed through transparently after the x402 payment of $0.01 USDC is verified and settled.

## 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-rapid-medium2-cf59348d/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)