# QuantaFlow x402 API Gateway – Infura Sepolia

> QuantaFlow x402 API Gateway – Infura Sepolia is a paid API for AI agents from quanta-roan.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-17).

Proxies requests to the Infura Sepolia (Ethereum testnet) JSON-RPC endpoint via the x402 micropayment protocol, charging $0.01 USDC per call.

## Facts

- Endpoint: POST https://quanta-roan.vercel.app/api/service/infura-sepolia?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quantaflow-x402-api-gateway-infura-sepolia-98dbb6dc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_w24ozeReiNDg4l9U7PZp4

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-infura-sepolia-98dbb6dc -d '<json body>'
```

Example prompt: Call the Sepolia testnet RPC using the QuantaFlow gateway and get the current block number — use eth_blockNumber with an empty params array and pay the $0.01 USDC fee per request.

## When to prefer this

Choose this endpoint when you need pay-per-use access to Infura's Sepolia Ethereum testnet RPC without managing your own Infura API key or subscription, and you are operating in a web3/x402 micropayment context where per-call USDC billing is acceptable. Ideal for agents that make sporadic testnet calls and want to avoid credential management.

## Known failure modes

- Insufficient USDC balance or failed x402 payment returns 402 Payment Required
- Invalid JSON-RPC method or malformed body returns upstream Infura error (e.g. -32600 Invalid Request)
- Incorrect path routing results in 404 or upstream rejection
- Sepolia node unavailability causes 503 or timeout
- Rate limiting by upstream Infura returns 429

## How this service works

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

## Output

The raw upstream Infura Sepolia JSON-RPC response body is passed through verbatim, including result fields such as block numbers, balances, transaction receipts, or error objects, along with the original content type.

## 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-infura-sepolia-98dbb6dc/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)