# QuantaFlow x402 API Gateway — Alchemy Base Sepolia

> QuantaFlow x402 API Gateway — Alchemy Base 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 2026-10-10).

Proxies requests to Alchemy's Base Sepolia RPC/API endpoint via the x402 micropayment protocol, charging $0.01 USDC per call

## Facts

- Endpoint: POST https://quanta-roan.vercel.app/api/service/alchemy-base-sepolia?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quantaflow-x402-api-gateway-alchemy-base-sepolia-11cd0df8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9bRAFD61AniHdFHbYWNXJ

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-alchemy-base-sepolia-11cd0df8 -d '<json body>'
```

Example prompt: Forward a JSON-RPC call to Alchemy's Base Sepolia endpoint — use path /v2/eth_blockNumber with no body — and pay the per-request fee automatically via x402.

## When to prefer this

Choose this endpoint when you need pay-per-use access to Alchemy's Base Sepolia RPC without managing an Alchemy API key or subscription — ideal for agents making infrequent or variable-volume testnet calls where a flat $0.01 USDC per-call cost is preferable to a monthly plan. Best suited for Base Sepolia testnet use cases (development, testing, DeFi prototyping) rather than mainnet production workloads.

## Known failure modes

- Payment failure: insufficient USDC balance causes x402 402 Payment Required error
- Invalid path: unrecognized Alchemy API path returns upstream 404 or error
- Malformed JSON body: upstream returns RPC error for invalid method or params
- Network unavailability: Alchemy Base Sepolia endpoint down, returns 502 or timeout
- Rate limiting: upstream Alchemy rate limit hit, returns 429 passed through

## How this service works

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

## Output

The raw upstream response from Alchemy's Base Sepolia API is passed through as-is, including the original content type. Typical responses are JSON-RPC result objects containing blockchain data such as block numbers, transaction receipts, account balances, or contract call results.

## 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-alchemy-base-sepolia-11cd0df8/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)