# QuantaFlow x402 API Gateway — Alchemy Celo Sepolia

> QuantaFlow x402 API Gateway — Alchemy Celo 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 2026-10-14).

Proxies requests to the Alchemy Celo Sepolia blockchain 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-celo-sepolia?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quantaflow-x402-api-gateway-alchemy-celo-sepolia-de33fe4c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NvmKiJjlryAs5mGGpEfbW

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-celo-sepolia-de33fe4c -d '<json body>'
```

Example prompt: Can you query the Celo Sepolia testnet via Alchemy and get the latest block number — use the x402 pay-per-call gateway, POST to the root path with the eth_blockNumber JSON-RPC body.

## When to prefer this

Choose this endpoint when you need pay-per-call access to the Alchemy Celo Sepolia RPC without managing an Alchemy API key subscription, and when your agent already supports x402 micropayment headers. Ideal for low-volume testnet interactions where a subscription is overkill, or for agents operating in web3/DeFi contexts that natively handle USDC micropayments on-chain.

## Known failure modes

- Insufficient USDC balance for x402 payment — returns 402 Payment Required
- Invalid or malformed JSON-RPC body — upstream Alchemy error forwarded
- Unsupported RPC method for Celo Sepolia — upstream 400/error response
- Path routing mismatch — incorrect path parameter results in 404 or upstream error
- Alchemy upstream outage — 502/503 passed through
- x402 facilitator unavailable — payment cannot be settled

## How this service works

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

## Output

The raw upstream response body from Alchemy's Celo Sepolia RPC endpoint is passed through transparently after the $0.01 USDC x402 micropayment is processed. This typically includes standard JSON-RPC result objects containing blockchain data such as block details, transaction receipts, account balances, or contract call return values.

## 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-celo-sepolia-de33fe4c/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)