# QuantaFlow x402 API Gateway — Alchemy Citrea Mainnet

> QuantaFlow x402 API Gateway — Alchemy Citrea Mainnet 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 API requests to Alchemy's Citrea mainnet node via x402 micropayment protocol, charging $0.01 USDC per call

## Facts

- Endpoint: POST https://quanta-roan.vercel.app/api/service/alchemy-citrea-mainnet?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-alchemy-citrea-mainnet-fd160361
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__erNuf3MCnBxhTCbelS1T

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-citrea-mainnet-fd160361 -d '<json body>'
```

Example prompt: Call the Alchemy Citrea mainnet node to get the latest block number — route it through QuantaFlow, forwarding the JSON-RPC body '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}' to the root path.

## When to prefer this

Choose this endpoint when you need pay-per-call access to Alchemy's Citrea mainnet RPC without committing to a subscription, or when building an agent that makes sporadic Citrea blockchain queries and wants to pay $0.01 USDC per request via the x402 protocol rather than managing API keys.

## Known failure modes

- Insufficient USDC balance causes payment failure and request is rejected
- Invalid path or method results in upstream 404 or 400 error passed through
- Malformed JSON body causes upstream RPC parse error
- Citrea mainnet node downtime leads to upstream timeout or 503
- Unsupported JSON-RPC method returns upstream error response

## 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 Citrea mainnet API is passed through unchanged, including the response body and content type, after the x402 micropayment of $0.01 USDC is 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-alchemy-citrea-mainnet-fd160361/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)