# QuantaFlow Mempool API Gateway

> QuantaFlow Mempool API Gateway is a paid API for AI agents from quanta-roan.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-16).

Proxies POST requests to blockchain mempool data services via the x402 micropayment protocol, charging $0.01 USDC per call.

## Facts

- Endpoint: POST https://quanta-roan.vercel.app/api/service/mempool?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quantaflow-mempool-api-gateway-fcfd4c41
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SB_xM624SRcP6HLrGmMzB

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-mempool-api-gateway-fcfd4c41 -d '<json body>'
```

Example prompt: Check the current mempool for pending transactions on the network — I want to see what's unconfirmed right now and get fee congestion data.

## When to prefer this

Choose this endpoint when you need pay-per-call access to blockchain mempool data without a long-term API subscription, especially in web3-native agent workflows already using the x402 micropayment protocol. Ideal for low-frequency or bursty mempool queries where per-call USDC billing is more economical than a monthly plan.

## Known failure modes

- Payment failure: insufficient USDC balance or wallet not configured for x402 micropayments
- Invalid path: upstream mempool endpoint not found returns a proxy error
- Upstream timeout: mempool service is slow or unresponsive, causing a gateway timeout
- Malformed body: invalid JSON in the body field causes upstream rejection
- Network error: Vercel deployment or upstream web3 node is down

## How this service works

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

## Output

The upstream mempool service's response body is passed through directly after successful x402 payment verification, including transaction lists, fee estimates, congestion metrics, or other blockchain mempool data depending on the path queried.

## 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-mempool-api-gateway-fcfd4c41/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)