# QuantaFlow x402 API Gateway – Zippopotam Proxy

> QuantaFlow x402 API Gateway – Zippopotam Proxy 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 requests to the Zippopotam postal code lookup API via x402 micropayment protocol, charging $0.01 USDC per call.

## Facts

- Endpoint: POST https://quanta-roan.vercel.app/api/service/zippopotam?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-x402-api-gateway-zippopotam-proxy-0c27eac0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FuzOPVREKyiS1Xr2Tev4G

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-zippopotam-proxy-0c27eac0 -d '<json body>'
```

Example prompt: Look up the city, state, and country for US ZIP code 90210 using the Zippopotam proxy — I need the place name and region details.

## When to prefer this

Use this endpoint when you need postal code geographic lookups (city, state, country, coordinates) and are operating in a web3/x402 micropayment context where per-call USDC billing is acceptable. Prefer it over direct Zippopotam access when you need payment-gated, metered usage without managing API keys, or when building DeFi-adjacent workflows that already use x402 payment rails.

## Known failure modes

- Payment failure if wallet lacks sufficient USDC, returning a 402 Payment Required error
- Invalid or non-existent postal code returns a 404 from upstream Zippopotam
- Malformed path or query parameters result in an upstream error passed through
- Rate limiting or upstream Zippopotam downtime returns a 5xx error
- Incorrect country code prefix in path yields empty or error response

## How this service works

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

## Output

Returns the upstream Zippopotam JSON response, which typically includes the postal code, country, country abbreviation, and an array of places with city name, state, state abbreviation, latitude, and longitude.

## 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-zippopotam-proxy-0c27eac0/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)