# QuantaFlow Overpass API Gateway (x402)

> QuantaFlow Overpass API Gateway (x402) is a paid API for AI agents from quanta-roan.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-16).

Proxies POST requests to the OpenStreetMap Overpass API via a micropayment-gated x402 gateway, returning geospatial and map data.

## Facts

- Endpoint: POST https://quanta-roan.vercel.app/api/service/overpass
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quantaflow-overpass-api-gateway-x402-f20ae927
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lXaMs05o68W08TO5bm0ay

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-overpass-api-gateway-x402-f20ae927 -d '<json body>'
```

Example prompt: Query the Overpass API to find all coffee shops within a 1km radius of 48.8566° N, 2.3522° E and return the results as JSON — use the QuantaFlow x402 gateway with the path set to the Overpass interpreter endpoint.

## When to prefer this

Choose this endpoint when you need programmatic access to OpenStreetMap geographic data via Overpass QL and want to pay per-query with USDC micropayments rather than manage API keys or subscriptions. Ideal for AI agents operating in web3 contexts where x402 payment rails are already integrated.

## Known failure modes

- Invalid Overpass QL syntax returns upstream query error
- Bounding box too large causes Overpass timeout or rate-limit rejection
- Payment failure or insufficient USDC balance blocks the request with 402 response
- Malformed JSON body results in forwarding error
- Overpass server overload returns 429 or 504 from upstream
- Path not pointing to valid Overpass endpoint returns 404

## How this service works

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

## Output

The raw upstream Overpass API response body (typically GeoJSON, OSM XML, or JSON depending on the query output format), along with the content-type header, passed through after the $0.01 USDC x402 micropayment is processed.

## 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-overpass-api-gateway-x402-f20ae927/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)