# PennyRail OpenAPI Search (nano)

> PennyRail OpenAPI Search (nano) is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Searches for proven OpenAPI specifications or operations matching a given query input

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/openapi.search--proven-openapi-search
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-openapi-search-nano-103781fa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2PrDnOwB9pY-Aa_VmEk3j

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 pennyrail-openapi-search-nano-103781fa -d '<json body>'
```

Example prompt: Search the PennyRail OpenAPI registry for proven API operations that handle payment webhooks — I want to find matching specs I can use in my integration.

## When to prefer this

Choose this endpoint when you need to programmatically discover or search for proven, curated OpenAPI specifications or operations by keyword or description, especially within the PennyRail micro-payment ecosystem. Prefer it over static API directories when you need machine-readable results tied to a pay-per-call discovery model.

## Known failure modes

- Missing or malformed 'input' object returns a 400-level validation error
- No matching OpenAPI specs found returns an empty result set
- Payment not settled (x402 protocol failure) blocks the request entirely
- Upstream registry unavailability returns a 5xx error
- Overly broad or ambiguous queries may return irrelevant or too many results

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing OpenAPI search results — likely matching operation names, paths, summaries, or specification references — corresponding to the submitted query input. The response schema is open-ended (additionalProperties: true), so results may vary in structure but will reflect operations proven to exist in the indexed registry.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-openapi-search-nano-103781fa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pennyrail.vercel.app](https://www.zero.xyz/host/pennyrail.vercel.app/llms.txt)