# PennyRail npm Package Info Lookup

> PennyRail npm Package Info Lookup is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Fetches the latest metadata for an npm package by name via a paid settlement endpoint

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/network/npm.latest--npm-package-info
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-npm-package-info-lookup-0471e797
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vRR0OWen31iBVrq8UwQxP

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-npm-package-info-lookup-0471e797 -d '<json body>'
```

Example prompt: Can you look up the latest npm package info for 'lodash' — I need the current version, description, and license?

## When to prefer this

Choose this endpoint when an AI agent needs programmatic, pay-per-call access to npm package metadata without managing npm registry API keys or rate limits. It is well-suited for agents that occasionally need to resolve package information as part of a larger workflow, such as auditing dependencies, checking licenses, or verifying package existence, and that prefer a metered USDC micropayment model over subscription-based access.

## Known failure modes

- Package name not found in npm registry — returns an error or empty result
- Invalid or empty input string — may return a validation error
- npm registry upstream unavailable — potential timeout or 5xx error
- Payment settlement failure via x402 — request not processed
- Malformed input object missing the required 'input' field — returns 400-level error

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing npm registry metadata for the specified package, including its latest version number, description, author, license type, dependencies, repository URL, and other registry fields.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-npm-package-info-lookup-0471e797/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)