# PennyRail NPM Latest Version Lookup

> PennyRail NPM Latest Version 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).

Returns the latest published version number of a given npm package

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/network/npm.latest--npm-latest-version
- 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-latest-version-lookup-acdd32cf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fVr__Fn27gJJW3JXud_rm

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-latest-version-lookup-acdd32cf -d '<json body>'
```

Example prompt: What is the latest published version of the lodash npm package?

## When to prefer this

Use this endpoint when you need a quick, pay-per-call lookup of the latest npm package version without setting up your own npm registry client or managing API keys. It is ideal for lightweight automation, CI checks, or agent workflows that occasionally need version data without the overhead of maintaining a full npm API integration.

## Known failure modes

- Package name not found on npm registry returns an error or empty result
- Malformed or empty input string may return a 400-level error
- npm registry downtime or rate limiting may cause timeouts or 5xx responses
- Private or scoped packages may not be accessible

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing the latest published version of the specified npm package, potentially including additional package metadata such as version string and release information from the npm registry.

## 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-latest-version-lookup-acdd32cf/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)