# PennyRail Numeric Statistics

> PennyRail Numeric Statistics 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).

Computes descriptive numeric statistics (e.g. mean, median, std dev, min, max) over an array of numbers, returning a statistics summary object.

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/number.stats--numeric-statistics
- 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-numeric-statistics-eb8fccf1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oT8xpmKXPJKTUasn36A9y

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-numeric-statistics-eb8fccf1 -d '<json body>'
```

Example prompt: Can you compute the numeric statistics — mean, median, standard deviation, min, and max — for this list of values: [12, 45, 7, 89, 34, 23, 56, 78, 3, 61]?

## When to prefer this

Choose this endpoint when you need quick, pay-per-call descriptive statistics over a numeric array without setting up a full data pipeline or library. Ideal for agents that occasionally need statistical summaries on arbitrary numeric datasets without a persistent compute environment.

## Known failure modes

- Empty array input returns error or undefined statistics
- Non-numeric values in the array cause computation errors or are silently ignored
- Very large arrays may hit size or timeout limits
- Malformed input (non-array) returns 400-level error
- Payment failure (x402) blocks the request before processing

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing descriptive numeric statistics computed over the input array, typically including fields such as count, sum, mean, median, mode, standard deviation, variance, min, max, and possibly percentiles or range.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-numeric-statistics-eb8fccf1/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)