# PennyRail Word Frequency Analyzer

> PennyRail Word Frequency Analyzer 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).

Counts and ranks word occurrences in a given text string, returning frequency data for each word

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/text.word-frequency--word-frequency
- 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-word-frequency-analyzer-52f7075a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_buGznGzcpadwe1jyPk5lS

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-word-frequency-analyzer-52f7075a -d '<json body>'
```

Example prompt: Can you count how often each word appears in this paragraph: 'The quick brown fox jumps over the lazy dog. The dog barked at the fox.'

## When to prefer this

Choose this endpoint when you need a quick, pay-per-call word frequency computation without standing up your own NLP infrastructure. It is ideal for lightweight text analytics tasks, NLP preprocessing pipelines, or ad-hoc content analysis where a simple word count is sufficient. Prefer it over heavier NLP APIs when you don't need sentiment, entity recognition, or embeddings — just raw word counts.

## Known failure modes

- Empty input string returns empty frequency map or error
- Very large text inputs may time out or hit payload limits
- Missing required 'input' field returns validation error
- Non-string input type may cause schema rejection
- Payment failure via x402 protocol returns 402 status before processing begins

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object mapping each unique word (typically lowercased) to its integer occurrence count within the input text, allowing the caller to identify high-frequency terms and word distribution patterns.

## 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-word-frequency-analyzer-52f7075a/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)