# 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 2026-09-13).

Counts and returns the frequency of each word in a given text string

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/f/text.word-frequency
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-word-frequency-analyzer-49944511
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_y9zAE6JLWlbD7d80H7ryO

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-49944511 -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, cheap ($0.001 USDC) word frequency count from a raw text string without spinning up a local NLP pipeline. Ideal for lightweight text analytics tasks in agent workflows where you want a pay-per-call model rather than maintaining infrastructure.

## Known failure modes

- Missing 'input' field returns a validation error
- Empty string input may return an empty frequency map
- Very large text inputs may time out or exceed payload limits
- Non-string input types may cause a schema validation failure

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing the operation name and a result map where each key is a unique word from the input and its value is the number of times that word appears in the input string.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "operation",
  "result"
 ],
 "properties": {
  "result": {},
  "operation": {
   "type": "string"
  }
 },
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-word-frequency-analyzer-49944511/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)