# Character 1-gram Frequency Counter

> Character 1-gram Frequency Counter is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).

Counts the frequency of every individual character (1-gram) in a given text string, returning exact character-level occurrence counts.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/ngram-char-1?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/character-1-gram-frequency-counter-305f3216
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xge5Eq2CAIloex0cTeJsn

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 character-1-gram-frequency-counter-305f3216 -d '<json body>'
```

Example prompt: Count the character-level 1-gram frequencies in this text: 'The quick brown fox jumps over the lazy dog' — I need to know how many times each individual character appears.

## When to prefer this

Use this endpoint when you need exact, deterministic character-level 1-gram frequency counts without relying on an LLM or external network call. Prefer the free sandbox endpoint (/v1/sandbox/ngram-char-1) for testing or cost-sensitive flows. Choose this paid endpoint when operating in production and the sandbox is unavailable or rate-limited.

## Known failure modes

- Empty string input (minLength:1 violated) — returns validation error
- Input text exceeding 100,000 characters (maxLength violated) — returns validation error
- Malformed JSON body — returns 400 bad request
- Payment not included or insufficient — returns HTTP 402 Payment Required (use sandbox endpoint for free testing)

## How this service works

Call when an agent needs counts of char 1-grams. No network and no LLM. Exact $0.005 USDC. Prefer unpaid POST /v1/sandbox/ngram-char-1 first.

## Output

Returns a map or object where each key is a single character found in the input text, and the value is the integer count of how many times that character appears. Covers all character types including letters, digits, punctuation, and whitespace.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "examples": [
    "ab ab"
   ],
   "maxLength": 100000,
   "minLength": 1,
   "description": "Input for this SKU. The route description says whether it is plain text, a URL, base64 bytes, or an already-encoded token."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/character-1-gram-frequency-counter-305f3216/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)