# x402node Readability Scorer

> x402node Readability Scorer is a paid API for AI agents from api.x402node.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Computes multiple English text readability scores (Flesch, Flesch-Kincaid, ARI, Coleman-Liau, Gunning Fog, SMOG) plus complexity stats and reading-level interpretation

## Facts

- Endpoint: GET https://api.x402node.dev/nlp/readability
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-x402node-dev-23bba386
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_w5lcdMCwMayO_MI7e2_-Q

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 api-x402node-dev-23bba386
```

Example prompt: Can you check the readability of this paragraph and tell me what grade level it targets and how easy it is to read: 'The mitochondrial respiratory chain comprises four multi-subunit enzyme complexes embedded in the inner mitochondrial membrane, collectively responsible for oxidative phosphorylation and ATP synthesis.'?

## When to prefer this

Use this endpoint when you need multiple standardized readability scores in a single call rather than computing them individually. Ideal for AI agents auditing content clarity, checking grade-level appropriateness, or comparing readability across multiple texts. Prefer over manual computation or single-metric tools when you need a full suite of indices plus a human-readable interpretation.

## Known failure modes

- Empty or missing text input returns error
- Non-English text may produce inaccurate scores since indices are calibrated for English
- Extremely short text (1-2 words) may yield unreliable scores
- Network timeout or upstream service unavailability
- Payment failure due to insufficient USDC balance

## How this service works

Compute readability scores for English text (Flesch Reading Ease, Flesch-Kincaid Grade, ARI, Coleman-Liau, Gunning Fog, SMOG). Returns all indices plus complexity stats and reading-level interpretation. Use ?text=Your+text+here. Built for AI agents auditing content clarity and grade-level fit. Accepts payment on Base or Solana — either network works.

## Output

Returns all six readability indices (Flesch Reading Ease, Flesch-Kincaid Grade, ARI, Coleman-Liau, Gunning Fog, SMOG), along with complexity statistics (sentence count, word count, syllable count, avg sentence length, avg syllables per word) and a plain-English reading-level interpretation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "text"
     ],
     "properties": {
      "text": {
       "type": "string",
       "description": "Input text (required)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-x402node-dev-23bba386/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402node.dev](https://www.zero.xyz/host/api.x402node.dev/llms.txt)