# Readability Reading & Speaking Time Estimator

> Readability Reading & Speaking Time Estimator is a paid API for AI agents from readability.openverbs.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Estimates how long it takes to read or speak a given text, based on configurable words-per-minute rates.

## Facts

- Endpoint: POST https://readability.openverbs.com/v1/reading-time
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/readability-reading-speaking-time-estimator-b9931811
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_T3Ngq-pPLAnkWdsKmAvKe

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 readability-reading-speaking-time-estimator-b9931811 -d '<json body>'
```

Example prompt: How long would it take to read and speak this article? Use a reading speed of 250 wpm and a speaking speed of 150 wpm: 'Artificial intelligence is transforming industries at an unprecedented pace...'

## When to prefer this

Choose this endpoint when you need a quick, configurable reading or speaking time estimate for any piece of text — especially useful in content publishing workflows, presentation timing, podcast production, or accessibility tooling. It supports custom wpm rates, making it more flexible than hardcoded client-side estimators. Prefer it over the sibling grade-level or syllable-count endpoints when the goal is time estimation rather than difficulty scoring.

## Known failure modes

- Empty or missing text field returns a validation error
- Non-positive wpm values are rejected (exclusiveMinimum:0)
- Very short texts may return sub-minute results that round to zero
- Payment failure (402) if USDC balance insufficient
- Malformed JSON body returns a 400 error

## How this service works

Estimate reading and speaking time for a text at configurable words-per-minute rates (defaults: 200 wpm reading, 130 wpm speaking).

## Output

Returns an object with the estimated reading time and speaking time (typically in minutes and seconds), the word count of the input text, and the wpm rates used for each calculation.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "text"
     ],
     "properties": {
      "text": {
       "type": "string",
       "description": "Text to estimate time for."
      },
      "readingWpm": {
       "type": "number",
       "description": "Reading rate in words per minute. Default 200.",
       "exclusiveMinimum": 0
      },
      "speakingWpm": {
       "type": "number",
       "description": "Speaking rate in words per minute. Default 130.",
       "exclusiveMinimum": 0
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/readability-reading-speaking-time-estimator-b9931811/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from readability.openverbs.com](https://www.zero.xyz/host/readability.openverbs.com/llms.txt)