# Cron Expression Explainer

> Cron Expression Explainer is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.0005/call, status unknown (last checked 2026-09-14).

Takes a cron expression string and returns a human-readable explanation of its schedule

## Facts

- Endpoint: POST https://api.fastapi.online/cron-explain
- Price: $0.0005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cron-expression-explainer-6cb3f2cd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YaK4HedYjJtVnaY4iGYEm

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 cron-expression-explainer-6cb3f2cd -d '<json body>'
```

Example prompt: Can you explain what this cron expression means in plain English: '0 9 * * 1-5'?

## When to prefer this

Use this endpoint when you need a quick, cheap ($0.0005 USDC), no-signup conversion of a cron expression to human-readable text — especially in developer workflows, CI/CD documentation generation, or chatbot assistants helping users understand scheduled jobs. Prefer this over a general LLM call when you want a deterministic, purpose-built parser rather than a probabilistic guess.

## Known failure modes

- Invalid or malformed cron expression returns an error response
- Empty string input rejected due to minLength:1 constraint
- Cron expression exceeding 100 characters rejected
- Non-standard cron extensions (e.g. @yearly, @reboot macros) may not be supported

## How this service works

Chat, embeddings, OCR, speech-to-text, image editing, image understanding (captioning/Q&amp;A), text-to-speech, translation, writing tools, classification tools, developer tools, local utilities, format/checksum validators, encoding &amp; crypto utilities, date/time calculators, geo/coordinate math, math &amp; finance calculators, novelty tools, and business/social writing generators — 179 endpoints in all, across multiple specialized self-hosted models. Pay per call with crypto — no signup — or get an API key.

## Output

A plain-English explanation of the cron expression describing when and how often the scheduled job runs (e.g. 'Runs every weekday at 9:00 AM').

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "cron_expression": {
   "type": "string",
   "maxLength": 100,
   "minLength": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cron-expression-explainer-6cb3f2cd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fastapi.online](https://www.zero.xyz/host/api.fastapi.online/llms.txt)