# Vextorium Cron Expression Validator & Explainer

> Vextorium Cron Expression Validator & Explainer is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-16).

Validates a cron expression, explains it in plain English, and lists upcoming run times with DST-aware timezone support

## Facts

- Endpoint: POST https://api.vextorium.com/cron-explicar-pago?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-cron-expression-validator-explainer-a4a94747
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UUlNMCvHieRX-sB34DXdJ

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 vextorium-cron-expression-validator-explainer-a4a94747 -d '<json body>'
```

Example prompt: Is the cron expression '*/15 9-17 * * mon-fri' valid, explain what it means in plain English, and show me the next 10 run times in the Europe/Madrid timezone.

## When to prefer this

Choose this endpoint when you need to validate cron syntax (including @-aliases like @daily), understand what a cron expression actually does in plain English, or preview upcoming run times with correct DST handling in a specific IANA timezone. Prefer this over generic cron parsers when timezone-awareness and human-readable explanations are both required in a single call.

## Known failure modes

- Invalid cron syntax — returns valida: false with no run times
- Unknown IANA timezone string — likely rejected or defaults to UTC
- proximas out of range (must be 1–50) — schema validation error
- Invalid ISO datetime in 'desde' field — parsing error
- Missing required 'expresion' field — 400 bad request

## How this service works

Validate a 5-field cron expression (ranges, steps, names, @daily aliases), explain it in plain English and list its next run times in any time zone, DST-aware.

## Output

Returns a JSON object with: a boolean validity flag, the normalized cron expression, a plain-English explanation of each field, an array of the requested next run timestamps in ISO 8601 format (with UTC offset), the resolved timezone, and the maximum number of executions per day.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "zona": {
   "type": "string",
   "description": "IANA time zone (default UTC)"
  },
  "desde": {
   "type": "string",
   "description": "Start from this ISO date-time (default now)"
  },
  "proximas": {
   "type": "integer",
   "maximum": 50,
   "minimum": 1,
   "description": "Next runs to list (1-50, default 5)"
  },
  "expresion": {
   "type": "string",
   "description": "Cron expression, e.g. 0 8 * * 1-5 or @hourly"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "zona": "Europe/Madrid",
  "valida": true,
  "expresion": "*/15 9-17 * * mon-fri",
  "explicacion": "minute 0, 15, 30, 45, hour 9, 10, 11, 12, 13, 14, 15, 16, 17, any day of month, every month, weekday Monday, Tuesday, Wednesday, Thursday, Friday",
  "proximas_ejecuciones": [
   "2026-10-02T16:45+02:00",
   "2026-10-02T17:00+02:00",
   "2026-10-02T17:15+02:00",
   "2026-10-02T17:30+02:00",
   "2026-10-02T17:45+02:00"
  ],
  "ejecuciones_por_dia_max": 36
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-cron-expression-validator-explainer-a4a94747/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)