# Cron Expression Explainer

> Cron Expression Explainer is a paid API for AI agents from api.strale.io, paid per call via x402, $0.0216/call, status unknown (last checked 2026-09-14).

Parses a cron expression into a human-readable explanation and returns the next N scheduled execution times

## Facts

- Endpoint: GET https://api.strale.io/x402/cron-explain
- Price: $0.0216/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-strale-io-c94b9f16
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SB0KOMtmLXHVfg6MAMdSv

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-strale-io-c94b9f16
```

Example prompt: Can you explain what the cron expression '0 9 * * 1-5' means in plain English and show me the next 10 times it will run in the America/New_York timezone?

## When to prefer this

Use this endpoint when you need to interpret or validate a cron expression for a human user, preview upcoming job execution times, or debug a scheduled task. Ideal for DevOps dashboards, CI/CD pipelines, or any workflow that needs to translate cron syntax into understandable schedules without spinning up a scheduler.

## Known failure modes

- Invalid cron expression format returns a parse error
- Unsupported number of fields (fewer than 5 or more than 7) may cause failure
- Unknown or malformed timezone string returns an error
- Missing required cron_expression parameter returns a 400-level error
- num_next set to an excessively large value may be rejected or truncated

## How this service works

Parse a cron expression into human-readable explanation + next N execution times. Algorithmic — instant.

## Output

Returns a human-readable description of what the cron expression does (e.g. 'At 9:00 AM, Monday through Friday') along with a list of the next N scheduled execution timestamps, computed for the specified timezone.

## Example request

```json
{
 "num_next": 10,
 "timezone": "America/New_York",
 "cron_expression": "0 9 * * 1-5"
}
```

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "cron_expression"
     ],
     "properties": {
      "num_next": {
       "type": "integer",
       "description": "Number of next runs (default 5)"
      },
      "timezone": {
       "type": "string"
      },
      "cron_expression": {
       "type": "string",
       "description": "Cron expression (5-7 fields)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-strale-io-c94b9f16/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.strale.io](https://www.zero.xyz/host/api.strale.io/llms.txt)