# Cron Expression Validator

> Cron Expression Validator is a paid API for AI agents from cron.agentutil.net, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Validates and normalizes a cron expression, returning whether it is syntactically correct

## Facts

- Endpoint: POST https://cron.agentutil.net/v1/validate
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cron-agentutil-net-c32e8ec4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ta1G40MiM7EY4HwjQcjQZ

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-agentutil-net-c32e8ec4 -d '<json body>'
```

Example prompt: Can you check if this cron expression is valid: '0 9 * * 1-5'?

## When to prefer this

Use this endpoint when you need to programmatically verify that a cron expression is syntactically correct before deploying a scheduled job, storing it, or passing it to a scheduler. Ideal for CI/CD pipelines, configuration validators, or any agent workflow that accepts user-supplied cron strings and needs to confirm correctness before acting on them.

## Known failure modes

- Missing or empty expression field returns validation error
- Malformed JSON body returns 400 error
- Expression with unsupported fields or syntax returns invalid result
- Payment not provided or invalid x402 payment header returns 402 error

## How this service works

Validate and normalize a cron expression

## Output

Returns whether the cron expression is valid or not, along with normalization details or error information explaining why the expression is invalid.

## Example request

```json
{
 "expression": "0 9 * * 1-5"
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "expression": {
   "type": "string",
   "description": "Cron expression to validate"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "valid",
  "fields",
  "service",
  "normalized",
  "request_id",
  "related_services"
 ],
 "properties": {
  "valid": {
   "type": "boolean"
  },
  "fields": {
   "type": "object",
   "required": [
    "hour",
    "month",
    "minute",
    "day_of_week",
    "day_of_month"
   ],
   "properties": {
    "hour": {
     "type": "string"
    },
    "month": {
     "type": "string"
    },
    "minute": {
     "type": "string"
    },
    "day_of_week": {
     "type": "string"
    },
    "day_of_month": {
     "type": "string"
    }
   }
  },
  "service": {
   "type": "string"
  },
  "normalized": {
   "type": "string"
  },
  "request_id": {
   "type": "string"
  },
  "related_services": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "url",
     "name",
     "description"
    ],
    "properties": {
     "url": {
      "type": "string"
     },
     "name": {
      "type": "string"
     },
     "description": {
      "type": "string"
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cron-agentutil-net-c32e8ec4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from cron.agentutil.net](https://www.zero.xyz/host/cron.agentutil.net/llms.txt)