# fastapi.online — Cron Expression Parser

> fastapi.online — Cron Expression Parser 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).

Parses a cron expression and returns the next N scheduled execution times

## Facts

- Endpoint: POST https://api.fastapi.online/cron-parse
- 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/fastapi-online-cron-expression-parser-e309c4c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rXFGVjh4zywaqy9GEqLA2

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 fastapi-online-cron-expression-parser-e309c4c8 -d '<json body>'
```

Example prompt: Can you parse the cron expression '0 9 * * 1-5' and show me the next 5 times it will run?

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call cron expression parser with no signup required, especially useful in serverless agent pipelines that need to validate or preview scheduled job timing on demand. Prefer it over implementing cron parsing locally when you want a hosted utility callable via HTTP with crypto micropayments.

## Known failure modes

- Invalid cron expression syntax returns an error response
- count outside 1–20 range is rejected with a validation error
- Malformed JSON body returns 422 Unprocessable Entity
- Expression too long (>100 characters) is rejected

## 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

Returns a list of up to 20 upcoming datetime timestamps representing the next scheduled execution times computed from the provided cron expression, allowing the caller to verify correctness and cadence of the schedule.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "count": {
   "type": "integer",
   "maximum": 20,
   "minimum": 1
  },
  "expression": {
   "type": "string",
   "maxLength": 100,
   "minLength": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-cron-expression-parser-e309c4c8/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)