Odel
cron explainer

cron explainer

@idoazacallsCommunicationTypeScriptMITUpdated 2mo ago

Cron expression parser: explains any cron + returns next N fire times. Timezone-aware.

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Server endpointStreamable HTTP
https://cron-explainer.cron-explainer-prod.workers.dev/mcp

This is the third-party server itself — Odel doesn't run it. Hitting this URL directly talks straight to the upstream server with no auth or proxying. Connect through Odel to front it with managed auth.

cron-explainer

A tiny pay-per-call API that parses cron expressions, returns the next N fire times, and produces a short English description. Timezone-aware (IANA).

Live: https://cron-explainer.cron-explainer-prod.workers.dev/ Pricing: 0.01 EUR per successful call, prepaid via Stripe Checkout in packs of 500 / 5,000 / 50,000 calls. Non-2xx responses are refunded. No subscription. Keys never expire.

Quick start

  1. Get a key at https://cron-explainer.cron-explainer-prod.workers.dev/ (Stripe Checkout, €5 minimum).
  2. Copy the key — it's shown exactly once.
  3. Call the API:
curl -X POST https://cron-explainer.cron-explainer-prod.workers.dev/v1/explain \
  -H "content-type: application/json" \
  -H "x-api-key: $YOUR_KEY" \
  -d '{"cron":"0 9 * * 1-5","tz":"Europe/Lisbon","n":3}'

Response:

{
  "input": {"cron":"0 9 * * 1-5","tz":"Europe/Lisbon","n":3},
  "valid": true,
  "description": "At 09:00, Monday through Friday",
  "next": ["2026-04-24T08:00:00.000Z","2026-04-27T08:00:00.000Z","2026-04-28T08:00:00.000Z"],
  "flags": {"dst_transition_ahead": false, "ambiguous": false, "notes": []},
  "errors": []
}

Check remaining balance:

curl -H "x-api-key: $YOUR_KEY" \
  https://cron-explainer.cron-explainer-prod.workers.dev/v1/balance

MCP

The server is listed on the official MCP registry as io.github.IdoAzaCalls/cron-explainer with a Streamable HTTP endpoint at POST /mcp. It exposes one tool, explain_cron. Pass your x-api-key as an HTTP header on the MCP transport; billing is identical to the REST path.

Registry entry: https://registry.modelcontextprotocol.io/v0/servers?search=cron-explainer

Endpoints

MethodPathPurpose
POST/v1/explainParse + describe + next fire times (billed)
GET/v1/balanceRemaining balance for an x-api-key
POST/v1/checkoutCreate a Stripe Checkout Session
GET/v1/schemaJSON Schema for request/response
POST/mcpMCP Streamable HTTP (JSON-RPC 2.0)
GET/.well-known/mcp.jsonStatic tool manifest
GET/healthLiveness probe
GET/legal/{tos,privacy,disclaimer,notices}Legal docs

Limits

  • Cron: 5-field POSIX/Vixie syntax (minute, hour, day-of-month, month, day-of-week).
  • Timezones: IANA names (e.g. Europe/Lisbon, America/Los_Angeles). Defaults to UTC.
  • n clamps to [1, 100].
  • Best-effort accuracy. See /legal/disclaimer for warranty terms.
  • Zero PII: inputs are cron strings and IANA timezones only. Request and response bodies are never logged.

Stack

TypeScript on Cloudflare Workers. Cron parsing via croner (MIT). English descriptions via cronstrue (MIT). Full NOTICE text at /legal/notices.

Contact

azariaido@gmail.com — billing issues, bug reports, custom pricing.