Cron Translator Explain API
The Explain API from Cron Translator — 1 operation(s) for explain.
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This API
curl "https://apis.io/api/v1/apis/crontoenglish-com:crontoenglish-com-explain-api"
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OpenAPI Specification
openapi: 3.2.0
info:
title: Cron Translator Explain API
version: 1.0.0
summary: Translate cron expressions to plain English — and back.
description: 'Explain any cron expression in plain English, see the next run times in any timezone, and catch the gotchas that make schedules misfire: day-of-month/day-of-week OR semantics, steps that do not divide evenly, impossible dates, and daylight-saving shifts.
**Not for:** Does not run, install, or manage scheduled jobs. Does not support Quartz extensions (L, W, #, ?) beyond detecting and reporting them.
Free tier: 250 calls per UTC day per caller. Past that, endpoints return 402 with x402 payment requirements. An MCP server exposing the same capabilities is available at https://crontoenglish.com/api/mcp.'
contact:
url: https://github.com/bwalvoord/gumball
servers:
- url: https://crontoenglish.com
description: Production
tags:
- name: Explain
paths:
/api/v1/explain:
get:
operationId: explainCron
summary: Explain a cron expression in plain English
description: Returns an English description, a per-field breakdown, warnings about common cron traps (day-of-month/day-of-week OR semantics, uneven steps, impossible dates, DST), and the next run times.
parameters:
- name: expression
in: query
required: true
description: 'Standard five-field cron expression: "minute hour day-of-month month day-of-week". Accepts *, numbers, ranges, lists, steps, three-letter month/day names, and the @daily/@hourly/@weekly/@monthly/@yearly macros.'
schema:
type: string
examples:
- 0 9 * * 1-5
- '*/15 9-17 * * 1-5'
- '@daily'
- name: timezone
in: query
required: false
description: IANA timezone name. Cron expressions carry no timezone, so this decides when the schedule fires.
schema:
type: string
default: UTC
examples:
- UTC
- America/New_York
- name: count
in: query
required: false
description: How many upcoming run times to return.
schema:
type: integer
minimum: 1
maximum: 25
default: 5
responses:
'200':
description: The expression, explained.
content:
application/json:
schema:
type: object
required:
- input
- expression
- description
- fields
- warnings
- timezone
- nextRuns
properties:
input:
type: string
expression:
type: string
description: Normalised five-field expression.
description:
type: string
description: One-sentence plain English description.
fields:
type: array
items:
type: object
properties:
name:
type: string
enum:
- minute
- hour
- dayOfMonth
- month
- dayOfWeek
label:
type: string
raw:
type: string
description:
type: string
values:
type: array
items:
type: integer
warnings:
type: array
items:
type: object
required:
- code
- severity
- title
- detail
properties:
code:
type: string
severity:
type: string
enum:
- info
- caution
- error
title:
type: string
detail:
type: string
fixHint:
type: string
timezone:
type: string
nextRuns:
type: array
items:
type: object
required:
- iso
- local
properties:
iso:
type: string
format: date-time
description: UTC instant, ISO 8601.
local:
type: string
description: Wall-clock rendering in the requested timezone.
runsPerDayEstimate:
type: integer
macro:
type:
- string
- 'null'
'400':
description: Invalid input. The body names the field and how to fix it.
content:
application/json:
schema:
type: object
required:
- error
properties:
error:
type: object
required:
- code
- message
- fix_hint
- docs
properties:
code:
type: string
description: Stable machine-readable error code.
message:
type: string
fix_hint:
type: string
description: What to change before retrying.
field:
type: string
token:
type: string
examples:
type: array
items:
type: string
docs:
type: string
format: uri
'402':
description: 'Free quota of 250 calls per UTC day exhausted. Body is an x402 v1 payment requirement ($0.001 per call, USDC on Base). While settlement is disabled the body carries payment_enabled: false and the call cannot be unblocked by paying — wait for quota.resetsAt.'
content:
application/json:
schema:
type: object
properties:
x402Version:
type: integer
error:
type: string
payment_enabled:
type: boolean
accepts:
type: array
items:
type: object
quota:
type: object
fix_hint:
type: string
docs:
type: string
tags:
- Explain
externalDocs:
url: https://crontoenglish.com/llms-full.txt
description: Full documentation for agents