AVAILABLE

Scheduling

Cron Schedule & Runtime Guard

Inspect strict five-field UNIX cron expressions, return bounded prior or future reference runs, summarize windows, compare schedules, and apply explicit runtime policy with IANA timezone evidence.

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CONTRACT

Predictable for agents. Legible for reviewers.

REST
POST /v1/cron-schedules/policy-check
MCP tool
check_cron_schedule_policy
Inputs
One strict numeric UNIX_5_FIELD expression, a separate IANA timezone, offset-aware reference or half-open window times, and optional caller run-budget, minimum-gap, local-hour, weekday, and offset-change policy.
Returns
CLEAR, REVIEW_REQUIRED, or BLOCKED with normalized fields, bounded local and UTC occurrences, exact gaps, UTC-offset changes, schedule differences, stable findings, and a non-executing next action.
Latency
Synchronous
Usage unit
Cron schedule operation

The suite also exposes /v1/cron-schedules/inspect, /next-runs, /previous-runs, /window-summary, and /compare plus /mcp/cron. Version one intentionally rejects names, aliases, embedded TZ/CRON_TZ, seconds, year, ?, L, W, #, H, and provider-specific extensions. It creates no job, invokes no target, accesses no scheduler, predicts no delivery guarantee, and stores no payload. Its RapidAPI release is queued behind the provider's twenty-public-API cap.

AGENT-READABLE EXCEPTIONS

CRON_DIALECT_MISMATCHCRON_UNSUPPORTED_SYNTAXCRON_FIELD_OUT_OF_RANGECRON_DAY_FIELDS_USE_ORCRON_TIMEZONE_UNKNOWNCRON_OCCURRENCE_HORIZON_EXCEEDEDCRON_OCCURRENCE_LIMIT_EXCEEDEDCRON_TIMEZONE_OFFSET_CHANGEDCRON_SCHEDULES_DIVERGECRON_RUN_BUDGET_EXCEEDEDCRON_MINIMUM_GAP_VIOLATEDCRON_LOCAL_HOUR_NOT_ALLOWEDCRON_LOCAL_WEEKDAY_NOT_ALLOWEDCRON_OFFSET_CHANGE_BLOCKED
HTTP request
POST /v1/cron-schedules/policy-check
Authorization: Bearer apc_...
Content-Type: application/json

{
  "schedule": {
    "expression": "0 9 * * 1-5",
    "timezone": "America/Denver",
    "dialect": "UNIX_5_FIELD"
  },
  "window_start": "2026-08-10T00:00:00Z",
  "window_end": "2026-08-20T00:00:00Z",
  "maximum_occurrences": 100,
  "minimum_gap_minutes": 60,
  "maximum_runs_in_window": 10,
  "allowed_local_hours": [
    9
  ],
  "allowed_local_weekdays": [
    0,
    1,
    2,
    3,
    4
  ],
  "block_timezone_offset_changes": true
}
cURL (bash)
curl --request POST \
  --url 'https://api-production-9502.up.railway.app/v1/cron-schedules/policy-check' \
  --header 'Authorization: Bearer ${AP_CONTROL_API_KEY}' \
  --header 'Content-Type: application/json' \
  --data '{
  "schedule": {
    "expression": "0 9 * * 1-5",
    "timezone": "America/Denver",
    "dialect": "UNIX_5_FIELD"
  },
  "window_start": "2026-08-10T00:00:00Z",
  "window_end": "2026-08-20T00:00:00Z",
  "maximum_occurrences": 100,
  "minimum_gap_minutes": 60,
  "maximum_runs_in_window": 10,
  "allowed_local_hours": [
    9
  ],
  "allowed_local_weekdays": [
    0,
    1,
    2,
    3,
    4
  ],
  "block_timezone_offset_changes": true
}'
Representative response
{
  "status": "COMPLETED",
  "decision": "CLEAR",
  "normalized_expression": "0 9 * * 1-5",
  "timezone": "America/Denver",
  "window_start": "2026-08-09T18:00:00-06:00",
  "window_end": "2026-08-19T18:00:00-06:00",
  "occurrence_count": 8,
  "first_occurrence": {
    "local_time": "2026-08-10T09:00:00-06:00",
    "utc_time": "2026-08-10T15:00:00Z",
    "utc_offset": "-06:00",
    "fold": 0
  },
  "last_occurrence": {
    "local_time": "2026-08-19T09:00:00-06:00",
    "utc_time": "2026-08-19T15:00:00Z",
    "utc_offset": "-06:00",
    "fold": 0
  },
  "minimum_gap_seconds": 86400,
  "maximum_gap_seconds": 259200,
  "offset_change_count": 0,
  "truncated": false,
  "findings": [],
  "allowed_by_policy": true,
  "evaluated_policy": {
    "minimum_gap_minutes": 60,
    "maximum_runs_in_window": 10,
    "allowed_local_hours": [
      9
    ],
    "allowed_local_weekdays": [
      0,
      1,
      2,
      3,
      4
    ],
    "block_timezone_offset_changes": true
  },
  "ruleset_version": "UNIX_5_FIELD_REFERENCE_2026",
  "scope": "CALLER_SUPPLIED_CRON_FACTS_ONLY",
  "scheduler_accessed": false,
  "job_created": false,
  "target_invoked": false,
  "delivery_guaranteed": false,
  "payload_stored": false,
  "next_action": "Verify the target platform preview, permissions, concurrency, misfire, retry, and idempotency settings before deployment."
}
One explicit UNIX dialectVersion one accepts exactly five numeric fields with bounded wildcard, list, range, and step syntax; incompatible aliases and provider extensions are rejected.
Local and UTC evidenceOccurrences include IANA-zone wall time, UTC time, offset, fold, gap statistics, and offset-change findings inside caller-bounded horizons.
No scheduler or job actionThe service creates no job, invokes no target, accesses no scheduler, predicts no delivery guarantee, and stores no payload.

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