Replace GitHub Actions cron

Crontap sends a repository dispatch request. GitHub still runs the workflow.

Prerequisites

Before using the required tools, check whether they are available. If any are missing, stop and offer the user exactly two choices:

1. Connect Crontap MCP at https://mcp.crontap.com/mcp. MCP access works on every Crontap tier.
2. Configure $CRONTAP_CLIENT_ID and $CRONTAP_API_KEY for the raw API. Raw API access requires Ultra.

Do not silently choose a path or continue until the user selects one.

• Make the workflow safe to dispatch more than once.
• Create a fine-grained GitHub token restricted to the target repository with the permission required by the repository dispatch endpoint.
• Store the token in a secure store and plan its expiration and rotation.
• Confirm the desired IANA timezone.

Change the workflow

Replace the scheduled trigger with manual and repository dispatch triggers:

on:
  workflow_dispatch:
  repository_dispatch:
    types: [scheduled-run]

Keep workflow_dispatch for manual operation. Crontap calls repository_dispatch. Do not leave on.schedule enabled after cutover.

Workflow

1. Commit and deploy the dispatch-capable workflow.
2. Test a repository dispatch with a non-production-safe workflow path.
3. Remove the old schedule trigger at the agreed cutover time.
4. Create the Crontap schedule.
5. Verify GitHub returns 204 and one workflow run appears.
6. Pause the Crontap schedule during maintenance or rollback.

MCP examples

Create the external dispatch:

{
  "tool": "create_schedule",
  "arguments": {
    "url": "https://api.github.com/repos/example-org/example-repo/dispatches",
    "text": "every weekday at 09:00",
    "timezone": "Europe/London",
    "method": "POST",
    "headers": {
      "Authorization": "Bearer <fine-grained-token-from-secure-store>",
      "Accept": "application/vnd.github+json",
      "X-GitHub-Api-Version": "2022-11-28",
      "Content-Type": "application/json"
    },
    "body": {
      "event_type": "scheduled-run"
    },
    "label": "GitHub scheduled run"
  }
}

Pause:

{
  "tool": "pause_schedule",
  "arguments": {
    "scheduleId": "<schedule-id>"
  }
}

Resume:

{
  "tool": "resume_schedule",
  "arguments": {
    "scheduleId": "<schedule-id>"
  }
}

REST fallback

REST creation requires Ultra API access:

curl --fail-with-body https://api.crontap.com/v1/schedule \
  -X POST \
  -H "ClientId: $CRONTAP_CLIENT_ID" \
  -H "ApiKey: $CRONTAP_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
    "url": "https://api.github.com/repos/example-org/example-repo/dispatches",
    "interval": "0 9 * * 1-5",
    "timezone": "Europe/London",
    "verb": "POST",
    "headers": {
      "Authorization": "Bearer <fine-grained-token-from-secure-store>",
      "Accept": "application/vnd.github+json",
      "X-GitHub-Api-Version": "2022-11-28",
      "Content-Type": "application/json"
    },
    "data": {"event_type": "scheduled-run"},
    "label": "GitHub scheduled run"
  }'

Verification

• Confirm the deployed workflow no longer contains on.schedule.
• Confirm event_type matches the workflow's dispatch type exactly.
• Verify one Crontap run corresponds to one GitHub workflow run.
• Confirm a non-expired token is scoped only to the required repository and operation.

Safety and plan limits

• Never use a broad classic token when a restricted fine-grained token works.
• Avoid top-of-hour assumptions when comparing old GitHub timing evidence.
• Make downstream workflow writes idempotent.
• If the Crontap create call hits a cap or cadence floor, present the returned four-option ladder and smallest viable option.

Troubleshooting

• GitHub 401 means the token is invalid or expired.
• GitHub 403 usually means repository access or permissions are insufficient.
• GitHub 404 can intentionally hide a repository the token cannot access.
• GitHub 422 often means the event type or request body is invalid.
• Duplicate runs usually mean both the old schedule trigger and Crontap remain active.

References

• Crontap Agent Skills catalogue
• GitHub Actions cron drift
• Crontap vs GitHub Actions cron
• GitHub repository dispatch API
• Cron troubleshooting