Create an HTTP cron job with ChatGPT and Crontap

This guide connects ChatGPT to Crontap, proves that a harmless write works in your target account, then creates a weekday HTTP schedule for https://example.com/daily-digest. The plan check matters because OpenAI's official pages currently disagree about who gets full MCP writes. Once created, Crontap calls the endpoint independently. It does not wake ChatGPT or turn this conversation into a recurring task.

Before you start

• Use ChatGPT on the web. OpenAI's current custom MCP documentation describes the developer-mode app flow as web-only.
• You need a Crontap account and a public HTTPS endpoint that is safe to call more than once.
• Treat plan access as an account-level test, not a universal promise. Workspace role, interface, model, and admin policy can affect availability.
• Verified against the Developer mode API guide, Help Center MCP article, and Scheduled Tasks article on 2026-09-15.

The current official ChatGPT MCP conflict

Two current OpenAI pages give different plan statements. The Developer mode API guide lists Plus, Pro, Business, Enterprise, and Education for full MCP read and write tools on the web. The Help Center says Pro can connect MCPs with read/fetch permissions, while full MCP is limited to Business and Enterprise/Edu. The pages also show different individual and managed-workspace setup paths.

One real ChatGPT account connected the production Crontap MCP server and completed a write tool on 2026-09-15. That confirms the tested account and flow, not every plan or workspace policy. Step 3 below tests the reader's own account before the real schedule is created.

Connect ChatGPT to Crontap MCP

1. Open Settings, then Security and login, and enable Developer mode.
2. Open ChatGPT Plugins, then choose the plus button to create an app.
3. Enter https://mcp.crontap.com/mcp as the MCP Server URL.

The Developer mode API guide's individual path is Settings > Security and login > Developer mode, followed by ChatGPT Plugins > + to create a developer-mode app. The Help Center's managed-workspace path is Workspace settings > Apps > Create, after an admin enables the relevant permission. Use the path your account actually presents.

Ask ChatGPT with copyable prompts

Select the Crontap draft app for each message that needs fresh tool data.

Use only the Crontap app. First list my schedules. Then create a temporary schedule named "mcp write test 2026-09-15" against my harmless test endpoint. Show the full non-secret input and ask for confirmation before the write. Retrieve the created schedule by ID. Do not create the real daily-digest schedule yet.

Use Crontap to preview "weekdays at 9am" in America/Los_Angeles. Do not write anything. Show the resolved cron and three upcoming runs.

Create a POST schedule named "weekday daily digest" for https://example.com/daily-digest using the cadence we previewed. Ask for confirmation, then retrieve the created schedule and report its ID, status, timezone, and next run.

Verify the ChatGPT cron job worked

Expand the tool call and inspect its JSON input and output, which the Developer mode guide explicitly recommends. The result should contain a schedule ID. Ask ChatGPT to list schedules and retrieve that ID without changing it.

Open Crontap separately and compare the endpoint, method, timezone, cadence, and active state. After the first fire, read schedule history. A recorded 2xx confirms that Crontap got an HTTP success response. Check application logs to confirm the route performed the intended work.

If your write test fails but reads succeed, your account may match the Help Center's read/fetch-only description, or workspace action controls may disable the write. Check the app's enabled actions and ask an admin to confirm policy. Rewording cannot unlock a write the plan or policy disallows.

ChatGPT Scheduled Tasks or Crontap?

Use ChatGPT Scheduled Tasks when you want ChatGPT to perform supported recurring work or send a notification. Availability, cadence, model support, and active-task limits depend on the account and workspace. The official article says Free tasks can run no more than daily, while eligible paid plans can use hourly schedules and exact delivery times.

Use Crontap when you want a durable HTTP request to your API, webhook, or cloud function. Crontap retains request history and can manage uptime monitors and heartbeats through the same MCP connection.

A ChatGPT task is not a generic replacement for an HTTP scheduler. Likewise, creating a Crontap schedule does not cause ChatGPT to return to this chat later.

Troubleshooting

Developer mode or Create is missing

Check both the account type and workspace role. Follow the Help Center admin path in managed workspaces, then use the harmless write in Step 3 to test the target account.

Tool scan finds reads but no writes

Refresh the app's tools and inspect workspace action controls. Pro accounts may exhibit the Help Center's read/fetch limitation even though the Developer mode API guide uses broader eligibility language.

ChatGPT answers without calling Crontap

Select the app for that message, name it explicitly, and say not to use browsing or another scheduling tool. App selection applies to the message that invokes it.

OAuth expires or reconnects repeatedly

Remove and recreate the draft after checking OAuth metadata. OpenAI notes that refresh-token support and offline_access metadata affect long-lived connectivity.

The schedule runs but the endpoint rejects it

A 401 or 403 in Crontap history is an endpoint-authentication failure. Check request headers outside the chat and avoid exposing the secret in tool instructions.

Next steps

• Return to the Crontap MCP hub for the complete tool and security model.
• Compare established desktop flows in Cursor and VS Code Copilot Chat.
• Read Scheduled tasks for AI-built apps before publishing a retry-safe endpoint.

Ready to test your ChatGPT account? Free forever tier. No credit card. Create your Crontap account →

Verified with current OpenAI documentation plus a live write test on 2026-09-15. Sources: Developer mode API guide, Help Center MCP guidance, and ChatGPT Scheduled Tasks.