Ask Claude to remember it: putting a to-do into an iPhone alarm with MCP

Where does "don't let me forget" actually go?

Ask an AI assistant to remember something and, most of the time, it becomes a note inside the chat. Close the chat and it is gone. If you really must not forget, the request has to reach an alarm on your iPhone that rings until you stop it.

MustDo: To-Do Alarm exposes its to-dos to AI clients through MCP (Model Context Protocol). Everything is written to your own iCloud. Once a to-do lands there, the iPhone app wakes within seconds and schedules the alarm.

Route A: a custom connector in claude.ai (no Mac needed, works in the iPhone app too)

The simplest route. Our relay lets claude.ai and the Claude app on iPhone read and write your MustDo to-dos.

1. Open MustDo on your iPhone once. With iCloud signed in, the app creates its storage area in your iCloud on first launch.
2. In claude.ai, go to Settings > Connectors > Add custom connector. Name it "MustDo" and enter https://ltng.jp/api/mustdo/mcp as the URL.
3. Press Connect and sign in with your Apple ID. A consent page on ltng.jp explains what we keep (only your iCloud sign-in token; never the content of your to-dos). Sign in to iCloud with the Apple ID you use in MustDo.
4. Ask in the chat. "Add 'Call the dentist' to MustDo for tomorrow at 9:30." Once connected, the same connector works in the Claude app on iPhone.

To stop, open https://ltng.jp/api/mustdo/disconnect and verify it is you; the token we hold is deleted immediately. Details are on the MCP page.

Route B: a local MCP server on your Mac (Claude Code / Claude Desktop)

If you use Claude Code or Claude Desktop on a Mac, you can run a small MCP server locally instead. No server of ours is involved at all.

1. Create an API token for MustDo in CloudKit Dashboard
2. Put the token and "environment": "production" in ~/.mustdo/config.json
3. Register it: claude mcp add mustdo -- node /path/to/mustdo-app/mcp/dist/index.js
4. The first tool call asks you to run sign_in; sign in with your Apple ID in the browser

The full setup (Node.js version, environment variables, error codes) is on the MCP page.

What you can ask for (the tools)

A request without a time lands on "tomorrow at your default time" (9:00 AM unless you changed it), exactly like typing one line in the app. The iPhone mirrors your default time to iCloud so the AI and the app give the same answer.

Why MCP, and not a shortcut or an email to yourself

You could ask the assistant to draft an email to yourself, or wire up a Shortcut that creates a reminder. Both stop at the notification layer: an email is something you read when you get to it, and a Shortcut-created reminder is still a notification that stays quiet on Silent mode. MCP goes one level deeper. The assistant calls the same tools the app itself uses, the to-do lands in your iCloud with a real time attached, and the iPhone turns it into an alarm that rings until you stop it. There is no middle format to lose information in, and nothing for you to re-type.

MCP is also two-way. Because the assistant can list, complete and snooze to-dos, you can run your day from the chat: "what's left today", "I did the medicine", "push the laundry to 10". The phone stays in your pocket and still rings when it has to.

Requests that work well, and ones to phrase differently

• Works well: a task plus a time ("call the dentist tomorrow 9:30"), a task plus a repeat ("bins out every Tuesday at 7:30"), or just a task (it lands on tomorrow at your default time).
• Works well: questions about a day or a range ("what's on Friday", "anything this week?").
• Phrase differently: vague timing such as "sometime next week". The to-do needs a concrete time to become an alarm, so say "Wednesday at 10" or let it default to tomorrow and move it later.
• Phrase differently: several tasks in one breath. Each becomes its own to-do and its own alarm, so it is clearer to add them one by one, or to say "three to-dos: …" so the assistant separates them.

About privacy

When you use MCP, the content of your to-dos (title, notes, time) is passed to the AI client you chose, and what happens next is governed by that client's privacy policy. The relay in Route A stores your iCloud sign-in token encrypted in the AWS Tokyo region, but never stores the content of your to-dos and never writes it to logs. In Route B, none of our servers are involved. See section 7 of the privacy policy.

In short

Take "don't let me forget" out of the chat. Connect MustDo's MCP once, and what you ask for becomes an alarm that rings until you stop it. For the app side, read how to make a reminder that rings until it's done.