Privacy Policy

Last updated August 11, 2026

Messy Calendar is a Chrome extension that shows your Google Calendar in a side panel and helps you add buffers, hold time slots, and keep an eye on your routines. This page explains what it can see, where your information lives, and what it never does. The short version is that your calendar stays on your device and there is no server of ours sitting in the middle.

Who runs Messy Calendar

Messy Calendar is an independent project. If you have a question about privacy or anything else, you can reach the developer at the contact address at the bottom of this page.

What Messy Calendar can access

When you connect your account, Chrome asks Google for permission to view and edit the events on your primary calendar. Messy Calendar uses that access to show your day, to create the events you ask it to create such as buffers and holds, and to update or delete events when you tell it to. It reads and writes calendar events. It does not touch your email, your contacts, your files, or anything else in your Google account.

Sign in happens through Chrome's own identity flow. Messy Calendar never sees your Google password. Chrome holds the access token and Messy Calendar asks Chrome for it when it needs to talk to your calendar.

Where your information lives

Your calendar is read and worked on right inside your browser. Messy Calendar does not send it to any server that we run, because there is no server that we run. The only data it keeps is small and stored locally by Chrome:

• Your settings, such as how many weeks to show and your default buffer length. These use Chrome's synced storage, so they can follow you across the Chrome browsers where you are signed in.
• Small notes the extension keeps for itself, such as which buffer belongs to which meeting, which slots were held together, whether you marked a habit done, and which habits you chose to untrack. These stay in local storage on the device.
• An AI key, only if you add one. If you choose a cloud AI engine, your key is kept in local storage on this device and is never synced.

How the chat and AI work

The chat turns what you type into times and slots. It never reaches into your calendar by itself. Every change to your calendar is made by the extension after you confirm it, and it will never create or change more than five events in a single action.

You choose which engine powers the chat:

• On device (the default). Chrome's built in AI runs on your own machine. Nothing leaves the device.
• Your own key. If you prefer, you can use Claude, OpenAI, or Grok by adding your own API key. In that case your typed message is sent straight to that provider using your key. Your calendar is never part of that message. Availability is worked out on your device, so your events are not sent to the model. Requests go directly from your browser to the provider you picked.

When you use a provider with your own key, that provider handles your message under its own privacy terms. It is worth a look if you plan to use one.

What Messy Calendar does not do

• It does not run its own servers or send your calendar to one.
• It does not use analytics or track what you do.
• It does not show ads.
• It does not sell or share your information with anyone.
• It does not read anything in your Google account beyond your calendar events.

The permissions it asks for, in plain terms

• Calendar access lets it show your day and make the changes you ask for.
• Identity lets Chrome sign you in to Google without the extension ever seeing your password.
• Storage keeps your settings and the small notes described above.
• Side panel is what puts Messy Calendar next to your pages.
• Clipboard lets it copy a ready to paste reply when you ask for one.
• Network access to a few named sites. It talks to Google's calendar service, and, only if you turn on a cloud engine, to that AI provider. It does not talk to anywhere else.

Third parties

Google provides the calendar that Messy Calendar reads and writes. Your use of Google Calendar is covered by Google's own privacy policy. If you turn on a cloud AI engine and add a key, your messages to that provider are covered by that provider's privacy policy. Messy Calendar adds no other services.

Keeping and removing your data

The settings and notes stay until you clear them. You can disconnect from inside the extension, which signs you out and removes the cached access token. Removing the extension from Chrome clears the local data it kept on that device. Events that Messy Calendar created on your calendar, such as buffers and holds, remain on your calendar until you delete them, the same as any other event.

Children

Messy Calendar is a productivity tool meant for a general audience. It is not directed at children and does not knowingly collect information from them.

Changes to this policy

If this policy changes, the date at the top will change with it. When the change matters, the update will be made clear before it takes effect.

Contact

Questions about privacy are welcome. You can reach the developer at hello@messycalendar.app.