It is in your own database, in your own account, and it is yours to take away. Here is what that means in practice, and what you control.
Your Second Brain is an Airtable base in your own Airtable account. Not a copy synced to us — the actual system of record. You created it, you can open it without this site existing, and you can export or delete the whole thing whenever you like.
That is a deliberate design decision and it is the one that matters most. A product that holds your life in its database can change its mind about your access to it. This one cannot, because it never had it.
Disconnecting is one click in Settings. Your base stays exactly as it is; this site simply stops being able to reach it.
Your data is never shown to another user, never pooled with anyone else's, never sold, and never used to train any model. There is no aggregate view, no analytics built on your content, and no "anonymised" export — because anonymised personal calendars and messages are not anonymous.
If other people use this, their brains and yours never meet.
A source is read only because you added it. Nothing is discovered, guessed at or helpfully included. Your sources are listed in the brain, and you can pause any of them at any time — it stops being read on the next run.
On your Mac specifically: reading Messages needs macOS Full Disk Access, which is off unless you turn it on. It is optional. If you would rather your iMessages were not part of this, do not grant it — mail, calendar, files, notes and tasks are entirely unaffected. Declining one permission is not declining the product.
Tokens for Airtable, Todoist and anything else you connect are encrypted before they touch disk and are never written into your base, never sent to a browser, and never included in a brief or an export. Revoking one in Settings deletes it here.
What is written here is how the system actually behaves today, not a statement of intent. If any of it changes, this page changes with it in the same release — and anything that would let more people see more of your data will be said plainly rather than absorbed into a longer document.
If there is something you want to know that this page does not answer, ask. The answer you get will be the true one.
Anything here that is unclear or that you want changed — say so from the note panel on any page. It reaches a person.