What exactly is a vault?
A named space that owns four things: its notes, its table of contents, its conversations, and its settings for handling duplicates.
On disk it is a directory: <your folder>/<vault-slug>/, containing base.md with the generated table of contents and a notes/ directory with one Markdown file per note.
The important part is not the structure, though. It is that the vault is the unit the application reasons about. Every query the app makes for data is scoped to one owner and one vault — that is enforced in the repository layer rather than remembered case by case, which is a much stronger guarantee than a filter someone might forget.
What does "boundary" mean in practice?
When you ask a question inside a vault, the model receives that vault's table of contents and the most relevant notes from that vault. Notes from your other vaults are not included, ever. There is no ranking that might pull one in, no "related across vaults" feature waiting to surprise you.
This is the feature that makes the app usable for more than one part of your life at once. Your consulting work and your personal research can both contain the phrase "the migration" and mean nothing like each other, and neither will contaminate the other's answers.
It is also a privacy property you can reason about. If a piece of material is in a vault you do not open, it is not being sent anywhere.
How should I decide where the boundaries go?
The question to ask is not "what is this about" but "what should be in the room when I ask about this".
That framing tends to produce fewer, larger vaults than a topic-based one, and that is usually right. Context is what makes the answers good, and a vault too small to have context is doing nothing for you that a folder would not.
A useful test: if you would be annoyed to get an answer that ignored a particular note, that note belongs in the same vault as the question. If you would be annoyed to get an answer that used it, it belongs somewhere else.
Do vaults have their own settings?
Yes — the duplicate mode and the similarity threshold live on the vault, not on the account.
The mode is one of three. Ask shows you the candidate and lets you decide, and the decision can be deferred rather than blocking your work. Always merge folds new material into the matching note automatically. Always create keeps them separate.
The threshold applies in all three, because it is the definition of "matching" that the mode then acts on. A study vault and a daily log genuinely want different answers here, which is exactly why the setting is per vault.
Can I move a note between vaults?
Not as a single action inside the app today, and it is worth understanding why rather than treating it as an oversight.
A note is entangled with its vault: it sits at a numbered position in that vault's chapter tree, and it links to other notes in that vault by relative filename. Moving it means re-filing it and rewriting links on both sides.
The practical route is the export: download the vault, take the file you want, and let the other vault take it back in. Because everything is plain Markdown, this is a file operation rather than a migration.
How many vaults should I have?
Fewer than you first think. The common failure is one vault per project, which produces twenty containers holding four notes each, none of which can answer anything.
A shape that works: one vault per domain of thinking that lasts longer than a project. Work. A field you are studying. A long-running interest. Projects become chapters inside those, which is what the six-level table of contents is for.
You can always split later — exporting a vault and taking half of it out is a normal file operation, not a migration.
What happens to a vault when I stop paying?
It stays readable. An unpaid account can still open its vaults and export them; what stops is starting new conversations.
This is not a courtesy setting that could quietly change. The notes are .md files in a folder you chose — even with no application at all, they open in any text editor.
The licence itself is a signed token valid for seven days, which is also the offline grace period. A week without a network is a normal working situation, not a lockout.
Is a vault shared, or mine alone?
Yours alone. There is no multi-user vault, no sharing link and no collaborative editing.
There is also no synchronisation between your own devices yet. Your laptop and your phone each hold their own set of notes; the data model carries the revision and change-log columns a future sync would need, but the feature is not there today and we would rather say so than imply otherwise.
What you can share is the output: a ZIP of Markdown, a PDF or a PowerPoint deck. That covers the common case — sending someone what you concluded — without pretending the app is a team tool.
Seven days, no card, one dollar after that
Point SumizAI at a folder, connect the AI provider you already pay for, and start a conversation. The first note files itself.