# Privacy and costs

> What is sent where, what costs money and where your files are kept.

## What leaves your machine

| Where | When | What is sent |
|---|---|---|
| Your Calibre Content Server | Always; by default it is on your own computer | Requests for your library, book files and covers; accepted changes |
| Open Library | Looking for covers or a book's details, unless you turn online lookups off | The book's ISBN, title and author |
| Google Books | The same, only if you add an API key | The book's ISBN, title and author |
| The providers you set up in Model Hub | Anything that uses a model | For summaries, the book's text. For lookups, its first pages. For shelves, its title, authors and a sample of its text |

Model calls go through Model Hub. With a local provider there, a book's text never leaves your computer.

There is no telemetry and there are no ads.

## What costs money

Books & Shelves is free. Syncing notes and finding covers cost nothing. The providers you set up in Model Hub may bill you for the rest:

- **Summaries** are the large cost: a whole book's text is read. Each run shows an estimate first.
- **Book vectors** are small per book and are made once.
- **Lookups** read a few pages per book.

A call billed well above its listed price stops a run. Model Hub's limits and budgets apply, and its usage view shows what Books & Shelves has spent.

## Where things are kept

| What | Where |
|---|---|
| Book notes | `Books/Library` by default |
| Shelf notes | `Books/Collections` by default |
| Review notes | `Books/Review` by default |
| Cover images | `Books/Covers` by default |
| The reading queue | `Books/Up Next.md` by default |
| Logs, the write queue and book vectors | The plugin's folder, inside your vault's configuration folder |
| A Calibre login and a Google Books key | Obsidian's keychain |

## Your Calibre library

It changes only through the write queue, after you accept a change, and when you agree to an EPUB conversion that another plugin asked for.

## Other plugins

Another plugin in your vault can read your book list, shelves and book files through this plugin's API, as any plugin can read your vault.