> ## Documentation Index
> Fetch the complete documentation index at: https://docs.quarkle.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Keeping the Atlas current
> How the Story Atlas and Memory stay current without re-reading your whole book.
The [Story Atlas](/ai/story-atlas) keeps itself up to date as you write. New characters appear, summaries extend, profiles stay current. The trick is doing this **cheaply and quietly**, without re-reading your entire manuscript every time you change a comma. Here's how.
## Only what changed
Quarkle keeps a fingerprint of each chapter's content. A background process wakes up periodically and compares fingerprints. If a chapter hasn't changed, it's **skipped entirely**. No model is called, nothing happens. Only the chapters you've actually edited get looked at, and only a handful are processed at a time so the work stays light.
## Briefed on the diff, not the book
When a chapter *has* changed, Quarkle doesn't re-read the whole thing from scratch. For a small edit, the maintenance agent is briefed on **what changed**, the diff, and asked to update just the affected notes: this chapter's summary, and any character, world, or plot notes it touches. The first time it builds notes for a brand-new chapter, it reads the full text. This is why a two-sentence tweak doesn't trigger a full rebuild of your Atlas.
## A cheap, fast worker
Because this runs constantly in the background, it uses a **fast, inexpensive model** suited to reading a diff and tidying notes, not a frontier model. It runs at a low priority so it never competes with your Chat or review requests. You'll simply notice the Atlas's **sync** status update, and new or revised notes appear.
## Freezing pins the canon
The one thing that overrides all of this is a **frozen** note. When you freeze a note in the Atlas, the maintenance process leaves it alone, permanently, until you unfreeze it. That's the intended way to lock in canon: write the definitive version of a character or a rule, freeze it, and the background upkeep will treat it as ground truth.
## How Memory travels
[Memory](/ai/memory) (your preferences) is part of the same system, but it's special in one way. It's **injected into every Chat conversation** automatically, so your standing instructions apply everywhere without you re-stating them. Turning on **Memory Lock** in a chat simply tells Quarkle not to write new memories from that conversation.
The reader-facing controls (sync, freeze, history, and adding your own notes) are covered in [The Story Atlas](/ai/story-atlas) and [Memory](/ai/memory).
What's private and how mature content is handled.