Privacy and security

This page describes, in plain terms, what Lunar stores and the principles that guide how your data is handled.

What is stored

• Your account — the identifier you sign up with, so your data belongs to you and follows you across devices.
• Your study content — chats, classes, Spaces, microchats, saved citations and the study material derived from them (session context, anchors, concept trees).
• Your files — uploaded documents are processed into readable text and stored with their metadata; Lunar works with that extracted content, not the original binary. For PDFs, the extraction itself happens locally in your browser.

Principles behind the design

• Summaries, not full histories. When features share context between chats, classes or microchats, they exchange lightweight summaries — not full transcripts. Data minimization limits how much of your content travels between parts of the system.
• Only what the session needs. Space memory, session context and file summaries exist to answer your questions in your sessions. Nothing in the product is designed to broadcast your content beyond your own account.
• Processed, not opaque. The study layer's artifacts — summaries, concept trees, context notes — are visible to you and often editable, so you always know what Lunar "remembers".
• Inspectable, perishable memory. What Lunar remembers about you as a learner is visible in Settings → Memory, always with its evidence; and what stops being confirmed fades from daily work instead of piling up forever.

Anonymous usage

You can try Lunar without an account. Anonymous usage is limited, and what you do is tied to the device session — it is not carried over if you create an account later. Creating an account is what makes chats, Spaces and files persist.

Deleting your data

• You can delete individual chats, microchats and Spaces at any time.
• You can delete your account from your account settings. This action cannot be undone, so export anything you want to keep first.

[!IMPORTANT] Follow the minimum-information rule: avoid sharing personal data, credentials or sensitive information in prompts. If you need to discuss a real case, use anonymized descriptions, and review private documents before uploading them — once a file's text is extracted, it becomes part of the conversation context.