What we collect
When you create an account and use LibLantern, we collect the following:
- Email address — provided when you sign up via Auth0, our authentication provider.
- Photos you upload — the images you take of book shelves. We store these so you can review your scan history.
- Location data (GPS coordinates) — if your photos contain EXIF location data (embedded by your phone's camera), we extract those coordinates. See the Location Data section below for details.
- Scan history — a record of the scans you've performed, including which books were identified.
- Usage statistics — anonymized events about how you use the app (e.g. features visited, actions taken). See Third-party Services below.
We do not collect payment information — LibLantern is free with no paid plans.
How we use it
We use the data we collect solely to operate and improve LibLantern:
- Your photos are sent to Google Gemini AI to identify the books in them. The identified titles are then looked up via the Google Books API to fetch cover art, descriptions, and ratings.
- Your email address is used to manage your account and, if needed, to contact you about your account or service updates.
- GPS coordinates extracted from photo EXIF data are used to map where books were discovered on a community map.
- Scan history is stored so you can revisit books you've scanned.
- Usage statistics (via PostHog) help us understand which features are useful and where the app can be improved.
We do not sell your data to anyone, and we do not use your data for advertising.
Location data
When you take a photo with a smartphone, your camera app often embeds GPS coordinates into the image file as EXIF metadata — this happens automatically in the camera, not through LibLantern.
When you upload a photo to LibLantern, we read this EXIF data if it's present. We use the coordinates to place a pin on the community map showing where those books were found.
Third-party services
LibLantern relies on the following external services. Each has its own privacy policy:
Google Gemini AI
Your photos are sent to the Gemini API to identify books. Per Google's API terms, images sent via the API are not used to train Google's models and are not stored by Google beyond the time needed to process your request.
Gemini API termsGoogle Books API
We use the Google Books API to retrieve cover images, descriptions, ratings, and other metadata for identified titles. Book title queries (not your photos) are sent to this API.
Google Books APIPostHog
We use PostHog to collect anonymized usage events — things like which features are used and how often. Events do not include your photos or the content of your scans. PostHog is configured to avoid collecting personally identifiable information.
PostHog privacy policyAuth0
Account creation and sign-in are handled by Auth0. Your email address and authentication tokens are managed by Auth0 on our behalf. Auth0 does not have access to your scans or photos.
Auth0 privacy policyGoogle Cloud Storage
Your uploaded photos are stored in Google Cloud Storage. Files are stored in our controlled bucket and are not publicly accessible by default.
Google Cloud privacy noticeData security
We take reasonable steps to protect your data. Photos are stored in a private cloud storage bucket with access controls. Authentication is handled by Auth0, a dedicated identity platform. Data in transit is encrypted using HTTPS.
That said, no system is perfectly secure. If you ever believe your account has been compromised, please contact us right away at hello@liblantern.com.
Data retention
We retain your data — including your photos, scan history, and account information — for as long as your account is active. We don't have a fixed deletion schedule for inactive accounts at this time.
If you delete your account, your data is removed. See Your Rights below for how to request deletion.
Your rights
You can:
- Access your data — contact us and we'll tell you what we hold about you.
- Delete your account and data — email hello@liblantern.com with the subject "Delete my account" and we will remove your account and associated data.
- Correct your data — if something is wrong, let us know and we'll fix it.
We'll respond to requests within a reasonable time. Because LibLantern is a small community project, we handle these manually — thanks for your patience.
Changes to this policy
If we make significant changes to this policy, we'll update the effective date at the top. For major changes that affect how your data is used, we'll make a reasonable effort to let you know (for example, via a notice in the app).
Contact
Questions or concerns about your privacy? We'd love to hear from you.
Email: hello@liblantern.com
LibLantern is an unincorporated community project, not a registered company.