Privacy Policy
Last updated 29 October 2026.
What I keep, who else sees it, and how to make it go away. No fine print hiding behind the fine print.
Your chats are encrypted
Your conversations with Keph are encrypted in your browser before they are stored — the words, the titles, the files you handed Keph and what he read in them (a voice note, attached or recorded in the chat, is turned into words by Google’s Gemini or OpenAI and the recording is never kept), the sources he found — with keys tied to your account, so they open on any device you sign in on. Your account’s key is kept encrypted by Google Cloud’s key service and handed only to your own signed-in browser. To answer you, each message (with the files and links in it) passes through our servers and our AI providers below, and is not kept in the clear. Besides the encrypted chats we keep only what we must to run the chat: that a chat exists and whose it is, how many messages you sent each day (for the free limits), and which version of the Covenant you accepted, and when. A chat stays until you delete it, unless you choose for it to erase itself 24 hours, 7 days or 30 days after its last message (Settings → Your chats).
Chats we may read
Your chats can be read by us, to improve the Service. A chat you start — signed in or not, free or pledged — after accepting the Covenant of 29 October 2026 gets a key of its own, which your browser hands to us and we keep encrypted by Google Cloud’s key service, so the keeper of the Library (its owner) can read that chat to improve the Service. The Covenant tells you this before your first message, and a line under the chat box says it while you type. A pledge (Keph Monthly) does not change this. Chats whose keys we erased before 29 October 2026 — a pledger’s, and every chat started before its seeker accepted the Covenant of 28 October 2026 — stay unreadable by us for good.
Keph's memory
Signed in, Keph remembers you from one chat to the next — unless you turn it off (Settings → Keph’s memory; it is on to start). After each exchange, our AI model provider reads it to note what is worth remembering about you — short notes such as your name, what you are working on, or how you like answers — and the notes a new message brings to mind are handed to Keph with it. The notes are encrypted in your browser with your account’s key and stored that way. In Settings you can read them, erase any of them or all of them, or turn memory off (Keph then starts every chat fresh; the notes stay until you erase them). Notes that stop mattering fade and are let go on their own; all of them go when your account does. Anonymous visitors have no memory.
What we collect
Your chats, sealed as above, and the daily count of your messages and files. Messages and files you send to the support desk, the page you wrote from, and an email address if you choose to leave one there. Account details from Google sign-in (name, email, profile image, locale). In the Library: prompts you submit, files you attach as source material, and the volumes you create; an email address you choose to leave so we can tell you when a volume is ready (used for that one message, then deleted); optional demographics you choose to provide (birth date, gender); and purchase records (for Keph Monthly the PayPal subscription id, its status, and your pledge’s locked price and seat; lamp refills; passes bought before they were retired — never card details, which only PayPal sees). Usage and analytics, including a hashed form of your IP address (also kept on each support thread to prevent abuse) and the site or link that brought you here. Google does not provide us your age or gender.
How we use it
To answer you and keep your encrypted conversations so you can return to them; to read chats as described above, to improve the Service; to enforce the free limits and the chamber’s daily budget; to read support threads when we need to fix problems, prevent abuse, or improve the Service; to generate and store your volumes and operate the public library; to process payments; to send transactional email; to send the one launch letter to an address left on the waitlist (any other letter only if you say yes; every letter has a one-click unsubscribe, and an address that unsubscribes is kept only as a fingerprint of it, so we never write to it again); and to understand the Service in aggregate. We do not train AI models on your conversations, and we never sell them.
Who sees your conversations
You — and, for a chat as described above, the keeper of the Library. Conversations are never published, and they are stored encrypted; the Covenant says who can read them before Keph answers your first message, which goes nowhere until you sign. While Keph answers, each message passes through the AI providers below. What you send the support desk is different: it is a message to us, and we read it. A line you “Inscribe” stays on your device unless you share it.
Third parties
We share data only as needed to run the Service, with: our AI model provider, which carries each chamber message and the conversation before it to the open-weights model that writes Keph’s replies, sends the images you attach to open-weights vision models that describe them, decides whether a message needs a web search, notes what is worth remembering about you (Keph’s memory, above), and is a backup route for requests the Library’s main models decline — it receives the conversation’s text and those images, not your name or email, and prompt logging is kept off; a web search provider, which runs the web searches Keph makes while answering you (it receives the search terms, not your name or email). When you paste a link, our own server fetches that page — the site sees our server, not you. Also: Google Cloud (hosting, database and file storage, including support attachments, and the Gemini models that read what you attach and write and illustrate volumes); OpenAI (backup writing and images, and transcribing audio you attach); Tavily, Wikipedia, Crossref, Semantic Scholar and Open Library (research searches for volumes, which carry search terms drawn from your request, not your name or email); PayPal (payments); and Resend (email). Our analytics are our own: no outside analytics or advertising service receives your data. We do not sell your personal information.
Cookies & your device
We use a signed, first-party cookie to keep your free chat trial, your sealed conversations, your lamp and your volumes before sign-in (kept up to a year), and a session cookie once you sign in. Two more first-party cookies count visits: a random visitor id (kept up to a year) and the name of the site or link that brought you here, such as a search engine or a post, with the campaign or post the link was tagged with (kept 30 days), so we can tell which places send readers. Your browser’s own storage holds the keys that seal your chats, your signed Covenant, the conversation you left off in, the chamber’s opening line for the session, the inscriptions you keep, and your settings; these stay on your device. We do not use third-party advertising or tracking cookies.
Retention & your rights
A conversation stays until you delete it, unless you choose in Settings for it to erase itself — from our servers, so from every device — 24 hours, 7 days or 30 days after its last message; you can delete any chat, or all of them, at any time. A chat left with no owner (its account deleted) is erased 30 days after its last message. An erased chat can’t be brought back. The files you attach are read once and never kept. Keph’s memory notes stay until you erase them, fade away, or your account goes. Daily message counts are kept five weeks. Your other data is kept while your account is active. In Settings you can download a copy of your data (your chats are opened for it in your own browser), delete all your chats, or delete your account — which removes it with your chats, your account’s keys, support threads and anything you made here, and cancels a Keph Monthly subscription first. Payment records (amount, date, the PayPal reference) are kept for our accounts, tied to no one. You can also ask for access or deletion at z@greatlibrary.ai.
Children
The Service is for adults 18+, and the Covenant asks you to confirm it. We do not knowingly collect data from children; if you believe a minor has used the Service, write to z@greatlibrary.ai and we will delete what they left.