Mono Brain privacy policy

The short version

• Your personal history is stored on your computer. The record of your thinking is kept by the Mono Brain app on your computer: your recordings, their transcripts, what Mono Brain understood from them, your direction and your Threads.
• Content is sent to AI providers only for processing. To transcribe what you say and to read it, Mono Brain sends the content each task needs through its cloud service to AI providers, to answer that request (what a provider may keep is described below). The result comes back to your computer. The cloud keeps records about these requests (what ran, when, what it cost), not their content.
• The cloud keeps what it needs to run your account: your identity from sign-in, your devices, your access, the messages you send us, and operational information about how the app is working.
• What you send from Chrome with the Companion goes only to the Mono Brain app on your computer. It reaches an AI provider only if you choose Talk about it on it in Mono Brain, with the thought you then record.
• You can delete a thought, and export a copy of your data, in the app. When you dictate into another app, Mono Brain keeps the recording and its words for a day, unless you choose Save as a Thought.
• We don’t sell personal information, show advertising, build advertising or behavioral profiles, or use third-party analytics.
• Mono Brain does not use your content to train AI models.

On your computer

The app keeps these on your computer, under your Windows account:

• recordings and transcripts, and your corrections to them;
• what Mono Brain understood from them (thoughts, Threads, endeavors, moves, Focus sessions), what you tell it about your thoughts, and your direction;
• pages and selections you send from Chrome;
• the exact content of each request it sent for processing;
• backups made before updates and, if you restore one, the data it replaced, set aside rather than deleted;
• a record of what was deleted, so that nothing deleted comes back: identifiers and times, and a recording’s length and sound levels, never its words or audio;
• the app’s logs, which don’t contain what you said.

Your sign-in is kept in Windows Credential Manager.

These files, and the copies you export, are protected by your Windows account; Mono Brain doesn’t add encryption of its own. Signing out keeps them.

Dictation. When you dictate into another app, Mono Brain keeps the recording and its words on your computer for a day. If you don’t choose Save as a Thought, they are erased, as a deleted thought is, once 24 hours have passed. Mono Brain looks for them once an hour while it is running, so this can happen a little later. If you remove a dictation from your Thoughts, it is erased 24 hours after you removed it, unless you take it back. The text in the other app is never touched. A dictation you saved as a Thought is kept like any thought.

Deleting a thought. In a thought’s Details, choose Delete thought. Its recording, your words, what Mono Brain understood from them, what you told Mono Brain about it, the moves that came from it, and the copies of every request that carried any of it are erased from Mono Brain’s data at once. Then they are erased from its backups, from data a restore set aside, and from the exports Mono Brain made that are still where it put them. The app says “Deleted from Mono Brain on this computer” when all of that is done. Thoughts whose reading drew on the deleted one are read again without it, a few on their own and the rest when you choose Read them again. The spellings it taught stop going with your recordings. If it came from your phone, see “Thought Relay”. This can’t be undone.

Delete can’t reach copies you made or moved elsewhere (an export you moved, or a folder synced to a cloud service), what your drive itself may still keep of overwritten data, or what Mono Brain’s cloud and AI providers keep, as this policy describes. Your direction, what you say in Focus, and what you send from Chrome can’t be deleted one by one, and deleting a thought about something you sent keeps what you sent.

Deleting a Thread takes it out of your Threads and keeps its thoughts; it erases nothing. To erase its thoughts too, choose to delete the Thread and its thoughts: each is erased as Delete thought erases it. A name you gave the Thread yourself stays in Mono Brain’s data.

Your copy. In Settings › Privacy & data, under Your data, Export a copy writes a new folder in your Documents folder, under Mono Brain exports. It holds your thoughts, Threads and direction as files any program can read, your recordings, a complete copy of Mono Brain’s database, and a checksum for every file. Nothing is sent anywhere. If your Documents folder is synced to a cloud service, such as OneDrive, the copy is synced with it. When you later delete a thought, Mono Brain removes it from the exports it made that are still where it put them.

Deleting everything. Uninstall Mono Brain and choose “Also delete my Mono Brain data from this computer”, which also removes your sign-in, or delete the app’s data folder. Uninstalling without that option keeps your data for a reinstall. Exports stay in your Documents folder until you delete them there.

What is sent for processing, and to whom

Transcription. The audio of a recording is sent through Mono Brain’s cloud to Google’s Gemini API, and the transcript comes back to your computer. Recordings without speech aren’t sent unless you ask. Longer recordings may be uploaded to Google as temporary files, which Mono Brain deletes as soon as the transcript is back.

With each recording go up to 30 of your own spellings of names and words, so that they come out right. Mono Brain learns them on your computer, from names you write in your direction and from the words you corrected with Edit words.

A recording can be sent again: when you choose Hear it again, and when its words came back in a language you haven’t used with Mono Brain. In that case the names of the languages you have used go with it; Mono Brain learns them on your computer from your own words.

Reading. To read a thought, Mono Brain sends its words, as transcribed or as you corrected them, up to 60,000 characters, when you said it, how long the recording was and the language it is in, together with the context needed to place it:

• your current direction, and the words you set it with;
• the endeavors your direction names, and up to three that an earlier direction named and that something of yours is still in (six at most);
• up to twelve of your Threads most likely to be relevant. Each comes with its name, where it sits among your Threads, its status and how many days ago it last changed, the endeavor it is in, what it began with, and its newest thought: a one-sentence summary, or your own rewording if you said it differently; whose view you said it was; where you stood in it, as Mono Brain read it (what you decided, changed your mind about or gave up, what holds only if something is so, other people’s views you reported, and what you left open); and up to three decisions in that Thread you told Mono Brain about, with what you decided, in your words, if you said it;
• your most recent moves, up to three; the move the thought answers, if it answers one; and questions you recently set aside;
• what you told Mono Brain about this thought in its Details, in your words: that a reading isn’t what you meant, and what you meant; whose view a part of it is; where a decision in it stands, and what you decided; or the thought said differently;
• if you chose Talk about it on something you sent from Chrome, what you sent: its title, its address, and the words you selected or, if the page’s text was sent, up to 24,000 characters of it, marked as the page’s words, not yours.

The same content can go in more than one request: a long thought is read in parts and then as a whole, and an answer that isn’t in your language is asked for once more.

To read your direction, it sends what you said or wrote about it, the names and kinds of the endeavors you already have (up to six), and, when you answer a question Mono Brain asked about it, your earlier words and that question. These requests carry no name, email address, account or device identifier. They go through Mono Brain’s cloud to OpenRouter, which passes them to the provider of the AI model that answers.

Not sent for reading: text you dictate into other applications, unless you choose Save as a Thought on it; anything you send from Chrome, unless you choose Talk about it on it; your answers in Focus; your other recordings (a reading sees your other thoughts only as listed above); and drafts you didn’t confirm. Dictation and Focus answers are still transcribed, as above: transcription turns your voice into words and reads nothing into them.

How providers handle it. Google processes the audio, and the spellings and languages sent with it, to return the transcript, under the Gemini API terms that apply to Mono Brain’s use of it, and may keep requests for a limited time, for example to detect abuse. For reading, Mono Brain has OpenRouter send each request only to model providers that keep nothing after answering (zero data retention) and that don’t collect it; providers that train on or publish requests are not used.

What the cloud keeps about requests: the operation and model, sizes, durations, token counts, cost, outcome, and a fingerprint of the input. When Google declines to transcribe a recording, the cloud also keeps the reason and the safety categories Google gave (for example, “dangerous content”), and its logs record them too. It never keeps the audio, the content sent, including your spellings and languages, or the answer.

The Mono Brain Companion for Chrome

• Only what you choose to send. The Companion sends something only when you choose Send page or Send selection.
• What it reads, and when. When you open the Companion on a tab, it reads that tab’s address and title, the text you selected on it (never from a password field), and, if a video or audio is playing, the moment it is at, so you can see what you would send. Send page sends the address and title; Send selection sends the selected text with the page it came from. Either one also sends that moment.
• Where it goes. Only to the Mono Brain app on the same computer, over a local connection on this computer (127.0.0.1) that only a Companion you connected can use. The Companion contacts no server: not Mono Brain’s, and no one else’s.
• Connecting. You connect the Companion in Mono Brain, approving a code shown on both sides. That creates a credential the Companion keeps in its own storage in Chrome, and that lets it send to the app on this computer and nothing else. The app keeps only a fingerprint of it, and either side can disconnect.
• When the app isn’t running. What you send waits in the Companion’s storage in Chrome, at most 50 sends and 1 MB, and the Companion tries to deliver it once a minute. It leaves that storage when the app has received it, or when you remove it.
• It doesn’t follow your browsing. The Companion runs nothing on pages in the background, reads no other tab, and has no access to your browsing history.
• What happens to it. What you send is kept by the Mono Brain app on your computer with your other Mono Brain data. It reaches an AI provider only if you choose Talk about it on it in Mono Brain. It then goes through Mono Brain’s cloud, which doesn’t keep it, with the thought you record about it, as described under “What is sent for processing, and to whom”. Mono Brain’s cloud keeps only whether a Companion is connected, and its version.
• No advertising or profiling. Nothing the Companion handles is used for advertising or for building a profile of your browsing. The Companion uses it only to deliver what you sent to the app on your computer; there, it is used only as this policy describes.

The use of information received from Chrome by the Companion adheres to the Chrome Web Store User Data Policy, including the Limited Use requirements. The Companion uses it only for its single purpose, sending what you choose to the Mono Brain app on your computer. It is not sold, not used for advertising, not used to determine creditworthiness or for lending, and not transferred to anyone, except to the AI providers that read a thought you chose to record about it with Talk about it, as described above.

Thought Relay (your phone)

To connect a phone, Mono Brain on your computer shows a code that works once, for 10 minutes, and only for your account. The cloud keeps only a fingerprint of it.

A recording made on your phone stays there until it is sent. It is then held in Mono Brain’s cloud storage only until your computer has saved it, and for at most 7 days from when your phone sent it; after that it is deleted from the cloud. If it wasn’t delivered, your phone keeps its copy, and Send again sends it once more, for at most another 7 days. After delivery, the phone deletes the audio and keeps a short list of recent recordings.

If you delete on your computer a thought you recorded on your phone, your computer won’t take that recording again. If your phone hadn’t yet heard that your computer had it, or sends it again, Mono Brain’s cloud deletes its copy at once, and your phone deletes the audio and shows “Deleted on your computer”.

The cloud keeps a record of each recording (when, length, size, fingerprint, status) for 30 days after its delivery window ends.

When your phone shows a move Mono Brain suggests, its title and question are stored in the cloud while it is open, for at most 24 hours. They are erased when it closes, which it also does when you delete the thought it came from, and the record of it is deleted 30 days later.

Your account and access

You sign in with your Google account through Auth0. Mono Brain receives and keeps your Google account identifier, email address and name, updated each time you sign in, and, for each computer and phone you use, its platform, system version, app version, and when it was first and last seen. For a computer, we also keep the name Mono Brain gives itself there (for example “Mono Brain”), so that you can tell which one receives your phone’s recordings; never your computer’s own name or a hardware identifier.

Sign-in sessions are stored only as fingerprints. On app.monobrain.me, cookies are used only for signing in and keeping you signed in.

Founding Alpha access is recorded with a keyed fingerprint of your invited email address (not the address itself), your access state and its history. If you were invited from the monobrain.me waitlist, we also keep that waitlist entry’s number and the date you joined.

To show your setup on your account page, the app reports whether your direction is confirmed and whether the Companion is connected, and its version.

Operational information and diagnostics

While you’re signed in, the app periodically reports first-party counts: for example, how many recordings were saved or failed, how background tasks ended, and whether its connections work. These counts contain no content or text and are kept for 90 days.

Diagnostics are sent only when you choose to attach them to feedback, after you’ve seen exactly what will be sent: app and Windows versions, connection states, counts of task outcomes, and recent warnings from the app’s log, reduced to fixed messages and codes. They are kept for 90 days.

Mono Brain’s cloud logs each request’s time, route, status and duration, and for some events an account or device identifier. These logs never contain content or email addresses. Our hosting provider keeps them for its own retention period.

Feedback and email

Feedback you send is kept with your account so we can reply, until you ask us to delete it or your account is deleted. Our reply appears in Mono Brain’s Help and on your account page at app.monobrain.me. We may also send you an email saying that a reply is waiting; it never contains your feedback or our reply.

The monobrain.me website and waitlist

Joining the waitlist. We store the name, email address, what you do and the country you enter; the page that referred you and any campaign tags in the link; and when you joined. We may send you an email confirming that you joined. We use the list to invite people to Mono Brain and to write to you about it. To be removed, write to privacy@monobrain.me.

Visiting. The site uses no third-party analytics or advertising tools. It records first-party usage events under a pseudonymous visitor code that changes every month and isn’t linked to your email address: which parts of the page were viewed, where you clicked within them, and how long the visit lasted; the referring site and campaign tags; device type and language; and your country, derived from your IP address. Your IP address itself isn’t stored. The referring page and campaign tags are kept in your browser’s session storage until you close the tab. The site sets no cookies for visitors. These events are kept until we delete them.

The website’s server logs can include what you entered in the waitlist form when your signup could not be saved, so that you don’t lose your place; until 3 October 2026 they also recorded the address when it was already on the list. Our hosting provider keeps those logs for its own retention period.

Service providers

We use these service providers to run Mono Brain:

• Auth0: sign-in;
• Google: signing in with your Google account; the Gemini API, for transcription;
• OpenRouter, and the AI model providers it routes to: reading;
• Railway: hosting the cloud service, the website, databases and storage;
• Resend: sending email.

We update this list when it changes.

Training

Mono Brain does not use your content to train AI models. How the AI providers above handle your content is described in “What is sent for processing, and to whom”.

How long we keep information

Deleting your cloud account

Write to privacy@monobrain.me from the address you sign in with. After confirming it’s you, we stop your access and delete, from Mono Brain’s cloud, your account and everything linked to it (devices, sessions, access records, feedback, diagnostics, operational counts, Thought Relay data and request records), and your identity at Auth0.

The cost of past requests is kept only as daily totals for everyone in the Founding Alpha together, by operation, provider, model and outcome, with nothing that links them to you. If you ask, we also remove you from the monobrain.me waitlist. When everything is done, we send you a reference number for the deletion.

Deleted information can remain in backups of the cloud database until they expire, within 28 days. If we ever restore a backup, we delete it again before the service is used. Logs kept by our service providers expire under their own retention.

Your data on your computer is yours: delete it there, as described above.

Security

Connections between your devices and Mono Brain’s cloud are encrypted (HTTPS). Sign-in sessions are stored as fingerprints, and access tokens are short-lived. The Companion communicates only with the app on your own computer.

Changes

When this policy changes, the date at the top changes. If a change affects what leaves your computer, the app update that brings it says so in its release notes.

Contact

privacy@monobrain.me, for questions, what the cloud holds about you, deletion, or anything in this policy.