Your thoughts stay yours.

The short version

Second Brain works without an account. Your library (captures, recordings, attachments, tasks, notes and everything made from them) is stored on your device. With no account, the app sends us nothing at all.

Three things change that, and each needs your choice:

• iCloud sync (Light and Pro) copies your library to your own private iCloud storage. We cannot read it.
• Cloud AI ("Luna") sends the text needed for one request through our server to OpenAI, when on-device AI can't help or when you choose Luna. If Luna is your engine, a recording your iPhone was not sure of goes the same way to be transcribed. Nothing is sent unless you sign in and turn it on.
• An account (Sign in with Apple) lets our server keep a small record: an account ID that is a one-way hash, your plan, your consent choices and your usage counts. We never ask Apple for your name or email.

This policy applies to the Second Brain app for iPhone and iPad and to this website, both published by TOPSOL ("we", "us"). The app's own Settings → How your data is handled screen says the same in shorter form.

What we collect

"Collect" here means data that leaves your device and is kept somewhere we can read it. Data that only reaches your own iCloud storage is not collected by us.

Tracking: the app never asks for Apple's permission to track you, so it never reads your advertising identifier, and iOS blocks the parts of Meta's SDK that need that permission. Meta measures our ads from the events above, in aggregate, with its Aggregated Event Measurement and Apple's SKAdNetwork. We do not show ads in the app or share anything with data brokers.

What stays on your device

Second Brain stores your library in its own private storage on your device, protected by iOS data protection and your passcode:

• Captures: what you said or typed, exactly as you said it, plus any corrections you made to it.
• Recordings and attachments: audio, photos, PDFs, files and links you added, and the text read from them on your device.
• What was made from them: tasks, events, notes, ideas, projects, review history and undo history.
• Search data: the meaning-based search index, built on your device with Apple's language models.
• Settings: language, reminders, widgets, AI choices, and the calendars you picked.
• In the iOS Keychain: your sign-in session and the monthly count of free voice captures, Smart fills and questions. The count only holds numbers and stays on this device, even if the app is reinstalled.

A guest library and each signed-in account have separate stores on the device. If you use iCloud Backup or an encrypted computer backup, Apple may include this data in that backup under your Apple Account. We have no access to it.

Widgets and Spotlight. Widgets show item titles only if you turn on Show titles in widgets. Saved items appear in Spotlight only if you turn on Show saved items in Spotlight. Both stay on your device.

AI on your device, and Luna in the cloud

On-device AI

On supported devices, Smart fill, organizing, answers and summaries run on Apple's on-device model. What you write does not leave your device, and on-device use never counts against a cloud allowance.

Luna, our cloud AI

Luna is a model from OpenAI that we call from our own server. Your device never contacts OpenAI directly, and no API key is in the app. Luna runs only if you have signed in and turned on Use Luna to organize and answer. It is used when on-device AI is unavailable or can't complete a request, or first if you have Light or Pro and chose Luna as your engine. Turning the switch off stops new cloud AI requests straight away.

For each request, only the text needed for it is sent:

• Organizing and Smart fill: the text of the capture being organized, including text read on your device from an attached photo or PDF, your time zone and language, and the names and short summaries of up to 30 of your projects.
• Transcribing a recording (Light and Pro with Luna as the engine): the recording itself, only when your iPhone was not sure of its words, with your language and a short list of vocabulary hints. See Voice, speech and recordings below.
• Ask your notes: your question and short excerpts from up to 12 saved items your device picked as relevant.
• Tidy-up (Light and Pro): the text of the note you asked to tidy.
• Daily summary (Pro): counts of what's due and short excerpts from up to 10 of your items for that day.

Never sent: images or files themselves; audio, except a recording that goes to Luna for transcription as described under Voice, speech and recordings; captures marked Keep only on this iPhone; your Apple Calendar events; your name or email (we don't have them); any identifier that could tell OpenAI who you are.

How long it is kept

Our server keeps a result for up to 24 hours, so a request that is interrupted can be finished without running it, or charging your allowance, twice. After that the text is removed, and a content-free receipt (a one-way hash of the request, the IDs of the items it used, and the time) is kept for up to a year for allowance accounting. Permanently deleting an item also removes any results made from it, and deleting your account removes them all.

A recording sent for transcription is not stored by us at all. Only its one-way hash enters the receipt, so the request can be finished or refunded, and its transcript is kept with the result for the same 24 hours.

We ask OpenAI not to store responses. Under its API terms, OpenAI does not use this data to train its models. It may keep inputs and outputs for a limited time to monitor for abuse, as described in its API data policies.

AI-generated suggestions and answers can be wrong. That is why every Smart fill field can be checked before it is saved, and every answer lists its sources.

iCloud sync

With Light or Pro, you can turn on Sync my library. Your library, including captures, items, projects, corrections, history and attachments, is then stored in a private CloudKit database in your own iCloud account, so your devices stay in step. Apple stores it under its own privacy policy. We, the developer, cannot read your private iCloud data, and our server never receives a copy of your library.

Captures marked Keep only on this iPhone are never synced. When sync is on, iOS may deliver silent notifications from Apple's push service to tell the app that something changed. No push token is sent to us.

Your account and our server

An account is optional. When you sign in with Apple, we request no name and no email. Our server, which runs on Cloudflare, keeps:

• An account ID: a one-way hash of the identifier Apple gives us. The original Apple identifier is not stored.
• Sign-in data: sessions, stored only as hashes and expiring after 30 days, and Apple's sign-in token, encrypted and used only to revoke it when you delete your account.
• Device check: the public key Apple's App Attest creates on each device you sign in on (up to 20), so the server knows it is talking to a genuine copy of Second Brain.
• Your choices and plan: whether sync and cloud AI are on, your plan and its renewal dates, and the transactions Apple sends to confirm it.
• Usage counts: how much of this month's cloud allowance you have used.
• Cloud AI results, kept briefly as described above.

To protect the service from abuse, the server briefly holds a one-way hash of your IP address combined with the current minute. It is deleted within minutes. We keep no request logs, and our server never receives your library.

Page import (Pro): when you ask to import a web page's text, our server fetches that public page itself and returns its readable text to your device. The page's address and text are not stored and are not sent to Luna.

Voice, speech and recordings

Voice capture uses the microphone only while you are recording. Speech is transcribed on your device with Apple's speech recognition. Your recording is not sent to Apple or to us for transcription, although the first use of a language downloads Apple's speech files. There is one exception, described next.

When a recording goes to Luna. From 4 November 2026: if you have Light or Pro and chose Luna as your engine in Settings, and your iPhone was not sure of the words it heard (its recognizer's confidence was low, or it produced no final transcript), the recording itself is sent to Luna to be transcribed before Luna organizes it. A recording your iPhone was sure of is not sent; only its transcript text is, as before. The recording travels once, over an encrypted connection, to our server and on to OpenAI's speech-to-text model (gpt-transcribe). We do not store it: only a one-way hash of it enters our usage ledger, so an interrupted request can be finished and a failed one refunded, and the transcript is kept with the AI result for up to 24 hours, like other results. Transcribing and organizing a recording together count as one cloud capture of your plan's monthly allowance. None of this applies to the on-device engine, to free plans or to captures marked Keep only on this iPhone: those are always transcribed on your device. You can still send a recording yourself with Re-transcribe with Luna on the review screen, if cloud AI is on; it is handled the same way.

Vocabulary hints. So that names are spelled correctly, the app gives the speech models a short list of words to listen for: the names of your projects and tags, and names that appear in the titles of your saved items. The list goes to Apple's recognizer on your device and, with a recording sent to Luna, to our server and OpenAI. Neither our server nor OpenAI keeps it beyond the request.

Recordings are kept in your library. Once a transcript is complete, the audio is deleted 7 days after saving unless you tap Keep this recording. A recording whose transcript failed stays until you delete it. Transcripts stay after their audio is gone.

Connected AI apps

Pro, optional. You can let an AI app such as Claude or ChatGPT add tasks, events and notes to Second Brain. You connect it with a one-time code shown in the app; no password or Apple sign-in happens on the web. For this feature our server keeps:

• The connection: the app's name, when it connected and was last used, and one-way hashes of its access tokens. You can disconnect it at any time in Connected apps.
• Items on their way to you: what the app asked to add waits in a server inbox until your iPhone saves it, then it is deleted. Anything not collected is deleted after 30 days.
• Your project names (ids and names only), while an app is connected, so it can file items.
• Your open tasks, only if you turn on Let connected apps see open tasks: the titles, due dates, priorities and project names of tasks not yet done, so the app can list, complete and reschedule them. Turning it off deletes them from the server at once.

When an app adds something, the notification sent to your iPhone through Apple's push service carries that item's text and details, so it can be shown and saved at once. Connected apps cannot read your notes. Every item an app adds waits for your confirmation in the app unless you choose to save that app's items without review, can be undone, and names the app it came from. Items created this way are also governed by the privacy policy of the AI app you used.

Permissions

You can change any of these in iOS Settings → Second Brain. The app never asks for your location or contacts.

Purchases

Light and Pro are sold through Apple's App Store. Payment happens between you and Apple, under Apple's privacy policy, and we never see your payment details. You can buy a plan without an account: your iPhone checks the transaction Apple signs, and our server keeps nothing about the purchase. If you sign in, our server checks that transaction and stores it with your account, so the plan can follow you to your other devices. A purchase made without an account is linked to the first account that sends it. Our server also receives Apple's notices about renewals, refunds and cancellations, and applies them only to purchases linked to an account, so your plan stays correct.

Service providers

Second Brain contains one third-party SDK: Meta's, used only to measure our ads. It has no access to your library, and there is no other analytics, advertising or crash-reporting code. These companies process data for us, each only for the purpose listed:

• Apple: Sign in with Apple, App Attest, the App Store and purchases, iCloud sync in your own account, push delivery for sync, and the on-device AI and speech models.
• Cloudflare: hosts our server and its database, and routes requests to it.
• OpenAI: runs Luna for the cloud AI requests you allow, including transcribing the recordings sent to it, as described above.
• Meta: measures our ads on Facebook and Instagram from the events listed under What we collect, sent by its SDK in the app. Meta handles that data under its own privacy policy.

We do not sell or rent personal data. Apart from the ad measurement Meta does for us, we share nothing with advertisers or data brokers. We may disclose information if the law requires it. Because we hold so little, there is little we could disclose.

How long we keep it

Export and deletion

Everything is in your hands, inside the app:

• Export: Settings → Prepare an export creates a ZIP with your whole library, your original files and a list of anything that couldn't be included.
• Delete from this device: Settings → Delete all local data removes the library on this device. It does not delete your account or its iCloud copy.
• Delete your account: Settings → Cloud sync and AI choices → Delete account and library deletes your iCloud copy, everything our server holds about the account, and the account's library on this device, and revokes Second Brain's Sign in with Apple access.

After an account is deleted, our server keeps only a content-free marker: the hashed account ID flagged as deleted, its usage counts, and one-way hashes of its purchase and device identifiers. That marker lets an interrupted deletion finish and stops a purchase or the free cloud sample being claimed twice. It contains no content, name or email. Step-by-step instructions are on the Your data page.

Your rights

Depending on where you live, including under the GDPR, the UK GDPR and California's CCPA/CPRA, you have the right to access, correct, export, restrict, object to and erase personal data we hold about you, to withdraw consent at any time, and to complain to your data protection authority. Most of these rights are built into the app: export, delete, and the sync and cloud AI switches. For anything else, write to topsol.org@gmail.com and we will respond within 30 days.

Where the GDPR applies, we rely on: contract to provide the features you use and the plan you bought; consent for iCloud sync and cloud AI, which you can withdraw with their switches; legitimate interests in keeping the service secure and preventing abuse (App Attest and abuse protection); and legal obligation for purchase records.

Children

Second Brain is not directed at children under 13, or under the age of digital consent where you live. We do not knowingly collect personal data from children. If you believe a child has created an account, write to topsol.org@gmail.com and we will help delete it.

Where data is processed

Cloudflare runs our server on its global network, and OpenAI, Apple and Meta may process data in the United States and other countries. Where the law requires it, these transfers are covered by the providers' data processing terms, including standard contractual clauses. Data stored on your device stays where your device is.

Changes to this policy

If the app changes what it does with data, we will update this policy and the date at the top. We will mention material changes in the app's release notes and, where the law requires, ask for your consent again. We will never start sending your content anywhere new without a new choice from you.

Contact

TOPSOL, the publisher of Second Brain, is the controller of the personal data described here. For privacy questions or requests, write to topsol.org@gmail.com.