Privacy Policy

Effective date: June 22, 2026 · Last updated: August 28, 2026

Cortex is built on a simple promise: your notes are yours, and they stay on your device. This policy explains exactly what Cortex handles, where it lives, and the few choices that ever send anything anywhere.

Cortex collects no analytics and never receives readable note content. Optional managed Sync sends only encrypted blobs to the relay, as described below; plaintext notes stay on your device.

Who we are

Cortex is published by JTR Labs LLC ("JTR Labs," "we," "our," or "us"), an independent software studio based in the United States. Cortex is available as iOS and macOS apps and as a web app.

What Cortex stores — and where

Everything you create in Cortex is stored as files and local data on the device or in the folder you use, except the encrypted blobs sent when you choose managed Sync:

• Your notes: plain Markdown (.md) files, including their text, frontmatter, tags, links, and any canvases (.canvas).
• The local index: a regenerable .cortex/ folder holding the search index and the on-device embeddings used for semantic search and recall. You can delete it at any time without losing a single note — it rebuilds from your files.
• App settings & status: your preferences, the folder you've chosen, and your subscription status.

On iOS, notes live in the app's Files-visible Documents folder. On macOS, they live in the local vault folder you choose. In the web app, you can grant Cortex access to a real folder on your disk via the browser's File System Access API, or use private in-browser storage; in both cases the files stay on your machine. If you delete the app — or revoke folder access — the data stays in your folder (or is removed with the app's storage), under your control.

On-device AI

Cortex's "Power" features — Smart (semantic) search, forgotten-knowledge recall, and Insights — are computed locally on your device using an on-device model. Your note content is not transmitted to JTR Labs or to any third party to power these features. There is no cloud inference and no "training on your data." Apple app builds bundle the model with the app; the web app downloads it from our own origin.

Voice and image recognition. On iPhone, iPad, and Mac, Cortex uses Apple's on-device Speech and Vision frameworks in your current language; no separate recognition model is downloaded and Cortex does not upload the selected audio or image. In the web app and non-Apple builds, these features use open-source models that run locally but may be downloaded once from a third-party content-delivery network such as Hugging Face or jsDelivr. That download exposes your IP address to the model host, but your audio, images, and note content are never uploaded. If you never use dictation or OCR in those builds, no recognition model is downloaded.

Share context with Onda (optional)

Cortex can provide bounded, read-only note context to JTR Labs' separate Onda app on the same Apple device. This bridge is off by default, has no network transport, and requires you to enable sharing in Cortex; Onda separately asks before each retrieval. On Mac, Cortex answers live through authenticated XPC and verifies Onda's code signature. On iPhone and iPad, where iOS may suspend Cortex, Cortex writes a size-limited snapshot of note text to an Apple App Group restricted to the signed Cortex and Onda apps. The snapshot has a finite authorization lease, is refreshed when Cortex opens or notes change, excludes locked notes, and is deleted after Cortex writes a disabled marker when you turn sharing off. Onda cannot browse or edit your vault. Excerpts already saved in an Onda goal remain in Onda until you remove that goal data there.

Sync (optional, paid feature)

In the native iOS and macOS apps, Cortex Sync uses an end-to-end-encrypted relay. The default managed relay is operated for JTR Labs by our infrastructure provider; advanced settings let you use a compatible relay you control. Before anything leaves your device, Cortex compresses and encrypts the sync state with a key derived on-device from your passphrase and a random vault salt. The passphrase, salt, and encryption key stay in Apple Keychain and are never sent to the relay.

The relay receives an opaque vault route, a random app-specific device replica identifier, authenticated ciphertext, and standard network request information such as IP address and user-agent. It stores the latest encrypted blob for each paired device so the other devices can retrieve it. The relay cannot decrypt your blobs or read note titles, text, links, or attachments. Disconnecting Sync removes the credentials from that device and stops future transfers, but does not automatically erase ciphertext already stored by the relay. In the web app, folder-based Sync writes through the folder or storage provider you select, under that provider's terms.

Purchases and subscriptions

Cortex Plus is sold and processed by Apple through the App Store using Apple's in-app purchase system. We never receive or handle your payment-card details. To unlock paid features, the app receives your entitlement status (whether a valid subscription exists) from Apple's StoreKit — not your financial information. Apple's handling of the transaction is governed by Apple's Privacy Policy.

The website

Our marketing pages and the web app are served by our hosting provider (Cloudflare). Like any website, the host may process standard technical request information (such as IP address and user-agent) transiently to deliver and secure the site. We do not set advertising or cross-site tracking cookies, and we run no third-party analytics that profile you.

Browser extension (Web Clipper)

We also offer an optional Cortex Web Clipper browser extension. It runs entirely on your device. When you clip a page or selection, or save posts from your X (Twitter) Likes/Bookmarks as you scroll, the captured items are stored only in your browser's local extension storage. You export them as a single file that you choose to save and import into Cortex. The extension sends nothing to JTR Labs or to any server — it contains no analytics, no tracking, and no remote endpoint, and it reads page content only while you are actively using it. The X capture is passive: it saves only the posts that the site loads for you as you scroll, and never scrolls, paginates, or sends any request to the site on your behalf. You are responsible for the content you choose to clip and for complying with the terms of the sites you clip from (for example, X's Terms of Service).

What we do not collect

• No account, name, or email is required to use Cortex.
• No analytics SDKs, no advertising IDs, no behavioral tracking.
• No location data, contacts, or device identifiers for tracking.
• We never sell, rent, or share your personal information.

Children's privacy

Cortex is a general-audience productivity tool and is not directed to children under 13. We do not knowingly collect personal information from children. Optional managed Sync handles only the encrypted blobs and network information described above.

Security

Because your notes live on your device, their security is anchored to your device's own protections (passcode, encryption, and OS sandboxing). Managed Sync encrypts data before transmission, and the sync passphrase is stored in Apple Keychain rather than browser storage. We recommend keeping your device and operating system up to date and maintaining your own backups — since your notes are ordinary files, you can back them up however you like.

Your rights and choices

Privacy laws such as the GDPR and CCPA may give you rights to access, correct, delete, and port personal data. You exercise control over your note content directly: your notes are plain files you can read, edit, export, or delete at any time, with any tool. Cortex has no user account that links a person to an opaque relay vault. For questions about managed-relay ciphertext or standard request information, contact us and we'll help with the information reasonably available to us.

International users

Cortex processes note plaintext locally on your device wherever you are. If you enable optional Sync or make a purchase, encrypted sync data or purchase information is handled by the managed relay infrastructure, a provider you choose, or Apple in their respective jurisdictions.

Changes to this policy

If we make material changes, we'll update the effective date above and note significant changes in the app's release notes or on this page. Continued use after a change means you accept the updated policy.

Contact

Questions about this policy or your data: hello@jtrlabs.com — JTR Labs LLC, United States.