Privacy Policy
Effective date: June 22, 2026 · Last updated: June 26, 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 is currently in public beta. Our privacy promise below applies during the beta just as it does at launch — we still collect no analytics and never receive your notes. Because beta software evolves, we may update this policy as features are added; any change that would affect what leaves your device will be described here before it takes effect.
The short version
- Your notes are plain Markdown files stored on your own device (or a folder you choose). We don't operate servers that receive, store, or read them.
- The AI — semantic search, forgotten-knowledge recall, and insights — runs entirely on your device. Your note text is never sent to us or to any third party for processing.
- We collect no analytics, no advertising identifiers, and no tracking. We do not sell or share data. Cortex requires no account.
- The only data that ever leaves your device is data you route there — by enabling optional sync through a cloud folder you control, or by making a purchase through Apple. Two optional features (voice dictation and image OCR) download their model once from a third-party CDN; even then, your audio, images, and notes are never uploaded.
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 an iOS app 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:
- 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/trial status.
On iOS, notes live in the app's Files-visible Documents folder. 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." The model these features use is served from our own origin, so they involve no third-party request.
One-time model downloads (voice & image features). Two optional features rely on open-source models that run on your device but are downloaded once, on first use, from a third-party content-delivery network (such as Hugging Face or jsDelivr): voice dictation (a speech-recognition model) and image text extraction / OCR (a text-recognition model). The first time you use one of these, your browser fetches the model files from that CDN — which, like loading any web resource, makes a request that exposes your IP address to that provider. Your audio, images, and note content are never uploaded: only the model is downloaded, and the recognition then happens entirely on your device. If you never use dictation or OCR, no such download occurs.
Sync (optional, paid feature)
If you enable Sync, Cortex reconciles your notes across your devices through a storage location you choose and control — such as iCloud Drive, Dropbox, or another synced folder. In that case your files are handled by that provider under their privacy terms, exactly as any file you place in that folder would be. JTR Labs does not operate a server that receives, stores, or reads your note content as part of Sync.
Purchases and subscriptions
Cortex's paid tiers (Plus and Believer) are 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 or purchase 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. Because Cortex collects no personal information on our servers, we do not knowingly collect data from anyone, including children.
Security
Because your notes live on your device, their security is anchored to your device's own protections (passcode, encryption, and OS sandboxing). 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 give you rights to access, correct, delete, and port your personal data. Because Cortex holds no personal data on our servers, you exercise these rights directly: your notes are plain files you can read, edit, export, or delete at any time, with any tool. If you have any question about this policy, contact us and we'll help.
International users
Cortex processes your data locally on your device wherever you are. Where you enable optional sync or make a purchase, that data is handled by the provider you chose (your cloud folder) or by 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.