OSL

Early access. OSL is being built toward its v1 launch, so some of what you see here is still being finished.

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Frequently asked questions

Questions and answers about OSL Privacy, grouped by topic.

About OSL #

What is OSL?

OSL is a desktop privacy hub for social media and email. It keeps connected accounts in isolated local profiles and adds OSL Protected mode where a connector supports it. Messages between approved OSL users are encrypted on the sender's computer and opened on the recipient's computer.

How is OSL different from Signal?

Signal is a messaging network built around its own identity and privacy model. OSL is a local hub for accounts you already use. It can protect content on supported connectors, but the underlying social or email service still sees account and delivery metadata. For a threat model that requires a purpose-built private network, Signal may be the better choice. See our threat model.

Why publish the crypto code?

Privacy claims are only as good as the code behind them. If the encryption is wrong, no amount of marketing fixes it. The client, cryptographic core, service adapters, and server components are public so you can inspect or build them yourself.

Does OSL work on mobile?

Not yet. OSL launches on Windows desktop only. macOS and Linux are planned for later. Mobile (Android/iOS) is on the longer-term roadmap but isn't committed.

Privacy & Security #

What encryption does OSL use?

X25519 elliptic-curve key exchange combined with ML-KEM-768 post-quantum key encapsulation. Direct messages are sealed per-message to the recipient's published keys. Protection for group chats and server channels is Planned: the group code exists in the repository but it is switched off in the shipping app, so treat anything you write in a group or a channel as unprotected. See how OSL works for details.

Why is post-quantum encryption important?

State-level adversaries are recording encrypted traffic now to decrypt later, once quantum computers catch up. ML-KEM-768 is a post-quantum key-encapsulation mechanism designed to resist that. OSL pairs it with X25519 so your messages stay protected even if one of the two algorithms is later broken.

Can my friends read encrypted messages without OSL?

No. OSL recipients need OSL installed to decrypt. Anyone without OSL, including the connected service or someone reading its stored message data, sees ciphertext only.

Can I encrypt voice/video calls?

No. OSL protects supported text today. Encrypted image sending is Planned and is not in the shipping app yet. Voice and video calls still use the connected service's normal infrastructure and security.

What if I forget my password?

OSL displays separate recovery phrases for your identity and the main-password gate. Save both during setup. Source inspection shows the main-password recovery phrase can authorize setting a new main password, but it does not prove that every local record is password-protected. Peer, membership, and other conditional JSON can be plaintext without the file-storage key; Hub configuration, renderer localStorage, provider-managed profiles, the active-slot marker, and a fixed-label startup trace can also be plaintext; and removing the storage key restores plaintext writes. OSL cannot recover either phrase from its servers.

What happens to my data if OSL shuts down?

OSL infrastructure may relay bounded ciphertext and public-key or control records, but it cannot decrypt protected message content. The reviewed source seals accepted message-store values, while SQLite row counts, order, burn timing, sizes, and blind-index equality patterns remain visible; conditional JSON, Hub configuration, renderer localStorage, provider-managed profiles, the active-slot marker, and a fixed-label startup trace can also be plaintext. This is source and focused-test evidence, not proof that a named release, existing profile, backup, or migration is complete. Network-dependent delivery and recovery actions may stop if OSL infrastructure disappears.

Installing & Using #

Can a connected service restrict my account?

Possibly. Each service has its own rules, and some restrict modified clients or accessibility automation. OSL labels experimental interaction modes and leaves them off by default. Review the rules for every account you connect.

Why is there a Windows security warning?

SmartScreen flags new applications from independent developers until enough users have run them to establish reputation, or until the developer pays for an extended-validation code-signing certificate. We're working on the certificate. See the explanation on the download page for how to proceed past the warning.

Can I use OSL on multiple devices?

Each OSL installation can have different device state. Multi-device identity and group-state coordination are not complete yet. For now, OSL Protected conversations are best used from one primary computer.

Can I export my encrypted messages?

Not currently. Local export to a portable encrypted archive is on the roadmap.

What happens when I uninstall OSL?

Uninstall and migration behavior has not been verified on a named release. The reviewed source seals accepted message-store values, but database structure, conditional JSON, Hub configuration, renderer localStorage, provider-managed profiles, the active-slot marker, and a fixed-label startup trace can remain visible or plaintext. Do not assume uninstall removes either category. Where available, use OSL's in-app full cleanup before uninstalling, then verify remaining OSL app data, local webview and provider-profile data, and osl-startup-trace.txt; that cleanup sequence itself is not release-verified. Back up required recovery material before deleting anything.

Is there a beta program?

We'll announce a beta program before public launch. Sign up on the landing page to be notified.

Pricing & Support #

Is OSL free?

Yes. Free includes protected text on supported connectors with no ads and no message limit. Free Scrub is Planned for v1 and is not available in the shipping app yet. The intended Pro price is $5 for one month, but checkout is paused until one-month redemption and expiry are implemented. Encrypted image sending Planned is not in the shipping app yet. Pro is not a subscription — nothing renews, and we never store your payment details.

What does "burn" mean in OSL?

Burn is Planned and is not a working peer action today.

PWS acts before disclosure. Burn acts after disclosure. They are separate planned safeguards for two different moments; after information leaves your device, OSL can only clean up reachable OSL or service-held copies and report the result.

Burn acts after disclosure. It is a Planned cleanup and cooperation flow for reachable copies and reported outcomes, with no promise about copies outside OSL.

Burn does not revoke recipient keys or control copies outside OSL. A recipient device, connected service, export, backup, screenshot, camera, or already viewed content can remain.

  • Local deletion. Delete the local OSL state that this device controls.
  • Authenticated cooperative peer request. Ask the other OSL client to delete its copy; the peer must cooperate.
  • Host deletion attempt. Ask the connected service to remove its hosted item without claiming the service complied.
  • Unavoidable copies and screenshots. Copies, screenshots, exports, and backups outside OSL can remain.

View-once and timed deletion are shown only where the active client can enforce and report their real outcome.

What exactly do I get for paying?

Today, Pro buys one thing: new privacy tools early, as they reach the public beta channel. Encrypted image sending — PNG and JPEG — Planned is built but is not wired into the shipping app, so do not buy Pro today expecting to send images. It is the next thing Pro is meant to unlock, and it is labelled Planned until a released build proves it.

Not included yet, and clearly labelled everywhere on this site: sending other kinds of file Planned, AutoScrub Planned and AI-written cover text Planned. Planned tools are never sold as finished features.

What are processing credits?

Planned, and not on sale. When the optional AI features arrive, Pro will include a small allowance of cloud processing, and you will be able to buy more separately. Credits would be a separate purchase that never renews. Choosing local processing instead uses no credits and is the more private option, and cloud processing would always need its own explicit consent because the server has to see the text it is working on — that part is not end-to-end encrypted. Encryption never stops working because credits ran out or a payment failed.

Is all of OSL open source?

Almost all of it. The client, the cryptography, the wire formats, trust and identity, deletion receipts, local storage boundaries and Free Scrub are all public and inspectable. The only exception would be a future optional AutoScrub module, which would stay closed source purely to make trivial cloning harder. It is not available yet; if introduced, it would be separately downloaded only after a plain closed-source warning and explicit consent, and a fully open-source build would remain usable without it.

How do I report a bug or request a feature?

Email OSLPrivacy@gmail.com with a description of what you saw and what you expected. Include the OSL version (visible in the about screen) and your OS version. For features, the more context on what problem you're trying to solve, the better.