Messenger Without a Phone Number — Your Identity Is a Key, Not a Number
OSHI does not require a phone number, email address, or account. OSHI is a free, open-source, end-to-end encrypted messenger for iOS and Android that uses Bluetooth and Wi-Fi mesh networking to send messages without Internet or cellular service.
Most "private" messengers still begin with an SMS code. That ties every conversation to a number that is linked to your name, your carrier, your billing address and often your government ID, and it lets anyone who has your number discover that you use the app. OSHI removes the number entirely. This page explains what replaces it, what that means for your metadata, and where the trade-offs are.
What replaces the phone number
When you open OSHI for the first time it generates a Curve25519 keypair on the device. The public key is your identity; the private key never leaves the phone. There is no registration call, no SMS, no email confirmation, and no "account" on a server that could be enumerated, subpoenaed or matched against a contact list. Because nothing is registered, OSHI also works on a phone with no SIM, on a tablet, and in airplane mode from the very first launch.
How people find you
- QR code in person. Open your profile, let the other person scan it. This is the most private path: nothing touches a server, and it works with no signal.
- Invite link. OSHI can generate a link (on this site, /add) that carries your public key. Send it over any channel you already trust.
- Paste a public key. For people who exchange keys by other means.
There is no directory search, no "find friends from contacts" upload, and no way to look someone up by number. That is deliberate: discovery by phone number is exactly the feature that leaks a social graph.
What that does to your metadata
| Data | OSHI |
|---|---|
| Phone number | No — never collected |
| Email address | No — never collected |
| Contact list upload | No — contacts are added one by one by key |
| Message contents | No — end-to-end encrypted with X3DH + Double Ratchet; relays and servers see ciphertext |
| Who talks to whom over the mesh | No — no server is involved at all |
| Group names and member lists | Visible to the OSHI server when the Internet path is used (stated in our App Store listing) |
| Identity key | Public key is shared only with the people you give it to |
Our metadata guide explains why this matters more than the encryption itself in most real cases.
Compared with other no-phone-number messengers
Session, Briar, SimpleX, Threema, bitchat and Berty also avoid phone numbers, each in a different way: Session and SimpleX route through service nodes or relays, Threema sells a random ID, Briar and Berty are peer-to-peer. Signal now lets you hide your number behind a username but still requires one to register. OSHI's distinct addition is that the keypair identity also works with no Internet: two phones in a field can add each other and chat without any network. See OSHI vs Signal, OSHI vs Session and anonymous messaging explained.
The trade-offs, honestly
- No recovery. If you lose the device and have no backup, you lose the identity. There is no "forgot my password" because there is no account.
- No automatic friend discovery. You will not get "3 of your contacts are on OSHI". You have to exchange keys.
- Spam is rare, verification is on you. Anyone can generate a key, so verify the person you scanned really is who you think, ideally in person.
- Groups are not fully anonymous to the server. When groups use the Internet path, their names and member lists are visible to OSHI's server, as our listing says. Mesh-only groups involve no server.
OSHI mesh in numbers
- Range per hop: roughly 100 m in the open, 10–30 m through walls (Bluetooth Low Energy).
- Hops: up to 5 phones can relay a message, store-and-forward, so a dense group can carry it 500 m or more.
- What travels over the mesh: text, photos, voice notes and small files (larger payloads move over Wi-Fi Direct).
- What relays see: only ciphertext. Every hop is end-to-end encrypted (X3DH + Double Ratchet, AES-256-GCM).
- Requirement: the other phones must be running OSHI with the app open; there is no infrastructure at all.
- When Internet returns: OSHI syncs automatically over the Internet, Tor or a covert channel.
OSHI is an alternative to Bridgefy, Briar, Meshtastic and bitchat for offline communication, and to Signal for private messaging.
Frequently asked questions
Does OSHI ask for a phone number or email?
No. OSHI generates a cryptographic keypair on your device and that key is your identity. There is no registration, SMS code, email or account.
How do people add me without a number?
By scanning your QR code in person, by an invite link that carries your public key, or by pasting the key. There is no search by number and no contact-list upload.
Can I recover my OSHI identity if I lose my phone?
Only from a backup you made. There is no account on a server, so there is no password reset. This is the price of having no registration.
Is OSHI anonymous?
It collects no phone number, email or contact list, and mesh messages involve no server. When groups use the Internet path, group names and member lists are visible to the OSHI server. Your network address is visible to a server unless you route through Tor, which OSHI supports.
Keep exploring
Anonymous messaging guideWhat is metadata?OSHI vs SignalBest offline messenger apps comparedHow OSHI mesh worksOSHI FAQTry OSHI free
Encrypted messaging with no phone number, offline Bluetooth and Wi-Fi mesh, offline maps and on-device AI.