📖 Support & Documentation

Everything you need to know about OSHI — the truly private messenger

⚡ Quick Navigation

🔒 About 🚀 Getting Started ✨ AI Intelligence 🛡️ Security 📡 Delivery ❓ FAQ 🔧 Troubleshooting 📞 Voice Calls 📧 Contact

🔒 About OSHI

OSHI is a private messaging app that combines end-to-end encryption with mesh networking. Your conversations stay private and keep working even with no internet connection.

🔒

End-to-End Encrypted

Double Ratchet protocol

📡

Three Delivery Modes

Mesh, our relay, Tor

🚫

No Registration

No phone or email

👁️

Minimal Metadata

No account, no analytics

📴

Works Offline

Local mesh network

💻

Open Source

Auditable code

🚀 Getting Started

📱 First Time Setup

  1. Download OSHI from the App StoreGoogle Play
  2. Open the app — No registration required
  3. Your identity is created automatically using cryptographic keys
  4. Start messaging by scanning a contact's QR code

👥 Adding Contacts

To add a contact:

  1. Tap the "+" button or "Add Contact"
  2. Scan their QR code with your camera
  3. Start chatting securely

To share your QR code:

  1. Go to Settings
  2. Tap "My QR Code"
  3. Let others scan it, or share the link

✨ AI Intelligence

OSHI includes a powerful on-device AI assistant powered by Apple Foundation Models. All processing happens locally on your device — no data is ever sent to external servers.

✏️

Smart Correction

AI-powered spelling and grammar correction in 16+ languages. Context-aware using Apple's 3B parameter on-device language model.

🎭

Tone Reformulation

Rewrite any message in 6 tones: Formal, Casual, Friendly, Professional, Playful, and Persuasive.

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Instant Translation

Translate outgoing and received messages to 16+ languages. Long-press any received message and tap Translate.

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Ask AI

Ask any question directly from the chat input area. The AI responds concisely in the same language you ask in.

How to Use

1

Type a message, then tap the ✨ sparkles button next to send

2

Choose: Correct, Improve, Translate, Tone, or Ask AI

3

Review the AI result, then tap Apply to replace your message

4

To translate received messages: long-press → 🌍 Translate

🔒 100% On-Device

All AI processing uses Apple Foundation Models running locally on your device. No text is ever sent to any external server. Your messages remain private even during AI processing.

ℹ️ Requirements

iOS 26 with Apple Intelligence enabled. On older iOS versions, basic rule-based corrections and the iOS Translation framework (iOS 18+) are used as fallback.

🛡️ Security & Privacy

🔐 Encryption Technology

OSHI uses the Double Ratchet protocol (the same protocol used by Signal) which provides:

  • Forward Secrecy (v3 sessions only): in v3 sessions the Diffie-Hellman ratchet limits what a stolen key exposes. v2 sessions, which are still most of the installed base, do not ratchet and do not provide this.
  • Hybrid post-quantum key exchange: on iOS 26 and macOS 26, and only when both ends support it, sessions negotiate X-Wing (ML-KEM-768 with X25519), so recorded traffic resists later decryption by a quantum computer.
  • Unique Keys: Each message encrypted with its own unique key

🔣 Cryptographic Algorithms

Key ExchangeCurve25519 (ECDH)
Message EncryptionAES-256-GCM
Key DerivationHKDF-SHA256
SignaturesEd25519

🚫 Privacy Guarantees

  • No phone number required
  • No email required
  • No personal data collected
  • Minimal metadata: the relay sees public keys, time and size, never contents
  • No message analysis
  • No server access to your messages
  • No backdoors

📡 Delivery Methods

Messages automatically switch between delivery methods based on availability.

🔵

Local Mesh

Direct iPhone-to-iPhone

  • No Internet needed
  • Range: Up to 100m
  • Perfect for events
  • Bluetooth & WiFi
☁️

Our Encrypted Relay

A server we run ourselves

  • Cannot read your messages
  • Sees public keys, timing and size
  • Used only when no peer is in range
  • Auto-deleting
🧅

Tor Network

Hides your IP from the relay

  • Relay sees a Tor exit, not you
  • No location tracking
  • Helps bypass network blocking
  • Onion routing

❓ Frequently Asked Questions

General

Do I need to create an account?
No. OSHI generates a cryptographic identity automatically. No registration, phone number, or email required.
Can OSHI read my messages?
No. All messages are end-to-end encrypted. Only you and your recipient can read them. We have zero access to your content.
Do you collect my data?
No. We collect no personal data: no phone number, no email, no tracking, no analytics. When a message goes through our relay, it sees the sender and recipient public keys, the time and the size, never the contents.
Can I use OSHI without Internet?
Yes. The local mesh mode works directly between iPhones via Bluetooth and WiFi without any network connection.
Is OSHI compatible with Signal or WhatsApp?
No, OSHI is a separate network with its own protocol. Both users need OSHI installed to communicate.

Technical

What encryption does OSHI use?
Double Ratchet protocol (Signal protocol) with AES-256-GCM encryption and Curve25519 key exchange.
How long are messages stored?
Messages are stored locally on your device. Messages held on our relay for later collection are available for 30 days, then automatically deleted.
Where are undelivered messages kept?
On a server the project runs itself. They are stored encrypted and addressed by their content hash, and are not published to the public IPFS network, so public gateways cannot retrieve them.

🔧 Troubleshooting

📨 Messages Not Sending

Problem: Messages stuck in "Sending..." status

  • Check your Internet connection (for relay/Tor mode)
  • Make sure you are within range (for mesh mode ~100m)
  • Force-close and reopen the app
  • Check if recipient is online

📷 Can't Scan QR Code

  • Grant camera permission: Settings > OSHI > Camera
  • Ensure good lighting
  • Hold phone steady and centered on the QR code

🔒 Messages Showing as Encrypted

ℹ️ Solution

This is a temporary sync issue. Both users should go to Settings > Advanced > "Clear Session Keys" and send a fresh message to re-establish the session.

💥 App Crashes

  • Force close the app and reopen
  • Restart your iPhone
  • Check for app updates in the App Store
  • If problem persists, contact support

📞 Voice Calls

OSHI supports encrypted voice calls with regional adaptations for compliance.

🌍

Global (Most Countries)

Full CallKit integration with native call UI, lock screen answering, and VoIP push notifications.

  • Native iOS call interface
  • Answer from lock screen
  • VoIP push notifications
  • Call history integration
🇨🇳

China Region

CallKit is disabled in China per MIIT regulations. Calls use in-app UI with APNs push notifications.

  • In-app call interface
  • APNs push notifications
  • MIIT compliant
  • Same encryption quality

ℹ️ How It Works

OSHI automatically detects your region via the App Store storefront. In China, CallKit and VoIP push are replaced with an in-app call UI and standard APNs notifications. All calls use the same end-to-end encryption regardless of region.

📧 Contact & Support

Get Help

✉️ Email Support 🐛 Report Bug 💻 Source Code

Response time: Usually within 24-48 hours

⚠️ Security Issues

If you discover a security vulnerability, DO NOT post publicly. Email directly: contact@oshi-messenger.com. We take security seriously and will respond promptly.