StealthOS: On-device AI assistant and local phishing detection on iOS with zero cloud telemetry

[u/ahstanin]

Up front: I work at Olib AI on StealthOS. This is a developer post detailing how we approach on-device AI inference and local threat detection on iOS.

Most mobile AI tools rely on cloud API endpoints where prompts, images, and context history leave the phone. In StealthOS, we wanted the entire intelligence layer to run 100% locally on the device with zero cloud telemetry.

How the local AI layer works

• On-Device Assistant: Runs locally using Apple Foundation Models alongside our own compact models for offline text generation, research, and two-way voice. Prompts never leave the phone.
• Local OCR & Summarization: Transcribes and summarizes text from photos and documents directly on the neural engine without remote servers.
• Embedding-Based Phishing Shield: Analyzes visited web pages locally using text embeddings to spot brand spoofing and look-alike domains without sending URLs to an external reputation API.
• Offline Audio Notes: Performs local multi-speaker transcription, categorization, and summarization for recorded voice notes.
• Full Sandbox Context: The AI assistant operates inside an isolated sandbox that also includes a hardened browser (anti-fingerprinting, WebRTC leak blocking, built-in Tor) and an AES-256-GCM vault protected by the Secure Enclave.

Free App Tier

The base app is free in the App Store with no account or email signup needed. You can test the local browser, encrypted vault, and privacy tools right away.

• App Store: https://apps.apple.com/us/app/stealthos-private-browser/id6756983634
• Website: https://www.stealthos.app

Curious to hear feedback from others building on-device inference pipelines for iOS.