CortexOS - Private AI Journal

CortexOS is a private AI journal and mood tracker that understands how you think. Write freely in a secure, encrypted diary and let on-device AI analyze your emotions, detect patterns, and surface insights you can't see on your own. No email, no password, just a recovery phrase. Everything stays on your phone.

SMART JOURNAL WITH AI MOOD TRACKING

Most journal apps store your words. CortexOS reads between the lines. The AI detects over 20 emotions in every entry, tracks mood patterns across days and weeks, and identifies cognitive distortions like catastrophizing, black-and-white thinking, and emotional reasoning. Think of it as a mood diary that actually understands what you're feeling.

Whether you journal for anxiety, depression, stress relief, or personal growth, CortexOS gives you data no gratitude journal or simple diary provides.

WHAT CORTEXOS DOES

• AI Emotion Tracker: Detects specific emotions, not just positive or negative. Tracks emotional health over time.

• Mood Analysis: See trends across 7, 30, 90 days, and a full year. Identify what triggers stress, burnout, and anxiety before they spiral.

• Behavioral Patterns: 15 cognitive distortion types, recurring thought patterns, avoidance behaviors. Watch patterns emerge, stabilize, fade, or resolve.

• Deep Analysis: On-device LLM provides CBT-informed observations with reframing suggestions and coping strategies grounded in CBT, DBT, and ACT.

• Reflection Sessions: AI-guided conversations that adapt to your emotional state. A thought partner that remembers your patterns and history.

• Psyche Layer: A unified psychological profile that evolves with every entry. Learns your emotional baseline, cognitive tendencies, recurring themes, and unresolved topics.

• Therapist Export: 11-section PDF report with emotion trends, cognitive distortions, and domain-emotion correlations. Customizable. No journal content included.

• Voice Journal: On-device Whisper transcription, 99 languages. No cloud speech recognition.

• Smart Nudges: AI observations after every entry. Reflection nudges, reminders, and personalized prompts. Never face a blank page.

ZERO-KNOWLEDGE ENCRYPTION

This is not a diary app that promises privacy in its terms of service. CortexOS uses zero-knowledge encryption, meaning we are mathematically unable to access your entries.

• AES-256-GCM encryption, the same standard used by governments
• Keys derived locally from your recovery phrase via Argon2id
• Optional encrypted cloud backup (we can't decrypt it, ever)
• Biometric lock with auto-lock after 30 seconds
• Zero tracking, zero analytics on your content
• If we're subpoenaed, we have nothing to give. Literally.

If you've been looking for a secure journal, locked diary, or encrypted journal app that actually means it, this is it.

BUILT FOR YOUR MENTAL HEALTH JOURNEY

Whether you're working through therapy, managing anxiety, practicing mindfulness, or building self-awareness, CortexOS goes beyond a simple daily planner.

Use it for:
• Anxiety and stress management
• Depression tracking and mood journaling
• CBT and cognitive behavioral therapy exercises
• Emotional regulation and anger management
• Self-reflection and personal development
• Grief processing and trauma journaling
• Burnout recovery and work stress
• Building emotional intelligence
• Gratitude practice and positive thinking

THE CORTEXOS PROMISE

We can't read your journal.
We can't sell your data.
We can't train AI on your thoughts.
We can't comply with requests for data we don't have.

Zero-knowledge encryption isn't a feature we added. It's why we exist.

FREE TO START

Start with a 14-day free trial of Premium. Full AI analysis, reflection sessions, behavioral patterns, therapist export, and adaptive intelligence. Free tier continues after with 50 entries/month and essential analysis.

Your Mind, Encrypted.
https://cortexos.app